unequal heating, air pressure and winds. atmosphere atmosphere: a mixture of gases that surrounds...
TRANSCRIPT
Atmosphere
• Atmosphere: a mixture of gases that surrounds Earth: acts like a blanket– Contains oxygen– Protects from sun– Keeps heat in– Protects from meteors
Greenhouse Effect
• These gases absorb the heat and act as a “blanket” to keep Earth warm.
• Some greenhouse gases: water, methane, carbon dioxide.
Air Pressure Review
• Air has mass.• Air takes up space.• Air has density.• Air pressure is the
weight of a column of air pressing down on an area.
Atmosphere/Pressure• Pressure strongest at
surface-more air above you
• *as altitude (height above surface) increases, air pressure decreases– Stack of books
The Teacher Has Performed An Experiment and Asks That YOU Help Make Some Conclusions About the Data or Information Gathered.
Experiment Materials and Procedures: The Teacher Used A Thermometer, A Heat Lamp, A Cup of Sand, and A Cup of Water to Find the Temperatures of Both the Sand and The Water Over Two Hours.
DATA FROM THE EXPERIMENT
TEMPERATURES OF THE SANDThe First Hour It Was Heating Up & The Second Hour It Was Cooling Down15 Minutes
30 Minutes
45 Minutes
1 Hour 15 Minutes
30 Minutes
45 Minutes
1 Hour
68 Degrees
74 Degrees
88 Degrees
93 Degrees
88 Degrees
76 Degrees
68 Degrees
68 Degrees
TEMPERATURES OF THE WATERThe First Hour It Was Heating Up & The Second Hour It Was Cooling Down
15 Minutes
30 Minutes
45 Minutes
1 Hour 15 Minutes
30 Minutes
45 Minutes
1 Hour
68 Degrees
71 Degrees
83 Degrees
89 Degrees
87 Degrees
81 Degrees
77 Degrees
73 Degrees
CONCLUSION• Land Heats Up And Cools Down Faster Than Water!
During the day, land heats faster than a body of water, so the air above the land becomes warmer. The warm air expands and creates a low-pressure system. The cooler air above the body of water blows inland and under the warm air. At night, the opposite happens.
Unequal HeatingWhat heats up quicker?What heats up slower?
At night, which cools down quicker?Which cool down slower?
Unequal HeatingWarm air rises and creates a low pressure system.
Cold air sinks and creates a high pressure system.
Local Winds
Have you ever flown a kite at the beach on a hot summer day?
Even if there is no wind inland, there may be a cool breeze blowing in
from the water toward the beach. This breeze is an example of local
winds!
Local Winds
Local winds are winds that blow over short distances.
They are caused by unequal heating of Earth’s surface within a small area.
4 types › sea breezes and land breezes› Mountain breeze and valley breeze
Sea Breeze (Morning)
Land heats up faster than water. Hot air over land rises (Low Pressure), cool air over water falls (High Pressure). Winds move from the water (High Pressure) to the land (Low Pressure).
Land Breeze (Evening)
Land cools off faster than water. Cool air over land falls (High Pressure), warm air over water rises (Low Pressure). Winds move from the land (High Pressure) to the water (Low Pressure).
Animation of Sea Breeze & Land Breeze
• http://www.classzone.com/books/earth_science/terc/content/visualizations/es1903/es1903page01.cfm?chapter_no=visualization
Valley Breeze (Day)
During the day the sun warms the air slopes, creating a valley breeze…
at nightfall, the air along the mountain slopes cools…
Mountain Breeze (Night)
This cool air moves down the slopes into the valley, producing a mountain breeze!
Global winds
Warm air rises from the equator and sinks at the poles.
› Warm air = less dense = low pressure
› Cool air = more dense = high pressure
Global Winds… cont… The movement of air
between the equator and the poles produces global winds.
Coriolis effect produces patterns of air circulation called global winds.
Coriolis Effect.
As the Earth rotates, winds and currents move in a curved path, called the coriolis effect.
Doldrums• Where the trade winds meet around the equator• Very little wind because the warm air rising = low
pressure
Jet Streams Bands of high speed winds Upper troposphere and lower
stratosphere Blow from west to east at
speeds of 200-400 km/hr. Help airplanes save fuel and
time when traveling east.
Study Jams Video- Air Pressure and Wind
http://studyjams.scholastic.com/studyjams/jams/science/weather-and-climate/air-pressure-and-wind.htm
Measuring Wind
Winds are described by their direction and speed.
Wind direction is determined with a wind vane – points in the direction the wind is moving!
Wind speed is measured with an anemometer.
The increased cooling that a wind can cause is called the wind chill factor.
Anemometer – The cups catch the wind, turning faster when the wind blows faster.
Wind Vane