Vertical temperature profile is important to understand the actual concentration of atmospheric constituents and atmospheric pressure at pa particular height from the sea level in the earths's atmosphere. The vertical temperature profile for the standard atmosphere is depicted in the figure.
On the basis of vertical temperature profile,, the atomsphere has four layers. These are troposphere, stratosphere, mesosphere and thermosphere. The top of each sphere are respectively called tropopause, stratopause, mesopause and thermopause as shown in the figure above.
Troposphere:
It is the bottom layer where temperature decreases with increase in altitude with average value of lapse rate as 6.6 K/km. The temperature decrease continues to an average height of approximately 12 Km. However, the thickness of the troposphere is not same everywhere. It reaches to a height of 16 km in the tropic region, but in polar region it is about 9 Km. Most of the weather activities, for example cloud, rain, frost, fog, strom etc occur in troposphere. This layer contains nitrogen, oxygen, carbondioxide, dust and water vapour.
Stratosphere:
It is the layer of the atmosphere which lies above the tropopause. On this layer the temperature at first remains nearly constant to a height of about 20 Km. It begins a sharp increase that continues until the stratospause is reached at a height of about 48 km. Ozone occurs chiefly in this layer. In addition thhin layer of aerosol is also observed to persist for long period of time within certain altitude rane of stratosphere. It is also called Ozonosphere.
Mesosphere:
It is the layer of atmosphere above the stratopause in which temperature decreases with altitude wntil at the mesopause to about 80 km above the surface. Temperature of this layer decreases upto about -100*C. It has very less ozone. Mesosphere has very strong winds blow eastward in winter and westward in summer. The upper boundary of this layer is Mesopause.
Thermosphere:
Extending upward from the mesopause and having no well defined upper limit in the atmosphere is the thermosphere.In the extremely rarified air of this outermost layer, temperature again increases as a result of the absorption of very short wave of solar radiation by the atoms of oxygen and nitrogen. Dute to which temperature increases sharply and reaches more than 1000*C.
Ozone is mostly found in stratosphere. A maximum in O3 is achieved near 30 Km. The radiative energy budget is controled by shortwave heating due to Ozone absorption in the 9.6Km. Ozone thus determines the thermal structure of the middle atmosphere.
why there is temperature variation occurred in different layers??....specially in stratosphere???
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