5.INSOLATION
The energy received by the earth from the incoming solar radiation is known as insolation. Solar radiation is a power per unit area. Received from the Sun in the form of an electromagnetic radiation. It is the primary source of energy of the earth. insolation varies on account of various factor:
Latitude: latitude is the Geographic co-ordinate that specifies the north -south position of a point on the earth surface. Insolation varies with latitude at the same amount of sun rays is required to cover a larger area at the the poles than at the equator. Thus, sun rays are more concentrated at the equator and diffused at the poles. Latitude is an angle which ranges from zero degree at the equator to 90 degree at the pole. The region located up to 40 degree latitude are heat surplus region of the world , whereas region located outside 40 degree latitude are deficit region of the world.
Transparency of the atmosphere: maximum amount of insolation is received over the subtropical desert on account of cloudless sky and high insolation. The most important factors is the transparency of the atmosphere is the measure of how clear the sky is on a given light determined by clouds dust and haze.though the amount of insolation is maximum over equatorial regions ,it is blocked by the layer of Clouds.
3.altitude: insolation is is higher and higher altitudes. Altitudes is a distance measurement, usually in the the vertical or ” up” direction , between a reference datum and a point or object . The lower altitude are hotter than the high altitude because heat is transferred in the atmosphere through the contact with earth. consequently the layer of air is in contact with the surface of the Earth is the warmest. the heat from the lower layer of troposphere transferred to the upper layer.
The temperature of a place is affected by insolation as well as some other factor, which are as follows:
🔸️ movement of air mass: they move with the Global pattern of winds. in most of the United States, air masses generally moves from west to east . Air masses from low latitude region To High latitude regions bring heat along with it. On the other hand air masses from high latitude regions to low latitude regions brings coldness along with.
🔸️ ocean currents: ocean currents are continuous, predictable ,directional movement of seawater driven by Gravity, wind and water density. Ocean current from low latitude region To High latitude region brings heat along with it, on the other hand ,ocean currents from high latitude region to low latitude region brings coldness along with it.
6.ALBEDO.
It is a measure of how much light that hits the surface is reflected without being absorbed. Albedo refers to reflectivity of a surface. It is expressed as percentage on a scale from zero,for no reflection to 1 the average albedo of earth ranges from 32 to 35% but it varies from region to region depending on various factors:
🔸️snow: snow is the precipitation in the the form of of ice crystal. It originates in the clod whentemperature are below the freezing point( 0 degree Celsius, or 32 degree fahrenheit), snow has a high albedo which ranges from 0.9 for fresh snow to about 0.4 for old snow comprising high amount of Dirt.polar ice caps comprise pure form of Snow. as a result ,Antarctica has a high Albedo of 0.8.
🔸️ water: water has a low albedo of 0.1 however ,reflectivity varies depending on the angel of incident light ray. Water is a Excellent solvent for a wide variety of substances both mineral and organic; when the angle of incident ray is low, as in the case of low latitudes during summers, albedo is also low.
🔸️Clouds: clouds is a mass of water drops on ice crystal suspended in the atmosphere. Clouds form when water condense in the sky. Clouds usually exhibit high albedo, actual albedo of Clouds depend on the density of cloud ,which reflect more sunlight than that by land and water . collectively .as a result, Clouds keep the Earth cool.
🔸️land: any part of the Earth surface not covered by the body of water. The part of earth surface occupied by continents and Islands. Forest has low albedo and absorb more sunlight desert area have the highest albedo among landforms.
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.IMPACT OF INSOLATION AND ALBEDO. If the albedo of a surface is high , more radiation will be reflected then if the albedo is low . The temperature of a region depends on the collective impact of albedo and insolation. Such as Arctic and Antarctic regions , have low temperature. desert such as Sahara have high albedo but are hotter on account of higher insolation. At the same time and solution in tropical region is higher than that of temperature reason the tropical forest have a higher temperature than that of temperate forest . As snow fields and ice sheets expand as a result of A reduction in solar insolation induced air temperature the surface albedo will be increased and the net amount of solar radiation help by the earth will be reduced.
▪️ALBEDO AND CLIMATE CHANGE .
Albedo is a measure of reflectivity of the Earth surface. ice albedo feedback is a strong positive feedback in the climate system. The surface composition of Earth determine the albedo. The average temperature of earth is about 15 degree celsius. If the entire Earth is frozen,the average temperature would have been -40 degree Celsius.ice reflects some of solar energy back to space because it is highly reflective . The average Temperature of earth would drop to zero degree celsius. if the entire Earth is covered with water the average temperature of earth would rise to 27 degree Celsius. Melting of ice glaciers on account of global warming is exposing surface ocean water to sunlight . Ocean water has far low albedo than that of ice ,exposure of ocean water to direct sun rays would further accelerate the Global Warming.
▪️ALBEDO AND DAY- TO- DAY LIFE.
The measure of the diffuse reflection solar radiation out of the total solar radiation and measured on the scale from 0. Corresponding to a black body that absorb all the incident radiation,to 1, corresponding to a body that reflects all incident radiation. In summer dark coloured clothes are not recommended because dark colour has low albedo and thus, absorb heat. Light coloured clothes reflect sunlight and help our body to remain cool.
TRANSFER OF HEAT IN THE ATMOSPHERE….
Conduction radiation Convection all play role in moving heat between earth surface and the atmosphere. Since there is a poor conductor, the transfer of heat occurs by three processes;
Terrestrial radiation: Terrestrial radiation refers to sources of radiation that are in the soil,water and vegetation. Isolation from the sun heats the surface as well as the atmosphere of the earth. The surface of the earth, being solid, retains more heat than that retained by the atmosphere. Earth, after being heated, itself start radiating heat. These heat waves from the earth and warm up the atmosphere. These waves are known as Terrestrial radiation. Major isotopes of concern for Terrestrial radiation are potassium Uranium, and the decay product of Uranium, such as Thorium, radium and radon. Terrestrial radiation absorbed by atmospheric gases ,particularly by carbon dioxide and other greenhouse gases. atmosphere is indirectly heated by the earth radiation..
Conduction: conduction is a movement of something such as heat or electricity medium . It takes place when two bodies of unequal temperature are in contact with one another. There is a flow of heat energy from the warmer of to the colder body till both the bodies are of the same temperature. The surface of the earth transfer heat to the lower layer of atmosphere, and is lower layer transfer heat to the upper layer of the atmosphere. Please an important role in heating the lower layer of the atmosphere.
Convection: convection is a heat transfer due to the bulk movement of molecule within fluids such as gases and liquid. It is transfer of heat on account of motion of a fluid such as liquid or gas when the fluid is moved away from the source of heat carrying energy with it the air in contact with the earth Rises vertically on heating in the form of currents and further transmits the heat of the atmosphere by the process of convection.
Advection: advection is the transport of substance or quantity by bulk motion. The transfer of heat through horizontal movement of air is called advection.. the horizontal movement is relatively more important than the vertical movement. The properties of that substance are carried with it. The middle latitudes most part of the diurnal variation in daily weather is caused bye advection alone full stop in the tropical region particularly in Northern India local winds during the summer season called “loo”…
8.HEAT BUDGET OF THE EARTH..
Earth heat budget of all the solar radiation reaching Earth, 30% is reflected back to space and 70% is absorbed by the earth. The earth receives all its heat in the form of insolation from the Sun. The heat received by the earth in the form of insolation is reflected back in the form of Terrestrial radiation. The earth radiates back 51 units in the form of Terrestrial radiation. Of these 51 units, units and directly radiated back to the space and the remaining 34 units are absorbed by the atmosphere. The Heat absorb by the land ocean Exchange with the atmosphere through radiation ,conduction latent heat. Thus there is continuous inflow and outflowof heat on the earth. Global Warming occurs on account of increasing concentration of greenhouse gases such as CO2 which trap the Terrestrial radiation and prevented from going outside into the space..
