the atmosphere-history 3.2 billion years ago (bya) atmosphere mostly __________ and ________ (life...

The Atmosphere-history

• 3.2 billion years ago (bya) atmosphere mostly __________ and ________ (Life begins in sea)

• 2.3-2.7 bya photosynthetic bacteria (cyanobacteria) began producing __________

• 400-500 mya ______________ levels in stratosphere sufficient to protect land plants from UV radiation.

The Atmosphere-current composition

• _______ % N2

• 21 % _______• Around 1% Ar2

• 0.01-4% _______• 0.037 CO2

The Atmosphere-current composition • The __________________________________

- Natural warming effect of the troposphere1. sunlight hits the Earth’s surface turning

into infrared (heat) radiation2. heat risessome escapes into space

some heats greenhouse gases emitting infrared radiation

which warm the troposphere

+

The Atmosphere-current composition

• Major greenhouse gases:- ________________________________

(primary)- CO2

- O3 (ozone)- _______________________ (methane)- N2O (nitrous oxide)- CFCs (chlorofluorocarbons)

The Atmosphere-current composition

• Mean global temperature 14.53oC or 58.14oF (2000-2008)14.0oC or 57.2oF (1951-1980)(Source http://data.giss.nasa.gov)

-18oC or 0oF without greenhouse effect

The Atmosphere-Climate• Climate: ____________________ patterns of

atmospheric conditions-mainly influenced by average _____________ and __________________________________-globally follows a cyclic pattern+ glacial periods lasting around _________ yrs+ interglacial periods lasting around

________________________ yrs+ Holocene epoch—nearing end of

interglacial period

The Atmosphere-climate

Factors that affect global climate __________ of the Earth’s orbit (eccentricity) ___________ of the Earth’s axis (precession) changes in the _________ of the Earth’s axis

(obliquity) volcanic activity changes in _____________________ output atmospheric composition

The Atmosphere-climate

Factors that affect regional climate uneven ____________ of the Earth’s surface

(varies by ________________ and season) ______________ of the Earth ocean currents mountains altitude _____________________ of the Earth

The Atmosphere-factors that affect regional climate

Uneven heating of the Earth’s surface Consistent, year-round heating at equator More seasonal variation as latitude increases Uneven heating produces atmospheric areas of

low pressure (less dense, rising air) and high pressure (more dense, falling air.)

Pattern alternates about every 30 degree change in latitude (p. 125)

The Atmosphere-factors that affect regional climate: Earth’s rotation

Coriolis Effect—The apparent deflection of a moving object due to the motion of the Earth underneath it

The Atmosphere-factors that affect regional climate: ocean currents

• Water’s high ___________________________ causes it to gain and lose heat slower than land masses

• Oceans produce _________________ climates• Changes in _________due to temperature and

salinity differences and the Earth’s _________ produce ocean circulation patterns

• Europe is warmer than it should be due to warm ________________________________

The Atmosphere-factors that affect regional climate: ocean currents

The Atmosphere-factors that affect regional climate: mountains

• Mountains force air masses to __________ as they pass across them

• Rising air _________ and moisture condenses producing precipitation on the “windward’ side

• Descending air on the “leeward” side has ____ moisture producing areas of lower precipitation

• Called the “Rain shadow effect”

The Atmosphere-factors that affect regional climate: mountains

The Atmosphere-factors that affect regional climate: altitude

Average temperature decreases about ___oF for every _________________ feet in altitude

Barrons p. 117

The Atmosphere-factors that affect regional climate: tilt of the Earth

• The _________________________!

The Atmosphere-weather• Weather-The short-term conditions in the

troposphere at a location.• Includes atmospheric conditions such as

- ______________________________- ______________________________- ______________________________- ______________________________- ______________________________- ______________________________

The Atmosphere-weather: temperature

• Measure of _____________________ energy• Differences produced by ___________ heating

of Earth’s surface• Maps of areas with the same temperatures

are called _____________________________

The Atmosphere-weather: temperature

The Atmosphere-weather: temperature• Normally troposphere gets _______________

with altitude

• Temperature _______________________--a layer or warmer air above cooler surface air

The Atmosphere-weather: temperature

The Atmosphere-weather: temperature

• _________________ Front—leading edge of advancing mass of cold air-more dense so slides __________ warmer air lifting it-rising warm air produces thunderheads and rainstorms

The Atmosphere-weather: temperature-Cold Front

The Atmosphere-weather: temperature

• __________________ Front—leading edge of advancing mass of warm air-__________ dense so rises up over colder air-more gradual lifting produces thickening clouds and longer periods of rain

The Atmosphere-weather: temperature-Warm Front

The Atmosphere-weather: temperature (note symbols)

The Atmosphere-weather: clouds

• ______________________________ of water vapor in rising air due to lower temperatures.

• ____________________ conditions determine cloud type

• Cloud names indicate _________________ and ______________________________

The Atmosphere-weather: Clouds

Cirrus Clouds:-_______ altitude-Thin and wispy

The Atmosphere-weather: Clouds

Stratus Clouds-_____________ altitude-layered and sheetlike

The Atmosphere-weather: Clouds

Cumulus Clouds-Low to medium altitude-______ bottom and fair weather-Cumulonimbus are _____________ clouds

The Atmosphere-weather: Pressure

Earth’s _________ pulling down on molecules in the atmosphere creates atmospheric pressure

Atmospheric pressure at sea level is:- 760 mm of Hg- 29.9 in. of Hg- 14.7 psi- 1013.25 millibar

The Atmosphere-weather: Pressure

• Maps of areas with the same barometric pressure are called ____________________

• Areas of _______ pressure bring cloudy rainy weather. Counterclockwise (NH) (cyclone)

• Areas of ______pressure usually indicate clear weather. Clockwise (NH) (anticyclone)

• Air moves from areas of ______ pressure into areas of _____________ pressure—wind!

The Atmosphere-weather: Pressure

The Atmosphere-weather: Jet Stream

• Narrow, fast-moving wind current in the upper ___________________________________

• Position usually coincides in part with the regions of greatest ____________________ in the lower troposphere

• Also called ____________ jet stream, because of the importance in moving cold, polar air.

The Atmosphere-weather: Jet Stream

Atmospheric-Oceanic Interactions: El Nino-Southern Oscillation (ENSO)

• Normal conditions in eastern equatorial Pacific Ocean

Atmospheric-Oceanic Interactions: ENSO

Atmospheric-Oceanic Interactions: ENSO

• El Nino-A ___________ of the surface water of the eastern and central Pacific Ocean, occurring every 4 to 12 years and causing unusual global weather patterns.

• trade winds that usually push warm surface water ______________ weaken, allowing the warm water to pool as far eastward as the western coast of South America.

Atmospheric-Oceanic Interactions: ENSO

Atmospheric-Oceanic Interactions: ENSO

Atmospheric-Oceanic Interactions: La Nina

• _______________ of the surface water of the eastern and central Pacific Ocean, causing similar, generally opposite disruptions to global weather patterns.

• Trade winds blow more strongly than usual, pushing the sun-warmed surface water farther west and increasing the upwelling of cold water in the eastern regions.

Atmospheric-Oceanic Interactions: El Nino vs. La Nina

Typical vs. El Nino vs. La Nina• Typical • Winds off the western coast of equatorial South America blow

_______________________, pushing surface waters west.• Cooler deeper waters _______(upwelling) to replace moving

surface water, bringing nutrients to the surface, increasing fish populations.

• El Nino• Winds off the western coast of equatorial South America

lessen, stop or start to blow _________________________.• Warmer surface waters deepen as they “run into” western

South America. Deep nutrients do not rise, ______________ fish populations.

• La Nina • Winds off the western coast of equatorial South America

strengthen, blowing east to west, pushing surface waters __________.

• Surface waters off of the west coast of equatorial South America _________________ due to increased upwelling. Increased fish populations.

Typical vs. El Nino vs. La Nina• Typical • Normal _____________________ in western South America,

southeastern Asia, eastern Africa, southeastern South America and southeastern U.S.

• Normal rainfall in southern Africa, Australia, eastern South America, northwestern and northeastern Canada and U.S.

• El Nino• ___________ rainfall in western South America,

southeastern Asia, eastern Africa, southeastern South America and southeastern U.S.

• Less rainfall/_________________ in southern Africa, Australia, eastern South America, northwestern and northeastern Canada and U.S.

• La Nina • Decreased rainfall in western South America, southeastern

Asia, eastern Africa, southeastern South America and southeastern U.S. Increased ________________ in the U.S.

• More rainfall in southern Africa, Australia, eastern South America, northwestern and northeastern ________________.

Typical vs. El Nino vs. La Nina• Typical • Normal number of Atlantic and Pacific ______________• _________________ temperatures in eastern Asia,

northwestern Canada and U.S. and northeastern Canada and U.S.

• El Nino• _____________ Atlantic and more Pacific hurricanes• ____________________ temperatures in eastern Asia,

northwestern Canada and U.S. and northeastern Canada and U.S.

• La Nina • “Sometimes” _____________ Atlantic and fewer Pacific

hurricanes• Cooler ___________ temperatures in southeastern and

southwestern U.S. • ____________ winter temperatures in north central

U.S.

Don’t Forget the 5-Question Quick Quiz on Tuesday