What actually happening in land breeze?

Question

From childhood we are taught about land breeze and sea breeze , but I always had a doubt.

Look at diagram

Book just say " air above ocean become warm so it rise up creating a low pressure zone so air from land that is cool during night and is comparatively higher pressure flow to ocean creating land breeze and cycle continues"

But they never clearly explain what is happening above the land breeze I.e see those two arrows parallel to land and ocean near moon in diagram and 3rd arrow with down head towards land,

So what actually happening there?

Can you please explain me what those three arrows mean actually? ( 2 arrow parallel to land and one arrow pointing on the land) why arrow direction is drawn in such way ?

Answer 1

Warm air is less dense than cold air and so warm air will rise above cold air and so convection currents can be produced.

In the case of your example at night the land becomes colder than the sea so the ait in the vicinity of the sea is warmed and rises and is replaced by the colder air on the land (the right pointing arrows).

The warmer air moves above the colder air (arrows $2$ and $1$) and on cooling sinks (arrow $3$). So there you have a circulation of air called a convection current.
At ground level what is observed is the movement of air (breeze) from land to sea.