Koppen System Climates (A B C D E)
Csa, Csb: Mediterranean
- Central to Southern CA (RILEY WAS BORN IN THIS CLIMATE) -Characteristics: * Dry summers & wet winters with annual precipitation between 40 & 80 cm (16 - 32 in). -Mechanisms: * Dominated by frontal activity in winter as a result of the interaction between mP and mT air masses. * Dominated by the stable eastern side of an oceanic STH cell in summer. This weakens in winter and allows the frontal systems to move in from off the adjacent ocean. - Cs climate areas are also influenced by cold water currents in the adjacent oceans.
Cw: Subtropical Monsoon (Subtropical Winter Dry)
- NE India, South-Central Africa -Characteristics: essentially the same as A climate, but cooler Tºs than A * very wet summers, with dry winters -Mechanisms: seasonal reversal in direction of winds set-up by changing pressure patterns; general pattern of wind changes 180 degrees * shifting ITCZ in summer; STH influence in winter
B: Areas where the Potential Evaporation > Precipitation
- the only climates based on precipitation **Potential Evapotranspiration (PE) is the amount of moisture that, if it were available, would evaporate from a given area.**
Dfc, Dfd, Dwc, Dwd: Subarctic
- western Alaska across Canada to Newfoundland - Characteristics: long, cold winters; short, warm summers * Exhibit the greatest annual T° ranges (Siberia up to 145°F). - Mechanisms: high latitudes = little solar radiation = low T°s
How to Determine Arid from Semi-Arid Area
-Arid locations (desert) receive <10 inches of precipitation per year. -Semi-Arid locations (steppe) receive 10-20 inches of precipitation per year.
Am: Tropical Monsoon
-Develops a large Sea/Land Breeze with very wet summers, and dry winters. -Mechanisms: There is a seasonal shift in the location of the ITCZ and STH between summer & winter. The ITCZ is the primary mover in this event.
Aw: Tropical Savannah
-In the U.S., only the southern tip of Florida has this climate. -Characteristics: These areas have a distinct wet/dry season, with a winter dry season & a summer wet season. -Mechanisms: The shifting of the ITCZ (low pressure belt) north & south with the seasons. * Summer: ITCZ is in the region & brings rain (wet season) * Winter: ITCZ moves out (dry season)
EF: Ice Cap
-Location: Confined to the ice caps of Greenland & Antarctica. -Characteristics: Avg T° of warmest month < 0°C. - -Mechanisms: * high latitudes = low solar radiation input * Permanent ice = low T°s = perm. ice = low T°s = ... (An example of a negative feedback mechanism.)
Dfa, Dfb, Dwa, Dwb: Humid Continental
-Location: ~ 40° to 55° N; Midwest U.S. to east coast -Characteristics: COLD winters, warm summers; * large annual T° variations; cP air dominates -Mechanisms: Far northern latitudes = relatively low amounts of solar radiation & thus little energy (heat). * Continentality * dominated by the Polar Front
Cfb, Cfc: Marine West Coast
-Northern CA to Alaskan Panhandle -Characteristics: Precipitation all year round, often with winter maximum, but no real distinct dry season. * These areas exhibit relatively mild winters with cool summers. -Mechanisms: High precipitation from orographic effects especially in NA.
Cfa: Humid Subtropical
-U.S. Gulf Coast thru SE U.S. up to Washington, D.C. -Characteristics: * Relatively mild winters with hot, humid summers. * Winter precipitation is primarily the result of passing mid-latitude wave cyclones. * Summer precipitation is the result of a combination of passing wave cyclones & afternoon convective thunderstorms. * Hurricanes are most numerous in this climate region but these areas are also highly prone to tornadoes. -Mechanisms: * Dominated by mT & cP air masses. * unstable air associated with western side of STH in summer
ET: Tundra
-north coast of Alaska, & Canada; coastal Greenland -Characteristics: * Average T° warmest month > 0°C & < 10°C. * Severe winters & cool summers, with low precipitation. - Mechanisms: * Dominance by stable air & Polar High Pressure cell. * Cold air cannot hold much moisture = low precipitation.
Af: Tropical Rainforest
e.g. Hawaii Mechanisms: The ITCZ (low pressure belt) is present all year with extensive heating all year.
D: Humid continental & Subarctic climates
* Average Tº of coldest month is <= -3ºC (26ºF) & avg. T of warmest month is > 10ºC (50ºF). NONE IN THE SOUTHERN HEMISPHERE Types:Dfa, Dfb Humid Continental Dwa, Dwb Humid Continental (onlyAsia) Dfc, Dfd Subarctic Dwc, Dwd Subarctic (only in Asia)
E: Polar Climates
* Little solar radiation so very low T°s, BUT large T° variation. Types: ET: Tundra EF: Ice Cap
C: Humid Mid-Latitude Climates
* Locations with an average T° of the coldest month <18°C (64°F) & > -3°C (26°F). Types: Cw: Subtropical Monsoon Cfa: Humid Subtropical Cfb, Cfc: Marine West Coast Csa, Csb: Mediterranean
A: Tropical Humid Climates
* Those locations which have an average Tº > 18ºC for each month Af: Tropical Rainforest Aw: Tropical Savanna or Tropical Wet & Dry Am: Tropical Monsoon
BWh & BSh: Tropical Desert & Tropical Steppe
BWh: North America: northern Mexico, southwestern U.S. BSh: North America: on the fringes of the deserts named above,central Mexico -Mechanisms: Dominated by STH cells most or all of the year.
BWk & BSk: Mid-latitude Desert & Steppe
BWk: North America: Great Basin area (Nevada) BSk: North America: Great Plains in central U.S. & Canada Characteristics: Hot summers, BUT cool to cold winters. -Mechanisms: * Rainshadow Effect: Great Basin & Great Plains, Patagonia, Eurasian Steppe, Taklamakan * Remoteness from water sources (continentality): Gobi desert, Eurasian Steppe, Great Plains
