2Day 1 Climate Classifications (Intro) We have previously discussed general meteorology principles and ocean circulations now we will start to focus on general patterns of climateThe first test will follow this material, then we will look at regional climates all over the globe
3Day 1 Koeppen Climate System Wladimir Koeppen (Köppen) ( ), Russian-born, German meteorologistDeveloped a climate system in 1900 dealing with vegetation then revised in 1918 based on temperature and precipitationMost widely used climate classification done, modified by many most notably by Glen Trewartha of University of Wisconsin
5Day 1 Major Classification Divisions 5 basic climate categories (A) Tropical moist climatesTropical moist climates extend northward and southward from the equator to about 15 to 25 degrees of latitude. In these climates all months have average temperatures greater than 18 degrees Celsius. Annual precipitation is greater than 1500 mm.Three further subdivisions of (A)
6Day 1 Subdivisions of (A) Af or tropical wet precipitation occurs all year long.Monthly temperature variations less than 3 degrees Celsius. Daily highs ~32 degrees Celsius while lows ~22 degrees Celsius. .cumulus and cumulonimbus clouds form early in the afternoons.
7Day 1 Am is a tropical monsoon climate. Annual rainfall is equal to or greater than Af, but falls in the 7 to 9 hottest months. During the dry season very little rainfall occurs.The tropical wet and dry or savanna (Aw)has an extended dry season during winter. Precipitation during the wet season is usually less than 1000 millimeters. and only during the summer season.
8Day 1Dry Climates (B)The most obvious climatic feature of these climate is potential evaporation and transpiration exceed precipitation. These climates extend from degrees North and South of the equator and in large continental regions of the mid-latitudes often surrounded by mountains.2 minor subdivisions
9Day 1 Subdivisions of (B) BW - dry arid (desert) is a true desert climate. It covers 12 % of the earth's land surface and is dominated by xerophytic (cacti) vegetation.k mid-latitude desert, arid, coolh tropical desert, arid, hot
10Day 1BS - dry semiarid (steppe). Grassland climate that covers 14% of the earth's land surface. It receives more precipitation than the Bw either from the intertropical convergence zone (ITCZ) or from mid-latitude cyclones.h, hotK, cool or cold
11Day 2 Moist Subtropical Mid-Latitude Climates (C) This climate generally has warm and humid summers with mild winters. Its extent is from 30 to 50 degrees of latitude mainly on the eastern and western borders of most continents. During the winter the main weather feature is the mid-latitude cyclone. Convective thunderstorms dominate summer months.3 major subdivisions, other subdivisions
12Day 2 3 Major Subdivisions Cf: Humid Subtropical Cs: Mediterranean Cw: Monsoon RegionsFurther Classify them by precipitation amount and temperature patterns
13Day 27 SubdivisionsCfa: Humid Subtropical, mild winter, moist in all seasons, long hot summer, Found on the Southeastern side of continents primarily between degreesCfb: Marine. Mild winter, moist all seasons, warm summer.The west coast of U.S. from N. California Southern Chile (narrow band because of mountains).NW Europe - extends far inland because of lack of North-South trending mountains.Cfc: Marine. Mild winter, moist all seasons, cool short summer.Northern EuropeWestern N.A. coast in Alaska
14Day 2 7 subdivisions (cont.) Csa: Interior Mediterranean, mild winter, dry summer, hot summerCsb: Coastal Mediterranean, mild winter, dry summer, short warm summerCwa: Subtropical monsoon, mild and dry winter, hot summerCwb: Tropical Upland. Mild and dry winter, short warm summer
15Day 2 Moist Continental Mid-latitude Climates (D) Moist continental mid-latitude climates have warm to cool summers and cold winters. The location of these climates is poleward of the C climates. The warmest month is greater than 10 degrees Celsius, while the coldest month is less than -30 degrees Celsius. Winters are severe with snowstorms, strong winds, bitter cold from Continental Polar or Arctic air masses.
16Day 2Like the C climates there are 2 Major Subdivisions: Dw - dry winters; Df - wet all seasons.Additional SubdivisionsMoist all seasonsDfa: Humid continental, severe winter, long, hot summer, North Central US
17Day 2Dfb: Humid continental, severe winter, short warm summers, Southern Canada, European RussiaDfc: Subarctic, severe winter, short cool summer, Northern Canada, RussiaDfd: Subarctic, extremely cold winter, short summer, exterior Siberia
18Day 2 Additional Subdivisions (cont.) Dry winters Dwa: humid continental, severe winter, long hot summer,Korea, Northern ChinaDwb: humid continental, severe winter, warm summer, Eastern RussiaDwc: Subarctic, severe winter, short cool summer, NE RussiaDwd: Subarctic, extremely cold, short cool summer, interior Siberia
19Day 2Polar Climates (E)Polar climates have year-round cold temperatures with warmest month less than 10 degrees Celsius. Polar climates are found on the northern coastal areas of North America and Europe, Asia and on the landmasses of Greenland and Antarctica. Two minor climate types exist.
20Day 2ET or polar tundra is a climate where the soil is permanently frozen to depths of hundreds of meters, a condition known as permafrost. Vegetation is dominated by mosses, lichens, dwarf trees and scattered woody shrubs.EF or polar ice caps has a surface that is permanently covered with snow and ice.
21Day 2Highlands (H)Additional climate classification to deal with the higher elevations generally greater than 1500 m. Most of Tibet is covered in this classification and there are many subdivisions due to the variations of the mountainous terrain.
22Day 2SummaryHandouts explain the temperature and moisture characteristics defining the major subdivisionsThis is a general view of the climates of the world, after the first test we will start taking apart the continents one by one and further dividing up the world as we see necessary
23Day 3 SE Asia and the Monsoon This region is the largest in the world with rainfall over 100 inches in a year (windward mountains over 150 inches, rain shadows still get near 40 inches)Highest precip during the retreating phase of the SW Indian Monsoon (autumn)
24Day 3 Components of the SE Asia Monsoon Australia High Cross-equatorial jetSW Monsoon
37We Are All EarthlingsWe are all earthlings We are all earthlings Spinning around together On a planet of the sun Floating down a river Swinging through the trees Climbing up a mountain Going with the breeze All of us can have a happy healthy place to be If we can float and swim and climb in earthling harmony We are all earthlings We are all earthlings Spinning around together On a planet of the sun Spinning around together On a planet of the sun
38Day 4 Climate Change and modelling Define Climate Change and then review 5 components of climate systemEarly in the year we discussed 5 components of the climate system. Now let us examine how the modeller looks at the problem: (draw)
39Day 4Then discuss new drawing Do internal forcing and give examples positive feed backs ice albedo / global warming / generic Negative feedback clouds / temps and generic exampleThen do external forcing and give examples. Key to climate change is balance of energy at the boundaries
40Day 4Concept of change in climate variable = sum of sources and sinks.
41Day 4 Climate change: five important questions: 1 Climate change on time scales (go over 3 ways to infer past climate, obs, historical, and proxy), then go over climate since 200 BC and 20 KYA)
42Day 4 2. Climate change regionally: CO2 warming 3. Climate change driven by External or internal?
43Day 4 4. Fast response versus slow response? Can we identify? 5. Model improvement?