• characterized by seasons (precip & temp fluctuations)
• precip exceeds annual potential evaporation
• most inhabited regions

Mediterranean (Csa)

• remarkable regularity around world (30 - 40 latitude)
• result of subtropical high pressure system
• summer drought (opposite norm)
• months of no rain at all (May to Dec.)
• two subdivisions
  • hot (Csa)
  • mild summers (Csb)
• coastal summers moderated by fog
• cool at night; compare San Francisco to Red Bluff
• westerly winds (jet stream) in winter
• most rain in winter from cyclonic storms
  • 15 to 30 inches
• evaporation rates lower, water retained in ground
• plants adapted to harsh summer droughts
• called sclerophylous (hard-leaved)
  • tough, leathery, shiny, deep roots
  • low scrubby bushes called chaparral

• 40 degrees west coast & 15 to 20 east coast
• roughly same as Med. but on east coast
• humid conditions created by lack of subsidence & warm ocean currents
• sticky from high relative humidity (sensible heat); sultry evenings
• year-round rains (no dry season like Med. climate)
• from 25 to 100 inches of rain yearly (frontal & convection)
• receives maximum precip in summer
• monsoon effect bringing moisture inland in summer
• southeast Asia
• mild winters influenced by warm waters and distance from continental air
• typically lush and tropical feeling with broad-leaf deciduous trees
• long growing season for agriculture and plants
• abundant pine forests (plantations in southern U.S.)
• 2 to 4 times growth than in colder regions such as New England
• limited fertility of soils due to rapid removal of soluble nutrients
• drier regions are great grasslands (Pampas, Argentina)
• intensive agriculture such as rice, tobacco, cotton (limited irrigation)
• feeds much of the world with careful stewardship and soil conservation

• most temperate climate with moderating effect of ocean
• between 45 and 65 (extremely high lat) when influenced by winds
• North Atlantic Drift warms northern Europe (Norway to Arctic)
• ocean influence even stronger than latitude
  • compare Portland, OR with Eau Claire, Wisconsin
  • rains through the summers but cool
• daily temperature ranges are mild, although can swing
• limited to adjacent coastal areas; mtns can block effect
• limited growing season due to frost
• crops like hops, grains, sod, (grapes); ranching
• in winter, dreary and cloudy due to instability & fog
• greatest precip. along coast windward mtns sides
• great temperate rainforest such as in British Columbia
• some snow but melts, esp. in lowlands
• Pacific Northwest, Germany & France, New Zealand

• found in Alaska, eastern Canada & US, Russia, China
• lacking in Southern Hemisphere due to lack of land
• three (3) types based on temp. and severity of winter
  • see below
• longer and colder poleward and toward interiors
• all experience cold winters with freezing & snow cover
• snow reflects heat back to space (albedo factor)
• all precip exceeds potential evaporation
• with exception to Siberia, all have year-round precip
• precip maximum in summer

• limited on Eurasian landmass with greatest agricultural potential
• US from eastern seaboard to midwest
• produces great grain crops with longer growing seasons
• rich glacial & alluvial soils from past ice ages
• land of tall prairie grasses, also adding to soil richness
• distinct four seasons marked by temp changes
• summers in hot zone are often long and produce much rain
• afternoon thunder showers and humidity help grow tall corn
• in winter saturated with frontal storms

• less precipitation, less humid and drier
• winter is dry in regions like eastern Russia (Vladivostok)
• shorter growing season (1 to 3 months shorter)
• more firs, pines and spruce and less oak, hikories, and maple
• more root crops (like potatoes, beets, turnips) and spring wheat
• corn does not have enough time to mature; apples, plums, cherries
• dairy products where soils are thin and cool summers
• wide areas of wilderness, lakes and standing water

• furthest poleward regions with at least 1 mo. above 10 (50 F)
• forest cannot survive without some warmth
• line between Polar and Subarctic clear (no trees)
• severe winters with clear skys from dominant High pressure
• larger areas on Eurasian continent compared to N. America
• in summer can actually get hot from long days and high sun
• largest temperature range of any climate (see climograph)
• limited precip because air hold little moisture (>20in)
• anticyclones (Highs) block lifting and movement of moist, southerly air
• great rolling tracts of single species, stunted growth "taiga" forests
  • also known as boreal forest with patches of open areas
• no agriculture and little permenant occupation

• averages do not rise above 10 (50 F) mark (no warm summer)
• for 9 months below freezing
• trees cannot survive where tundra covers surface
• other areas covered with ice year-round
• above arctic circle all sunlight and no sunlight
• permafrost of soils creates marshy lands "muskeg" in Canada
• lots of insects and large migratory herds (Caribou, reindeer)
• precip is low, yet mass amount of snow with no thaws

• like moving poleward in latitude (Sierra Nevada example)
• create variations in climate zones, even Tropical regions
• become enclaves of heat relief, yet exposed by sun & wind
• become biotic island with coolness and moisture
• home to remnants like Sequoia, bristle cone pine, birds in desert
• at roughly 10,000 feet reach tree line
• areas of precip for drier regions (Med. & deserts) with orographic precip
• in S. America serve as zones of agriculture and habitation (see figure)
• last preserves for wildlife and pristine habitat