factors affecting daily insolation and annual insolation?

Answer 1

The factors affecting insolation are latitude,transparency of the atmosphere,ozone layer,nature of the soil,calender date,cloudiness etc.
Latitude:-The angle of incidence of the sun's rays at the earth's surface increases from the tropics towards the poles.So, the insolation received on a given area diminishes towards the poles.
Transparency of the atmosphere:-Absorption and scattering by the molecule matter such as dust and smoke in the atmosphere reduce the intensity of the incoming solar radiation.
Ozone layer:- This layer in the lower stratosphere absorbs the ultra-violet radiation present in the solar radiation.
Nature of the soil:-Part of the solar radiation,on reaching the earth's surface,is obsorbed by the surface and part of it reflected back into space, the proportions depending upon the nature of the surface(soil).
Calender date:- Due to the tilt of the earth's axis, the period of daylight at a place varies with the time of the year and is maximum in summer and minimum in winter.
Cloudines:-If clouds are present,they sometimes reflect the solar radiation back and sometimes prevent it from reaching the ground.
These are the factor affecting the daily insolation.
Latitude,ozone layer,nature of the soil and the annual percentage of cloudiness affect the annual insolation.

Answer 2

insolation is the amount of sunlight falling on an area. In the context of this question it is assumed to mean 'insolation on a level area at the earth's surface'. The major factor is the angle at which the sunlight hits the surface, the higher the sun is in the sky, the higher the insolation. This is dependent on latitude (with maximum annual insolation at the equator, mimimum at the poles) and the time of year (maximum in summer, minimum in winter). When the sun is lower in the sky, sunlight is reduced due to passing through more atmosphere. It then has to spread over a larger area due to the angle of arrival. Also the distance from earth to sun is not constant, in January the sun is closest, with the result that the seasonal variation in insolation for the northern hemisphere is lower than for the southern hemisphere. At a particular location, there will also be variations due to the sunlight being reduced by local factors such as clouds or smog.