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Welcome!
Jr. Meteorologist!
Why do we need to study weather?
How would you like to attend an outdoor picnic in
the rain?
Do you like to know when a severe storm is coming?
We get this information from television, radio,
newspapers, and weather radios.
We receive this information from trained individuals
called meteorologists.
A meteorologists is a scientist who studies the
atmosphere and its changes in order to predict daily
weather.
Weather and Climate
What is the weather like today?
Is it like this EVERY day? Why?
Or why not?
Prediction: What is the difference between
WEATHER and CLIMATE?
The Layers of the Atmosphere The layers of the atmosphere are
defined by changes in temperature.
For example, -sphere means “ball,”
which suggests that each layer of
the atmosphere surrounds the Earth
like a hollow ball. Tropo- means
“turning” or “change,” and the
troposphere is the layer where
gases turn and mix. Strato- means
“layer,” and the stratosphere is the
sphere where gases are layered
and do not mix very much. Meso-
means “middle,” and the
mesosphere is the middle layer.
Finally, thermo- means “heat,” and
the thermosphere is the sphere
where temperatures are highest.
Layer by Layer
The troposphere is
the first layer above
the surface and
contains half of the
Earth's atmosphere.
Weather occurs in
this layer.
The Atmosphere
BIG IDEA: Earth’s
atmosphere is a mixture
of gases that distributes
heat and enables life to
exist on Earth.
What makes up DRY air in the
atmosphere?
– 78% nitrogen--used to make protein
– 21% oxygen (from photosynthesis)—
processes that use oxygen:
cellular respiration (plants and animals)
oxidation (like rust, tarnish)
combustion*
--1% other gases (argon,
carbon dioxide, other)
What makes up air (atmosphere)?
Weather
Weather is constantly
changing, and it refers to
the state of the
atmosphere at a given
time and place
In other words…
In other words…what it’s
like OUTSIDE, right
HERE, right NOW
Measureable
properties of weather
air temperature
humidity
type and amount of
precipitation
air pressure
speed and direction of wind
Climate – The long-term
environmental conditions across
a large area and long time.
Climate, however, is based on the
average, year-after-year
conditions of temperature,
precipitation, winds, and clouds in
an area.
Climate helps describe
a place or region
Reading Check:
What is the
difference between
WEATHER and
CLIMATE?
What affects weather and climate?
There are two major factors that affect the
overall environment and climate…
-The tilt of the Earth in relation to it’s
orbit around the Sun
- The direction of that tilt that
changes as the Earth travels around
the Sun
First, some basic vocabulary…
Revolution – one ORBIT, or trip around the
Sun. This takes the Earth 365 ¼ days
Rotation – one
SPIN of the
Earth on it’s
axis. This
takes about 24
hours…one
DAY.
Earth’s TILT
The Earth is not vertical (straight up-and-
down) in relation to it’s orbital path, it’s tilted
23 ½ degrees from vertical.
This tilt means
that the Sun’s
energy doesn’t hit
the Earth equally.
Earth’s TILT
This tilt results in uneven heating of the
Earth’s surface.
“Direct”
sunlight
“Indirect”
sunlight
Distributing the Sun’s Heat - WIND
RULE #2 OF NATURE – Nature seeks
balance (equilibrium)
Create Wind is the
movement
of air from High
pressure to Lowpressure
HOT
air
RISES
COLD
air
SINKS
Precipitation – Nature’s Thermostat There are 3 basic causes for rain. They are:
– Convection – due to evaporation and cooling
Sun’s energy causes surface water to evaporate and become humidity
As the day cools off, the air cools and condenses, causing storms and rain
Usually in tropical environments
Precipitation
–Frontal – due to changes in temperature
Starts with warm, moist air at the surface and above
As a cold front approaches, it stays low, forcing the moist air aloft
This cools and condenses the air, creating rain on the “leading edge” of the front
Usually in mid-latitudes where warm and cold air systems collide
Precipitation cont. Orographic – due to changes in elevation
– Moist air travels over land and approaches a steep rise in
elevation
– As the air is forced up the side of the rise, the air cools,
causing precip. on the “windward” side of the
mountain
– As the (now dry) air continues over and down the
“leeward” side of the mountain, it warms up and
absorbs any available
moisture, creating a “rain
shadow desert”
– Found in areas of
mountains or other
rapid elevation change
Latitude
Due to the Earth’s tilt, the amount of sun
energy changes over the earth’s surface…
Tropical (Low Latitude) zone –
year-round direct sunlight, always
hot
Temperate (Mid-Latitude) zone
– seasonal, most varied climates
Polar (High Latitude) zone –
either mild temps. or extreme cold
RULE: The HIGHER the latitude,
the COLDER the temps.
Altitude (Elevation) Higher elevation = thinner less
air, therefore less air to hold heat
makes it colder.
RULE –
The HIGHER
the elevation,
the COLDER the
temperatures.
Nearness to Water Land heats up and cools down QUICKLY.
Water heats up and cools down SLOWLY.
Therefore, water acts like a blanket… holdingheat and releasing it slowly.
This results in smaller daily and seasonal temperature changes near large bodies of water.
“Coastal” areas are humid, “continental” areas are dry
30 degree change
in Houston45 degree change
in Denver
Direction of Currents Global wind and ocean currents transfer heat
and moisture around the world, and help carry
moisture from the oceans to the land
– Warm water moving toward the land brings moisture (H2O)
– Warm water moving parallel to the coast brings heat, no H2O
– Cool water brings cool, dry air -> mild or desert climates
Reading check
How do humans
impact the
atmosphere and how
does this affect our
lives?
Climate Zones Climate zones are divided into regions: The
three climate zones of the world are the tropical
zone, the temperate zone, and the polar zone.
There are two key characteristics differences:
– Amount of moisture (rain), and
– Typical temperature range through the year
These two characteristics are affected by
balancing the effects of four factors:
Latitude
Altitude
Nearness to water
Direction of atmosphere and ocean currents
How it Works...
Tropical Wet Climate
Latitude – in the
tropics HOT
Altitude – low land
doesn’t stop air flow
until mtns. in the west
Nearness – flat land
“acts coastal”, allows
moisture inland
Direction – air flow
brings in warm, moist air
from the ocean which then hits the mountain and rains
The Tropical ZoneFigure 1 Biomes of the Tropical Zone
Temperate and Polar Zones
Temperate and Polar Zones
Reading check
Why are there
different climates on
the earth? Explain
with details.
Student led closingThe arrows in the cross section below show winds moving across
northern New York State into Vermont during the summer.
Compared to the climate of location A, the climate of location B is… Why?
a. warmer and wetter c. cooler and drier
b. cooler and wetter d. warmer and drier
The map shows an imaginary continent on Earth. Arrows represent wind
direction. Letters A through D represent locations on the continent.
Locations A and B are at the same latitude and at the same elevation at
the base of the mountains.
The climate at location C is much drier than at location D. This difference is
best explained by the fact that location C is located….
a. at a latitude that experiences longer average annual daylight
b. at a latitude where air is sinking and surface winds diverge
c. farther from any mountain range
d. closer to a large body of water
Done?