Air in a winter high-pressure system doesn’t warm by compression like air in a summer high-pressure system why

Question

Air in a winter high-pressure system doesn’t warm by compression like air in a summer high-pressure system does.

why is this?

Answer 1

Air does warm by compression in any part of the year.  However, there are other ways that an air mass can cool or warm that can be a bigger factor then compression alone.

  Examples include:

- the surface temperature the air mass is in contact with.

- radiational energy absorb from the sun

- convection will mix air from different levels

- cold or warm air advection will transport or bring cooler or warmer air to another location

- with colder winter temperatures near the zero degrees C, moisture may change phases.  This process will absorb heat energy when going from ice to liquid and release heat energy when going from liquid to ice.

Answer 2

You may be confusing the cold surface high pressure systems in winter with the warm upper level high pressure systems in summer.  High pressure in the middle of the atmosphere basically allows the surface air to be heated more due to an inversion that is created above the ground by sinking air in the high pressure area.  The wintertime surface highs are cold simply because the cold air is dense and thus slides along at the surface.