Q7.Major hot deserts in the northern hemisphere are located between 20-30 degrees north and on the western side of the continents. Why?

Major hot deserts in the Northern Hemisphere are predominantly found between 20-30° N latitude on the western margins of continents. This specific distribution is attributed to a combination of atmospheric and oceanic factors.

• Subtropical High-Pressure Belts: Between 20-30° N, descending dry, stable air from Hadley Cell circulation inhibits cloud formation and precipitation.
• Cold Ocean Currents: Along western margins (e.g., California, Canary), these currents cool overlying air, stabilizing it and preventing convection, reducing moisture and rainfall.
• Prevailing Trade Winds: Easterly trade winds lose moisture over eastern continents, arriving dry at western margins.
• Adiabatic Heating: Descending air heats adiabatically, further decreasing relative humidity and creating extreme aridity.
• Lack of Moisture Systems: Absence of significant moisture-bearing winds or frontal systems contributes to persistent dryness.

Thus, the interplay of atmospheric circulation, cold ocean currents, and prevailing wind patterns collectively creates these arid zones on the western sides of continents.