bio 126 climate and weather
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Bio 126 Climate and Weather. Earth from the moon. Meteorology. Climate- over all combination of temperature and precipitation that a region experiences Mediterranean= winter precipitation followed by long hot, dry summers Weather- daily, weekly variations in these phenomena. - PowerPoint PPT PresentationTRANSCRIPT
Bio 126Bio 126Climate and WeatherClimate and Weather
Earth from the moonEarth from the moon
MeteorologyMeteorology
Climate- over all combination of temperature and precipitation that a region experiences– Mediterranean= winter precipitation
followed by long hot, dry summers Weather- daily, weekly variations in
these phenomena
Solar radiationSolar radiation
Climate zonesClimate zones
Warm at equator, cooler towards poles.– Caused by intensity of sunlight at
equator.– Poles receive less on a per area basis.
Solar radiation around the Globe
Solar radiation around the Globe
SeasonsSeasons
Caused by tilting of earth on its rotational axis.– Intensity of sunlight varies.– Most extreme at poles– Little change at equator.
Causes of SeasonsCauses of Seasons
PrecipitationPrecipitation
Varies by latitude.Wet at equator 00, and 600 N / SDry at 300, and 900 poles
– Poles are frozen desertsCaused by formation of Hadley Cells
Hadley CellsHadley Cells
Air currents in Hadley Cells caused by air density not just temperature.
Uneven heating in different regions on the earth cause winds.
Hadley CellsHadley Cells
Air rises (0, 60) due to warming of surface.
– Adiabatic Cooling as air rises as rises the air becomes less dense and cooler this cause water to condense and fall as rain, snow
Air falls (30, poles) – Adiabatic warming as air falls
air becomes compressed, and heats. air absorbs moisture, falls as dry air and absorbs
moisture from the environment.
Global air circulation, precipitation, and winds: Hadley cellsGlobal air circulation, precipitation, and winds: Hadley cells
Global Air CirculationGlobal Air Circulation
West Coast LatitudesWest Coast Latitudes
San Diego=32.5; LA= 34; Sta. Barbara= 34.5 ; Sta. Cruz=37, SF 37.75; Eureka= 40.75
Approx. Portland= 45.5; Seattle= 47.5 ; Juneau= 58; Anchorage = 61
CA large enough to span climate zones between Hadley cells.
– South dry– North wet
Seasons- Seasons-
tilting of earth moves solar equator. Effectively moves 300 dry zone
north in summer– descending dry air belt is pushed
farther north in our summer, the wet belt moves farther south
giving us wet winters
Causes of SeasonsCauses of Seasons
Prevailing windsPrevailing winds
These Hadley cell wind currents move North or South
The spinning of the earth makes it seem like they come at an angle.– In CA our winds, storms usually come
from the south west.– Rains often bring warmer weather
Ocean currentsOcean currents Prevailing winds cause ocean waters to
move in the prevailing direction. huge gyres form due to earth’s spinning
known as the Coriolus effect – In Northern Pacific clockwise general
direction of flow from our coast.– Ca. Current, with its cold, nutrient rich water
flows from Alaska southwards along our coast
– At Sta. Barbara coastline moves east, current flows due south, allowing Southern Ca. water to warm
Hadley cellsHadley cells
Barometer measures air Barometer measures air pressure pressure
Low pressure (rising air) associated with storms.
High pressure (descending air) blocks storms.
– High pressure off California in summer blocks most storms
Global Trade Wind PatternsGlobal Trade Wind Patterns
Ocean CurrentsOcean Currents
BiomesBiomes
Major vegetation types that also determine the animal community present.
Determined mostly by climate – Soil also important factor
Figure 50.3 A climograph for some major kinds of ecosystems (biomes) in Figure 50.3 A climograph for some major kinds of ecosystems (biomes) in North AmericaNorth America
BiomesBiomes
Patterns of distribution in the biospherePatterns of distribution in the biosphere
Major BiomesMajor Biomes
Coniferous forest, Lady Bird Grove (top left), Sequoias (right), rain forest Coniferous forest, Lady Bird Grove (top left), Sequoias (right), rain forest (bottom left)(bottom left)
Temperate deciduous forest, Great Smokey Mountains National ParkTemperate deciduous forest, Great Smokey Mountains National Park
Tropical forestsTropical forests
SavannaSavanna
Desert. Organ Pipe State Park (top), Joshua Tree National Park (bottom left), Death Desert. Organ Pipe State Park (top), Joshua Tree National Park (bottom left), Death Valley (bottom right)Valley (bottom right)
Temperate grassland- PrairieTemperate grassland- Prairie
Tundra. Denali National Park (left), reindeer (right)Tundra. Denali National Park (left), reindeer (right)
Rain shadow Rain shadow Precipitation increases as storms
are pushed up over mountians.– accordingly rain becomes snow
– As air moves up slope in the Sierras it cools 3-5 degrees per 1,000 ft.
This is the same effect as moving 300 miles farther north !
Causes deserts in Nevada
Most islands with mountains have wet and dry sides
RainshadowRainshadow
RainshadowRainshadow
Summer Fog Summer Fog
– Inland air warms quickly. This rising air, pulls in coastal air.
– Cold water off CA. cools incoming warm, moist ocean
– Coast causes summer fog. Essential for southern ranges of
Coast Redwoods, and relic pines, cypress species
Temperature Inversion layersTemperature Inversion layers
dense air flows downhill and collects in low spots, valleys. Great Central valley is an example.
– This dense air may be blocked by hills etc. from warmer winds which blow over the top of dense air, leaving it alone.
– Dense tule fog may form for days. Inversion layer (cold air higher up) also traps
pollutants. Mexico City problems Reno, Tahoe now ban fireplaces.
Often “burn off” in summer but leave the haze of phytochemical smog behind.