00:00Now we will study the vertical distribution of temperature.
00:16Here we have two concepts of lapse rate and temperature inversion.
00:30Temperature inversion.
00:34We have a lapse rate of 6.5 degrees centigrade.
00:40Temperature decreases as we move upward every 1 km.
00:53Every 1 km, 6.5 degrees centigrade or 3.6 degrees centigrade for a high degree, 500 feet.
01:03This is called a lapse rate.
01:06Do you remember when we were studying the atmosphere in the first lecture?
01:13As we move upward in the troposphere, temperature decreases.
01:17Now what is the rate of decrease?
01:19Every 1000 meters or every 1 km, temperature decreases by 6.5 degrees.
01:24For a high degree, every 100 feet, temperature decreases by 3.6 degrees for a high degree.
01:29This is called the lapse rate.
01:31So we are studying the vertical distribution of temperature.
01:33This is the first concept.
01:35The second concept is of temperature inversion.
01:38In inversion, the temperature reverses.
01:41Temperature increases instead of decreasing in the troposphere.
01:44But this does not happen everywhere.
01:45So why does it not happen?
01:46That concept is that the temperature of the surface inverts.
01:49Instead of decreasing, the temperature increases.
01:51So what is the reason why it increases?
01:53We make it into two categories.
01:54Surface inversion and upper air inversion.
02:05Surface inversion and upper air inversion.
02:11Now what do we have in surface inversion?
02:14Look at the source.
02:15This is our surface.
02:18Usually the temperature decreases here.
02:20Now suppose the temperature here has come to 20 degrees centigrade.
02:25Suppose that.
02:27Okay?
02:28Now what happens is that the cold wind moves from one side to cover the low atmosphere,
02:41which is comparatively low temperature.
02:43This is called cold wind.
02:47Now when the cold wind has reached here, it is 20 degrees centigrade.
02:50When the cold wind has reached here, the temperature here is 10 degrees centigrade.
02:53The temperature here is 20 degrees centigrade.
02:57Obviously, the temperature here will be 18 degrees centigrade.
03:00But when the cold wind has reached here, it has reduced the temperature of the whole area.
03:04Now in this scenario, when you see that point A is here.
03:08This was point B.
03:10So if we don't make A move, the temperature here should be 30 degrees centigrade.
03:17It should be 20 degrees centigrade on B and 10 degrees centigrade on C.
03:22Okay?
03:23Because the cold wind moved.
03:25So that cold wind reduced the temperature by 30 degrees centigrade and made it 10 degrees centigrade.
03:28Now this is reversed.
03:30The temperature of the atmosphere should be decreased.
03:33But here it is 10 degrees centigrade and then 20 degrees centigrade.
03:35So this is called surface inversion.
03:37Atmospheric inversion, but surface inversion.
03:47Let's do it.
03:49This is also an aspect.
03:51All the winds that move towards the ocean,
03:54they obviously balance the temperature of the surrounding land area.
04:01That is a concept.
04:03I just want to tell you that if you keep on writing that the wind is causing the impact,
04:07then what is our problem here?
04:09It is in the lapse rate.
04:10Geographically, the lapse rate should be 20 degrees according to temperature.
04:13But when we say it is 20 degrees, it is 20 degrees centigrade.
04:15So if you look for the reason, there is a new concept of surface inversion.
04:17Let's study one more wind.
04:19What is the effect of winds?
04:21Now two points are important in vertical distribution.
04:23Lapse rate and temperature inversion.
04:25Okay?
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