Chapter 4: Global Climates and Biomes

Climate

Climate

Average weather conditions for a region over a long period of time.

Weather

Short-term conditions of the atmosphere in a local area. Includes temperature, humidity, clouds, precipitation and wind speed.

Troposphere

Closest layer to the surface 0-16 Km

Stratosphere

Layer above troposphere 16-50 Km

• Amount of solar energy varies by location

Albedo

% of incoming sunlight reflected

• Water 10-60% reflected

• Earths Average 30%

• Clouds 10-90%

• Fresh Snow 80-95%

• Asphalt 5-10%

• Cropland and Forest 10-5%

Things that control Air Movement

• Density (less dense air rises, more dense air sinks)

• Water Vapor (Warm air holds more water, Cooler air holds less)

• Adiabatic Heating/Cooling

• Latent Heat Release

Saturation Point

The maximum water that the air can hold at a given temperature.

Ex. dew (water has to get out of air.)

Adiabatic Heating

Heating effect of reduced pressure on air as it sits and shrinks.

Adiabatic Cooling

Cooling effect of reduced pressure on air as it rises and expands.

Ex. Lake Effect Snow

Latent Heat Release (LHR)

Release of energy when water vapor in the atmosphere condenses into liquid water.

• Causes the air that is lost the liquid gets warmer and rises (Ex. Storm Clouds)

Convection Currents

-Equatorial heating causes air rise at the equator

Has to do with entire global air pattern

Convection Cells

Hadley, Polar, and Ferrell

Hadley Cells

Warm air rises at 0 degrees cools and falls at 30 degrees.

• Extend North or South to 30 degrees latitude

• These cells form at the Intertropical Convergence Zone (ITCZ) where warm moist air rises

• Unequal warming at equator

  • Driven by solar energy at the equator

Polar Cells

Less dense air rises at 60 degrees and falls at 90 degrees

Ferrell Cells

A convection cell controlled by the other 2

Coriolis Effect

Deflection of an objects path due to rotation of Earth

-Don’t see it on a small scale

Ex. Weather Patterns effected by Ball on a merry go round.

Global WInd Patterns

The convection cells and Coriolis Effect give us our global wind patterns.

Rain Shadow

Moist Warm Air comes off of a body of water, rises up mountain ranges and cools and precipitates on windward side. There is little moisture left on leeward side.

Ocean Currents

Driven By:

• Temperature

• Gravity

• Prevailing Winds

• The Coriolis Effect

• Salinity

• Location of Continents

Gravity Movin Ocean

• Warm Water expands and rises just like air

• The equator is warm

• Equatorial Water expands so that it is 3 inches taller than mid-latitude water

  • Gravity pulls water away from the equator

Gyres

Large scale patterns of water circulation. The ocean surface currents rotate in a clockwise direction in the Northern Hemisphere and a counterclockwise direction in the Southern Hemisphere.

Upwelling

Some places, surface waters diverge, colder waters from below rise bringing nutrients from ocean floor with them. Feeds producers and supports large marine ecosystems.

Thermohaline Circulation

Thermo= Heat, Saline=Salt

Oceanic circulation pattern that drives the mixing of surface and deep water evaporates, freezes gets colder and dense, sinks, circulates, at the equator.

El Nino

• Normal year Pacific tradewinds flow east to west. Surface flow East to West. Upwelling off S America.

• El Nino year, Increased surface water temp. in West Pacific Tradewinds West to East, surface current West to East no upwelling

• 3-7 year cycle can be weeks or years in length

• Warm water spans from South America to Australia

• Decreased Thermohaline

  Impacts

  • Dry Australia and Indonesia

  • South America and Southern US cooler and heavy precipitation

    Global Impacts

  • Increased ocean warmth enhances concentration which then alters the jet stream such that it becomes more active over parts of the US during El ninos.

  • Enhanced precipitation across Southern U.S. during winter and temps. are often cooler than normal.

  • Fewer hurricanes develop in Caribbean or Atlantic.

La Nina

• Warm weather pushed further West

• Colder water off coast of South America

  US Impacts

• Reduced precipitation in Southern U.S.

• In U.S. winter temps often watmer than normal in South East and cooler than normal in North West.

• Increase in hurrican production in Carribean and Atlantic.

Biomes

The combination of temp. and precipitation determines what biome can exist.

Tundra

• Cold and Dry

• Permafrost

• No trees, bitter cold winters, and cool summer

• Big coats for cold temps

Boreal Forest, Taiga

• Moderate/Lower rainfall snowy

• Evergreen forests

• Cold Winters/Mild Summers

Temperate Rainforest

• Mild winters, Cooler Summers

• Very Large Trees

• Ocean currents deliver moisture moderate temperature

Temperate Seasonal Forests (Desciduos)

• Warm Summers Cold Winters

• Broad Leaf forests lose leaves in Winter

• Steady rainfall all year

Temperate Grasslands/Cold Desert

• Hot summers and Cold Winters

• Mostly Grass

• Less Rain gives way to desert

Tropical Rainforest

• Warm, Hot and Rainy all year

• Thick canopy, highly diverse

• Equatorial

Tropical Seasonal Forest/Savanna

• Hot monsoon/Rainy season Dry season

  • Grasses where drier, Forrests where wetter

    Ex. Lion King

Subtropical Desert

• Hot and Dry

• Cactus, Sand, Rocks

Freshwater Facts

• 3% of Earth’s water is fresh- 75% of that is frozen

• Our Great Lakes hold 20% of all liquid fresh water

  African Rift Lakes 27% (Victoria, Malawi, Tanganyika)

  Siberia’s Lake Bikal 20%

Rivers and Streams (Creeks and Criks)

• Flow rate and topograph determine kind of life present

• Slow algae and plants

• Fast runoff delivers base of food pyramid

  • Rapids help to mix O2 into the water

Riprarian Zone

Oxygen Mining

Lakes and Ponds

• There is no specific size where a pond becomes a lake

  • Have standing water where at least part is too deep for vegetation to grow.

Littoral Zones

Shallow, Soil, and H20 emergent vegetation and algae most photosynthesis.

Limnetic Zones

No rooted plants, only phytoplankton, goes as deep as sunlight.

Benthic Zone

Muddy bottom of lake, pond, or ocean, goes up on sides as well.

Oligotrophic

Low Productivity (deeper lakes)

Mesotrophic

Middle/Moderate Productivity

Eutrophic

High productivity (shallow lakes)

Freshwater Wetlands

(Wet most of the year)

• Help absorb run off, slowly releases into groudwater or streams

• Wetlands are some of the most productive biomes

• More productive than rivers, lakes and streams

Swamp

Trees growing in the wetland, not so deep

Marshes

Mostly nonwoody plants, often on edge of lake

Bog

Highly acidic, sphagnum moss and spruce, squishy flatness.

Saltwater Biomes

• Salt Marshes

• Mangrove Swamps

• Intertidal Zones

• Coral Reefs

• Open Oceans

Salt Marshes and Mangrove Swamps

One of the most productive biomes in the world. Mostly some frunction as freshwater counterpart.

Intertidal Zone

The vary narrow zone of coastline between high and low tide. Organisms must handle extreme temperature changes, dryness, and direct sunlight.

Coral Reefs

Coral have symbiosis, algae within coral, coral builds giant colonies. Highly diverse.

Coral Bleaching

Algae die, then the corals die, leaving just coral rock. Ocean acidification and higher temp to blame.

Photic Zone

Upper layer of ocean enough light for photosynthesis

Aphotic Zone

Too deep for sunlight

Chemosynthesis

Used by deep ocean bacteria uses methane and hydrogen sulphide to produce energy.

Phelagic Zone

Little stuff swims around