weigand earth systems - Temperature Notes #2 Fall 2023

Summary

This educational script explores the factors affecting temperature variations, emphasizing the impact of dry air, coastal influences, and latitude. It explains how dry air heats up and cools down quickly, the moderating effect of large bodies of water like the Pacific and Atlantic Oceans on nearby climates, and the decrease in temperature as one moves northward from the equator due to the sun's energy dispersion. The script also delves into the reasons behind seasonal changes, illustrating how the Earth's tilt creates varying amounts of sunlight and consequently different temperatures throughout the year.

Takeaways

• 🌞 The Earth's tilt and its position relative to the Sun are the primary reasons for the change in seasons and temperature variations.
• 📅 The solstices (summer and winter) are when the Earth's tilt towards or away from the Sun is at its maximum, leading to the longest and shortest days of the year.
• 🌡️ The angle of the Sun's rays affects the intensity of sunlight received, which in turn influences temperature. More direct sunlight results in higher temperatures.
• 🌎 The curvature of the Earth causes solar energy to be spread out at higher latitudes, leading to lower temperatures as you move away from the equator.
• 🌤️ The presence of water in the atmosphere affects temperature changes; humid air doesn't change temperature as quickly as dry air.
• 🌿 The proximity to large bodies of water, like the Pacific and Atlantic Oceans, moderates temperature changes, but the effect differs due to prevailing wind patterns.
• 🏞️ Coastal areas tend to have less temperature variation than inland areas because of the moderating effect of the ocean.
• 🌬️ Wind direction, influenced by the Earth's rotation, affects how temperatures change across the U.S., with the East Coast experiencing more variation than the West Coast.
• 📈 The temperature difference between the North and South of the United States is significant, with the North generally being colder due to the spread of solar energy over a larger area.
• 🌡️ Humidity levels play a crucial role in how quickly temperatures change. Dry air heats up and cools down more rapidly than humid air.

Q & A

What is the significance of the date April 29th in the context of the script?

April 29th signifies a time well past the equinox, indicating the start of the period when temperatures begin to rise due to increased direct sunlight.

Why is the humidity on the day described as 'insanely low' for Georgia?

The humidity is described as 'insanely low' because it is only 24%, which is unusually low for Georgia, indicating very dry air that heats up quickly.

How does the absence of clouds affect the temperature in the script's description?

The absence of clouds means there is no water in the sky to absorb and disperse heat, leading to direct sunlight and rapid heating of the air.

What causes the significant temperature drop when moving from sunlight to shade as described in the script?

The significant temperature drop is due to the exceptionally dry air, which heats up quickly in sunlight but cools down rapidly in the shade.

How does the script explain the difference in temperature changes between the Pacific and Atlantic coasts?

The script explains that the Pacific coast generally experiences more stable temperatures because the air coming from the Pacific Ocean has a consistent temperature. In contrast, the Atlantic coast experiences more temperature variation because the air crossing the U.S. can be significantly hotter in summer or colder in winter.

Why do coastal locations on the Atlantic coast experience less temperature change compared to inland locations?

Coastal locations on the Atlantic coast experience less temperature change because the water moderates temperature changes. Inland locations, however, are more subject to temperature extremes due to the land's ability to heat up and cool down more drastically.

What is the concept of 'insolation' as it relates to temperature in the script?

Insolation refers to the spreading out of the sun's energy due to the curvature of the Earth, causing sunlight to be less concentrated and resulting in lower temperatures as one moves away from the equator.

How does the Earth's tilt affect the amount of sunlight and temperature?

The Earth's tilt causes different amounts of sunlight and thus varying temperatures in different seasons. When the Earth is tilted towards the Sun, it experiences summer with longer days and higher temperatures. When tilted away, it experiences winter with shorter days and lower temperatures.

What would happen to the Earth's temperatures if the Earth was not tilted as described in the script?

If the Earth was not tilted, it would receive consistent sunlight throughout the year, leading to stable temperatures without seasons.

What are the specific dates associated with the start of summer and winter according to the script?

The summer solstice, which marks the start of summer, usually occurs around June 20th or 21st. The winter solstice, marking the start of winter, is about December 21st.

Outlines

00:00

🌤️ Temperature Variation and Its Causes

The script discusses the importance of noting down key terms and concepts related to temperature studies. It highlights the significance of the date April 29th, which is past the equinox, leading to increased direct sunlight and temperatures. The absence of clouds and low humidity are noted as factors causing rapid temperature changes, especially in dry air. The script contrasts temperatures in sunlight and shade, explaining how dry air heats up quickly. It also touches on the influence of oceans on coastal temperatures, with the Pacific and Atlantic having different effects due to prevailing wind directions. The conclusion emphasizes the greater temperature fluctuations on the East Coast compared to the West Coast due to the land's temperature variations.

05:00

🌡️ Understanding Temperature Patterns Across the U.S.

This section delves into why temperatures vary from north to south in the United States, with colder temperatures in the north and warmer in the south. It explains that although the sun is the same for everyone, the energy received from the sun varies due to the Earth's curvature, causing different temperatures. The concept of insolation, where sunlight spreads out more at higher latitudes leading to lower temperatures, is introduced. The script uses a light meter to demonstrate how energy received from a light bulb (simulating the sun) decreases as one moves away from the equator. It also compares temperatures in Hawaii, Atlanta, and Michigan to illustrate this point.

10:03

🌍 Impact of Earth's Tilt on Global Temperatures

The script explains how the Earth's tilt affects the amount of sunlight received at different latitudes, leading to temperature variations. It describes how during summer, the Northern Hemisphere is tilted towards the sun, receiving more direct sunlight and thus higher temperatures. In contrast, during winter, the hemisphere is tilted away, receiving less sunlight and experiencing cooler temperatures. The concept of solstices and equinoxes is introduced, with the summer solstice marking the longest day with maximum sunlight and the winter solstice the shortest day with minimum sunlight. The equinoxes are described as times when both hemispheres receive equal sunlight, marking the start of spring and fall.

15:05

📅 Seasonal Changes and Their Relation to Earth's Orientation

This part of the script discusses the specific days that mark the beginning and end of each season, all related to the Earth's orientation to the sun. It explains that the summer solstice usually occurs around June 20th or 21st, the winter solstice around December 21st, the fall equinox on September 23rd, and the spring equinox on March 20th. The script emphasizes how the Earth's tilt and its position in its orbit around the sun affect the amount of sunlight received, leading to seasonal temperature changes. It also describes how the sun's position in the sky changes throughout the year, affecting the length of shadows and thus the concentration of sunlight and temperature.

20:05

🌡️ Seasonal Temperature Changes Explained

The final section summarizes the relationship between the Earth's tilt, the amount of sunlight received, and seasonal temperature changes. It explains how temperatures increase during summer due to increased sunlight, decrease in fall as daylight hours shorten, reach their lowest in winter, and start to rise again in spring as daylight increases. The script reinforces the idea that the Earth's tilt and its position relative to the sun are responsible for the changing temperatures throughout the year, leading to the distinct seasons experienced in the Northern Hemisphere.

Keywords

💡Temperature

Temperature refers to the degree of hotness or coldness of a body or environment. In the video's context, it is central to understanding the changes in weather and climate. The script discusses how temperature varies with sunlight exposure, humidity, and geographic location. For example, the temperature difference between standing in the sunlight versus the shade is used to illustrate how dry air heats up quickly.

💡Humidity

Humidity is the amount of water vapor in the air. The script mentions a humidity level of 24%, which is considered very low for Georgia, and this dryness affects how quickly the air can heat up or cool down. Humidity is a key factor in the comfort level of the air and plays a significant role in the variation of temperature.

💡Equinox

An equinox is one of the two points during the year when the day and night are of approximately equal length. The script explains that after the equinox, the sun is higher in the sky, leading to warmer temperatures. It also distinguishes between the fall equinox, which marks the beginning of fall, and the spring equinox, which marks the beginning of spring.

💡Solstice

A solstice is an event that occurs twice each year, when either the Sun is at its highest or lowest point in the sky. The script describes the summer solstice as the longest day with the most sunlight, leading to higher temperatures, and the winter solstice as the shortest day with the least sunlight, leading to lower temperatures.

💡Latitude

Latitude is the geographical coordinate that specifies the north-south position of a point on the Earth's surface. The video explains that the higher the latitude, the more the sunlight is spread out, resulting in lower temperatures. This concept is used to explain why it is colder in the north and warmer in the south.

💡Insolation

Insolation is the amount of solar radiation energy received on a given surface. The video uses the term to describe how the Earth's curvature causes sunlight to be more concentrated at the equator, leading to higher temperatures, and more spread out at higher latitudes, leading to lower temperatures.

💡Seasons

Seasons are the different periods of the year characterized by specific weather patterns and changes in daylight hours. The script explains the seasons by the tilt of the Earth and its position relative to the Sun, causing variations in temperature and daylight throughout the year.

💡Direct Sunlight

Direct sunlight refers to rays of the sun that reach the Earth without being scattered by the atmosphere. The video mentions that when standing in direct sunlight, the temperature is higher due to the absence of clouds and dry air, which heats up quickly.

💡Shade

Shade is the darkness or coolness caused by obstruction of light from the sun. The script discusses how standing in the shade can cause a significant drop in temperature, illustrating how dry air cools down rapidly compared to humid air.

💡Pacific and Atlantic Ocean

The video discusses how the Pacific and Atlantic Oceans affect temperatures differently due to prevailing wind patterns. The Pacific Ocean's consistent temperature leads to more stable weather on the West Coast, while the Atlantic Ocean's influence brings more temperature variation to the East Coast.

💡Tilt of the Earth

The Earth's tilt is its inclination relative to its orbit around the Sun. The script explains that this tilt is responsible for the changing seasons and the variation in temperature and daylight hours throughout the year.

Highlights

The importance of noting vocabulary, ideas, and terms for a notes check.

April 29th is a bright sunny spring day, past the equinox, with the sun high in the sky.

Direct sunlight and temperatures start to increase in spring.

The sky is cloudless, indicating dry air and not yet hot humid summer days.

Humidity is exceptionally low at 24% for Georgia.

Dry air heats up quickly under direct sunlight, reaching about 77 degrees.

Temperature drops quickly in the shade due to dry air, showcasing a 12-degree change over 20 feet.

In summer, humid air doesn't change temperature as easily due to its wetness.

The Pacific Ocean's temperature is more consistent compared to the Atlantic's varying temperatures.

Wind direction affects how temperatures change on the East and West Coasts of the U.S.

The Atlantic coast experiences more temperature changes due to land temperature variations.

Coastal locations experience less temperature change than inland locations.

The Earth's tilt causes different amounts of sunlight and thus varying temperatures.

The angle of the sun's rays hitting the Earth affects temperature due to the concept of insulation.

The sun's energy is more concentrated near the equator, leading to higher temperatures.

Seasons are caused by the Earth's tilt and its movement around the Sun.

The solstices mark the maximum tilt towards or away from the Sun, indicating the start of summer or winter.

The equinoxes occur when both hemispheres receive equal sunlight, marking the start of spring or fall.

The Earth's tilt and its position relative to the Sun dictate the changing temperatures throughout the year.

Transcripts

so this is temperature notes number two

write down any vocabulary or ideas or

terms you feel is important in your

notes because you do have a notes check

at the end of this presentation

so here it is April 29th it's a nice

bright sunny spring day

it's April 29th so we're well past the

Equinox the sun's really high in the sky

and we're getting a lot of direct

sunlight and it's the time of the year

our temperatures really start to heat up

but if you'll notice the sky there is

not a single Cloud up there which means

we haven't gotten into that hot humid

days of summer yet and it's still

a chance that we get really dry air and

you can see that in the sky the humidity

today is 24 which is just insanely low

for Georgia

what this means for our temperatures if

you can see this this says about

77 degrees standing out here into the

direct sunlight

and that makes sense no water in the sky

very dry air a lot of sunlight so dry

air will heat up very very quickly but

we're going to come right over here and

we're going to stand

in the shade

and watch

what happens to the temperature once I

press the hold button

look how quickly the temperature starts

to drop

there was a big change in the

temperature from out there in the

sunlight

to over here in the shade and that's

because the air is exceptionally

exceptionally dry and dry things change

temperature easily wet things do not

so over there in the sun it's 77 degrees

over here in the shade it's dropping

it's going to be less than 65 degrees a

12 degree temperature change and a

distance of about 20 feet and that's

just because we have such dry air that

heats up and cools down very easily if

we do the same experiment in the

summertime

we wouldn't notice the big change in

temperature because the air would be

humid and wet things don't change

temperature very easily

okay so we understand the

importance of water and then how if

you're near the Pacific or the Atlantic

Ocean your temperatures are going to

change a whole lot but as it turns out

there's a difference between the Pacific

and the Atlantic Ocean in terms of the

effect they have on temperatures and it

has to do with how wind moves in our

country primarily air or wind in our

country moves that direction so if I am

over here on the West Coast the air that

is coming to me is always coming to me

from over the Pacific Ocean Pacific

Ocean pretty much always has the same

temperature because it's such a big body

of water it doesn't change temperature

that much so I always have about the

same temperature

but if we go over here on the East Coast

the air that is coming to me has gone

across the United States well that's a

bunch of land and that land can have

significantly different temperatures in

the summertime because there's a bunch

of land that air gets to be pretty hot

and what comes to me is hot air so I'm

hotter but in the winter time this part

of the country can get cold so what

comes to me is cold air so on the

Atlantic coast my temperatures change a

lot more than on the Pacific coast

because the air that is coming to me is

coming from Overland and that land can

be either hot or cold depending on the

season

but let's clarify something a location

here on the Atlantic coast location here

that is not on the coast

the location on the coast is going to

change temperatures less

than a location that is not on the coast

however

the East Coast changes temperatures a

lot more than the West Coast

so there's a big idea big conclusion the

temperatures in the U.S change much more

on the east coast and the West Coast

because of how the wind blows across our

country that's going to be something we

have to look at when we're trying to say

well how much is the temperature

changing here or how hot or how cold is

it yeah it's on the water for the

Atlantic coast and Pacific Coast have

different

influences over an area's temperature

now there is another big factor that we

got to get to

and I want to ask you this where is it

cold and where is it hot in the United

States well you guys know this you know

the general we say it is cold up north

and we originally say that it is

pot down south and you would not be

wrong in seeing that

here's a little graphic of the hottest

and coldest cities in the United States

and you'll see what we what we are know

to be true seems like all the cold

cities are up north and it seems like

all the warm cities are down south and

that is true the question becomes why

why is it cold up north and the hot down

south

take a look at these average annual

temperatures

Texas 65 Oklahoma 60. look at this

pattern as you go north notice what

happens to the average annual

temperatures it gets colder up north

it's warmer as you go south

and it is colder as you go north once

again the question becomes why

well let's review again temperatures are

measure of friction right which is from

moving particles air

and the air moves because it's got the

energy to move and all that energy comes

from the sun

but if we're all sitting under the same

Sun shouldn't everything have the same

temperature

well here's breaking news and that is

that the sun is not the same up north as

it is down south now physically the sun

is saying is the same but the energy we

get from the sun is not the same up

north as as it is down south

so let's look at how the sun's energy

impacts the Earth and hence temperatures

light bulb models the sun here's my

Earth energy is coming from the Sun hits

the Earth the amount of energy received

from the Sun determines the temperature

now this is the same light bulb no

matter where you are on the earth just

like it's the same Sun but we know the

temperatures are different let's explain

that using a light meter this is a

device that will measure in the unit of

lumens how much actual light you're

getting and hence how much actual energy

you're getting from this light bulb I'm

going to hold it right here at 90

degrees

from the light bulb basically right at

the equator and I see that my reading is

about

almost 900 lumens which means nothing

but let's see what happens as I go away

from the equator I get up here

it's dropping to 400 lumens

the same thing as I go this way it's

dropping once again to about 400 lumens

even though this light bulb is giving

the same amount of energy constantly

where you are on this globe

changes the amount of energy you're

receiving from that light bulb and

that's because the angle at which the

Rays hit the globe are different in

different places the angle here is 90

degrees it's hitting

the globe straight up

which means all the energy is directly

overhead is focused and concentrated in

a very small area

as you go away from the equator and the

Earth is curved you can see that that

Angle now is not 90 degrees and the sun

Sun's Rays when they hit the earth now

gets spread out a little bit more well

if the energy from the Sun is spread out

over a larger area that means the

sunlight isn't as concentrated so you're

not getting as much energy and you're

therefore going to have lower

temperatures this is a concept known as

insulation insulation is the spreading

out of the sun's energy because of the

curvature of the earth and the farther

away you get from the equator the more

spread out sunlight is and hence the

lower your temperatures tend to be

this might give you a better visual

representation of what I'm talking about

with concentrated light so in this

picture over here I held the flashlight

directly over the Lego character right

at 90 degrees and you can see the light

the brightest circle of light is that

big but then I took the flashlight and I

held it at an angle

and now you notice

the bright Circle where the majority of

the light is is a lot bigger so the same

amount of light is spread out over a

bigger area which means you're actually

getting less concentrated sunlight less

concentrated energy that would equate to

a lower temperature

let's take a look at three locations

we've got Hawaii down there pretty close

to Equator then we've got Atlanta and

we've got Mackinaw City Michigan which

is over halfway to the North Pole

halfway

away from the equator

I took some pictures of a ruler and the

shadow caused by that ruler based on

where the sun is in the sky at the same

time for all three of these locations

what we call solar noon or when the sun

is highest in the sky and you'll notice

that for Hawaii there is practically no

Shadow because the sun is directly

overhead which means the light is all

being concentrated into a very small

area now here in Atlanta there is a bit

of a shadow which means the sun isn't

hitting at 90 degrees and the sunlight

is spread out a little bit more than it

is in Hawaii

in Michigan the farthest north of the

farthest away from the equator you can

notice the shadow is a lot bigger which

means the sunlight is spread out over a

larger area and that's going to equate

to cooler temperatures because you're

not getting as direct or as concentrated

of sunlight

and you can actually see this on a

temperature graph of the Earth the

highest temperatures for the Earth are

here in the middle of the planet because

that's where the sunlight tends to be

more concentrated right alongside the

equator up here where sunlight is really

spread out and down here it tends to be

very cold because you're actually not

getting that much sunlight because it's

not concentrated it's spread out over a

large area so that's our first really

big conclusion from this presentation is

that the farther away from the equator

or the higher the latitude the lower the

temperatures are going to be because the

sunlight is more spread out

so we've been talking a lot about the

difference in temperatures between

summer and winter and you guys all know

the temperatures change from Summer to

Winter the question becomes why what

explains that it's the same Sun year

round and yet we know where you are on

the earth because that curvature of the

earth that insulation affects how much

sunlight you get and how spread out it

is and what your temperatures are going

to be but aren't you on the same place

in the earth year round your latitude

your curvature of the earth doesn't

change so why do temperatures change

from Summer to Winter and that's what

we're going to get into here this is the

discussion of the seasons and why we

have them take a look at our globe here

if you've never noticed most Globes are

tilted they are not straight up and down

with the equator being horizontal

our Earth is actually oriented like this

in outer space it is actually tilted at

23 and a half degrees from vertical so

our Earth is tilted

here's our sun and you'll notice our sun

is hitting the Earth as you look at this

this is the Northern Hemisphere you can

see the United States right here and I

want you to look at the part of the

northern hemisphere that is lit up this

much of the northern hemisphere is

receiving light but look at the southern

hemisphere

a lot smaller portion of the southern

hemisphere is receiving light

because the northern hemisphere is like

leaning into the sun because it's tilted

that way or if you're getting more

sunlight it means you're getting more

energy you're going to have higher

temperatures and we can actually prove

that with the light meter again we'll

turn it on and we'll see down here at

the equator

we're getting about

1400 lumens and I'll go up to 45 degrees

north and I can see I'm getting about

868 lumens but I'll go to 45 degrees

south

so it's the same curvature of the Earth

it's just now we're in the opposite

Hemisphere and down here now I'm getting

only about 400 lumens so even though

you're at the same latitude the same

part of the curve of the Earth when the

earth is tilted like this you're

actually getting less sunlight at your

location

one of the tricks with the Earth is it

doesn't stay right here it keeps moving

around the Sun in six months from now

the Earth is going to be

oriented like this now if you'll notice

how our northern hemisphere

doesn't have as much sunlight hitting it

as it did when it was leaned into the

Sun and now the southern hemisphere has

a lot more sunlight more sun some more

sunlight means you're going to have

higher temperatures less sunlight means

you're going to have lower temperatures

so when the earth is tilted away from

the Sun when your hemisphere is tilted

away from the Sun you're in winter

when

your section of the earth your

hemisphere is tilted or leaned towards

the sun you're in summer and that's what

causes the seasons it's because the tilt

of the earth is at 23.5 degrees so it's

some times of the year you're leaning

into the sun you get more sunlight

higher temperatures other times you're

leaning away from the Sun and you

actually get less sunlight and lower

temperatures

so that begs the question what would

happen if the Earth wasn't tilted well

look at the amount of sunlight both

hemispheres are getting

it would be the same

no matter what time of the year it was

if the Earth wasn't tilted we wouldn't

have seasons and everybody would have

basically the same temperatures they

have year round

so here we can see the changing angle of

the sun and the sky due to the tilt of

the earth if we look at the shadow that

the sun creates at solar noon or at its

highest point in the sky these here were

all taken in Atlanta and this is on June

20th notice there's not much of a shadow

what that means the sun's pretty much

directly overhead we go to September

however we notice that shadow has gotten

longer which means the sun is lower in

the sky now the sun hasn't changed

position if the Earth has and because

we're tilted at 23.5 degrees where we

see the sun in the sky changes

throughout the year we get to December

and the Sun appears to be very low in

the sky because now we are tilted away

from the earth and we see the sun at a

lower angle than when we do when we're

tilted towards it in the summertime

obviously as we see the sun lower in the

sky and that shadow gets longer that

means the sunlight is more spread out

and we have less energy hence lower

temperatures and you know that to be

true in December that's when it's

getting colder whereas in June when the

sun's directly overhead you know when

that that's when it's hotter

take a look at London this is London on

December the 20th and notice how long

that shadow is that's because London is

really far north and due to the

curvature that insulation and the fact

in December they're pointing so much

away from the Sun the shadow was really

long which means the sun is very spread

out in terms of its energy and you're

going to have lower temperatures you can

see the picks on the right I'm trying to

model that angle the sun makes with

London in December the picture at the

bottom is London once again but it's in

June you notice the shadow is much

shorter and you can see from this

picture over here the angle that the

light bulb makes with the globe when

it's tilted towards the sun is a lot

lower so the sunlight ends up being a

lot more directly overhead and get more

energy and you have higher temperatures

so let's talk about the seasons the

seasons we know what they are they're

different times of the year summer

spring winter and fall and we know that

you have different temperatures

throughout those seasons and you have

different amounts of daylight which

is amateurs however which you might not

realize that there are very specific

days of the year

that start and end each season and it's

all dependent upon how is the earth

oriented to the sun now we're going to

talk about everything in terms of our

hemisphere this Northern Hemisphere and

you can tell by this diagram that's the

United States and we're going to

describe everything relative to Northern

Hemisphere because that's where we live

I want you to look at this right here

our hemisphere here's the Earth instead

of being oriented straight up and down

we know it is tilted and our hemisphere

seems to be kind of tilted more towards

the Sun at that location whereas over

here our hemisphere is kind of pointing

away from us as tilted not towards the

sun it is tilted away from the Sun Well

if you're tilted towards the sun it

means you get more sunlight

if you're tilted away from the Sun you

get less sunlight we would associate

those with summer and winter

this one particular day right here is

that day where our hemisphere is tilted

the most towards the Sun

over here this is the one day where we

are tilted most away from the Sun a day

where you are tilted most of either

towards or away from the Sun is called a

solstice

that's when you have your maximum tilt

in relation to the sun but there's a big

difference between being tilted towards

the Sun or being tilted away when you're

tilted towards that is called the summer

solstice because you're leaning into the

sun you're getting more sunlight that

summer

this is called the

winter solstice these are also called

first day of summer

that's what makes summer summer is that

day where you have your maximum tilt

towards the Sun that starts summer this

would be called the first

day

of winter

now what do we experience physically

physically this is the longest day

of the year

it's the day when the Sun is up in the

sky the longest we get the most sunlight

this is the

shortest day

of the year

so this day this one day here starts

summer and this one day here starts

winter

we get our most sunlight and we get our

least sunlight now winter and summer are

not one day but that is the start of

summer and let's say the Earth is moving

along the path this way

so that's the first day of summer a day

later the Earth is here well it's still

summer

still summer still summer this is all

still summer

over here the day that we start winter

we stay in winter

until we get to that next special day

which is right here

on these two days we have another change

of season there's something very unique

happens here

in this situation we get the most of

most sunlight because we're tilted most

towards the sun and the southern

hemisphere actually gets there at least

sunlight because they're opposite than

us

same here we get our lease some they get

their most Sun

both hemispheres get the same or equal

sunlight and they are then it's called

an equinox

an equinox by definition is when both

hemispheres get the same amount of

sunlight

well there's a difference between these

two

and these are the hardest ones to figure

out because if we just look at the

picture of the earth they look exactly

the same both hemispheres have the same

amount of sunlight but we know after

summer

before winter

we go through the season of fall

so that would be the fall of Equinox

this would be the

spring equinox

so here we start summer and we're summer

summer summer because we are getting

more sunlight than the southern

hemisphere

right here at this day

both hemispheres get the same amount of

sunlight it's an equinox

that starts fall for us

so we're starting fall and we stay in

Fall until we get to this day here

which is the shortest day of the year

the winter solstice and we're in winter

winter winter winter until we get to

this day where we have the same sunlight

in the southern hemisphere again and now

we are in Spring we're in Spring every

day here we're in Spring until we get to

that particular day where we get our

most sunlight

and that starts our summer

now all of these particular orientations

of the Earth the Sun have a date

associated with them we know when these

happen these summer solstice

is usually about June 20th or 21st

the winter solstice is about

December 21st especially this year and

they can change sometimes the date can

change because of whether or not it's a

leap year or not this year the fall

equinox

was September 23rd we just had it we

just started fall the Earth right now

just past that we're like right here we

have started fall and the Spring Equinox

is this year anyway or was for 2023 was

March 20th now these are very special

days that Mark changes in the amount of

sunlight between the two hemispheres

the northern gets the most South gets

the least

Northern gets the least Southern gets

the most

here they have

equal and you've got to say to yourself

well what do you know about temperatures

from here to here in summer

temperatures are getting hotter because

you're getting a lot of sunlight you

know in Fall you're now starting to get

less sunlight

so in the date in the dates that fall

into this fall range you know you're

getting less sunlight and temperatures

are going to get cooler

in winter

you know the temperatures

get cooler to a point but by the time we

get closer to Spring to March our

temperatures have started to come up

because we're starting to get more and

more sunlight throughout the spring the

spring season

our days are getting longer and longer

and longer our temperatures are going up

and up and up until we get to summer

so at this point

you should have this diagram completed

and understand the concepts in there you

can see me now to take a notes check

over this material