This is the Thar Desert. It extends from Kutchch in Gujarat to the north-west of Rajasthan. It is mainly confined around the Indo-Pakistan border from Kutchch to Jaiselmer, Barmcr, etc. districts of Rajasthan.
This area is included in the High Pressure Zone of Pakistan and West Asia. In summer the equatorial belt which shifts to north is no doubt maritime but is prevented from ascent by the temperature inversion above.
Hence rainfall is almost absent except at some cloud bursts. The amount of warm upper air shows adiabatic tendency while descending. This makes it a rainless desert. However, the rainfall averages 10 cm but the rainfall is so erratic that many years pass without it.
During May and June the temperature remains above 33°C. Temperatures to the tune of 50°C arc not uncommon. Dust storms arc due to excessive heat. The main characteristic is the diurnal temperature range.
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It is about 15°C but rises sometimes abnormally high. As the skies are almost cloudlesss, the radiation is excessive during night and this is the cause of high diurnal range of temperature.
Dry grass and scanty stunted bashes are found here and there. Sand dunes arc a common phenomena. They usually shift their position.