Category Archives for "General"

What Is The Water Cycle, And How Does It Work?

What Is The Water Cycle

The flow of water is all around us. It runs from reservoirs into the faucets of our homes, and it's the rain falling outside. It is in the rivers and clouds, and the ocean contains more than 90 percent of all water.

No matter where you find water, whether it be in a vast lake in the mountains or a cloud high in the troposphere, it is part of the global movement of water. 

Even in all its states, whether it be solid (ice), liquid (water), or gas (water vapor), it still forms part of this interconnected water movement.

All movement and every path that water follows on a local and global scale, are part of what is known as The Water Cycle.

This article will focus to explain what The Water Cycle is, how it works, and its importance for all life one Earth.

What Is The Water Cycle

The water cycle is a large and complex system with many moving parts that may seem to work in isolation, or are part of a global network. Before we can start to delve deeper into its workings, we need to provide a broad description of what precisely the water cycle is.

What Is The Water Cycle?

The Water Cycle

The Water Cycle is the movement or path of water in its various forms across the world, both on land, sea, and the atmosphere.

This includes all related physical processes such as precipitation, evaporation, condensation, and transpiration.

As you can see, it is a very broad description, and to really understand it, one will need to look at some of the more specific processes involved, both on a local and global scale. 

Before we look at the steps involved in the creation of more specific water cycles, one should first establish a clear picture of the primary water sources (where the movement of water originated from.)

Sources Of Water

It is impossible to pinpoint exactly where a specific water cycled started by merely looking at the current phase in which the cycle is observed. What makes it even harder is that it is a never-ending process with no current start or endpoint.

What is certain, however, is that all processes and cycles need a primary source of water. By looking at the major water sources and where they are situated, one will get a much better idea of where and how some water cycles are set in motion.

Sea Water

sea water

The world's oceans contain 97 percent of all water on Earth. This is saltwater, though, which makes it unsuitable for consumption in its natural form. But this does not disqualify it from being part of the water cycle.

Water can evaporate from the surface water, and since oceans cover 71 percent of the entire surface of the planet, it serves as an almost unlimited supply of moisture.

Fresh Water

Even though the ocean can provide fresh water indirectly (through processes we will discuss later in this post), it is not water that is available for immediate use. This leaves the planet with only 3 percent of fresh water, of which less than a third is readily available.

Polar Ice Caps

Of the 3 percent of freshwater on Earth, two-thirds are stored in the polar ice caps, and to a lesser extent glaciers, and snowpacks at high altitudes. The location and make-up of this solid form of water make it inaccessible for an extended period of time.

Dams, Rivers, And Reservoirs

Most of the remaining freshwater can be found in more traditional sources of freshwater we are familiar with, like dams, rivers, and reservoirs. They receive their water through precipitation, melting snowpacks, and smaller streams. 

Groundwater And Aquifers 

A small percentage of water infiltrates the ground, allowing groundwater to replenish and aquifers to fill. Some of these subsurface water sources find openings on the surface and escape into surface water. Others flow directly into the ocean through underground run-off.

How The Water Cycle Works

As mentioned earlier in this article, the water cycle as a whole is a complex mechanism with many smaller processes involved in the broader global movement of water. The best way to explain it is to look at some of these processes in isolation.

By using a relatively simple example of how the water cycle works and highlighting each critical process along the way, one will be able to get a clear understanding of how the process works as a whole.

As a starting point, water needs a primary source and mechanism to enable it to turn into its gaseous form, which will allow it to be transferred through the atmosphere. Two processes make this possible:

  1. Evaporation
  2. Transpiration
  3. Sublimation

Both of these processes fundamentally do the same thing. They allow water to be transformed into its gaseous state and escape into the atmosphere. The only difference is the source from where it turns into water vapor, and the process through it takes place.



Evaporation occurs when the surface of a body of water in its liquid form is turned into water vapor. Primary sources include the ocean, dams, rivers, lakes, and other water bodies with their surfaces exposed to the atmosphere.

Evaporation is made possible by an increase in temperature. Solar radiation is usually the primary source of heat as the sun warms up the water's surface. The molecules in heated water become more energized, allowing it to break free from the surface as water vapor.


Evaporation is not the only source of water vapor. Depending on density and composition, vegetation provides a significant amount of water to the atmosphere. It occurs through a process called transpiration, where water vapor forms from the moisture created on leaves.

The roots of a plant or tree draw water from the ground. The moisture is then transported through the branches or stems into the leaves. The micro water droplets exist the leaves through small pores on their underside. From there, it escapes into the air as water vapor.


Sublimation is the transformation water from its solid form (snow and ice) directly into water vapor without turning into a liquid first. This usually happens on high snow-covered mountaintops or other regions at altitude.

The heat from the sun is also responsible for this process, but since the process sometimes occurs in subzero temperatures, wind plays a big part, as it carries the small amounts of water molecules that evaporate away without leaving any liquid water behind.

Once in the atmosphere, water vapor gets subjected to a variety of variables that will determine how far and high it will travel, as well as where and in which form it will change its state back into a liquid or solid form.

Global wind movement can literally carry water vapor around the globe, but for the sake of this illustration, we will focus on a water cycle that is the result of local and prevailing winds.

Once water vapor enters the atmosphere, the water molecules start to rise up in the air due to the difference in pressure and the buoyant properties of the lighter vapor particles. (Water vapor molecules are lighter than the surrounding particles in the atmosphere.)

As it continues to gain altitude, the temperature continues to drop until the water vapor reaches dew point and condensation takes place.


In this specific cycle, water vapor in the air gets carried towards the coast and inland by onshore winds. This horizontal movement of moisture is called transportation. A sea breeze is one example of the type of wind blowing inland from the ocean.



Condensation is the process through which water in its gaseous state (water vapor) gets turned back into its liquid (water) or solid (snow) form.

Both liquid and solid particles continue to grow in size until it becomes too heavy to stay in the atmosphere and fall to the ground in the form of precipitation.


Precipitation occurs when small water droplets or ice crystals grow and cling together. When they reach a certain size, they fall to the ground due to the Earth's gravity and the inability of wind flow in the atmosphere to maintain their buoyancy.  

When the temperature is above freezing point, precipitation is in the form of raindrops. In subzero temperatures, precipitation takes the form of snowfall, since the water vapor usually condensates directly into ice crystals (the solid form of water.) 

Very often, even the global transport of water starts at a local level. The relatively simple cycle of water vapor from the ocean that gets blown over land where precipitation takes place is one such case and serves as the perfect example to explain the water cycle.

Depending on where and in which form precipitation occurs, the water is captured and stored in different forms:

  1. Snowpacks
  2. Surface Water
  3. Groundwater

All these forms of water sources play a crucial part in the water cycle and the supply of fresh water throughout various locations on land.

1) Snowpacks

Snow and other forms of solid precipitation fall and accumulate in regions with subzero temperatures to form snowpacks. Even in areas where you usually don't experience snowfall, you often see the mountaintops capped with snow due to their high altitude.

Snowpacks are a valuable source of fresh water. When temperatures start to rise, the snow melts and flows from mountains and other elevated regions into streams and rivers where it can be captured and stored.

2) Surface Water

Surface Water

When rainfall occurs over land, it can fall directly into rivers, dams, and reservoirs. It can also fall on impermeable surfaces, where gravity will force it to flow via surface runoff areas into streams, rivers, and standing water bodies.

Sometimes the runoff areas direct the flow of water directly back into the ocean, or it may encounter soil or other porous surfaces where it gets absorbed as groundwater, which also serves an essential purpose.

3) Groundwater

A large percentage of water falls directly on land. If the surface it falls on is soil or a form of porous rock, the water gets absorbed and becomes groundwater. Below the surface, the moisture gets stored in aquifers.

The water table sits on top of the aquifer and serves as an indicator of the amount of water saturation in the ground. When the soil is fully saturated, the water table lies close to the surface. When the land is arid, it is situated far below the surface and may be unreachable.

Especially when saturated, very often, the groundwater does not stay in one place. It is absorbed by the roots of plants and trees, which is essential for their livelihood.

springs and geysers

When situated at a gradient, groundwater will continue to flow through the porous ground. Where it finds a weakness or opening, it sometimes escapes to the surface in the form of springs and geysers or escapes directly into existing bodies of water like rivers and dams.

Groundwater may not escape to the surface at all, but continue to flow in underground "rivers" where it will eventually return to the ocean.

All three forms of fresh water eventually find their way back to the ocean in some way, where the cycle starts all over again. And that is the water cycle in a nutshell.

Even in this fairly simplistic system we just discussed, there are variations and processes involved, with different outcomes that also play a part and have a significant influence on the larger cycle.

Variations In The Water Cycle

As just mentioned, the existing processes we highlighted throughout this post, can have a variety of different outcomes and influences, even within a relatively simple water cycle like the one we focused on in this article.

Here are just a few variations that may occur within this system:

  • Due to factors such as unexpected changes in wind movement, water that evaporates over the ocean can stay over the water, condensate and form precipitation. The precipitation occurs over the ocean and none of the moisture-filled air reaches land.
  • Similarly, water vapor can escape from inland water bodies, rise, and condensate over land. As a result, precipitation will occur over inland regions without ever reaching the ocean. A significant amount of water vapor stays in this cycle and not immediately return to the sea.
  • External weather systems can result in cold prevailing winds blowing over the ocean's water, preventing evaporation from occurring for sustained periods. As a result, areas close to the ocean can experience a water shortage, which can turn into drought conditions over time.
  • Finally, water evaporating from water sources on land can be carried back to the ocean as a result of off-shore winds, where condensation and rainfall take place over water. It will also put pressure on remaining water resources in regions affected by this loss of precipitation.

These are just a handful of scenarios that can occur within a localized system. There are numerous processes and patterns that can occur as a result of local and global influences. 


One clear conclusion that we can reach is that the water cycle is a very complex system that operates on a local and global scale. It is the result of the interaction between various weather systems and patterns that transforms and move water across the globe.

Although we used a relatively localized form of this cycle to explain how it works, it is clear to see that the water cycle doesn't operate in a vacuum. It was illustrated by showing some possible variations that may be the result of external or global weather behavior.

This post aimed to explain what the water cycle is and how it works, by describing a typical local process that can also apply to different and more globalized forms of this cycle.

Feel free to leave me any comments, questions, or suggestions, and I will get back to you as soon as possible.

If you like to be informed whenever a new article is released, and also receive helpful tips & information, you can stay updated by simply  following this link .

Until next time, keep your eye on the weather!


What Is a Jet Stream, And How Are The Different Types Of Jet Streams Formed?

What Is a Jet Stream?

We are all familiar with local winds caused by temperature gradients, changes in topography, etc. What most of us are not even aware of, is the strong bands of winds occurring high up in the atmosphere.

We don't experience or see the direct impact of these powerful winds, but they are essential for the creation of weather systems across the world. They are so influential that one can go as far to state that a large number of major weather events cannot occur without them.

These winds are called jet streams and occur in specific regions at different heights around the globe. But what are these powerful winds, and how do they form?

In this post, we take a look at what a jet stream is and how it forms. We also examine its effect on weather systems.

What Is a Jet Stream?

Before we can examine how jet streams are formed, and look at their effect on the weather, we need to define what a jet stream is first:

What Is a Jet Stream?

What Is A Jet Stream?

Jet streams are narrow winding bands of high-velocity winds blowing from west to east in the upper troposphere (tropopause).

These permanent strong winds form as a result of the temperature difference between warm and cold air and circumvent the earth following a fairly straight or meandering path.

These phenomena are referred to as narrow bands (or ribbons) of wind since it is hundreds of kilometers in width, but only a few kilometers in depth.

Although relatively stable in their position, they can move more to the south or north, depending on the season, and influence the weather conditions below them during the process.

Types Of Jet Streams

The atmosphere contains two primary jet streams:

  1. Polar Front Jet
  2. Subtropical Jet

Both the Northern and Southern Hemisphere have a polar and subtropical jet stream, creating four permanent jet systems in total surround the Earth. Both types of jets are created by a difference in temperature between two air masses.

Smaller, temporary jet streams also exist. African Easterly and Somali Jets are two of the better-known ones. Other occurrences include barrier and valley exist jet streams. They are not nearly as influential as two primary systems, though, which will be our focus. 

How Are Jet Streams Formed?

Both Polar Front and Subtropical Jets are formed in the same manner. There are subtle differences, though, which is why the formation and characteristics and of each system will be examined separately to avoid any confusion. 

Polar And Subtropical Jet Stream

Formation of the Polar & Subtropical Jet Streams in the Northern Hemisphere

The Polar Front Jet Stream And How It Is Formed

The polar front jet stream occurs at 60 degrees north and south of the Equator at heights of 9 - 12 kilometers (30 000 - 39 000 feet) in the troposphere. The wind speeds can reach and exceed 321 km/h (200 mph).

The Northern Polar Jet sits above the polar front and is the result of the temperature difference between the cold arctic air and warm tropical air. As the two air masses meet, the difference in air pressure between them produces what is called a pressure gradient force.

(Air always flows from an area of high to an area of low pressure. The warm tropical air has a much higher air pressure than the cold air from the North and South Poles, hence the strong pressure gradient force.)

The Coriolis Effect

The Coriolis Effect, deflecting winds to the right in the Northern Hemisphere and to the left in the Southern Hemisphere

In the Northern Hemisphere, one would assume the strong pressure gradient will cause the warm tropical air to flow northwards towards cold air over the poles. However, The Coriolis Effect forces the air to be deflected to the right.

In the Southern Hemisphere, the deflection is towards the left. As a result, a polar jet is a strong wind which is created along the border between the two different air-pressure masses, flowing parallel to the pressure gradient from west to east.

The Southern Polar Jet has the same characteristics as its northern counterpart and is created in the same way. Unlike the Northern Polar Jet, though, it follows a fairly consistent clockwise path around the Antarctic and does not shift or meander as much.

Since Antarctica is also far removed from any other landmasses and populated regions, the amount of seasonal north-south shifting in the jet stream will have very little if any significant effect on any human or plant life, as well the environment.

The Subtropical Jet Stream And How It Is Formed

The subtropical jet stream occurs at 30 degrees north and south of the Equator. It is slightly weaker and forms at higher altitudes than the polar jet and can be found at heights of around 10 - 16 kilometers (33 000 - 52 000 feet.)

The subtropical jet in the Northern Hemisphere is also a result of a strong pressure gradient that is created by the temperature difference between the warm air from the tropical region and the colder mid-latitude air.

Due to the strong temperature gradient and the deviation to the right due to the Coriolis Effect, a strong band of wind flowing westward is created, The Subtropical Jet Stream.

Keep in mind that the formation of a jet stream involves complex processes, and the ones described here are simplified explanations to make these phenomena easier to understand. It still manages to capture the essence and accurately portray the basics of these systems.

How Does The Jet Stream Affect Weather?

To say that jet streams affect the weather is a mild understatement. They create and are the main driving forces of numerous major weather systems and seasonal weather change across the world.

To name every possible event and occurrence that is either directly created or influenced by these powerful upper-atmospheric winds would be impossible, and take up a whole encyclopedia. We will focus on the most important ways in which jet streams affect weather.

Polar Jet Stream and Rossby Waves

Chicago in an icy grip as Rossby waves in the Polar Jet Stream meander south

During winter in the Northern Hemisphere, colder air over the Arctic shifts the polar jet south, bringing cold & wet weather to Northern Europe and the United States. During summer, the opposite occurs as warmer air from the Tropics moves into the region.

Jet streams do not follow a straight line but tend to follow wave-like and winding flows. These meandering flow are called Rossby waves, which are the result of variations in the Coriolis Effect, and the underlying topography on the planet's surface.

Rossby waves have a big effect on the weather of a region, as the dips and peaks in the waves bring entirely different weather to an area. Depending on its speed, Rossby waves can last for a short or very long period, enabling it to even affect climate patterns.

Jet streams also influence aviation. Due to its strong wind speed, airlines make use of it to reach their destinations faster with less energy. Flying against it must be avoided for obvious reasons, which is why airlines keep a close eye on the position of jet streams.   

The effect of jet streams is a lot more widespread than the few examples highlighted in this section, but these examples will help to explain how influential these powerful phenomena are in affecting weather globally, as well as the number of conditions it impacts.


As this article clearly illustrated, jet streams are one of the most crucial components in the forming of global weather patterns. They are formed in complex ways, and the explanations provided in this post were fundamental but enough to make it understandable.

In this article, we focused on explaining what a jet stream is and how it forms. The post also examined the different forms of jet streams and how each one is created.

Feel free to leave me any comments, questions, or suggestions, and I will get back to you as soon as possible.

Remember to join my Mailing List to be informed whenever a new article is released, and also receive helpful tips & information by simply  clicking on this link .

Until next time, keep your eye on the weather!


What Is Smog And How Is It Formed?

What Is Smog?

Apart from its brownish tint, smog looks and can easily be mistaken for fog or mist. Unfortunately, it is something completely different and much more hazardous. 

Yes, like fog, it is a semi-transparent layer in the atmosphere that reduces visibility. But it is here that the similarities stop.

You will normally see this brownish dirty cloud hovering above a city or industrial area when commuting to work in the morning or late afternoon, especially when there is little wind movement. Sometimes you see this occurrence persisting over a location for days or weeks.

The unsightly image and reduced visibility are not only inconvenient but also hazardous and highly toxic. The worst part is that it is entirely a creation of our own making.

This article examines what smog is, what causes it, and its effect on our health and the environment. We also look at the different types of smog.

What Is Smog?

Before we can examine how smog is formed and look at its composition, it's essential to define what exactly smog is:

What Is Smog?

What Is Smog?

Smog is a dense and visible form of air pollution which is the result of human activity. It consists of concentrated levels of smoke, nitrogen and sulfur oxides, as well as other particles.

It is the direct result of the burning of coal in factories and households, and emissions from automotive transport and heavy industries.

Apart from smoke and emissions, smog contains secondary pollutants that also play a part in the effect on humans and the environment. It may sound a bit vague but will be explained in the next section when we focus on the formation of the two different types of smog.

How Is Smog Formed And The Types Of Smog

While defining smog, the most crucial processes that cause this phenomenon were already briefly highlighted. It also mentioned the two primary forms of this pollution:

  1. Industrial Smog
  2. Photochemical Smog

The two types of smog not only consist of different substances, but each one also forms under separate atmospheric conditions. By looking at how each form of smog develops, you will gain a better understanding of how and why smog forms under different circumstances.

1) Industrial Smog

Also known as London or Winter Smog, industrial smog is the type of pollution that originated during the Industrial Revolution as a result of the large-scale burning of coal in industries and households.

Cities like London were severely affected by the burning of coal during the nineteenth and twentieth century. It was during the early 1900s that the word "smog" was formed, which was a combination of the words, "smoke and fog." 

Industrial Smog


The first element that needs to be in place for smog to form is a temperature inversion layer. It is a layer of warmer that lies on top of colder air, preventing the air underneath it from escaping. Inversion can occur naturally or as a result of the Heat Island Effect

No or minimal wind movement also promotes the creation of smog over a region, since it allows the pollution to build up and become more concentrated. A stronger wind would have blown and dispersed the smog away from the location from where it originated.

Cold and moisture-reach air is another necessary component for the formation of industrial smog. The burning of smoke releases smoke particles and sulfur dioxide in the atmosphere where it combines with the water droplets in the fog to create a thick layer of smog.  

2) Photochemical Smog

Also known as Los Angeles or Summer Smog, photochemical smog is the form of pollution that is the result of large scale emissions from the burning of fossil fuels from automobiles and large industries.

Photochemical Smog


Like industrial smog, temperature inversion, as well as little or no wind movement, are required for the formation of smog. Unlike industrial smog, however, this form of pollution requires sunlight, and not cold and damp conditions, for photochemical smog to form.  

The various emissions result in a high volume of nitrogen oxides and VOC (volatile organic compounds) to be released into the air. These components form a thick layer at the surface that has the same yellow/brown color of industrial smog, but with a different composition.

A secondary and toxic form of pollution is created when photochemical smog reacts with solar radiation. When exposed to oxygen in direct sunlight, a chemical reaction occurs which turn smog into harmful secondary pollutants of which ozone is the most dangerous.

Effect Of Smog

Both industrial and photochemical smog can have a severe impact on both the environment and human health. Each type of pollution has its own primary and secondary health and environmental hazards:

Effects Of Industrial Smog

Industrial smog is the original type of fog identified and named during the industrial revolution. Since the conditions in London were so favorable for this form of pollution, we have a clear picture of just how deadly and devastating this form of smog can be.

There are several records of multiple fatalities during periods of heavy smog in the city. The single worst event ever was recorded in December 1952 when the official reports showed that 4 000 people perished (but it is estimated that actual number may be as high 12 000.)

The majorities of deaths during this period, was a combination of respiratory related diseases, as well as heart failure.

In general, industrial smog has several short and long-term health effects, of which the vast majority is related to respiratory problems. It is mainly due to the amount of tar and acidity in the air that directly influence and damage the lungs.

Below is a list of some of the direct and related health risks related to industrial smog: 

  • Respiratory diseases which include bronchitis, tuberculosis, and pneumonia. 
  • A compromised immune system in children, which make them more susceptible to other diseases.
  • A strong relationship between smog and cancer have been established, especially those related to the respiratory system.
  • Ischemic heart diseases, which is the inability of arteries to provide enough oxygen in the blood to the lungs, is another result of exposure to industrial smog.

Apart from these conditions associated with this form of pollution, industrial smog also forms a secondary dangerous and toxic pollutant. Sulfur dioxide mix with the water moisture in the air, which leads to the formation of acid rain.

Acid rain has a widespread impact which includes:

Acid Rain Effect
  • Damage to vegetation, including plants and trees, stunting the growth of trees and washing away protective layers on leaves.
  • Changing the composition the make-up of water and soil, making it uninhabitable to both plants and animals.
  • Weakening and eroding of infrastructure, including concrete and stone.
  • Chronic long disease as an indirect result of the sulfur dioxide occurs in acid rain.

It is very clear to see the widespread dangers that industrial pollution pose.

Effects Of Photochemical Smog

Even though photochemical smog started to become a severe problem more recently than industrial pollution, it is even more widespread than the former in a majority of cases.

The effects of this form of pollution are as dangerous, if not more so than industrial smog. Photochemical pollution has a similar impact on human health and the environment than its industrial counterpart, especially when it comes to respiratory diseases.

Respiratory Problems

Different forms of respiratory diseases remain the primary and most dangerous effect of smog, including reduced lung function, trouble breathing, and triggering asthma attacks.

As earlier discussed, one of the most hazardous byproducts of photochemical smog is ozone. It contributes to and exasperates existing respiratory problems, but also has a widespread effect on other issues, including the environment.

Some of the more serious effects include: 

  • Reduced lung function and difficulty in breathing in humans and animals. 
  • Exasperating preexisting respiratory health conditions in children and the elderly.
  • Triggering or contributing to asthma attacks.
  • Permanent damage to the heart and lungs.
  • The damage or destruction of plants sensitive to this form of smog, including tomato and spinach crops.
  • The damage and killing of tree leaves in the presence of ozone.

These are just some the widespread effects of this "modern" form of visible pollution. 

(A quick note to clear up some potential confusion. Ozone is essential to protect life on earth against the sun's ultraviolet radiation. But this applies to ozone in the stratosphere where it as far away from direct contact with any human where it is extremely hazardous.)


After reading this article, there should be no doubt left in your mind about the seriousness of smog and how devastating it is, especially in countries which still rely heavily on the burning of fossil fuels for energy.

In this post, we did an in-depth exploration of what smog is, what causes it, and how exactly it affects both human life and the environment.

Feel free to leave me any comments, questions, or suggestions, and I will get back to you as soon as possible.

If you like to be informed whenever a new article is released, and also receive helpful tips & information, you can stay updated by simply  following this link .

Until next time, keep your eye on the weather!


How Does Altitude Affect Climate?

How Does Altitude Affect Climate

If you live at the coast and happen to travel inland to regions at higher altitudes, you will quickly realize things feel and react differently for some reason. The opposite is true as well.

At a few thousand feet or higher above sea level, the climate you experience is very different from the climate you will find in a coastal town. It all has to do with how weather elements change with an increase in altitude within the atmosphere.

How Does Altitude Affect Climate?

This article examines what causes these changes in weather elements as altitude increase, and also look at the prevailing weather conditions in a location at a high altitude compared to the environment at sea level.

A quick word about climate: There are similarities, but also significant differences between weather and climate. Weather is the atmospheric condition at any given time at a specific location.

Climate, however, is the average atmospheric conditions in a specific location calculated over a prolonged period. (At least 30 years in most cases.) You can read the in-depth article describing the difference between Weather and Climate by following this link.

How Does Altitude Affect Climate?

Before we look at what the climate conditions are like at a location a few thousand feet above sea level and then contrast it against a similar environment at sea level, one needs to see how an increase in altitude affects the different weather variables:

But first one needs to address the difference between confusion and altitude.

Altitude vs Elevation

In meteorology and aviation, altitude generally refers to an object/location's height above sea level. Elevation, though, refers to the height of an object relative to the physical terrain (ground level) beneath it.

In aviation, altitude also has a few different meanings. Here is a quick summary:

  • Indicated Altitude: The altitude displayed on the altimeter.
  • Absolute Altitude: The distance between the aircraft and the ground below it.
  • True Altitude: The height of the aircraft above sea level.
  • Height: The vertical distance between the aircraft and a specific point below it.

Pressure and Density Altitude also gets used, but it may make things too confusing and is not relevant to the context within which this article uses altitude.

For the purpose of this post, altitude will always refer to an object's height above sea level.

We can now focus the different elements and how altitude affects them:

How Does Altitude Affect Temperature?

The Earth and atmosphere get warmed up as a result of the sun's solar radiation, specifically the infrared component of solar radiation. The infrared radiation warms up the land and oceans which, in turn, warms up the air in the atmosphere. 

How Does Altitude Affect Temperature

Since the atmosphere gets warmed up from the bottom up, the air is usually at its warmest at the surface of the planet and cools down as altitude increases.

Although local variable conditions will influence the following figures, temperatures usually drop at a rate of 1° Celsius per 100 meters. More broadly put, temperatures fall by 5.4° Fahrenheit per 1 000 feet or 9.8° Celsius every 1 000 meters.

For example, a town can have a temperature of 22° Celsius (71.6° Fahrenheit) at sea level. When the same village gets placed at a height of 2 000 meters (6561 feet) on a plateau or mountain top, it can be as cold as 3.4° Celsius (38.1° Fahrenheit).

How Does Altitude Affect Air Pressure?

Atmospheric air has weight. It is not empty but consists of nitrogen, oxygen, argon, and other gases like carbon dioxide and methane. It also contains small particles like dust and pollen. This fact alone will help to explain the relationship between altitude and air pressure.

At the surface of the planet, you have the whole weight of the atmosphere (specifically the troposphere) pressing down on you. The Earth's gravity is also at its strongest at surface level, causing the air particles close to the ground to compress the most.

As an object starts to gain altitude, the atmospheric pressure around it begins to decrease. It is as a result of two factors. Firstly, with an increase in height the amount of air above the subject starts to lessen, meaning the weight of air pressing down on it gets less as well. 

Secondly, the more altitude you gain, the further you are from the Earth's surface and its gravitational forces, so you experience less gravity. It allows the particles in the air to expand, which reduces the air pressure even further.

In the upper troposphere and lower stratosphere, the atmospheric pressure is almost non-existent. The lack of oxygen is what makes life at this altitude impossible, but the thin air also allows airliners to fly without much air resistance and above any unstable weather.

How Does Altitude Affect Precipitation?

As already mentioned earlier in this post, temperatures continue to decrease as altitude keeps increasing. Atmospheric pressure also continues to drop with an increase in height.

How Does Altitude Affect Precipitation?

The combination of both processes contributes to locations at higher altitudes to receive a significantly higher amount of precipitation than low-lying regions. Please note that sufficient moisture must be present in the air for any precipitation to take place.

The type of precipitation, however, depends on how low the temperature has dropped when condensation takes place. 

When condensation takes place while the temperature is above freezing point, precipitation is usually in the form of rain. When the water vapor condenses in sub-zero temperatures, though, it will be in the shape of snow or another solid form of water.

Sometimes other factors such as physical barriers cause air to rise as well. The mountain effect is one such case. A change in the elevation of the physical terrain and not natural atmospheric processes forces air to gain altitude.

Wind forces moisture-filled air to rise against a mountain, condensate and result in precipitation on the windward side of the mountain, with warm, dry air flowing down on the leeward side. You can read all about this effect and how it occurs in this article.

The Difference In Climate Between Low-Lying And Regions At High Altitudes

Many of the climate conditions that are a result of an increase in altitude were highlighted throughout this post. A summary of these different conditions will explain just what a crucial role altitude plays in establishing the climate of any location.

The best way to summarize the key differences between regions separated by altitude is to list the different weather conditions each one experience. (Just note that there are many other variables involved in forming the climate of any region.)

Low-lying areas are typically characterized by:

  • Warmer temperatures
  • Less wind activity
  • Lower amounts of precipitation
  • Higher air pressure with high levels of oxygen

High-altitude areas are typically characterized by:

  • Colder temperatures
  • Strong and gusty winds
  • High amounts of precipitation
  • Lower air pressure with low levels of oxygen

As previously mentioned, these climate conditions can occur under a variety of conditions but are typical of the difference between locations at low and high altitudes.


As this article clearly illustrated, altitude causes lower-lying areas to have a very different climate than regions situated at a high altitude. If you experience any of the climate conditions described at the associated altitude, you now know why.

Feel free to leave me any comments, questions, or suggestions, and I will get back to you as soon as possible.

Remember to join my Mailing List to be informed whenever a new article is released, and also receive helpful tips & information by simply  clicking on this link .

Until next time, keep your eye on the weather!


Can You Tan Through A Window? A Look At The Sun’s Ability To Cause Sunburn Under Different Conditions

Can You Tan Through A Window - A Look At The Sun's Ability To Cause Sunburn Under Different Conditions

Ironically, despite all our racial differences and tension, most Caucasian/white individuals want a nicely tanned skin. You just feel and look more healthy and attractive. Despite health warnings, many still seek out the sun to get some color in their skin.

And this brings us to the subject of tanning. The trusted method of spending time or lying directly in the sun for a certain amount of time remains the most popular means of attaining a proper tan.

As recently as the late 20th century (and still today), people spend days in the sun with little protection to get that sought after bronzed look. Only when the medical community raised the alarm about skin cancer and the link to sun exposure, did society start to pay attention.

Since then, a lot happened to make tanning "safer." Sunbeds and tanning booths became very popular. "Tanning pills" and Melatonin 2 injections are also available, but all were shown to have questionable or severe side-effects. Some even worse than sun exposure.

With all these questionable, short-term, or dangerous alternatives available, many people decide to return to the "relative safety" of the sun. While taking care to limit time, avoid the most dangerous time of day, and using sunscreen, many are braving the sun every year. 

As a result, an increasing number of questions gets asked about the sun, tanning, and safety. This post examine what exactly tanning is, and look & address the common queries surrounding the subject. It also examine why extended UV exposure is so lethal.

What Is Tanning?

Before we can delve into the different questions surrounding sun exposure and how it affects tanning, we first need to define what tanning is:

What Is Tanning?

Tanning is the process through which the human skin changes into a darker tone as a result of prolonged exposure to the ultraviolet radiation from the sun.

It is the skin's defense mechanism in an attempt to protect it from the ultraviolet radiation by releasing a pigment called melanin which absorbs the radiation.

As the body release more melanin, the pigment darkens skin color, which is observed as a tan.

In low quantities, exposure to the sun is beneficial in more than one way. It helps you to look healthier by getting a base tan, and also triggers the release of vitamin D. This vitamin is vital to maintain bone and teeth health and support the immune system.

A surprisingly small amount of sunlight is necessary to achieve this result. Unfortunately, many people spend a lot more time directly in the sun, sometimes without realizing it and without any protection as a result.

Harmful Effects Of UV Rays

Exposure to UV radiation becomes harmful when you spend a prolonged period of time in direct (or indirect) sunlight. Even if you take precautions, like wearing sunscreen, at some point, the amount of time exposed to the Sun's UV rays will outweigh any protection. 

This exposure will lead to a number of short and long-term effects, which include:


Most of us are familiar with the sore red skin that you experience after spending too much time in the sun.

It has the short-term effect of experiencing a sore red skin, and the possible peeling of the upper layer of the skin at a later stage. Long-term effects are more severe, which include anything from sunspots, premature skin aging, and finally, different types of skin cancer.

Premature Skin Aging & Skin Damage

Premature Skin Aging

One of the delayed impacts of long periods of UV exposure is premature skin again. An adult with this condition has a skin that shows wrinkles, that also became thick and leathery. These symptoms can show up surprisingly early in an adult's life.

Other forms of skin damage include sunspots and skin growths which may turn into a type of skin cancer if it turns malignant and left unchecked.

Eye Damage

Research shows that UV radiation can increase the risk of cataracts, which is the creation of a fogginess and loss of transparency in the eye lens. If untreated, it can lead to blindness.

Other forms of eye damage include skin cancer around the eyes, degradation of part of the retina called the macula, and also pterygium, which is a type of growth that can block vision.

Skin Cancer

Skin cancer is the most serious and potentially life-threatening effect of long-term exposure to the sun's ultraviolet rays. Like other forms of cancer, skin cancer also comes in different types and levels of severity.

It varies from small malignant growths that can be treated with procedures as simple as cryotherapy, to melanoma which is the most aggressive form of skin cancer that can spread to internal organs and be fatal if left untreated for too long.

One of the most deceptive parts of skin cancer, is that many of the cases that appear and gets treated as an adult, is the result of sun exposure the individual experienced as a child or teenager.

The Most Commonly Asked Questions Asked About Tanning And Sun Exposure

With much more social awareness of the dangers of sun exposure, as highlighted in the previous section, most people are more sensitive about recklessly venturing into the sun. 

It also led to many questions about the conditions under which one can get sunburned. We take a look and answer some the most commonly asked questions about sun tanning under different circumstances.

Can You Tan Through A Window?

Tan Through A Window

It all depends on the type of window to which you are referring. Your average home or office window blocks 97 percent of all dangerous UV-B rays which cause sunburn and skin cancer.

However, it blocks only 37 percent of UV-A rays. So, in this case, the answer is yes. You can get a tan, but it will take much longer than standing in direct sunlight.

A car window, however, is something completely different. Due to the plastic layer between the layers of glass, all UV-B radiation gets blocked, while 80 percent of UV-A rays are also blocked. So while you might get boiling in hot in a car, you will not get much of a tan at all.

Can You Tan In The Shade?

Surprisingly, the answer is yes. Again, you won't build up a tan as quickly as in direct sunlight. However, you will still receive enough UV exposure to build a healthy skin color over time.

This exposure is possible due to indirect UV radiation. As sunlight hits objects on the ground, it reflects and scatters UV rays in all directions, including into shaded areas.

You can read all about solar radiation and the different types of visible and ultraviolet light in this article.

Can You Get A Tan Through Clouds?

The answer is a resounding yes, and the reason many people get severely sunburned every year. You may not feel the heat of the sun or even see the sun, but that does not mean that you are not getting exposed to ultraviolet radiation.

In fact, clouds let through as much as 80 percent of all UV rays. Since one does not see or feel the sun's effects, a person can spend extended periods of time outside without any sun protection. This is what makes this atmospheric condition so dangerous.

Can You Get Vitamin D Through Glass?

Unfortunately, the answer here is no. The Sun does not provide the human body with vitamin D, but our bodies produce it through a chemical reaction as a result of ultraviolet radiation exposure.

The ultraviolet light needed to produce vitamin D, UV-B radiation, gets practically completely blocked by glass, as discussed in an earlier section. It blocks approximately 97 percent of all UV-B light, making it impossible for the body to produce vitamin D indoors or in your car.

Can You Tan Through Clothes?

This question goes hand in hand with the question, "Do clothes protect from UV rays?". The answer is yes, and no. It all depends on the color and type of fabric the clothes are made of:

Tan Through Clothes

Density & Thickness: Density and density play an important role. A thick and tightly woven fabric will keep UV rays out, while thin and see-through material will let large amounts of UV radiation through.

Color: Dark and colored clothing absorbs, rather than letting UV rays through, so it protects the skin from any UV radiation. Light colors, on the other hand, tend to allow UV rays through and expose the sun to ultraviolet light.

Composition: The type of material used in clothing also plays a significant part in the clothing's ability to protect against UV radiation. Some glossy polyesters are very effective at reflecting the Sun's UV rays altogether.

Some cottons that are unbleached also contains a type of lignin that absorb UV radiation and provide protection against sunburn. Certain clothes are specifically designed to completely block out any ultraviolet light, which use sun protective materials.

As you will notice, it is impossible to give a definitive answer as to the capability of UV radiation to penetrate clothing and cause sunburn or give you a tan.

Can You Get Sunburn Under Water?

Like clothing, the answer is yes, and no. In principle, water can protect you from sunburn, but only when you are deep enough underwater.

Sunburn Through Water

Only 60 percent of UV-B rays gets blocked by water at half a meter. Realistically, though, few people who spend time in the ocean or swimming pool, have any part of their bodies covered with more than a few inches (or centimeters) of water.

In fact, when you swim or stand in shallow water, half your body is completely exposed to direct sunlight. It also gets exposed to the UV radiation that is reflected from the water's surface. Potentially, you can get more sunburned in water than out of it.

So yes, you will be able to catch a tan in most instances since your body is only covered by a small amount of water most of the time. Only when you dive below a depth of one meter of water, will it provide you with enough protection against any UV radiation.

Does Sunscreen Stop You From Tanning?

No, sunscreen will not stop you from tanning. It will slow down the speed at which you get a tan though. Since it protects you from sunburn and its associated dangers, a certain amount of UV radiation gets blocked, but it will not prevent your body from producing melanin.

There are still dangers, though. Using a sunscreen with a low SPF (sun protective factor) will only protect your skin to a certain degree and for a limited time, after which you can still get severely sunburned.

Using sunscreen with a high SPF will make it longer for your skin to tan, but will be much safer and protect you from sunburn.


As you can clearly see after reading this article, there so many different weather and environmental conditions influencing the way you tan or get sunburned, that you have to take each scenario on a case by case basis to inform yourself on how to get a safe tan.

Other factors, such as infrastructure, clothing, and water all play a role as well, which we covered in detail. Please note that there are still several other known and unknown factors that influence the sun's UV radiation and your skin's reaction to it.

This first aim of this post was to explain what tanning is and how it works. We then looked at why the Sun's ultraviolet radiation is so dangerous to the human skin. Finally, this article addressed the questions many people ask about tanning and the conditions surrounding it.

Even though some of the lesser asked questions were not covered in this article, by focusing on answering the most commonly asked ones as thoroughly as possible, you should be able to make the right deductions to answer most of these smaller questions for yourself.

Feel free to leave me any comments, questions, or suggestions, and I will get back to you as soon as possible.

If you like to be informed whenever a new article is released, and also receive helpful tips & information, you can stay updated by simply  following this link .

Until next time, keep your eye on the weather!


What Is A Rain Gauge, What Are The Different Types Of Rain Gauges And How Do They Work?

What Is A Rain Gauge - What Are The Different Types Of Rain Gauges - And How They Work

There is no need to emphasize the importance of water. Anyone able to reason knows how vital it is for the existence of all life on Earth. It should come as no surprise that measuring the amount of rainfall is an age-old practice that communities practiced for centuries.

To be more precise, evidence shows the practice of measuring rainfall dates back as far as 500 B.C. when the Ancient Greeks already measured precipitation.

Combined with the record high temperatures recorded in recent years which lead to a global reduction in precipitation, the accurate measuring of rainfall has become more critical than ever before.

This article will focus on what a rain gauge is, highlight the different types of rain gauges, and explain how they work.

What Is A Rain Gauge?

With any doubt about the importance of measuring and keeping a record of rainfall, out of the way, we first need to define what precisely a rain gauge is before looking at different types of devices and how they work.

What Is A Rain Gauge?

What Is A Rain Gauge?

A rain gauge is a meteorological instrument designed to measure precipitation in its liquid form in a specific area over a predetermined period of time.

Meteorologists and hydrologists use these measurements to determine current and predict future weather conditions, monitor the water cycle, and refine forecast models amongst others.

Also known as udometers and pluviometers, rain gauges are considered to be one of the oldest meteorological instruments ever invented and widely used.

To understand how a rain gauge works, one needs to look at the different types of devices for measuring rainfall, and examine the unique way in which each one works.

The Different Types Of Rain Gauges

If you look at different rain gauges closely, you will notice that the majority of them work on the same basic principle. The rain falls into a cylindrical funnel that collects the water which runs down into different measuring mechanisms.

It are these different mechanisms and methods of collecting and measuring the rainfall that makes each rain gauge different. There are mainly 5 type of rain gauges:

  1. Graduated Cylinder Rain Gauge (Standard Rain Gauge)
  2. Tipping Bucket Rain Gauge
  3. Weighing Precipitation Gauge
  4. Optical Rain Gauge
  5. Acoustic Rain Gauge

Each rain gauge serves a different purpose, depending on the needs of the meteorologist, hydrologist, or home weather enthusiast.

1. Graduated Cylinder Rain Gauge

Also known as the standard rain gauge, the graduated cylinder rain gauge is a simple, measured glass cylinder. It is used by all professional weather services in manned stations and is the most accurate way of directly measuring rainfall.

Graduated Glass Tube

The water gets collected by a cylindrical funnel, from where it flows directly into the graduated cylinder, or captured by a container and then poured measured cylinder.

This rain gauge has to be measured and emptied on a daily basis, which means it can only be used in a manned weather station. (Remote weather stations use automated rain gauges that empty themselves, which you will learn about shortly.)

The United States (NWS) and United Kingdom (Met Office) use two different methods for measuring rainfall in a graduated cylinder rain gauge:

National Weather Service 8 Inch Standard Rain Gauge (United States)

The United States' National Weather Service use the 8 inch Standard Rain Gauge. It consists of four main components:

  1. Collector Funnel
  2. Measuring Tube
  3. Overflow Can
  4. Measuring Stick

The collector funnel catches the rain and is 8 inches in diameter. From there, the water flows directly into the measuring tube. The tube is either a plastic or brass tube.

The measuring tube is housed in the overflow can, which catches all the water that overflows from the measuring tube. It can hold a maximum of 20 inches of liquid.

The fourth component of the rain gauge is the graduated measuring stick with distinct white markings. A meteorologist measures rainfall by dipping it through the funnel opening to the bottom of the measuring tube and record the reading.

If the rainfall exceeds the maximum 2 inches the measuring tube can contain, it flows into the overflow can which, contents get measured separately by pouring it into a graduated measuring tube which records the reading.

Met Office 5 Inch Standard Rain Gauge (United Kingdom)

The United Kingdom's Met Office uses the 5 inch Standard Rain Gauge. It also consists of three main components:

  1. Collector Funnel
  2. Glass Container
  3. Graduated Measuring Tube

The funnel catches the rain and is 5 inches in diameter. From there, the water flows directly into a plain large glass container.

Once a day the glass container is removed and its contents poured into the graduated measuring tube which measures the amount of rainfall.

2. Tipping Bucket Rain Gauge

Tipping Bucket Rainfall Gauge

The tipping bucket rain gauge is an automated rain meter that uses a "tipping bucket" mechanism to measure rainfall. It is used by professional weathers services' remote weather stations, and is also popular and widely used in home weather stations.

Like a standard rain gauge, it uses a collector funnel with a narrow pipe at the bottom to capture rainfall. From the pipe, the water drops onto a finely-balanced seesaw device with small buckets on each side.

At any point, one of the buckets is positioned directly under the pipe. When enough water collects in the bucket, it's weight makes it drops to bottom and empty itself while lifting the opposite bucket into position under the pipe.

This process keeps repeating as rainwater continues to flow through the funnel onto the buckets. Each time a bucket drops to the bottom, it triggers an electronic switch. In turn, the switch sends a wireless or landline signal to a base station.

Each signal represents a specific amount of rain which has been set up and calibrated in the tipping bucket mechanism. By counting each signal and adding it up, weather stations can calculate the rainfall over any given period.

As the water flows out of each bucket, it drains through predesigned openings in the rain gauge, meaning there is no need for anyone to maintain the system. This advantage makes it ideal for use in remote weather stations which is also hard to reach.

3. Weighing Precipitation Gauge

A weighing precipitation gauge consists of receiving bucket mounted on a weighing device, usually a mechanical mechanism such as a spring. The rain accumulates in the container, and the increased weight compresses the springs.

weighing precipitation gauge

The amount of compression gets measured and used to calculate the weight of the water. The measurement can be recorded manually with a pen on a drum, or electronically with a data-logger, and send to the base weather station via landline or wireless connection.

The weighing precipitation gauge has some advantage over the tipping bucket system, including the ability to capture and measure snow and other solid forms of precipitation. It is also better equipped to handle large downpours.

Most modern systems are also self-emptying, reducing the amount of maintenance required on this type of rain gauge. Some weighing gauges are heated as well, which allow them to melt solid forms of precipitation and prevent a build-up of snow.

4. Optical Rain Gauge

An optical rain gauge consists of a laser/infrared diode and photosensitive sensor situated in enclosed spaces on opposites sides and below a row of funnels that receive rainfall.

Each funnel has a small opening at the bottom through which raindrop forms when enough precipitation accumulates inside the container. Once the waterdrop grows large enough, it falls from the funnel and though the space between the laser diode and photosensor.

As the drop falls through the beam of light, it scatters it enough for the photosensor to detect and measure it. These measurements are recorded and send through a landline or wireless connection to the base weather station.

Optical rain sensors have the advantage of not only measuring the amount of rainfall but also the intensity and frequency of the rain through the precise detection by the photosensitive detector.

5. Acoustic Rain Gauge

acoustic rain gauge

Also known as hydrophones, acoustic rain gauges are used to measure the rainfall over large bodies of water like dams, lakes, and the ocean.

The device itself gets place underneath the water's surface. The hydrophone can sense and measure the impact of the raindrops, hitting the surface of the water.

Each raindrop makes a unique sound, depending on its size and speed, which is called a sound signature. An acoustic rain gauge is sensitive enough to detect the different sound signatures to calculate the size and frequency of different raindrops.


After reading this post, you will know just how vital rainfall is to scientists, especially meteorologists and hydrologists. This is the reason why so much focus and time is spent on measuring precipitation, and it also explains why so many different rain gauges are in use.

This article focused on what precisely a rain gauge is, and also examined the different types of rain measuring devices and how they work in different environments to make accurate precipitation measurements.

Feel free to leave me any comments, questions, or suggestions, and I will get back to you as soon as possible.

If you like to be informed whenever a new article is released, and also receive helpful tips & information, you can stay updated by simply  following this link .

Until next time, keep your eye on the weather!


What Is An Anemometer, What Are The Different Types Of Anemometers, And How Do They Work?

What Is An Anemometer-What Are The Different Types Of Anemometers-And How Do They-Work

One meteorological instrument that forms an essential and indispensable part of any professional or advanced home weather station is called the anemometer. 

Even though the basic design did not change much since its invention more than 500 years ago, no significant weather station setup is complete without one, from the "humble" home weather station to the professional systems used by national meteorological agencies.

In this post we examine what an anemometer is, how it works, as well as having a look at the different types of instruments. 

What Is An Anemometer?

As with any other meteorological instrument or weather event, it's important to define what an anemometer is before we examine it further:

What Is An Anemometer?

What Is An Anemometer?

An anemometer is a meteorological instrument used for measuring wind speed (the rate of airflow).

It forms an integral part of a weather station for measuring current and forecasting future atmospheric conditions.

Leon Battista Alberti developed the first anemometer in 1450. Since them, the original design was improved upon several times, but the fundamental principles remain the same.

Today, several different anemometers exist to suit specific needs or preferences. We discuss the three most significant types of anemometers and how they work in the next section.

The Types Of Anemometers And How They Work

They come in different shapes and sizes, but anemometers can be narrowed down into three types of devices:

  1. Cup Anemometers
  2. Vane Anemometers
  3. Hot-Wire Anemometers

Each anemometer will be separately described and examined to get a clear understanding of how each device works.

1) Cup Anemometers

A cup anemometer consists of 3-4 cylindrical cups on horizontal arms rotating around a central axis. It is connected to and drives a shaft inside the axis that starts to turn as the cups start spinning.

Cup Anemometer

As the wind speed increases, the cups spin faster, which results in the shaft rotating more quickly as well. The number of rotations is counted, which is used to calculate the wind speed and then gets displayed on a calibrated analog or digital wind speed meter.

For the most accurate readings, a cup anemometer must be installed approximately 10 meters (32.8 feet) above the ground in an open area. Placing it close to large objects that will influence airflow can lead to false readings.

2) Vane Anemometers

Vane anemometers, also known as a propeller or windmill anemometer, also make use of wind speed to rotate. Unlike cup anemometers, though, they use blades to rotate and is also horizontally mounted (as opposed to vertically mounted cup anemometers).

Vane Anemometer

The shaft that connects to the blades is also mounted in a horizontal position, parallel to the airflow. Like the cup anemometer, the rotating blades make the shaft turn, and the number of rotations is counted to calculate the wind speed.

The blades of a vane anemometer are in the shape of an airplane propeller (hence the propeller analogy), and also reacts in the same way to wind movement. This is the reason it must be mounted horizontally to operate correctly and make accurate measurements.

Crucially, the blades must also face directly into the wind to perform accurate readings. To ensure this positioning, the anemometer's body rotates freely on an axis, with a vane fixed on the opposite side of the blades. The vane forces the body to turn into and face the wind.

Vane anemometers have several advantages and increased in popularity as a result. Some benefits include the ability to be used outdoors and indoors. They can also be compact and used in handheld devices, and measure other atmospheric parameters besides wind speed.

3) Hot-Wire Anemometers

Unlike cup and vane anemometers which are mechanical devices, a hot-wire anemometer (also known as constant current anemometers) uses electricity and heat to measure and calculate wind speed.

It uses electricity to heat a thin wire suspended in the air. As the wind cools the wire down, the rate at which it cools down gets measured to calculate the wind speed.

hot-wire anemometers

Using this method to calculate wind speed is possible since a metal's temperature directly influences its ability to conduct electricity (its resistance). A hot metal has a high resistance and does not conduct an electrical current as well as a cold metal with much less resistance.

As the heated wire starts to cool down while air passes over it, the resistance begins to decrease as well. By measuring the rate at which the resistance in the wire decreases, the wind speed can be calculated.

Hot-wire anemometers also have several other benefits. They can be used in more applications than just the field of meteorology. They can be used to measure gas flow in pipes, and also be used in fluids to measure the flow rate of a liquid.

Since hot-wire anemometers are very sensitive to slight changes, they are particularly accurate at measuring very low wind speeds. This capability makes them important for use in environments where the slightest air movement is of importance.

The three types of anemometers can be considered to be the most relevant wind measuring devices in meteorology. They are by no means the only anemometers in existence, though.

Laser Doppler anemometers use lasers as the name suggests. Ultrasonic anemometers utilize sound waves. And plate anemometers are used to measure high wind speeds. 

The examples mentioned above are just a few examples of a broader range of anemometers also available.


As the article illustrated, anemometers are used to measure wind speed. However, they can be used in other applications as well. There are also several different types of anemometers, of which three most relevant ones were highlighted.

You will now have a good understanding of what an anemometer is, what it is used for, and how the different types of anemometers work.  

Feel free to leave me any comments, questions, or suggestions, and I will get back to you as soon as possible.

If you like to be informed whenever a new article is released, and also receive helpful tips & information, you can stay updated by simply  following this link .

Until next time, keep your eye on the weather!


How Do Weather Satellites Work And How Do Satellites Stay in Orbit?

How Do Weather Satellites Work And How Do Satellites Stay in Orbit

At any given time, the Earth is surrounded by 4 700 satellites of which roughly 1 800 is still active. They serve a range of purposes, including communication, navigation, biosatellites, and yes, weather satellites.

Although it's hard to pinpoint the precise amount of active weather satellites in orbit right now, its a significant number, and new ones with more advanced and accurate measuring equipment gets launched on regularly.

Over the past few decades, meteorological satellites have become an indispensable part of meteorology. Not only are they used to help make accurate weather predictions and create forecast models, but also track important weather events (like hurricanes) in realtime. 

This article examines what a weather satellite is, how it works, and also take a look at the different types of weather satellites

What Is A Weather Satellite?

A number of countries currently have multiple weather satellites in space to monitor the weather and climate, including Japan, The United States, China, Europa, and Russia.

Before examining them in more detail, we first need to clarify what a weather satellite is. 

What Is A Weather Satellite?

What Is A Weather Satellite

A weather satellite is a man-made object whose primary purpose is to measure and collect meteorological data of a range of atmospheric parameters. It gets launched into space, where it orbits the Earth or remain in a stationary position over a specific point over the equator.

Rain, snow, ice, fire, cloud systems, dust storms, air pollution, volcanic ash, and ocean currents are just some of the many parameters that a weather satellite measure.

All the data collected by these satellites get sent back to Earth where meteorologists and climatologists use it to monitor current atmospheric conditions, predict future weather events, and create or refine forecast models.

How Do Weather Satellites Work?

The essential workings of a weather satellite are not much different from other types of earth-orbiting satellites. The most significant difference is the type of equipment it carries onboard and its unique orbits and positioning around the Earth.

Before one can look at what sets weather satellite apart from other satellites, we need to look at the features that all satellites have in common and makes them work.

Components Of A Satellite

Almost all earth-orbiting satellites have basically the same make-up. The majority of satellites have the following make-up that they need to function:

  • Main Body: Containing instrumentation, fuel, solar batteries, communication hardware, etc.
  • Solar Panels: Providing power to all onboard instrumentation, sensors, navigation equipment, etc.
  • Rockets: The propulsion system using onboard fuel to make small orbital adjustments and minor maneuvers.
  • Antennas & Transponders: The crucial equipment for communicating with the ground, and the ability to be tracked and located.
  • Thermal System: For protecting electronics and sensitive equipment from the extreme heat and cold temperatures in space.

Several other components also form part of the make-up of a satellite. For example, the aluminum covering protects external equipment from solar radiation. These components, though, do not make up the crucial parts of a satellite.

How Do Satellites Stay In Orbit?

A satellite stays in orbit by balancing two parameters: Speed (velocity) and Gravity.

Satellite Launch

Before a satellite can establish its orbit around Earth, though, it needs to get into space first. To accomplish this, they need a rocket that is powerful enough to break free from the planets gravitational forces and carry the satellite into its designated orbit.

A rocket needs to reach speeds of at least  40 296 km/h (25 039 mph) to overcome the Earth's gravity. Once it cleared the strongest gravitational forces, it can carry the satellite in low, medium, or high orbit.

Once the predetermined orbit is reached, the satellite gets released at the right orbit speed to maintain the same height above Earth's atmosphere. This speed was calculated to balance the satellite's velocity with Earth's gravity to maintain a constant altitude.

The satellite's speed needs to be fast enough not to get dragged down by the planet's gravity, yet slow enough to not completely break free from all gravitational forces and travel straight into space.

In this way, a satellite can stay in orbit around Earth's surface for decades, and even make small adjustments in its orbit by using the small amount of fuel it carries onboard.  

What Makes A Weather Satellite Different

A weather satellite may look like any other satellite, but it is its imaging equipment it carries onboard that sets it apart. The high-resolution imagers (cameras) are able to capture images in the visible, near-infrared, and infrared (thermal) range of the solar spectrum.

The range of atmospheric and surface parameters that can be measured, are literally too numerous to mention. For example NASA's geostationary satellite, GOES-16, is capable of taking high-resolution images with 16 spectral bands. They include 10 infrared, 4 near-infrared, and 2 visible channels.

What this means is that satellites like the GOES-16 can capture detailed images of a wide range of parameters in the atmosphere, from cloud formation, land surface temperature, ocean currents, and even aerosols and vegetative health.

The images get sent back to ground stations where meteorologists, environmental agencies, etc. can access it. They use for accurate weather predictions, do impact studies, conduct meteorological risk assessments, and refine climate models, to mention just a few.

The images and data that gets captured come from two types of weather satellites that are classified according to their orbit around Earth, which will be discussed in the next section.

Polar And Geostationary Satellites

The two different types of weather satellites are categorized according to their orbit around Earth, which is either a geostationary or polar orbit. Each one has its own advantage and actually compliment each other.

Polar-Orbiting Satellites

Polar-orbiting weather satellites orbit the Earth around the North and South Poles. They get placed in a low orbit of around 850 km (530 miles) above the planet.

jpss-1 satellite

The low orbit allows a satellite to cover every location on Earth, and image the same area twice a day. The ability to cover the entire planet frequently at low orbit allow polar-orbiting satellites to get a much more detailed look at the surface and atmosphere at any given time.

The latest generation of these satellites are especially well-equipped to measure specific aspects of weather like atmospheric temperatures, various cloud parameters, as well as, humidity fields.

Like geostationary satellites, most major nations have their own polar-orbiting series of satellites. The United States makes use of their NOAA range of satellites, Russia operates the Meteor series of satellites, and Europe uses the Metop satellites.

Geostationary Satellites

Geostationary satellites orbit the Earth at altitudes of around 35 880 kilometers (22 300 miles), much higher than any polar-orbiting weather satellite. The vast distance from the planet's surface enables the satellites to take images of Earth's entire hemisphere at a time.

This ability helps meteorologists to get a global picture of atmospheric and surface conditions. Earlier in this article, you saw the broad spectrum of channels a geostationary satellite can use to monitor multiple meteorological conditions (in the form of the GOES-16.)

A geostationary satellite also orbits around the Equator at the same frequency the Earth rotates, which means the satellite always remains in one location above the planet.

One of the many advantages that this type of orbit provides is that a ground station can place a directional antenna in a fixed position, and it will stay in communication with the geostationary satellite without continuous adjustments.

Like polar-orbiting satellites, major nations of the world use their own group geostationary satellites. The United States uses the GOES series of satellites, Russia the Elektro-L, Japan the Himawari, and Europe operates the Meteosat range of satellites.


This article not only described weather satellites but the workings of satellites in general. This is necessary, as weather satellites use basic satellite design and operation to function.

One needs to understand how weather satellites operate in principle before one can focus on the instrumentation and positioning that make them unique.

And this is precisely what this article aimed to accomplish: Describe what a weather satellite is and how it works. And then continue to describe what makes these satellites different and highlight the different types of weather satellites.

Feel free to leave me any comments, questions, or suggestions, and I will get back to you as soon as possible.

If you like to be informed whenever a new article is released, and also receive helpful tips & information, you can stay updated by simply  following this link .

Until next time, keep your eye on the weather!


What Is A Dust Storm, And What Causes A Dust Storm?

What Is A Dust Storm

If you live in an arid or semi-arid region where plenty of loose dry soil is present, you may be used to dust storms. For the rest of, it's not a phenomenon we can simply dismiss as a localized event.

Dust storms can affect regions thousands of miles away. In fact, it can even cross oceans and effect countries on other continents. Dust from the Sahara desert in Africa can reach as far as as the Amazon in South America, and even parts of the United Kingdom.

We mostly associate dust storms with their negative effect on humans and the environment. However, they also have some unexpected positive impacts in some regions as you will learn in a later section. 

This article will examine what a dust storm is, how it is formed, and what its effects are. We also take a brief look at how often this phenomenon occurs.

What Is A Dust Storm?

Before one can start examining how a dust storm develops, we first need to define what precisely a dust storm is: 

What Is A Dust Storm?

What Is A Dust Storm

A dust storm occurs in arid and semi-arid regions when large sections of fine loose dirt and sand get picked up by strong winds and blown into the atmosphere.

Also called a sandstorm, this meteorological occurrence creates a wall of dust that can stretch for miles and be thousands of feet high. Strong winds can transport and displace large quantities of dust or sand over hundreds or thousands of miles during this process.

Even though many regard dust and sandstorms as the same phenomenon, dust particles are smaller and lighter, allowing them to be lifted higher into the atmosphere and travel over longer distances.

What Causes A Dust Storm?

For a dust storm to occur, the right conditions must be in place. These conditions include very loose pieces of dirt or sand, preferably spread out over a relatively large flat space. The vital component, though, is a strong wind to start and maintain the process.

The winds responsible for a dust storm normally originates from a thunderstorm or a strong pressure gradient. (A strong pressure gradient happens when air change from an area of high to low pressure over a short distance, resulting in a strong wind.)

What Causes A Dust Storm

As the wind blows over the ground, it loosens and picks up pieces of soil, which allows them to start to creeping and speed up and even briefly become airborne.

This leads to a process called saltation (where dirt gets picked up into the air before falling back to the ground.) Each time a piece of soil hits the ground, it gets broken down into smaller parts.

Once the dust particles are small enough, it stays suspended in the air. The process takes place over a large area, where billions upon billions of dust particle gets picked up and mobilized by the wind. This process creates the thick wall of dust we know as a dust storm.

At at any time during the creation of a dust storm, the creeping, saltation, and suspension of dust particles into the air all take place simultaneously to create this storm system.

Human activities further contribute to the creation of dust storms. Deforestation is leaving increasingly large areas of earth exposed to dry out. Large-scale crop farming in semi-arid regions also leave thousands of hectares of dry soil exposed when no crops are planted.

Effects Of A Dust Storm

Dust storms have several widespread consequences. Many of the well-documented repercussion is also well-known, but there are also one or two unexpected benefits. Some of the most important effects of a dust storm include:

1) Structural And Vegetation Damage

The combination of strong wind and dust particles of different sizes can cause severe damage to houses, buildings, and structure. Dust and sand can also bury large parts of a city or towns, especially low-lying areas like streets, motor vehicles, and smaller structures.

Some dust storm are strong enough to blow over trees and completely remove large sections of vegetation. It can also have a devastating effect on the agricultural sector, where complete crops can be destroyed over large areas. 

2) Desertification

Desertification is the process through which changes in climate, as well as human activities, causes a growing section of the planet to turn into deserts.

The irony of this process is that desertification allows for more dust storms to occur. In return, these storms remove large portions of topsoil from neighboring regions, which further contributes to the desertification process.

3) Effect On Human And Animal Life

People caught in dust storms can experience short-term effects like impaired vision, burning throats, and difficulty breathing. Larger sand particles can cause abrasions and irritation of the skin. In severe cases, some of these effects can have long-term consequences.

One of the serious consequences, though is the damage to the human respiratory system. Dust storms can seriously affect people with existing respiratory problems, but long-term exposure to dust can also lead to the development of new related ailments.

Animals in the open don't have the same protection humans do, which means a significant number of these creatures perish during a dust storm. It leads to a substantial loss in livestock in areas frequently hit by dust storms. Wildlife is unfortunately also not immune.

4) Reduced Visibility

Dust Storms - Reduced Visibility

As is the case with dense fog and blizzards, a dust storm can dramatically reduce visibility. This has a severe impact on all kinds of transport, especially road and air traffic.

It can be so severe that roads may be forced to close and flights delayed or canceled. In the long term, it has a negative effect on the larger economy as well.

5) Fertilization Of The Amazon

As mentioned at the start of this section, a dust storm can have a positive impact as well. Large storms can transport dust over vast distances, especially when carried by winds in the upper atmosphere. It can even reach as far as the Amazon Rain Forest in South America.

The deposition of dust (soil particles) in the Amazon leads to a welcome replenishment of soil and also help to fertilize the ground. This process helps to sustain and promote plant and tree growth in this critical part of the Earth.

How Long Do Dust Storms Last?

They may be big and impressive, but dust storms do not last nearly as long as you might expect. They usually last for a few minutes, and at the most, an hour.

However, some dust that gets kicked up in the atmosphere stays over cities and towns for days and weeks, contributing to the air pollution in the region. If it gets caught by winds in the upper atmosphere, it can also be transported over longer distances, as you already saw.


As you might have realized while reading this post, dust storms may not last that long, but they pack a powerful punch and cause a lot of disruption and damage over a short period.

After reading this article, you will know exactly what a dust storm is, how it is formed, and its effects on the environment and human/animal life.

Feel free to leave me any comments, questions or suggestions, and I will get back to you as soon as possible.

If you like to be informed whenever a new article is released, and also receive helpful tips & information, you can stay updated by simply  following this link .

Until next time, keep your eye on the weather!


What Is Solar Radiation, How Is It Formed, And What Are The Different Types Of Solar Radiation?

What Is Solar Radiation

We are all well aware of what sunlight is, and that it originates from the sun. But it is only part of a bigger picture. The visible light from the sun forms only around half of the total solar radiation we receive.

It leaves us with some questions, including what the remainder of solar radiation consists of, and what happens to it. We also don't know how this radiant energy affects us, the weather, and our environment.

Most observers don't even know how solar radiation is created in the first place and how it manages to travel so far to reach the earth's atmosphere.

In this article, we explore these questions, define what solar radiation is, how it gets produced, and also take a look at the different types of solar radiation.

What Is Solar Radiation?

Before we can examine how the sun produces solar energy and explore its characteristics in more detail, we first need to define solar radiation.

What Is Solar Radiation?

What Is Solar Radiation

Solar radiation is the general term used to describe the electromagnetic radiation (radiant energy) emitted by the sun. Half of it falls within the visible short-wave part of the spectrum, while the other half falls within the ultraviolet and infrared part of the spectrum.

It is the wavelength of the different types of solar radiation, that allows them to be visible or hidden from our view. The solar radiation with wavelengths that falls within the visible part of the radiation spectrum is the sunlight that we can see.

The longer wavelengths of infrared light make them fall outside the visible range of the solar spectrum, while ultraviolet light's shorter wavelengths also make them fall outside the visible scope.

How Does The Sun Produce Energy

Solar radiation is the energy produced by the sun as a result of massive internal processes. In a nutshell, it is the sun ability to create a powerful nuclear fusion in and around its core that allows it to emit such a massive amount of energy in the form of light and heat. 

Sun Surface

The whole process starts in the sun's core. Due to the immense pressure and temperatures present in its nucleus, hydrogen gets converted into helium, which creates a nuclear fusion which is responsible for the massive amounts of energy released.

To better understand the sheer magnitude of forces involved, the pressure at the core is estimated to be 25.33 trillion KPa (the equivalent of 250 billion atmospheres) and the heat 15.7 million degrees Celsius (28.26° million degrees Fahrenheit) during this process.

Almost all this energy gets produced within 24% of the Earth's radius. The remainder of layers that make up the sun's composition, transfer the heat to the surface where it reaches the solar photosphere (the surface of the sun) which emits the solar radiation into space.  

The amount of radiation energy the sun releases into space every second is equivalent to the energy created by 1.82 billion thermonuclear bombs. These massive amounts of solar radiation propagate through space where it reaches Earth and other celestial bodies.

The Types Of Solar Radiation

Solar radiation consists of three different types of electromagnetic radiation:  

  • Visible Light
  • Ultraviolet Radiation
  • Infrared Radiation

Visible light makes up 42.3%, infrared radiation 49.4%, and ultraviolet a fraction above 8% of the total solar radiation reaching Earth. To best way to understand each form of radiation and its influence, is to examine each one separately. 

Visible Light

Visible light is the sunlight we experience, which is responsible for illuminating the earth and atmosphere. Depending on cloud cover, the light is usually at its brightest during noon, and at its weakest during sunrise and sunsets.

The light we receive reach us in three different ways:

  • Direct Radiation
  • Diffused Radiation
  • Reflected Radiation

It is the combination of all three sources of light that determines how much light we receive in total. The intensity of the light also varies, depending on which type of light is dominant.

Direct Radiation

Direct Radiation

Direct radiation occurs when the sunlight travels directly to the Earth's surface without any interference. It creates the strongest light intensity, and is also the most beneficial type of lighting for equipment utilizing solar energy, for example, solar panels.

It also usually casts dark and well-defined shadows.

Diffused Radiation

Diffused Radiation

Diffused radiation occurs when light hits particles in the atmosphere and gets scattered in all directions. The most common example is the light that travels through clouds, resulting in a less intense light that comes from and is spread in multiple directions.

Depending on the cloud thickness, diffused radiation can cast light to no shadows at all. 

Reflected Radiation

Reflected radiation is just what the name suggests. It is the sunlight that gets reflected off an object in a general direction. The amount & focus of light that gets reflected depends on the properties and texture of the object from which the light reflects.

Reflected Radiation

For example, can asphalt absorb the vast majority of incoming radiation and only reflects around 4 percent of the light. Snow and ice, on the other hand, can reflect as much as 90 percent of all light. 

When it comes to shadowcasting, reflected light has "multitasking abilities". Depending on its texture, the sun can cast a shadow on the reflective surface. In turn, the reflective surface can cast a strong enough light to create shadows behind objects.

The ability for diffused and reflected radiation to spread light in all directions, and not just straight down (as is the case with direct radiation), is the reason we can see inside our homes and areas the in the shadow.

All three light sources combine to allow light to spread fairly evenly on the surface of a region, with brightly lid areas and shadows also scattered throughout the region.

Ultraviolet Radiation

Ultraviolet radiation forms the smallest part of solar radiation by contributing just over 8 percent to the total amount. It is not visible to the human eye since its wavelengths are shorter than the minimum required to fall within the visible part of the radiation spectrum.

Solar Radiation Spectrum

Although ultraviolet light makes up just over 8 percent of the total amount of solar radiation, it is the most dangerous and damaging form of radiation. It can be divided into three different types of UV light:

  1. UV-A (wavelength of 320 - 400 nm)
  2. UV-B (wavelength of 280 - 320 nm)
  3. UV-C (wavelength of 100 - 280 nm)

The shorter the wavelength, the more damaging the UV radiation is. This makes ultraviolet-c radiation the most dangerous of the three types. Luckily it on makes only 0.5 percent of total solar radiation, and the vast majority can't penetrate the ozone layer.

Ultraviolet-A and B, however, are able to penetrate through the ozone layer. The band of energy that makes up ultraviolet-B is very damaging and is one of the primary causes of skin cancer in humans. It also inhibits photosynthesis in some types of plants.

Ultraviolet-A is less damaging, but can still cause severe sunburn in human beings. It also has a more significant effect on plant life, as it inhibits the photosynthesis in many plants more than UV-B radiation can.

Infrared Radiation

Infrared Radiation can be found on the opposite side of the solar radiation with longer wavelengths, which makes it fall outside the visible part of the radiation spectrum. It makes up 49.4 percent of the total amount of solar radiation.

Infrared Radiation is a major source of heat that is primarily responsible for warming the Earth's surface. The warming process is possible since water and carbon dioxide can efficiently absorb and convert the radiation into heat.

Infrared radiation can also be reflected much easier than visible and ultraviolet light as a result of its longer wavelengths. This attribute is important since it allows ultraviolet radiation to exchange heat between the ground & water surface, and the air.


After reading this post, you will realize just how true the opening statement is. Sunlight is essential for all life on the planet, but still only forms part of a much bigger picture that is solar radiation.

In this article, we examined what solar radiation is, how it is formed, and also looked at the different components that make this form of electromagnetic radiation.

Feel free to leave me any comments, questions, or suggestions, and I will get back to you as soon as possible.

Remember to join my Mailing List to be informed whenever a new article is released, and also receive helpful tips & information by simply  clicking on this link .

Until next time, keep your eye on the weather!


1 2 3 8