Movements of air - Wind Video Lecture - Class 9

here's a riddle for you what's something
you can't see but something you can feel
I'll give you a hint it sounds a bit
like this hold on to your hats because
today we are talking about wind
last time we learned about how the land
absorbs more energy from the Sun than
the water does and it turns out this
unequal heating of the Earth's surface
is what produces wind you heard me
wind is part of the atmosphere but it's
often caused by two of the other spheres
the geosphere and the hydrosphere
remember those but what exactly is wind
and how does the sun's energy create it
well wind is air in motion it's the flow
of large amounts of air usually from a
high-pressure area to a low-pressure
area when I say pressure I mean the
amount of force that air in the
atmosphere puts on an object on earth
which I assume is where you are right
now how much pressure the air exerts on
stuff mainly has to do with its
temperature
specifically cool air produces high air
pressure and warm air produces low air
pressure so with all that in mind let's
take a look at how the hydrosphere and
the geosphere can work together to
create wind a good place to start is
that same Beach spot we visited in the
last lesson there you'll remember the
land absorbs more of the sun's heat so
it has a higher temperature those warmer
landforms heat the air above them and
that hot air has lower air pressure
meanwhile the nearby water absorbs less
heat and is cooler so it heats the air
less and creates higher air pressure
when those two environments with
different temperatures and different
pressures are basically next-door to
each other air rushes from one place to
another to try to balance out the
differences you and I call that rushing
air wind does this wind cycle stay the
same all day every day nope but it does
follow a pattern and if you want to see
how that wind cycle works well I hope
you packed your jammies because we're
going to have a sleepover on the beach
here's our little beach during the
daytime with the hot sand on one side
and the cool ocean right next to it when
the sun's shining down on it the land
heats up faster than the ocean the warm
air over the land rises and the heavier
cooler air from the water rushes in to
take its place
this causes what's called a sea breeze
that blows from the ocean on to the land
but what if you visit the beach at night
during the evening the land will cool
down faster than the ocean and the
opposite cycle will happen at Mike warm
air over the water will rise and the
heavier cool air from the land will blow
out to the ocean this is called a
this model is just one example of a
common wind pattern there are different
kinds of winds all over the world but
for the most part they follow patterns
based on what conditions are like nearby
so wind isn't just air randomly moving
from one place on earth to another it's
the movement of air that follows a
pattern usually bling from high-pressure
areas to low-pressure areas and these
patterns are caused by uneven heating on
the Earth's surfaces well while this
model we created might look pretty tame
don't be fooled wind isn't always just a
gentle breeze the fastest winds on earth
occur inside tornadoes where they can
reach a speed over 400 kilometers per
hour and that's nothing compared to wind
on other planets in our solar system
Neptune has winds I can gust up to 2,000
kilometers an hour wind can be a really
powerful force of nature I guess you
could say I'm a big fan and sorry if you
got sand in your jammies but it was
worth it to learn about the wind right
you