This effect is called thermal advection. If you’ve ever been hiking up a hill and suddenly found yourself shivering, you’ve experienced thermal advection.
So, what does this mean for us? Well, we can use elevation data to help predict what the weather might be like at a summit, for example.
However, it will be dependent on many factors such as snow, rain, or clouds.
With so many variables, traveling inland to areas located at a higher elevation, one realizes that atmospheric conditions start to differ for reasons unknown. Why does this happen?
What are the effects of such changes? And what are the differences between the climates found at high elevations and those found near the coast?
Atmosphere And Elevation
First off, it’s important to understand why atmospheric conditions change with an increase in elevation.
As mentioned earlier, temperature and air pressure reach their highest values close to Earth’s surface and decrease as altitude increases.
Moreover, since temperature and air pressure reach maximum values at different heights, we must take into account the fact that temperature decreases faster than air pressure.
As a result, we see that the average temperature drops by about 2 degrees Celsius per 1000 meters above sea level. Air pressure reaches its lowest value at around 10 kilometers above Earth’s surface.
Thus, the difference in temperature between a city located at sea level and a region located at 4 km above sea level is approximately 7 degrees Celsius.
Wind Speed
The second factor to consider is the wind speed. Wind speeds decrease as altitude increases. This is because the friction caused by the movement of air molecules against each other slows down the flow of air.
In addition to the aforementioned factors, there are many other variables that affect the climate in a specific area, including humidity and precipitation patterns.
However, the most significant factor is the amount of solar radiation received. Solar radiation also increases as altitude increases, which in turn, can lead to warmer temperatures.
Now let’s look at the effect of temperature and air pressure on the climate.
We can observe that as temperature goes up, air pressure decreases. Therefore, the density of air becomes less dense. This causes air to become lighter and move upwards.
Temperature
Why do high mountains look cold? You might think it’s because they are covered in snow, but that’s not why they look cold.
Mountains don’t feel cold due to melting ice and snow. Instead, what makes mountains seem colder than the surrounding area is something called thermal radiation.
Thermal radiation occurs when particles move around in space, like electrons moving around inside atoms. When light travels through matter, such as air, it slows down and becomes visible.
This slowing down causes some of the photons to become absorbed into the matter. Once they are inside the matter, the energy of those photons is converted into another form of energy – heat.
As light slows down, it emits infrared radiation. Infrared radiation is invisible to our eyes, but it’s still part of the electromagnetic spectrum.
Because we can see visible light, we know there must be invisible light too. And since the speed of light doesn’t change, invisible light must travel faster than visible light.
This is how infrared radiation gets up to the same as the speed of light.
This invisible radiation is responsible for most of the warmth felt on Earth.
If you could stand outside on a sunny day and measure the amount of infrared radiation coming out of the atmosphere, you would find that it’s much greater than the amount of visible light reaching the ground.
As mentioned earlier, the reason why mountains look cold is that the air above them is cooler than the air closer to the surface. As the air cools, it loses energy and moves slower.
So the infrared radiation emitted by the air near the surface is slowed down and absorbed into the air. In contrast, the air above the mountain is warmer because it hasn’t lost as many of its molecules.
Therefore, the infrared radiation emitted by that air is traveling at normal speeds and isn’t being slowed down enough to absorb into the air.
So why is the air above a mountain thin? Well, the air rises naturally. At lower elevations, the air is thicker and heavier than the air at higher elevations.
If the air is heavy, it takes longer for it to rise. That’s why the air over the ocean is thick while the air above the clouds is thin.
Altitude & Air Pressure
Atmospheric air has weight. When we talk about air pressure, we are talking about how much force there is pushing down on us.
If we go up into the sky, the air gets thinner because the molecules are moving further apart. This causes the air pressure to drop.
The lower the air pressure, the less force is pressing down on us. We feel lighter and lighter the higher we go.
The reason why we feel heavier at sea level is that our bodies have adapted over millions of years to deal with the low air pressures at ground level.
When we take off in an airplane, however, we don’t just jump straight up into thin air. Instead, we climb slowly while the air pressure decreases.
Once we reach a certain height, called cruising altitude, the air pressure is no longer enough to keep us aloft. So we start falling again.
Precipitation & Air Pressure
When it rains, we say that it is raining because water droplets are falling out of the atmosphere into our environment. If you look up high enough, though, you might notice something else: clouds.
Clouds are composed of tiny liquid droplets suspended in the air. These droplets are called cloud particles, or aerosols. Aerosols are very small compared to the size of the droplet.
They are so small that they do not affect the overall appearance of the cloud; they simply make individual drops visible.
The process of making clouds happens because of changes in atmospheric conditions. As the air rises, it cools down.
This causes the temperature to fall, and eventually, the temperature becomes lower than the dewpoint temperature. At this point, the air begins to become saturated.
Water vapor molecules begin to change into liquid water droplets. If the temperature falls further, the droplets grow larger and eventually fall out of the air altogether.
As the droplets fall, they release heat energy. This heat energy is transferred to the ground, causing surface warming and evaporation.
Evaporation increases the concentration of water vapor in the air, and thus, leads to more precipitation.
Mountains
We’ve already touched on mountains but another way of understanding this concept is to imagine a mountain range is like a giant wall surrounding a valley.
As you move toward the bottom of the valley, the air gets thinner and colder because there aren’t many things around to absorb it. This causes the air pressure to drop.
If you’re standing near the peak of a mountain, the air is thin enough that you feel cold even though it might be warmer than the air at sea level.
In addition, the farther away something is from Earth’s surface, the faster it moves relative to the ground. So the speed of molecules increases with increasing elevation.
Because molecules are moving faster, they bump into each other more often, causing collisions and giving off energy.
Mount Everest
If you fancy experiencing the effect of altitude on climate you could always check out the tallest mountain in the world is located in Nepal, just north of Kathmandu.
At 29,029 feet tall, it is taller than Mount Kilimanjaro, the second tallest mountain on Earth. The mountain is known as Mount Everest because it is the highest point on land. However, it may be a tad too challenging for a climbing novice.
Atmospheric pressure decreases as you go up in altitude, causing less air molecules to surround you, making breathing difficult.
You are exposed to cold winds coming off the Himalayas and Tibet Plateau, where the temperature drops well into the negative digits.
Temperatures near the summit range from -20 degrees Fahrenheit (-29 Celsius) to minus 50 degrees Fahrenheit (-45 Celsius).
In addition to the low levels of oxygen, there are few plants and animals living at such heights. There are no trees, and most species cannot survive without water.
Mountain goats live on the slopes of Mount Everest, and Marmots, Squirrels, and birds nest in the thin soil.
Altitude And The Body
Altitude doesn’t just affect climate but also the human body in different ways. For example, there are many things that happen to our brains, lungs, and cardiovascular system when we go up into the mountains.
Altitude sickness occurs when you’re exposed to too much oxygen at high altitudes. Most people who live near sea level breathe plenty of air containing 20% oxygen.
In contrast, most people living at higher elevations breathe less air containing 21% oxygen. This difference in oxygen concentration triggers a physiological process called acclimatization.
Altitude sickness happens when you don’t acclimatize well enough.
The main symptoms of altitude sickness occur within about six hours of ascending to altitudes greater than 2,500 meters.
If you’re already suffering from altitude sickness, it’s likely to worsen. However, even if you don’t suffer from altitude sickness initially, you still might later.
There are several factors that contribute to whether someone gets altitude sickness. Some people are genetically predisposed to develop altitude sickness.
Others are protected because they’re fit and highly trained. And others simply aren’t susceptible because they adapt better to changes in atmospheric pressure.
Our bodies adapt to the changes in pressure and oxygen levels. However, some people react differently to altitude than others. This is due to factors such as genetics, gender, age, fitness level, and diet.
The most common symptom of acute altitude sickness is a headache. Other symptoms include nausea, vomiting, fatigue, dizziness, difficulty sleeping, and shortness of breath.
Some people experience none of these symptoms, while others suffer severe consequences.
Conclusion
The effect of altitude on climate can be seen all over the world. It is not limited to only one continent or region. Maybe one day, if you head to the mountains or a high altitude area you’ll experience it firsthand!
