Solar energy input, Biology

Assignment Help:

Solar Energy Input

We know that the spectral distribution and the intensity of solar radiation incident on the earth's surface are known. Of the enormous'amount of energy that is radiated by the sun (5.6 x l07 cal/min), only about one-half of 1 billionth of that amount is intercepted by the eafth. Not all the solar.radiation can penetrate the earth's atmosphere; however, the amount of solar energy received at the top of atmosphere is constant. This energy is reffered to as solar constant. It is defined as the rate at which solar radiation falls on a unit area is a plane surface, which is oriented peqiendicular to the solar beam, when the earth is at its mean distance from the sun. On an average the value of solar constant is 2 cal/cm2/min.

As the solar radiation &vels through the atmosphere it interkts wiith it and gets diminished in three different ways: by reflection, scamring and absorption. About 30% of the total incoming solar radiation is reflected by clouds and a portion of it is back-scattered and lost in space. About 19% of it is directly absprbed by oxygen, ozone, water, ice crystals and suspended particles.'This absorbed radiation is converted into heat energy and the air is warmed to some extent. The remaining 51 % is absorbed or reflected by earth's surface that is converted to heat. Thus a total of 70% (19% by atmosphere aid 51% by earth) of the radiation absorbed by em and atmosphere is involved in the functioning of our biosphere.

The earth has a variety of surfaces - rough, smooth, ice-covered, or water-covered and areas with differeht types of vegetation. The amount of radiation absorbed or reflected depends upon the nature of surface. features i.e. topography of the area. The percentage of reflectivity of the incident radiation in meteorology is called albedo, which is Reflected radiation

Albedo = (reflected radiation)/(Incident radiation) x l00

Albedo of snow covered landscapes is higher than vegetated landscape or water column. Freshly fallen.sn6w typically has an albedo between 75 to 95%. Ocean waters have low albedo and therefore they appear darker thw the adjacent continental land masses. Rough surfaces have low albedo than smooth surfaces. Also the light coloured surfaces reflect more thandark surfaces. Reflectivity also depends upon the angle of incident radiation. The surfaces that are less perpendicular to sun's rays are more reflective than surfaces that make almost a right angle with the incoming solar radiation.  We have learnt that earth and atmosphere receive solar radiation, absorb a part of it and get warmed up. We also know that during night earth cools down. So where does the energy of radiation absorbed by the earth go? Actually, the absorbed radiation in turn is continually reradiatedfrom the earth as heat in the form of infrared radiation and is sent off to outer space continually. If it had not re-radiated the air temperature would rise steadily day by day.


Related Discussions:- Solar energy input

Principle of colorimetric method-2, Define Principle of colorimetric method...

Define Principle of colorimetric method-2, 4 dinitrophenylhydrazine? Ascorbic acid is oxidized to dehydro ascorbic acid by copper (Cu ++ ) ions. 2, 4 dinitrophenyl hydrazine re

Define the guidelines for calculating ideal body weight, Define the Guideli...

Define the Guidelines for Calculating Ideal Body Weight? What is the ideal body weight for me? Am I obese? Am I underweight? These are the questions that must have come to your

Explain the types of modified gellan gum, Explain the types of modified gel...

Explain the types of modified gellan gum There are 3 types of modified gellan gum.  (a) High acetyl gellan (partially deacetylated), which provides a thermo reversible gel,

What is pcr, What is PCR? How does PCR works? PCR, polymerase chain rea...

What is PCR? How does PCR works? PCR, polymerase chain reaction, is a process to synthesize many copies of exact regions of a DNA molecule known as target-regions. Its inventor

Proteins, Proteins Proteins are continually synthesised in the cells a...

Proteins Proteins are continually synthesised in the cells as they are the principal component required for growth. Proteins are composed of amino acids which are derived larg

Which of the following structures in a vertebrate, Which of the following s...

Which of the following structures in a vertebrate with a four-chambered heart would have blood with the highest oxygen concentration? And why? A. Arteriole end of a capillary B. Ri

Of what substance is the plant cell wall made, Q. Of what substance is the ...

Q. Of what substance is the plant cell wall made? Of which monomer is it made? The plant cell wall is made of cellulose. Cellulose is a polymer whose monomer is glucose. There

Explain chemical bonds in basic chemistry, Explain chemical bonds in basic ...

Explain chemical bonds in basic chemistry? Chemical Bonds :  Chemical bonds are forces that join atoms together in a functional unit. There are three types of bonds that can

#title, natural selection

natural selection

What are the characteristics of thin gingiva, Characteristics of Thin Gingi...

Characteristics of Thin Gingiva  Highly scalloped soft tissue and bony architecture  Delicate friable soft tissue  Minimal amount of attached gingiva  Thin underlying

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd