Insolation and Heat Balance of the Earth

The sun, as we all know, is the earth’s major source of energy. Solar radiation is the process by which the sun radiates its energy in all directions into space in short wavelengths. Only a small portion of this radiated energy reaches the earth’s surface (2 units out of 1,00,00,00,000 units of energy radiated by the sun). Insolation is defined as the energy received by the earth’s surface in the form of short waves.

Insolation and Heat Balance of the Earth:

• Because of the earth’s tiny size and distance from the sun, the quantity of insolation received on its surface is significantly less than that radiated by the sun.
• Furthermore, the atmosphere’s water vapour, dust particles, ozone, and other gases absorb a little amount of solar light.
• Due to differences in the distance between the earth and the sun, the solar energy received at the top of the atmosphere varies slightly over the course of a year.
• On July 4th, the earth is farthest from the sun during its revolution around the sun. Aphelion is the name given to the earth’s current position. The earth gets closest to the sun on January 3rd. Perihelion is the term given to this condition.
• Because of the difference in distance between the earth and the sun, the annual insolation received by the earth on the 3rd of January is somewhat higher than on the 4th of July.
• However, other factors such as land and sea distribution and atmospheric circulation obscure the impact of this variance. As a result, the fluctuation has no more impact on daily weather changes on the earth’s surface.

Factors influencing Insolation:

Rotation of the earth on its axis:

The earth revolves on its own axis, at a 66.5 degree inclination to the plane of its orbit around the sun. The amount of insolation received at different latitudes is influenced more by the earth’s rotation on this inclined axis.

The angle of incidence of the  rays of the sun:

The vertical rays always cover a smaller area in respect to the slant rays. The energy is spread as more space is covered, and the net energy received per unit area declines. Furthermore, rays impacting at a tiny angle cross the atmosphere more than rays striking at a big angle. The larger the amount of heat reflected and absorbed by the atmosphere, the longer the course of the sun’s beams. As a result, insolation intensity is reduced.

Duration of the day:

The length of the day varies depending on where you are and what season you are in. It determines how much sunlight reaches the earth’s surface.

The amount of insolation that is received is proportional to the length of the day. Shortening the day’s duration, on the other hand, results in less insolation.

The atmosphere’s transparency:

The amount of transparency in the atmosphere is determined by cloud cover and thickness, dust particles, water vapour, and other factors. Insolation is reflected, absorbed, or transmitted by them.

The ability of solar energy to reach the earth’s surface is hampered by thick clouds. Water vapour, on the other hand, absorbs solar radiation, resulting in less insolation reaching the surface.

Heating and Cooling of the Atmosphere:

The sun is the primary source of heat and energy in the atmosphere. The environment can be heated and cooled in a variety of ways. They are as follows:

Terrestrial Radiation:

As a result, the earth’s surface becomes a radiating body after being heated up by insolation (in the form of short waves).

Long waves begin to radiate energy from the earth’s surface into the atmosphere.

Terrestrial radiation is what we refer to it as. From the bottom to the top, this energy heats the atmosphere.

Conduction:

The process of heat transmission from a warmer to a cooler object when they come into contact is known as conduction.

Convection:

Convection is the movement of a mass or substance from one point to another, usually vertically, to transfer heat.

Advection:

Advection is the heat transfer that occurs when air moves horizontally (wind).

Conclusion :

When insolation interacts with the atmosphere and the earth’s surface, heat is created, which is measured in terms of temperature. Temperature is a measurement of how hot or cold something is in degrees.While heat reflects the molecular movement of particles that make up a substance, temperature is the measurement in degrees of how hot (or cold) a thing (or a place) is. It aids in the estimation of the size of a solar power installation. It aids in determining the projected production of solar panels and the most effective location on the planet for solar panels.