Local winds are much more variable than predicted global patterns ...

[crobinson2013]

Local winds are much more variable than predicted global patterns in Figure 20.3c. Explain the causes of these local variations.
 
  What will be an ideal response?

Question 2

What is wind?
 
  What will be an ideal response?

[DHRUVSHAH]

Answer to Question 1

Local variations in air pressure and atmosphere density occur near coastal areas, in mountainous areas, and near glaciers. Coastal lands are warmest in the afternoon, and when the air rises, it is replaced by lower density, cooler air over the ocean. This creates a wind that blows onshore in the day. The reverse happens at night, when the land cools relative to the ocean, driving an offshore wind. Cool or dry air descends from high elevation mountains into lowlands, and these winds are most intense where they descend from high, cold glaciers.

Answer to Question 2

Wind is the motion of gas molecules in the atmosphere that is caused by atmospheric convection and variations in atmospheric pressure. Warm air has a lower density than cool air and humid air is less dense than dry air. Higher density air sinks close to the surface, producing high pressure at the surface, and displaces lower density air upward to produce low pressure at the surface. Air moves from regions of high pressure toward regions of low pressure. Wind is the motion of air sinking and rising because of density differences, and moving from areas of high pressure toward low pressure.