C HAPTER 6 T HE P HYSICAL E NVIRONMENT

O VERVIEW OF C HAPTER 6 Biogeochemical Cycles Solar Radiation The Atmosphere The Global Ocean Weather and Climate Internal Planetary Processes

B IOGEOCHEMICAL C YCLES Matter moves between ecosystems, biotic & abiotic environments, and organisms Unlike energy Biogeochemical cycling involves Biological, geologic and chemical interactions Five major cycles: Carbon, Nitrogen, Phosphorus, Sulfur and Water (hydrologic)

T HE C ARBON C YCLE

T HE N ITROGEN C YCLE

T HE P HOSPHORUS C YCLE

T HE S ULFUR C YCLE

T HE W ATER (H YDROLOGIC ) C YCLE

EARTH SYSTEMS AND RESOURCES

S OLAR R ADIATION 69% of incoming solar radiation is absorbed by atmosphere and earth Remainder is reflected Albedo The reflectance of solar energy off earth’s surface Dark colors = low albedo (more sunlight absorbed) Forests and ocean Light colors = high albedo Ice caps o Sun provides energy for life, powers biogeochemical cycles, and determines climate snow-temperature feedback example

T EMPERATURE C HANGES WITH L ATITUDE Solar energy does not hit earth uniformly Due to earth’s spherical shape and tilt Equator (a) High concentration Little Reflection High Temperature Closer to Poles (c) Low concentration Higher Reflection Low Temperature From (a) to (c) In diagram below

T EMPERATURE C HANGES WITH S EASON Seasons determined by earth’s tilt (23.5°) Causes each hemisphere to tilt toward the sun for half the year o Northern Hemisphere tilts towards the sun from March 21- September 22 (warm season)

C HECK FOR UNDERSTANDING 4 - I can explain how solar radiation impacts earth to my peers 3 - I understand how solar radiation impacts earth 2 - I understand that solar radiation impacts earth, but I don’t really get how it happens. 1 - I am lost about solar radiation

T HE A TMOSPHERE Invisible layer of gases around earth Content 21% Oxygen 78% Nitrogen 1% Argon, Carbon dioxide, Neon and Helium (+ pollutants like methane, ozone, dust, CFCs) Density decreases with distance from earth Shields earth from high energy radiation

A TMOSPHERIC L AYERS Troposphere (0-10km) Weather occurs Temperature decreases with altitude Stratosphere (10-45km) Ozone layer absorbs UV Mesosphere (45-80km)

A TMOSPHERIC L AYERS Thermosphere (80-500km) Gases in thin air absorb x-rays and short-wave UV radiation = very hot Source of aurora Exosphere (500km and up) Outermost layer Atmosphere continues to thin until converges with interplanetary space

O ZONE (O 3 ) Bad Formed by UV light reacting with nitrogen oxide – from burned fossil fuels Irritates respiratory problems, slows photosynthesis and plant growth Good Shields UV rays Destroyed by chlorine compounds; CFCs (chlorofluorocarbons) in refrigerants, aerosol sprays, making of Styrofoam. Tropospheric ozone Stratospheric ozone

A TMOSPHERIC C IRCULATION – DISTRIBUTES THERMAL ENERGY Near Equator Warm air rises, cools and splits to flow towards the poles ( convection ) ~30°N&S sinks back to surface Air moves along surface back towards equator Hadley Cell This occurs at higher latitudes as well Moves heat from equator to the poles

S URFACE W INDS Atmospheric gases exert pressure; changes with temperature, altitude, humidity Winds blow from high to low pressure ; greater difference creates stronger wind Right side of diagram Low Low Low High High High High

C ORIOLIS E FFECT Earth’s rotation influences direction of wind Earth rotates West to East Deflects wind from straight-line path Coriolis Effect Influence of the earth’s rotation on movement of air and fluids Turns wind Right in the Northern Hemisphere Turns wind Left in the Southern Hemisphere

C ORIOLIS E FFECT Visualize it as a Merry-Go-Round (see below)

C HECK FOR UNDERSTANDING 4 - I can explain how atmospheric conditions impact earth to my peers 3 - I understand how atmospheric conditions impact earth 2 - I understand that, atmospheric conditions impact earth but I don’t really get how it happens. 1 - I am lost atmospheric conditions

G LOBAL O CEAN C IRCULATION Prevailing winds produce surface ocean currents and generate gyres Example: the North Atlantic Ocean Trade winds blow west Westerlies blow east Creates a clockwise gyre in the North Atlantic Circular pattern influenced by coriolis effect and land masses

G LOBAL O CEAN C IRCULATION Trade winds Westerlies

P OSITION OF L ANDMASSES Very little land in the Southern Hemisphere Large landmasses in the Northern Hemisphere help to dictate ocean currents and flow

V ERTICAL M IXING OF O CEAN ( OCEAN CONVEYOR BELT )

O CEAN I NTERACTION WITH A TMOSPHERE - ENSO El Niño-Southern Oscillation (ENSO) Def: periodic large scale warming of surface waters of tropical eastern Pacific Ocean Normal conditions- westward blowing tradewinds keep warmest water in western Pacific ENSO conditions- trade winds weaken and warm water moves eastward to South America Big effect on fishing industry off S. America – prevents upwelling of cold (nutrient-rich) water Causes abnormal weather: cooler/wetter  Southeast US; dry  Southern Africa/Southeast Asia

ENSO C LIMATE P ATTERNS Normal trade winds vs trade winds with El Nino

C HECK FOR UNDERSTANDING 4 - I can explain how the atmosphere interacts with the ocean (including El Nino) to my peers 3 - I understand how the atmosphere interacts with the ocean (including El Nino) 2 - I understand how wind influences currents, but I don’t really get El Nino or just need more practice. 1 - I am lost. What’s my name?

W EATHER AND C LIMATE Weather The conditions in the atmosphere at a given place and time Temperature, precipitation, cloudiness, wind, etc. Climate The average weather conditions that occur in a place over a period of years 2 most important factors: temperature and precipitation Other factors: albedo, angle of sunlight, altitude, distance to oceans, mountain ranges, pollution Earth has many climates climagraph

R AIN S HADOWS Mountains force humid air to rise Air cools with altitude, clouds form and precipitation occurs (windward side) Dry air mass moves down opposite leeward side of mountain

T ORNADOES Powerful funnel of air associated with a severe thunderstorm Formation Mass of cool dry air collides with warm humid air Produces a strong updraft of spinning air under a cloud Spinning funnel becomes tornado when it descends from cloud Wind velocity= up to 480 km per hour Width ranges from 1m to 3.2km

T ROPICAL C YCLONE / HURRICANE Giant rotating tropical storms, where trade winds merge Wind >119km per hour Formation Strong winds pick up moisture over warm surface waters Starts to spin due to Earth’s rotation (coriolis effect) Spin causes upward spiral of clouds Damaging on land High winds Storm surges

C HECK FOR UNDERSTANDING 4 - I can explain various weather patterns (rain shadow, tornadoes, hurricanes) to my peers 3 - I understand weather patterns 2 - I understand weather patterns, but I just need more practice. 1 - I don’t know the difference between weather and climate.

I NTERNAL P LANETARY P ROCESSES Layers of the earth Lithosphere Outermost rigid rock layer composed of plates; major element (crust) = oxygen Asthenosphere Lower mantle comprised of hot soft rock Core : solid, mainly nickel, some iron (dense) Plate Tectonics- lithospheric plates move over the asthenosphere Plate Boundary- where 2 plates meet Common site of earthquakes and volcanoes

P LATES AND P LATE B OUNDARIES

T YPES OF P LATE B OUNDARIES Divergent Plate Boundary-2 plates move apart = mid-oceanic ridges

Convergent Plate Boundary- 2 plates move together 2 continental plates = mountains (ex: himalayas); 1 ocean/1 continental (subduction)= volcano/earthquakes

Mount St. Helens, Washington on May 18, 1980

MAJOR VOLCANIC AIR POLLUTANT: SULFUR plus lots of CO2

May 17, 1980 August 13, 2005

T YPES OF P LATE B OUNDARIES Transform Plate Boundary- 2 plates move horizontally in opposite, parallel directions Get stuck, pressure builds, breaks apart = earthquake Ex: San Andreas Fault

E ARTHQUAKES Caused by the release of accumulated energy as rocks in the lithosphere suddenly shift or break Occur along faults Energy released as seismic wave Focus - the site where the earthquake originates below the surface Epicenter - located on the earth’s surface, directly above the focus Richter scale and the moment magnitude scales are used to measure the magnitude; size 8 is 10x greater than a 7 in shaking amplitude/ 31.6 times greater in energy release

T SUNAMI Giant undersea wave caused by an earthquake, volcanic eruption or landslide Travel > 450mph Not all ocean earthquakes create tsunamis Importance of mangroves vs. human development Tsunami wave may be 1m deep in ocean Becomes 30.5m high on shore Magnitude 9.3 earthquake in Indian Ocean (9.0 caused Japanese tsunami) Triggered tsunami that killed over 230,000 people in South Asia and Africa

C HECK FOR UNDERSTANDING 4 - I can explain tectonic plate movement and they create earthquakes and tsunamis to my peers 3 - I understand tectonic plate movement and how they create earthquakes and tsunamis 2 - I understand plate tectonic movement, earthquakes and tsunamis, but I just need more practice. 1 - Plate tectonics??????