Answer: Physical maps use color most dramatically to show changes in elevation. A palette of greens often displays elevations. Dark green usually represents low-lying land, with lighter shades of green used for higher elevations. In the next higher elevations, physical maps often use a palette of light brown to dark brown.
A high pressure area is an area where the air sinks. As it does, it warms up by the adiabatic effect of a greater pressure and that causes the clouds to evaporate, giving place to a clear sky