Question

•why do tropical deserts have a large annual range of temperatures
•equatorial regions have low atmospheric pressure throughout the year..why? give a reason​

Answer 1

Low air pressure in equatorial regions is due to the fact that hot air ascends there with gradual decrease in temperatur causing thinness of air on the surface. In polar region, cold air is very dense hence it descends and pressure increases.

Answer 2

The tropical desert has the highest mean annual temperature of any climate on Earth.The sky in the tropical desert remains cloud-free due to the subsiding air of dominant high pressure resulting in large amounts of insolation. The cloudless skies during the day lets insolation in, but also lets much heat out at night.

Low air pressure in equatorial regions is due to the fact that hot air ascends there with gradual decrease in temperatur causing thinness of air on the surface. In polar region, cold air is very dense hence it descends and pressure increases.