There was a time when the relative value and importance of clouds was not yet firmly established. Only when technology came into the picture did people really understand how important clouds could be. Meteorology has always existed as the science of studying the atmosphere, but only when technological breakthroughs arrive did meteorologists get a grasp of how clouds can really affect the weather. With modern advancements in the last few decades, meteorologists are now beginning to understand the value of cloud technology.
Using Clouds in Weather Forecasting
Since the beginning of time, people have always looked at clouds to predict the weather. Even with no meteorological instruments, a person can just look up at the sky, study how the clouds look like, and somehow predict if rain is coming or if a thunderstorm will soon come to pass. Of course, these predictions aren’t always accurate, but they only go to show that clouds have always been used for this purpose. With the advent of cloud technology, meteorologists can now accurately predict weather conditions using the clouds.
Weather forecasting is a complicated process that involves many aspects. To forecast the weather accurately, meteorologists use a variety of tools to measure the different factors involved. To measure precipitation, they use a rain gauge. To measure air pressure, they use a barometer. To measure wind speed, they use an anemometer. Of course, to measure temperature, they use a thermometer.
When it comes to clouds, meteorologists use radars to shoot radio signals. Through the Doppler Effect, these signals will be able to locate precipitation, measure it, and send vital information back to the transmitter. Through this technology, meteorologists can easily spot where storms are located and predict their movement. In addition to this, meteorologists use satellites from outer space to take pictures of the Earth. These pictures will show how dense the clouds are and how they are moving in the atmosphere. In addition, clouds are also observed from the ground, because their shape and movement say a lot about how the weather is developing.
Cloud Cover and Global Warming
Clouds are useful not only in forecasting the weather but in regulating it as well. Due to the presence of white clouds in the atmosphere, some of the radiation coming from the Sun is reflected back to space, and this contributes to the cooling of the Earth’s surface. But the clouds play a role in warming the surface as well. When the sunlight reaches the surface, radiation is emitted upwards, and the clouds absorb this radiation. The water in the clouds reacts to this by producing a downward radiation effect, effectively warming the surface of the earth.
When meteorologists realized this dual purpose of clouds as both a reflector (surface-cooler) and a radiator (surface-warmer), they realized that clouds actually play a big part in global warming. Meteorologists pay special attention to cloud cover because an abnormal increase or decrease in cloud cover can exacerbate global warming and climate change.
Cloud Cover in Aviation
Meteorologists measure cloud cover not only to monitor global warming but also to help in aviation. Pilots need accurate cloud cover readings because these can determine whether there are cold fronts or even warm fronts that they need to be wary of. Before airplanes are given the signal to fly, there’s a set of visual flight rules that need to be followed. If a cloud cover is too thick, indicating that it is not safe to fly, the pilots have to be alerted of this they are cleared for take off.
Interpreting Cloud Colors
In addition to the shapes and thickness of clouds, meteorologists have now found out that they can use the coloration of clouds as well. Through recent findings in cloud technology, by just observing the color of a cloud, they can identify what’s happening inside of it. Clouds normally appear white because they reflect the sunlight so when clouds exhibit different colors, this could be caused by various phenomena.
When a cloud appears yellow, it’s because of the pollutants in the air. When a cloud appears blue, it’s usually because big water droplets (the size of rain) in the cloud are scattering the blue rays of the spectrum. When a cloud appears green, it’s because ice droplets in the cloud are scattering the green rays of the spectrum. This is why when a greenish cumulonimbus cloud appears in the sky, it’s usually an indication of an approaching severe weather condition such us a heavy storm, intense winds, hail, and even tornadoes.
Precipitation comes from clouds, so without clouds severe droughts would occur. To prevent this from happening, cloud seeding can be utilized. As one of the advancements in cloud technology, cloud seeding is a form of weather modification. In Beijing, for instance, rainfall is way lower than what the rest of the world normally receives. To help alleviate this, China has used cloud seeding to create (or increase) rainfall. Cloud seeding is also used to form other kinds of precipitation, such as ice. In Australia’s Snowy Mountains, for example, sometimes snowfall is not adequate enough especially during the early days of winter. Ski resorts may utilize cloud seeding methods to generate more snowfall, which is needed to keep their operations going.
Currently, three methods for cloud seeding are being used, and these are:
- Static: This type of cloud seeding is used to help the moisture that can already be found in the clouds to precipitate faster. This is usually done through the help of silver iodide, dry ice, or liquid propane. These chemicals cause the formation of ice crystals, which will allow the cloud’s already-present moisture to turn into precipitation faster.
- Dynamic: This is a far more complicated type of cloud seeding comprised of 11 different stages, with the purpose of increasing the amount of rainfall.
- Hygroscopic: This type of cloud seeding still needs to be researched further, but essentially what it does is spread salts in the clouds through flares.