Author Question: What is air pressure, and how does it vary with temperature? What will be an ideal ... (Read 22 times)

joe · **on:** Jul 15, 2018

What is air pressure, and how does it vary with temperature? What will be an ideal response?

Question 2

Briefly describe the four main dune types and how they differ from each other? What will be an ideal response?

Benayers · **Reply #1 on:** Jul 15, 2018

Answer to Question 1

Air pressure is the density of air exerted on its surroundings. When air is heated, it expands and rises,
reducing its mass for a given volume and causing a decrease in air pressure. When air is cooled, it
contracts, and air pressure increases

Answer to Question 2

Barchan dunes are crescent-shaped dunes whose tips point downwind. They form in flat, dry areas
with little vegetation, limited sand, and nearly constant wind direction. Longitudinal dunes are long,
parallel ridges of sand aligned parallel to the direction of the prevailing winds; they form where the
sand supply is somewhat limited. Transverse dunes form long ridges perpendicular to the prevailing
wind direction in areas with abundant sand and little or no vegetation. Parabolic dunes are common in
coastal areas with strong onshore winds and a partial vegetation cover.