Hello and welcome back earth scientists
for another lecture. this one on the
introduction of Earth's atmosphere
composition and structure so this is
kind of a hefty topic to get through so
I've got quite a bit of information to
come across so you know if it becomes
too heavy or too dense go ahead pause
and then come back to it okay so what
I'd like to do is to introduce really
our atmosphere and how it operates how
it works and the structure then there'll
be another video later that kind of
discusses more about how it operates
especially when we get into whether
cells and systems but this is really
just kind of understanding the big
picture the the big broad picture so
again introduction and to the Earth's
atmosphere composition and structure so
let's start with this well what are
weather and climate there are actually
two different things although they
maintain the same variables they're
viewed differently mostly based on time
so weather is the current day-to-day
state of the atmosphere it's hot it's
cold it's wet it's dry it's calm is
stormy what is happening today
okay now climate is different climate is
the term for what we consider the
average atmospheric conditions over long
periods of time so I like to think of
generalizations okay
so as an example you know we could say
that today was hot but I could say that
generally the climate of Las Vegas in
July is also hot right so you're kind of
generalizing so when we talk about
especially in the science community
about climate change we're not saying
that today was different than yesterday
we're saying and there's actually a
measurable difference between today and
the patterns that we're experiencing in
today's weather compared to what
happened 30 plus years ago so it's
usually a 30 with a year window that we
use to categorize climate so you know
think about your life span you've lived
in maybe Santa Clarita your whole life
so we based on those general feelings
and notions and every year you went
trick-or-treating
you could generalize what October 31st
is like generally does it mean that it
can be different can you have a
different weather
then what is it generalized absolutely
you probably all have been to Vegas when
it's really hot and it rains out of
nowhere right so it's not uncommon that
you break that climate mold but climate
is a generalization so how do we
visualize that no I thought this was
kind of a funny diagram that's why I
shared it how do we do that well we look
at climate graphs climate graphs are
really really important to climatologist
and meteorologists when we start looking
at regions in locations and long-term
data so what if you wanted to generalize
the weather for a particular region so
let's say Los Angeles because I found a
climate graph here from Los Angeles so
what this does is this takes in
historical data 30-plus years as well as
what we're experiencing on a trend so
there's this is a very complicated
diagram I totally get it but has this
prompt says you know if you want to
visit Los Angeles you've never been and
you want to go in August but you don't
know what to expect maybe it's in
January well looking at a climate graph
we could say okay well this column here
represents August right so we can see
there's all kinds of information on this
the green boxes represent precipitation
so I can say well generally August seems
pretty dry we can see the maximum
precipitation so the that's right
maximum temperature in red excuse me
as we can see it's up in the high 70s we
can see the relative humidity which is
this gray Brown so on so forth we see
the maximum minimum than the average so
the average is this hot pink color that
I'm pointing at right here so we can see
that the average in Los Angeles is 70.5
that's the average now you might be
thinking let's think I word it seems
like it gets really hot in August well
it does but this is taking the average
of the high below the day and the night
time so it's taking the all those
averages so it's a lot of data because
think about it sure maybe it's maybe in
Los Angeles and August it's gonna be
over 110 degrees during the day but
maybe it you know it cools off to the
upper 60s well it's gonna take the
average of those two temperatures
so anyway there's lots of information on
here as we can see we've also got
average wind speed meaning what is the
average gusts of winds so we can see
that we're looking at this is done in
knots
two knots not pretty pretty calm at
three as we can see in August so anyway
this one also has average sea
temperature so you can see that this is
this lime green
is the sea temperature so we can see oh
is there a correlation with average
temperature also with sea temperature
and we can see there is a correlation
with that can we see that there's a
correlation with temperature and amounts
of precipitation yes we can we can see
that when it's warmer we seem to have
less precipitation when it's cooler it
rains more so simplified so this is a
way that we look at weather and climate
now some of the elements of weather
because whether it's not just weather
weather is a bigger broad term I
considered like a part-to-whole that we
have the term you know weather is like
this umbrella term and there's all kinds
of contributors underneath it so with
things that we look at when
understanding whether we look at clouds
humidity air pressure air temperature
wind direction and velocity also the
amount and the type of precipitation so
I put this little photo on here this is
what's considered a German Bambi
it's a barometric pressure and
thermometer if you've known someone
who's traveled to Germany or if they've
old people seem to have them in fact if
I tilt my hand I've got one on the wall
behind me as well right up there but
what ends up happening is based on
pressure differences the little man
comes out when it's more likely to rain
the little girl comes out it's more
likely to be sunny and then you have a
thermometer smack dab right in the
middle so these are the different things
we look at when understanding weather so
yeah we can see that today was hot that
is all that's very true that's looking
at the temperature of the air but we can
also say well this is the type of
pressure we were experiencing and this
is the type of humidity this is the type
of cloud coverage that we had so that
you know when you watch the news and
they're saying you know welcome to
beautiful
Town Los Angeles the highs today will be
in the upper 90s lows in the low 50s
we're expecting scattered showers and
the high mountain ranges and stuff like
that when they started rambling all the
information they're going through this
whole list because this is really that
idea of part to hold well where does
weather occur well it occurs in our
atmosphere so it's talk very briefly
about the composition of our atmosphere
no Earth's atmosphere is a mixture of
gases so yes we say mmm nice big you
know breath of air of oxygen right well
the reality is the air that we breathe
in air is a hole within our atmosphere
is actually a mixture of gases as you
can see from this very large pie graph
here a majority of the air that you
breathe in is nitrogen seventy-eight
percent of that breath you took is
nitrogen 21% is actually oxygen so we
can see that two gases make up about 99
percent of all of the volume of clean
dry air we use the phrase clean dry air
meaning clean has no particulate matter
that was you know maybe soot or ash or
any particulate matter of microns 10 and
smaller we also say there's an it's dry
because moisture is a different variable
and air and we'll talk about moisture in
a little bit so 99 percent of what you
breathe in our atmosphere is either
nitrogen or oxygen as a mixture of those
two and then the next one would be argon
and then everything else is trace
elements really really small so as we
can see here I've also identified that
we can observe these as either permanent
or variable gases so permanent gases
these I outlined in the green box those
are permanent gases that means that's
the amount that we have it's a set
amount in our planet that we deal with
so things come and go but it always
averages out to the same amount now the
ones below our variable gases so as you
can see some of the variable gases are
carbon dioxide neon helium methane
Krypton hydrogen well what is variable
mean well it means that it variates it
can go up and couldn't even go down you
know think about carbon dioxide what can
make you know carbon dioxide amounts
increase well
forest fires or volcanoes or combustion
of vehicles right or what can bring it
down well by not having those things
right so you know when this is being
filmed and we're dealing with the Cova
19 endemic well what do we know that's
about air quality well air quality is
beginning a lot better because we're not
driving we're not using you know
additional fossil fuels for factories
and things a lot of the non-essential
businesses have been closed so they're
noticing around the world that these
variable gases are becoming decreased in
the volume in which they're represented
well what does that do that's a bigger
picture that's a whole climate
discussion because the things that are
happening today will make an effect it
will see later on down the line now
water vapor is special it's varied from
zero to four percent it just kind of
depends on the atmospheric condition at
that time it depends really on the day
and maybe even the season so why why do
you think it makes a difference well do
we think that warm air versus cold air
which one would can hold more water you
know these are things that we'll talk
about but just think about it so well
how can it vary based on season how can
it variates based on the time of day
versus daytime versus nighttime miss is
there anything else you'll wanted to
point out well since we're looking at
these variable gases another one that I
always think is very interesting methane
because most of these as you acknowledge
you're probably greenhouse gases which
are important to have because without
greenhouse gases our planet would freeze
we need some some we don't want to
overdo it often methane volumes have
always been blamed on cows it's been
blamed on all kinds of different
situations humans stuff like that so
some studies came out they found that
actually rice produces a lot of methane
when the seed when it's harvest it pops
open it releases natural gas but another
thing that they're finding more and more
prominent and where methane comes from
in our atmosphere as a variable gas is
actually from agriculture from using
chemicals on the soils and the soil as
it breaks down because of these
chemicals releases natural gas as a
by-product so kind of interesting if you
seem to think so right well
we've messed that we've mentioned
moisture in the atmosphere so just hear
me out on this how do we view moisture
so I threw this together
I try to normally when we talk about
absolute and relative humidity or the
moisture that's an error we use beakers
and glasses and fine measurements and I
remember I'm starting to think that you
as students just you don't have those
hanging around your house but you have
probably one of these a Starbucks cup so
we'll use this as an example so there
are two types of humidity relative is
the one that you're most familiar with
when I think of the word relative I
think of the word ratio it's a
percentage so you know as an example you
know this glass is half-full well that's
a percentage now absolute is an absolute
measurement saying there's absolutely
this much we buy houses and maybe it's
my grams per kilogram whatever the
measurement might be so when we say that
there's absolute humidity we'll say in
this parcel of air so maybe that my
office here represents a parcel of air
there is exactly fifteen grams per
kilogram it's 15 grams of water for
every kilogram of air in the space it's
an it's an exact absolute measurement
well how can we view that because it's
hard to see water and you're on my
office space right well maybe you've had
a drink you've had ice in it and also
nice sort of sweat well that's the
process of condensation because the
contents are colder in the cup versus
the outside it's actually bringing the
moisture in the surrounding air to the
glass and condensing on the outside and
then making the water droplets well does
that happen everywhere no because as
we've already learned we haven't
discussed it a lot of it but we
understand that the amount of moisture
in the air ranges from zero to four
percent so we'll talk about that now so
what I've done is these are the three
most common cup sizes you've got of
course I always thought this was called
a tall but it carries a short there's a
taller than a grande so the short the
maximum capacity is 8 ounces of whatever
it is so I'm using an example of tea I
don't drink
he gives me heartburn so I want to say
then these short there's 8 ounces so my
nose itches it's one of those because
the seasons are changing the short has a
maximum capacity of 8 ounces that's
absolute the tall has a maximum capacity
of 12 and then the grande has a maximum
capacity of 16 ounces of tea
those are absolute numbers okay
well now if the actual contents so maybe
I measured a go well this cup is full it
has 8 ounces in the 8 ounce cup and
therefore see I'm using these colors
reds and grace 8/8 is a percentage it's
a hundred percent this is 100 percent
full so I could say that yeah the
absolute number is 8 but the actual
relative humidity the number that you
hear on the news you know today is a
high of 95 and the relative humidity is
somewhere around 52% well that's what
that means is that in this case your cup
is completely full well let's say that
you upgrade and you get a tall which
could hold 12 ounces and you pour your 8
ounce cup inside well now there's only
eight ounces of actual tea in a cup that
could hold 12 ounces so it's 67 percent
full right or maybe here we put 6 ounces
in a 12 ounce cup well it's only
half-full 50% or same thing I have the
top of the grande which is 16 ounces you
put 8 ounces in it's 50% full okay so
I'm hoping that makes sense just the
idea of how we're looking at what the
cup can hold and actually how much is in
the cup no I picked these two here in
particular in the end because if you
notice they're both 50% full this is 50%
full and that is 50% full I hope that
you acknowledge that this 50 percent is
different than this 50 percent right so
someone who has this cup and says all my
cup is half full they only have 6 ounces
if this person goes oh my gosh me too I
only have a half full cup yeah but you
have an extra 2 ounces okay well why is
that important
well because yes I'm using Starbucks
cups but these cups actually are trying
to represent temperatures of air the
colder the air the colder the cup
the warmer the air the warmer their cup
so maybe you've traveled some to
someplace within the tropics maybe
you've been in farther north maybe
you've been to Florida great example
during August or September so when they
say wow you know the humidity today is a
hundred percent and we're looking here
and their all sweating, and they're
all miserable and we're here thinking
well it's 100 percent humidity here in
Los Angeles and it's not that bad right
well because chances are their
temperature their cup is much fuller and
much larger because as warmer air so
this 100% cup is very different than
this 100% cup so think about that for a
moment well what does this mean well
first is that we know that the warmer
the air the more water can be held
within that parcel of air okay
so the warmer the air the larger the cup
the more water or in this case tea can
be put in that cup well let's take this
into an examples hopefully everything so
far makes sense let's say that
throughout the course the day your
grande cup here fills up 16 ounces so
it's nice and full and then all the
sudden the Sun sets and it gets cold
maybe it gets cold comparable to you
know maybe the shortcut so maybe this is
a hundred degrees and we'll say this
represents 50 degrees so the Sun sets
and it gets cold really quick you had
those days well you have a cup if I have
this fool I need to pour all that water
into this cup can you pour 16 ounces
into an 8 ounce cup yes you can but only
eight ounces what happens to the other
eight ounces it fills over and it spills
all over the place and you make a mess
so ideally
you would create clouds and probably
precipitation so that's what happens
when you have a temperature change in a
cloud that's maybe in a warmer parcel of
air merge into a colder parcel it's
gonna shrink down will condense will
probably produce some form of
precipitation so real quick again
absolute versus relative absolute is the
maximum capacity relative is the maximum
divided by essentially what is actually
in there okay
so absolute there's absolutely this much
okay all right so that's the next thing
next we'll move into pressure well we
also deal with atmospheric pressure so
air pressure is the force exerted on the
earth by the weight of the air molecules
so what does that mean well we have
about enough atmosphere pushing down on
us that it's equal to the weight of an
elephant on your back now it's not only
on your back it's gonna be covering
everything the walls yourself your body
in all directions that's why we don't
really feel it but maybe you have
experience a difference in pressure
maybe if you were down low by the beach
so you want straight up the mountains
did you have a harder time breathing did
you experience something different so
what ends up happening is because of
this when the air is compressed it
becomes we identify as high pressure so
this H here represents high pressure
this is a zone of high pressure this L
represents a zone of low pressure so we
have these imbalances on our planet our
planet is in constant equilibrium it
wants to be equal so we have this
constant turmoil of high versus low and
things trying to balance themselves out
I'm going to continue to talk about
pressure but there's a great TED ed
video shared in the can of the shell
that also explains pressure so let's
look at some different examples of
pressure so this is a classic diagram
showing here on the surface and way up
you know this case 36 kilometers over 23
miles up into straight up into the
atmosphere this
red line this line right here represents
the pressure we notice that the lower
the elevation this line is pushed
towards the right well this means that
the lower the elevation this means the
higher the pressure so this is 1,000
millibars and the more we move this way
as we go with altitude we see that then
the number is decreasing so the higher
the altitude the lower the pressure so
let's look at this here is a classic
diagram showing the water model as you
notice there's no water in it so what
happens
so this cup represents down here this
cup you know this model represents up
here well if you've ever traveled up to
Big Bear or mammoth there's somewhere an
altitude and you've been you had a bunch
of food that you picked up at the store
and you're driving up the mountain you
might hear we're all thematic start
popping open well because you're
changing altitude maybe your ears do it
too because the pressure is changing in
the air around you versus what's inside
your head well that's what happens in
this case so the higher you drive up the
lower the pressure the less atmosphere
that is above you pushing down so look
here if you had this water bottle up at
the top of the mountain and you drove
all the way down this mountain the water
bottle become crunched and compressed so
obviously this is empty right you know
so what is happening to that air within
that bottle well as we discussed we can
find that temperature makes a difference
in air right so the warmer it is it
expands and spreads out the cooler it is
it condenses and shrinks down but
pressure has the same ability because
these molecules are suspended they're
floating around so you're able to
compress these gasses and squish them
down so when's up happening is when you
if they're experiencing high pressure
all those molecules are being squished
and compressed when you go high up in
the mountain those molecules can spread
out okay so obviously this is empty what
it do the same thing if it was filled
water or maybe a soda well water does
not have the ability to be compressed
right because if that was the case our
bodies would experience that when you go
up to you know a high mountain you don't
get you know extra fluffy and then when
you drive down to the bottom of the
mountain you don't become Finn it
doesn't work like that
right so it's because we're mostly made
out of water in other things of course
that we're not able to be compressed
like that now you might be thinking well
what happens within the ocean because in
the ocean if you go really down deep
it's extremely low pressure you come
back up people can get the bends and
they can dive less because you have
oxygen in your blood that's when that
occurs because oxygen is a gas and that
can be compressed and expanded the
question was soda that's kind of a trick
question some sodas actually have gases
within them right carbonation and so
those gases can't expand so that's why
it is possible for you to be driving and
your can of cheery whatever it is it's
gonna you know might pop in the backseat
so this is kind of giving an example of
pressures so perhaps you've experienced
it so what does that look like well we
have high and low pressure that just
except we experience everywhere then on
this previous map which I'll click back
to we have these zones right so we have
pressure that is being regulated based
on altitude but we also have these
additional systems of pressure well what
do they look like well the first one is
called a low pressure system a low
pressure area otherwise known as a
cyclone is a region where the
atmospheric pressure is lower than the
surrounding area so this is usually
associated with cool and unstable
environments usually some form of
weather or extreme weather so what ends
up happening in this case as you can see
first this diagram on the Left
represents the way that air moves in the
northern hemisphere so it's moving
counterclockwise on the surface and it's
spinning like a corkscrew merging in the
middle and popping back up so we find
that the central part of that has lower
pressure than the surrounding air
because the air is being forced up so I
mentioned that this is for the northern
hemisphere because if this
system was in the southern hemisphere to
actually be spinning clockwise and doing
the exact same thing that we find that
things change direction based on the
hemisphere so low-pressure systems these
you know movements of air are spinning
counterclockwise they converge in the
middle and push upward so that is a
cyclone the next one is a high-pressure
system this is an anticyclone so this is
where the region of the atmospheric
pressure at the surface of the earth is
greater than the surrounding area so
this is often associated with windy
environments so the way that I explained
this in my classes is all have like a
bunch of paper sitting on the table and
I'll grab a big book and I'll drop it on
the desk well when that book hits the
desk what happens to the papers the
papers fly all over the place well why
well because as that book hits the
surface it's been pushing the air that
was between the top of the bottom of the
book and the top of the table when it
compacts it forces an air away and it
blows it outward which is exactly what's
happening here we have a system of high
pressure it pushes down and blows things
clockwise outward this is again in the
northern hemisphere southern hemisphere
it'll blow you know obviously pushes
down blows outwards but it'll be
counterclockwise but in the northern
hemisphere this spins clockwise
okay so again specifically dealing only
with northern hemisphere cyclones our
counterclockwise anticyclones or
clockwise okay how you doing okay
so we've just got a couple more slides I
want to get through and then we'll move
on for for this one so so we talked
about some of the attributes that make
up our weather system so let's talk
about our atmosphere now we've kind of
talked about some these different things
in which occur in our weather but what
about our atmospheres themselves so we
have four layers of our atmosphere that
we're going to talk about first there
are other different layers that are put
in I know that but we're trying to
simplify this a bigger topic so the
first we'll talk about is the
troposphere it goes from the Earth's
crust to about seven miles up before I
move forward just to kind of put it in
perspective
the atmosphere is really really thin and
it is so important to our existence
because if we did not have an atmosphere
we would not be living now to put in
perspective you know those big classroom
globes the big ones like a little ones
the 12-inch ones the bigger ones it
would be about the thickness of a really
very of a very very hard of seeing
contact lens you know maybe you know
about that thick would be the thickness
of our atmosphere on a globe of that
scale so it is a really really really
thin layer of gases that is so important
to our existence so the first layer
going to work down from the bottom and
work our way up is the troposphere so
I've highlighted here in my green box so
it is the lowest layer temperatures
decreased with increased altitude well
why does this occur well we know first
that the Sun shines and there's all
kinds of radiation given off and you can
look it up as part of the
electromagnetic spectrum okay all these
different types of radiation the one
that I want to talk about right now is
first shortwave visible light that's the
Sun sun's coming down shining down you
put your hand up to touch this the light
itself right the light is not hot the
Sun right it's the fact that your skin
is absorbing that shortwave radiation
and then giving off long wave radiation
that is the heat that is sensible heat
think about when you're driving you're
driving on the road and it's a nice
blacktop freeway and the sun is shining
and you can see those waves coming off
of the road well it's because the
sunlight is hitting the freeway the
freeway is absorbing that radiation and
giving off heat well our surface does
the same thing so as you can see in this
diagram here the sunlight shines down
the earth absorbs some of that energy
about 50% of the solar energy is
actually absorbed at the surface and
then it is given off as long wave
radiation which is sensible heat now
because heat rises it creates a
convection cell as you can see it kind
of explained that there but maybe you've
had a lava lamp at some point right next
to that that light bulb is the heat
source as that wax gets warm it
fans rises to the top and then as it
gets farther away from that heat source
it begins to cool down well that's what
happens here so yes he does rise right
but to a certain extent if it doesn't
have additional heat sources it'll start
to cool it condenses contracts and sinks
so that's what's happening within our
troposphere which is pretty much where
all weather takes place anyway so again
the layers heated indirectly by the Sun
the heat originates at the surface loses
energy as the air rises vertical
temperature variation causes convection
sinks back down we'll talk more about
these cells that occur later on but this
is the troposphere the next layer as
we'll see it's called the stratosphere
so this is between seven and thirty one
miles as you notice in this diagram this
red line I'm sorry I should have
mentioned this before the red line
represents temperature change so we can
see that it gets colder warmer really
cold and then really hot so in the
stratosphere you see it starts to warm
up well why well because we can see that
there's an ozone maximum so ozone is a
triple bond oxygen molecule that's very
very hard to make but it's very very
very easy to dissolve ozone is efficient
in absorbing radiation and so therefore
since it's absorbing radiation first
like a sunblock it's actually to get
hotter so that's why the stratosphere
starts to warm up a little bit because
it has that ozone layer that absorbing
blocking a lot of that other radiation
that would otherwise be given to us
which is quite harmful and it stores it
and transfers it into sensible heat so
as you can see that's why it gets warmer
throughout the stratosphere so my
question is what about the ozone layer
your mom's hairspray you know the Aqua
Net was always the big joke
well aerosols break down ozone and it
takes just moments to break it apart it
takes between 10 and 15 years for ozone
to replace itself so it's a very long
process so anyway what ends up happening
is we banned CFCs we ban aerosols and
then we started realizing that the ozone
layer began to close up well why was it
important that we needed to close it up
to begin with
you've all been somewhere in the Sun and
you've all put sunblock on your body
which would essentially be like your
ozone layer right and there's always one
spot you missed and that's the spot that
gets burnt the most right because it's
not it's not able to resist that
radiation in fact you absorb it because
it's exposed well when you have an ozone
layer a hole within it allows all that
bad radiation that otherwise would have
been given back out or absorbed and
stayed there is now able to enter
through and go into our local
troposphere and our Earth's surface and
you as a surface so that's why the ozone
layer hole was such a big situation and
big deal because it was letting in
tremendous amounts of bad radiation and
excess radiation that would otherwise be
very harmful all right moving on
the mesosphere so the mesosphere between
31 and 53 miles sense gases are really
scarce because remember the higher you
go up the lower the pressures those
molecules can spread farther apart very
little radiation is absorbed so
therefore it just gets colder mesosphere
is kind of it's kind of the boring layer
in that sense because it doesn't do a
whole lot because it's so thin the air
is so thin up there the oxygen itself
but what makes it cool is the fact that
this is the area that burns up most of
our meteors and asteroids so fun fact
about 40 tons of meteors fall towards
the earth each day and we hardly see any
of it because of the mesosphere so make
sure you think to mesosphere today at
some point because even though it is a
very thin and spaced out type of layer
that's again 31 to 53 miles away from us
it's really important in the sense that
a bit really burns up all of that
additional material that could then
impact our planet again if we didn't
have an atmosphere that 40 tons of
material would come towards the earth
and impact it so that's the mesosphere
and then the next we'll talk about is
the thermosphere well the thermosphere
thermo meaning heat right is between 53
and the 310 miles we think
there's really no well-defined upper
limit and Inc and because that it's
really really really thin the molecules
are so far spread apart that it's almost
incredibly challenging to measure them
as you can see I wrote and contains only
a fractal of the atmospheric mass
temperatures increase just the fact that
it's the closest to the Sun so it's
getting additional shortwave and solar
x-ray energy from that electromagnetic
electromagnetic spectrum from the Sun so
it's going to get the hottest and in
fact it's off the record hot it just
keeps going going going in fact
temperatures are more than one thousand
eighty eight degrees Fahrenheit yet it
would essentially be cold to your touch
I know mine Lord how does that work well
the example I always give my students is
imagine that we have a big bucket and
this big five-gallon bucket is filled
with one of those glow sticks sorry and
you fill that bucket with glow sticks
they're all condensed altogether that
would represent high pressure that would
be a beacon of light right so that would
be somewhere down here in the
troposphere
you're fired gallon bucket filled with
all of these glow sticks it's a beacon
of light well if I want her if each one
of those glow sticks was mixed with in
air molecules being you and I wanted to
represent the thermosphere I would just
say hey now everyone take a glow stick
home even though it's a beacon of light
in my bucket take yours home and we'll
see how bright it is as a collective
group so everyone goes wherever they
live San Fernando Palmdale Lancaster
wherever you go and people think why do
you have a random glow stick right well
it's because those heat molecules are so
far apart from one another that it
actually doesn't seem visually and
sensibly that it's that impactful but if
you took all those glow sticks now
spread all over the area and brought
them back into one place because of
pressure it would be incredibly hot or
incredibly bright I hope that makes
sense so those are the four layers of
our atmosphere,  Tropo, Strato, Meso
and then thermo now there are some
others that are you know that should be
mentioned and I'll do that right now we
have the heterosphere homosphere
exosphere okay so the heterosphere is
between zero and fifty-five miles so it
pretty much goes up through the Earth's
crust up to the meso-  mesopause which
is a transition zone out of the
mesosphere so that is another way that
we can categorize this so we would
categorize the heterosphere as being
from here to there zero to about 55
miles as the atmospheric layers by which
molecular weight and electrical charge
so what does that mean well trouble
Strato Meso and thermosphere are names
given to atmospheres based on
temperatures heterosphere and homosphere
we re divided this whole vision up into
two families specifically based off of
density that's all I'm saying so the
hetero sphere is the bottom part and
homosphere is the upper part the hetero
sphere is from 0 to 55 the atmosphere it
was with thinnest layers by is layered
by molecular weight and charge and the
homeless spheres from 55 about 310 miles
up into space and that is the
composition that everything is uniform
because everything is so far spread out
and then lastly there's the exosphere
which is about 310 miles to space the
final frontier
so the exosphere is just pretty much the
boundary between here in space we
identify that it exists because we're
still looking at the fact that the moons
within our orbit but it's pretty much
space at that point so that's why it's
really the final frontier so these are
some other ways that we can visualize
our atmosphere now one of these slides
this one here looking at the troposphere
going back as you can see the layers
heat him directly by the Sun loses
energy air rises vertical temperature
variation is caused but what happens the
decrease in temperatures as we go up is
called a lapse rate that's what I want
to talk about
what is the lapse rate well the lapse
rate is a fancy term meaning that we
know that as we hike a mountain it gets
colder right so what does that look like
it looks like this as air rises it gets
colder think about it
you've gone hiking up on top of a
mountain it's nice and cold you run down
the mountain to your car and it's warmer
at your car right so we have our values
we have the oops the DLR and the SLR we
can use DLR as well it's the dry lapse
rate and the saturated lapse rate but I
use adiabatic just because it's that way
in the book so what happens is that some
temperatures in the back up you go up a
mountain we use this arrow you go up a
mountain as you go up a mountain it gets
colder okay that's why it snows here but
it rains down here when we have rain it
doesn't snow here but there's snow on
all the mountains around us and along
the grapevine that's because they're at
a higher elevation a higher altitude now
we have two variables we know that if
the air is dry which is the DA L R the
temperature change is approximately 5.5
degrees Fahrenheit for every 1,000 feet
you go up so if you go up 2,000 feet
then the temperature difference should
be 11 degrees that's five point five
times two okay so that's how that works
now at some point it is possible you hit
something called dew point which is this
word right here dew point is because of
condensation that is the tip that is the
appropriate temperature at that location
in which the gases the water vapor in
the air is able to condense and turn
into a cloud and then perhaps turn into
precipitation now that being said if
this is occurring that means the air is
wet so we use the saturated value the SI
L R which is about three point three
degrees for every one thousand feet so
you know if you wanted a cow
the difference from down here to up
there you would use your 5.5 for every
thousand feet until you hit here where
it begins to rain and then we would use
a 3.3 until we hit the top well once you
hit the top and that cloud now passes
over this mountain range and zips on the
way down here because of pressure it
warms up abruptly so therefore it
creates the rain shadow effect a great
example of this Santa Monica area you go
up this apolar Pass go into Sherman Oaks
it's very dry very dry within the valley
and that's because it rained here and
not over here when I think of clouds and
we'll talk about clouds later I think of
sponges they hold water right so you're
able to wring out some of the water on
the on the windward side wring out some
of that moisture then as their spines
your cloud goes over the range and it
sinks back down because of high pressure
also gets warmer you don't have any more
moisture left in your sponge for de rain
on this opposite side especially at that
temperature okay
some people ask why are these numbers
different okay well thanks for asking
that it's a hard question to answer here
so what we know is that you remember at
some point learn about the stages and
change of matter right you have solids
liquids and gases in order to go from
one and another you must have a direct
change of energy right it is either
going to be absorbed or released okay so
if you wanted to say take an ice cube
and you want it to melt it the ice cube
would need to absorb heat in order for
it to turn into a liquid okay so in this
case if you would like a gas water vapor
to turn into a water droplet you want it
to condense to go from a gas to a
droplet you must release heat for that
process to occur because it's gonna get
colder so it's gonna release the heat
well in that case by doing so you're
gonna be adding additional temperature
to the surrounding air Percel which is
why this number decreases that's the
gist of it is that
because there is a change of energy
because this gas is turning into the
vapor is turning into a liquid there is
heat released and because that heat
released which happens to be two point
two degrees Fahrenheit as a measurable
value this number decreases that's the
only reason why so I hope that makes
sense it's kind of unique there are
additional videos on cannabis to kind of
explain that but it's kind of
interesting to think that okay so in
order for that gas to turn into a cloud
there has to be heat exchange has to be
given away right so I don't know I think
it's something that's kind of
interesting in that sense so because
that heat is then released that heat is
given out in lessons the number for the
saturated adiabatic lapse rate all right
I know that was a lot so what do we
cover we covered really all the
fundamental basics of going through the
Earth's atmosphere its composition and
basic structure covered a lot of content
again there are additional videos
there's a great TED edy video that
discusses what is and what is the
changes of pressure and how does that
work I highly suggest that otherwise I
hope you enjoyed and we'll talk soon
