14 DAY TRIAL // For quite some time now, climate researchers have figured out that clouds play a critical role in determining the amount of sunlight that makes its way to Earth, and is retained here to warm the planet. A new study has just found that the amount of light that passes through depends on the photons' wavelength.
Experts never thought about searching for this type of correlation before, which is why the process went unnoticed for such a long time. And yet, they did observe that clouds seemed to control Earth's exposure to sunlight.
This filtering mechanism was found to have different intensities at various wavelengths of sunlight passing through. The new data could go a long way towards improving climate models that we use to simulate Earth's potential future.
Also in this research, experts learned that clouds can contribute to Earth's energy budget even if they don't allow light through directly. The process, called sunlight scattering, is one of the main reasons why you can get sunburns on an overcast day.
The research was conducted by experts at the US Department of Energy (DOE) Pacific Northwest National Laboratory (PNNL). Their discoveries were published in a recent issue of the esteemed scientific journal Geophysical Research Letters, Science Blog reports.
“The amount of the sun’s energy that reaches the earth’s surface is the main driver of the Earth’s temperature. Clouds are one of the least understood aspects of climate change,” explains Evgueni Kassianov, who is an atmospheric scientist at the PNNL.
“They can block the Sun, but light can also bounce off one cloud into another cloud’s shadow and increase the solar energy hitting Earth,” the study investigator goes on to say.
Finding the mechanisms through which clouds regulate our planet's exposure to sunlight is very important because these structures tend to contribute to both cooling and warming the atmosphere.
Scientists also determined that minute, liquid or solid particles called aerosols now play a huge role in this matter. These particles are produced from a variety of sources, including human activities. Lately, the proportion of human-made aerosols in the overall mix has increased significantly.
The particles can “seed” new clouds, so the way they interact with existing clouds needs to be understood in great detail. Upcoming satellite missions are scheduled to do just that.