The Atmosphere-history 3.2 billion years ago (bya) atmosphere mostly __________ and ________ (Life begins in sea) bya photosynthetic bacteria (cyanobacteria) began producing __________ mya ______________ levels in stratosphere sufficient to protect land plants from UV radiation.

The Atmosphere-current composition _______ % N 2 21 % _______ Around 1% Ar % _______ CO 2

The Atmosphere-current composition The __________________________________ - Natural warming effect of the troposphere 1. sunlight hits the Earth’s surface turning into infrared (heat) radiation 2. heat rises  some escapes into space  some heats greenhouse gases emitting infrared radiation which warm the troposphere +

The Atmosphere-current composition Major greenhouse gases: -________________________________ (primary) -CO 2 -O 3 (ozone) -_______________________ (methane) -N 2 O (nitrous oxide) -CFCs (chlorofluorocarbons)

The Atmosphere-current composition Mean global temperature o C or o F ( ) 14.0 o C or 57.2 o F ( ) (Source o C or 0 o F 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 ___ o F 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

Normally troposphere gets _______________ with altitude Temperature _______________________--a layer or warmer air above cooler surface air

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: mm of Hg in. of Hg psi 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

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: 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