The excess water flows back to the oceans through rivers, streams, and groundwater where evaporation once again takes place and the cycle repeats itself. Heat Budget Earth's heat budget is more complicated than its water budget. An expression of the total solar energy received on Earth during some period of time and the total heat lost from Earth by reflection and radiation into space through the same period of time is called the heat budget . Solar energy that reaches Earth's surface is partially reflected and partially absorbed and converted to heat energy by the land and ocean waters. Tilt of Earth - since Earth's axis is tilted relative to the plane of Earth's orbit, the amount of sunlight reaching the poles varies with the seasons.
Most sunlight reaches the tropics.
This gradient sets up convection currents in the atmosphere between the poles and the equator. Winds - carry heat, mostly as water vapor, toward the poles. Clouds influence the amount of sunlight reaching Earth's surface. Aerosols - aerosols in the air may scatter sunlight. In addition to providing water and heat to the atmosphere as part of the hydrologic cycle, the oceans also distribute heat around Earth through ocean currents.