Falling raindrops and flowing water possess kinetic energy that loosen and move surface materials. Water can coexist in the Earth system as liquid, solid, and invisible vapor. As the principal greenhouse gas, water vapor brings temperatures into a range required for life on Earth . Some of this energy absorbed by the water vapor is emitted to Earth's surface as infrared radiation. The sun powers the global water cycle .
Solar radiation is absorbed at the Earth's surface and converted into heat.
On a global annual basis, solar radiation is most intense in tropical and subtropical latitudes. Go to online portion of investigation. The following portion of the Investigation file is delivered via the WES Homepage. This is the first of two online portions of investigations which will be available by noon, eastern time, every Tuesday and Thursday during the course. We hope the use of current environmental information will become a pleasant and anticipated daily experience.