APES Bell Ringer **Turn in any missing work from Tuesday-Friday of last week! Make sure to Include QUESTION and answer!
Miller Chapter 6.1-6.2 Atmosphere and Weather AP Environmental Science www.ai.mit.edu/people/jimmylin/pictures/2001-12-seattle.htm
Origin of Modern Atmosphere Original atmosphere: Hydrogen and Helium 2nd atmosphere evolved from gases from molten Earth H2O, CO2, SO2, CO, S2, Cl2, N2, H2, NH3, and CH4 Allowed formation of oceans and earliest life Modern Atmosphere evolved after Cyanobacteria started photosynthesizing oxygen produced did not reach modern levels until about 400 million years ago www.degginger.com/digitalpage.html
Continental Drift ~230 million years ago 1 giant landmass on Earth = Pangaea As the continents moved toward their present-day locations the Sea level dropped Volcanoes erupted Earth’s surface was pushed upward. Effects on weather: Drop in temperature and precipitation all over the Earth. These changes were gradual.
Extinction of the Dinosaurs? Climate change = Extinction of the dinosaur? Plants extinct Dinosaurs that ate these plants became extinct Meat-eating dinosaurs that depended on plant-eating dinosaurs died Other scientists believe that dinosaurs became extinct as the result of a giant asteroid striking the Earth 65 million years ago (many theories!)
Earth’s Atmosphere Compared to the size of the Earth (104 km), the atmosphere is a thin shell (120 km). If the Earth was an orange, the atmosphere would be the pesticides on its peel http://www.gsfc.nasa.gov/gsfc/earth/pinatuboimages.htm
Atmosphere Layers Exosphere Thermosphere (Ionosphere) Mesosphere Stratosphere Troposphere (closest to Earth)
Troposphere 8 to 14.5 kilometers high (5 to 9 miles) Most dense Temperature decreases as altitude increases Weather is found here!
Stratosphere Extends to 50 kilometers (31 miles) high Dry and less dense Temperatures increase as altitude increases Due to the absorption of ultraviolet radiation Ozone layer absorbs and scatters the solar ultraviolet radiation 99% of "air" is located in first two layers
The Atmosphere Mesosphere Thermosphere very little atmosphere coldest layer Thermosphere ionosphere aurora borealis hottest layer 1000 C
Atmospheric pressure (millibars) Altitude (kilometers) 200 400 600 800 1,000 120 75 Temperature 110 Pressure 65 Thermosphere 100 90 55 Mesopause 80 45 70 Mesosphere Altitude (kilometers) 60 Altitude (miles) Stratopause 35 50 Heating via ozone 40 25 Stratosphere 30 Tropopause 15 Ozone “layer” 20 Heating from the earth 10 Troposphere 5 Pressure = 1,000 millibars at ground level (Sea Level) –80 –40 40 80 120 Temperature (˚C)
Atmosphere Composition Nitrogen (N2, 78%) Oxygen (O2, 21%) Argon (Ar, 1%) Variety of other very influential components are also present which include the Water (H2O, 0 - 7%), "greenhouse" gases or Ozone (O3, 0 - 0.01%), Carbon Dioxide (CO2, 0.01-0.1%),
What gas was originally not in the atmosphere? A. Carbon dioxide B. Water C. Oxygen D. Methane Review Questions
The gas that composes 78% of the gases in the atmosphere is: A. Oxygen B. Nitrogen C. Carbon Dioxide D. Ozone Review Questions
The atmosphere layer in which most of the weather occurs is the: A. Troposphere B. Stratosphere C. Mesosphere D. Thermosphere E. Exosphere Review Questions
Weather: A Brief Introduction result of the atmospheric conditions in a particular area over short periods of time, typically over hours or days EX: temperature, pressure, moisture content, precipitation, sunshine, cloud cover, and wind direction
CLIMATE Average pattern of weather for a particular region LONG TERM
OBJ 6.2
Climate 2 Main factors Temperature Precipitation Amount Distribution Factors that affect temperature: Latitude Elevation Closeness to large bodies of water Climate
Closeness to Large Bodies of Water Water moderates the temperature creating cooler summers and warmer winters
Elevation
Short Term Changes in Climate Changes in ocean currents and global winds. Ocean currents help transfer heat to the atmospheregenerates global windshelp move ocean currents. Any major change in an ocean current can cause a change in climate El Nino!!! (We will discuss this at the end! )