Factors affecting insolation and the heating of the atmosphere

Altitude of land:

Land heats air above (conduction and convection)

As altitude increases there is less land to heat the air.

Air is less dense as altitude increases- thin air retains less heat. (1000m^=6.4 degree v)

Altitude of sun:

At higher lattitudes the suns rays have to pass obliquely through the atmosphere increasing absorption and scattering.

Proportion of land and sea:

Land heats and cools quicker than water.

Land doesn't retain heat as long as water. (e.g central Canada - heats and cools quickly- extreme continental climate)

Prevailing winds:

Air masses temps are determined by where they come from.

Therefore sea air masses tend to be cooler than land air masses in summer but warmer in winter.

Ocean currents:

Warm currents move pole wards and are replaced by cold water. The rotation of the earth pushes water westwards and creates circulation.

A circulating motion occurs called a gyre.

The warm north atlantic drift moves NE raising UK temps.

Seasonal changes:

Inputs of insolation vary with seasons. Northern hemisphere highest inputs are june, july and august. Reverse for southern hemisphere.

Diurnal range:

Length of day and night varies away from the equator. At poles no insolation in winter months-sun does not rise-in summer does not set.

At equator length of day remains constant.

Aspect:

Slopes alter the angle at which the sun hits the ground. In northern hemisphere south facing slopes recieve more insolation so are warmer.

Cloud cover:

On cloudy days heat can be trapped keeping temps warm if it was previously.

On clear days insolation quickly reaches the ground raising temps. Heat is lost rapidly at night as there is no cloud cover.

Urbanisation:

Urban heat islands are created as buildings absorb and radiate heat into the atmosphere.