The Atmosphere

By Raj Patel

Composition

• • • The Earth’s atmosphere is composed of 7 primary compounds: Nitrogen (78%), Oxygen (21%), Water Vapor (0-4%), Carbon Dioxide, Methane, Nitrous Oxide, Ozone (<<<1%).

Nitrogen is the most pervasive while CO2 has increased about 25% in the last 300 years.

Some of these compounds contribute to increased temperatures such as CO2, Methane, N20, etc.

Structure (Layers)

• • • • Troposphere -(0-11 km) above the surface. 75% of atmosphere’s mass is in the troposphere.

Stratosphere- Contains the Ozone Layer. Temperature increases with altitude due to absorption of heat by the ozone.

Mesosphere-It is the coldest layer and temperatures decrease with altitude. Meteors burn up in this layer.

Thermosphere (Ionosphere)-Temp. increases with height due to gamma rays, x-rays, and UV radiation. Also Molecules are converted into ions which results in the aurora borealis (Northern Lights).

Layers of the Atmosphere

• http://www.youtube.com/watch?v=0vcHBNM w2h0

Weather and Climate

• • • Weather is caused by the movement or transfer of heat energy which impacts the physical properties of temperature, air pressure, humidity, precipitation, available sunshine, and wind speed and direction.

Climate describes the total of all weather occurring over a period of years in a given place.

Regions nearer the equator receive much more solar energy (and are warmer) than regions nearer the poles.

• • • • • • • • • • • • • •

Factors that Influence Climate

Air Mass Air Pressure

Albedo-reflectivity. (ocean water=low albedo, land =high albedo)

Altitude Angle of Sunlight Carbon Cycle and Greenhouse effect and Pollution Clouds and Fronts Distance to Oceans

Landmass distribution-different materials absorb varied amounts of heat i.e. water has high specific heat

Latitude and Location Humidity Plate tectonics and Volcanoes Wind Patterns Human Activity

Coriolis Effect

• If not for the Earth’s rotation, global winds would blow in straight north-south lines. What actually happens is that global winds blow diagonally. The Coriolis effect influences wind direction around the world in this way: in the Northern Hemisphere it curves winds to the right; in the Southern Hemisphere it curves them left.

http://www.universetoday.com/73828/what-is the-coriolis-effect/#ixzz2Pw6ikLVn

Coriolis Effect

Rain Shadow Effect

• A rain shadow is a dry area on the mountainside facing away from the direction of the wind. The mountains block the passage of rain-producing weather systems, casting a “shadow” of dryness behind them.

El Nino

• • • • Occurs when the air pressure patterns in the South Pacific reverse direction, the trade winds decrease in strength and can reverse direction. The result is that the normal flow of water away from S. America decreases and ocean water piles up off S.A. This pushes the thermocline (the region in a thermally stratified body of water which separates warmer surface water from cold deep water and in which temperature decreases rapidly with depth) deeper and decreases the upwelling of nutrient rich deep water (leads to extensive fish kills). The Sea Surface temperature increases in the eastern Pacific.

Rainfall common in Central Pacific, while dearth in Western Pacific.

La Nina

• • • Trade winds blow east across the tropical Pacific are stronger than normal leading to increased upwelling and Cooler-than-normal sea surface temperatures. It brings nearly the opposite effects of El Nino to the U.S., with wetter conditions across the Pacific northwest and dryer and warmer conditions in southern states.

Responsible for heavier than normal monsoons in Southeast Asia and increase in hurricanes that occur during the same period.

http://library.thinkquest.org/5818/elnino.html

Natural Disasters

• • • Hurricanes-most sever weather phenomenon that begins over warm oceans where trade winds converge. Also comprised of convective storms.

Tornadoes- swirling masses of air with wind speeds close to 300 mph. Like hurricanes, the center is an area of low pressure.

Monsoons-strong, violent winds that change direction with the season. Monsoons blow from the land toward the sea in winter and from the sea toward land in the summer. (blow from cold to warm regions).

The Zone of the atmosphere in which weather occurs is known as the

• • • • • A) ionosphere B) mesosphere C) Troposphere D) Thermosphere E)Stratosphere

The ozone layer exists primarily in what section of the atmosphere?

A) Troposphere B) Stratosphere C) Mesosphere D) Thermosphere E) Ionsosphere

The Surface with lowest albedo is

A) Snow B) Ocean water C) Forest D) Desert E) Black topsoil

Along the Equator

A) warm, moist air rises B) Warm, moist air descends C) Warm, dry air descends D) Cool, dry air descends E) Cool, moist air descends

What process is responsible for dryness on one side of a mountainside?

A) El Nino B) La Nina C) Rain Shadow Effect D) Coriolis Effect E) Greenhouse Effect

Answers

• • • • • Troposphere Stratosphere Black topsoil Warm, moist air rises Rain shadow Effect