When the night comes, the radiation of the sun is finished and that is why the ground
cools, you touch the sand of the beach and it is cold right away.
While sea water,
as the heat has been mixed by the effect of the waves and because the water is a
liquid, because there the temperature of the sea is going to remain constant.
Therefore, the temperature typically of the surface of the sea will be higher
than the sand.
What's going to happen there?
Well, we're going to have something opposite from what happened to us during the day,
There will be a certain tendency of the air that is in contact with the water
from the sea to ascend, while from the ground will arrive a small
breeze that is going to come from land to the sea, and here it will be re-formed
this small Hadley cell, which is much smaller than the diurnal one.
This in Catalonia is called "terral", wind coming from the ground,
from land to sea, terral, which is in the opposite direction,
but that only takes a small portion of the soil and the sea.
That is why, if you sail at night in situations of anticyclone with safety
it is good to stick to the shore, because there you can find a portion of that wind
which comes from land to sea and that can propel you, while a little forward
there'll be lulls and you will not be able to sail, you will remain becalmed.
This, how does it work?
Early in the morning, calm wind, when the sun rises,
from nine o'clock, at ten o'clock in the morning, the wind begins to blow.
Perhaps the maximum of the daytime breeze,
is around the time of the maximum temperature, therefore,
around 4-5-6 in the afternoon.
That would be the maximum sea breeze, from sea wind to earth.
Then during the afternoon entrance, they go limp,
when the sun sets, sea breeze stops, and then,
in the first hours of the night begins to blow in the opposite direction,
And he would go back to bed with the sunrise.
Therefore, it is a cycle in one direction and another, and notice that,
If you fly a hand glider or paraglider, you would see that up to 200,
300, 500 meters, will depend on the shape of the coast and will depend
Also of this cell, you would find wind in the opposite direction.
That is, on the surface is a direction, but at 300,
400 meters high, the wind would be in the opposite direction.
We have seen this situation that is classic, typical of summer,
Practically all summer we would be in this same situation.
But what are perhaps the most dangerous situations, we could say,
that we have in the Mediterranean? Those that take place in autumn.
In autumn, if you remember, when we talked about the world,
I told you the world is a ball, and here.