What are four controls of atmospheric temperature?
The four controls of atmospheric temperature are (1) differential heating of land and water; (2) ocean currents; (3) altitude and geographic position; and (4) cloud cover and albedo (Pearson, The Atmosphere). Atmospheric temperature is defined as the temperature recorded on a thermometer placed in Earth's air where sheltered from direct solar radiation.
(1) Differential heating of land and water: The oceans and the land heat up and retain heat at different rates, at differential rates. This heating and cooling differential affects local temperatures resulting in varying inland and oceanside temperatures in relatively closely related vicinities. Compared to oceans, land heats and cools quickly while oceans heat and cool slowly. As a result, ocean waters can cool summer atmospheric heat and, conversely, heat winter atmospheric cold. This is because of the differential rates of quickly or slowly accumulating or releasing present levels of solar heat.
(2) Ocean currents: Directional movements of ocean currents affects land temperatures. Worldwide current movements are complex patterns that are affected by several things: ocean bottom topography; earth's rotation; ocean salinity; ocean heat content; and wind (Smithsonian, Ocean Planet). As these patterns move across the oceans, land masses are either warmed or cooled. A change to any factors affecting surface (surface circulation) or deep currents (thermoline circulation) can alter the effects of ocean currents on atmospheric temperatures.
(3) Altitude: Various altitudes have corresponding air pressure and air density that affect atmospheric temperature. As altitude increases from sea level, air pressure and air density inversely decrease. Correspondingly, atmospheric temperature also decreases as altitude increases. There is a direct correlation between air pressure, air density and temperature while there is the inverse, an indirect correlation between altitude and temperature.
Geographic position: Atmospheric temperatures tend to be similar on geographic distribution from east to west while temperatures tend to vary greatly in geographic distribution from north to south. Temperature decreases in a pole-ward direction while staying relatively equal in an east-west direction. In other words, the temperatures in Singapore and Washington D.C. will tend to be more similar than the temperatures in Buenos Aries and Nuuk.
(4) Cloud cover: Clouds affect temperature because they are a collection of frozen particles that have a cooling effect; they drop precipitation which cools; and they reflect and radiate heat into the space, outside Earth's atmosphere. By reflecting heat, clouds insure a stability of temperature so Earth doesn't overheat. By dropping precipitation, clouds cool the heat accumulation.
Albedo: The fractional amount of solar energy reflected back into space, as in when heat is reflected off clouds and radiated back into space. Below clouds, Earth's surfaces produce various amounts of albedo. For example, ice has a high albedo while water has a low albedo.