Clouds are powerful agents of global change. They affect the
overall temperature or energy balance of the Earth
and play a large role in controlling the planet's long-term
To understand the impact of clouds over time,
satellites measure the planet's
clouds and energy from space. Data from NASA's
ERBE and CERES satellite
instruments, for example, have made and continue to make significant
contributions to the understanding of clouds.
Making sure satellite instruments are accurate is very important. So,
scientists also study clouds and the Earth's energy from instruments
on aircraft and ground stations. This process is called validation.
You can view a
Webcast on the validation of the Aqua spacecraft (Quicktime; 14 MB).
Measurements from these experiments test the accuracy of satellite
instruments. Cloud observations made by people, such as S'COOL participants,
are also an important part of this ground truth