NASA MODIS Image of the Day: April 16, 2007 – MODIS Cloud Fraction Product
This image is what is called the the MODIS Cloud Fraction product. Cloud fraction is the measurement scientists use to determine how much of the Earth is covered by clouds. This particular image shows one month of data, from February 1, 2007 to March 1, 2007.
The cloud fraction measurement is important because clouds play a large role in regulating the amount of energy that reaches the Earth from the Sun as well as the amount of energy that the Earth reflects and emits back into space. Most clouds reflect sunlight very well. Globally, they reflect about 20 percent of the energy coming from the Sun back into space. At the same time, clouds trap the heat that radiates from the Earth’s surface, preventing energy from escaping into space. The balance between the amount of energy the Earth receives and the amount of energy it radiates into space is the Earth’s energy budget.
Scientists worry that climate change could alter the amount and type of clouds that form. Changes in cloud cover could tip the balance in Earth’s energy budget so that either more energy escapes into space or more energy reaches the Earth than it does now. A change in Earth’s energy budget would change temperatures and weather patterns.
For this reason, scientists want to measure how much of the Earth is covered by clouds. They want to understand how cloud cover affects climate and vice versa. By improving their understanding of clouds roles in the climate system, scientists aim to better predict how changes in cloud cover might change Earth’s climate in the future.
You can download a high-resolution image here.
