Download 08A - El Camino College

The Atmosphere & Winds Lecture Notes (Topic 8A) – page 1
The Atmosphere & Winds Lecture Notes
Convection Cells: Winds
Why is the air rising at the warm spot
on the surface of the Earth (arrow A)?
The air is
(A)_____________________
Clear
Skies
High Altitude Winds
B
C
D
Surface Winds
A
by the surface of the Earth,
Warm
Cold
so it rises because its density
becomes (B)_____________________.
Ocean
Why is the air sinking at the cold spot on the surface of the Earth (arrow C)?
The air is (A)__________________________ by the surface of the Earth
so it sinks because its density becomes (B)__________________________.
Why do the surface winds blow in the direction shown (arrow D)?
In other words, what is pushing or pulling the air in this direction?
The air moves towards the (C)___________________________ spot
to replace the air (D)__________________________ at this location,
and is pushed away from the (C)___________________________ spot
by the air (D)__________________________ at this location.
Why do the high-altitude winds blow in the direction shown (arrow B)?
In other words, is pushing or pulling the air in this direction?
The air moves towards the (C)__________________________ spot
to replace the air (D)__________________________ at this location,
and is pushed away from the (C)___________________________ spot
by the air (D)__________________________ at this location.
A: warmer, colder
C: warm, cold
B: higher, lower
D: rising, sinking
The Atmosphere & Winds Lecture Notes (Topic 8A) – page 2
Convection Cells: Clouds and Rain
What kinds of molecules is most of the atmosphere made of? ____________________________
What is the main source of the water in the atmosphere? In other words, where does most of the
water in the atmosphere come from? How or why does the water enter the atmosphere?
Most of the water in the atmosphere ______________________ from the ________________.
To condense into clouds and rain, water vapor needs to cool.
Why does most rain fall over the warm spot on the surface of the Earth and not the cold spot?
As air the __________________, it cools due to the change in ________________________.
Sea Breezes, Land Breezes, and Monsoons
DAY
Wind
Warm
Wind
HOT
Warm
NIGHT
HOT
Names of Winds
Winds and currents are often name for the direction ________________________________.
Monsoons
During summer in the Northern Hemisphere,
winds blow towards the ______________________________
to replace the air rising over the continent.
Equator
The Atmosphere & Winds Lecture Notes (Topic 8A) – page 3
Review Questions
What conditions are necessary to create winds at the surface of the Earth?
a. Earth rotates
b. Gravity
c. Sun is in the sky
d. Moon is in the sky
e. there is a temperature difference between 2 spots
f. there is a warm spot and a cold spot
What provides the energy to get the winds going?
______________________________
Which side of the mountain/island
gets more clouds and rain?
a. Location A (left side)
b. Location B (right side)
Temperature on the Surface of the Earth
Why are the Poles colder than the Equator?
a. At the Poles, sunlight strikes the surface at an angle, so it is spread out.
b. The Earth’s surface is darker at the Poles, so it reflects more sunlight.
c. The Poles are farther from the Sun than the Equator.
d. The thicker atmosphere at the Poles absorbs sunlight before it reaches the surface.
Why are there seasons?
a. The Earth is closer to Sun during summer.
b. The Earth’s rotation gets slower (longer days) and faster (shorter days) during a year.
c. The northern hemisphere is tilted towards the Sun during the summer
and away from the Sun during the winter because the Earth goes around the Sun.
d. The northern hemisphere’s tilt towards the Sun changes (“wobbles”) during a year.
e. The Sun gets brighter during the summer and dimmer during the winter.
The Atmosphere & Winds Lecture Notes (Topic 8A) – page 4
The Coriolis Effect
Objects moving over the surface of the Earth bend or turn off course instead of going straight.
Cause of the Coriolis Effect (Why do objects turn to the side instead of going straight?)
N
North
Pole
N
N
Objects
Basic Rules
rth s
Eaotate
R
Equator
Direction an Object Turns (Does it turn to the “right” or “left” of its direction of motion?)
Northern Hemisphere: Objects turn to the _______________ of their direction of motion.
Southern Hemisphere: Objects turn to the _______________ of their direction of motion.
Influence (Which objects will be affected?)
Strength (Where on the Earth is the Coriolis effect strongest? weakest?)
Review Questions
In what direction will the wind bend owing to the Coriolis effect?
In the northern hemisphere:
In the southern hemisphere:
The Atmosphere & Winds Lecture Notes (Topic 8A) – page 5
The REAL Global Wind Pattern (but it is still somewhat simplified)
There are 3 cells in each hemisphere, not one,
and the winds do not only blow north and south.
(90o N)
North
Pole
Why can’t the winds carry air
all the way from the Poles to the Equator?
60o N
30o N
Equator (0o )
Global Wind & Rainfall Pattern
Sketch the global surface wind pattern into the globe below that
includes the effects of the Earth’s rotation. The winds in the
wind belt between 0o and 30oN are done for you as an example.
What is the direction of the winds at
the following latitudes?
(Possible answers include: north, northeast,
east, southeast, south, southwest, west, and
northwest.)
75oN: ____________________
45oN: ____________________
15oN: ____________________
15oS: ____________________
45oS: ____________________
75oS: ____________________
At which latitudes are cloudy skies and rainfall more common?
_______________________
At which latitudes are clear skies more common?
_______________________
The Atmosphere & Winds Lecture Notes (Topic 8A) – page 6
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