Chapter 13: Global Climate A world with many climates A world with many climates Climatic classification - the Köppen system Climatic classification - the Köppen system The global pattern of climate The global pattern of climate

Global Temperatures controls on temperature climatology: - intensity of sunshine and its variation with latitude - distribution of land and water and ocean currents - prevailing winds - location of high and low pressure areas - mountain barriers and altitude controls on temperature climatology: - intensity of sunshine and its variation with latitude - distribution of land and water and ocean currents - prevailing winds - location of high and low pressure areas - mountain barriers and altitude Q1: Why is the Antarctic in the next slide not so cold? because a) winter and summer average out b) Antarctic is actually not too cold compared to Arctic c) only the equivalent sea-level temperature is shown d) Arctic is simply colder Q2: where is the hottest place on earth? a) subtropical desert; b) equatorial ocean; c) equatorial land; d) midlatitudes

Fig. 13-1, p. 355 Average annual sea-level temperature

Global Precipitation relationship to areas of rising and sinking air relationship to areas of rising and sinking air influence of ITCZ influence of ITCZ influence of orographic uplift and rain shadows influence of orographic uplift and rain shadows Precipitation is most abundant where air rises, and least abundant where it sinks.Precipitation is most abundant where air rises, and least abundant where it sinks. Q3: Why does snow still accumulate over Antarctic when the precipitation there is similar to that in the Sahara Desert? Because a) altitude is high; b) it is cold c) evaporation/sublimation is even smaller than precipitation; d) katabatic wind is too strong Q4: where are the wettest locations on earth? a) windward side of mountains; b) flat plains c) leeward side of mountains; d) valleys

mm/month

Fig. 13-2, p. 356

Climatic Classification - the Köppen System (1918) Tropical moist climates Tropical moist climates dry climates dry climates moist midlatitude climates with mild winters moist midlatitude climates with mild winters moist midlatitude climates with severe winters moist midlatitude climates with severe winters polar climates polar climates mountains mountains criticisms of the Köppen climate classification system: sharp boundary between climatic zones due to the use of vegetation to represent monthly temperature and precipitation. criticisms of the Köppen climate classification system: sharp boundary between climatic zones due to the use of vegetation to represent monthly temperature and precipitation.

Fig. 13-6, p. 361

The Global Pattern of Climate Major features of Earth’s climate distribution (moist tropical, dry, moist/mild winter, moist/severe winter, polar, highland) Major features of Earth’s climate distribution (moist tropical, dry, moist/mild winter, moist/severe winter, polar, highland) local variations within larger climate regions local variations within larger climate regions

Q5: Arizona climate belongs to a) semi-arid or steppe; b) tropical wet and dry c) moist climate with mild and dry winter Q6: Florida climate belongs to a) semi-arid or steppe; b) tropical wet and dry c) humid subtropical with mild winter Q7: Minnesota climate belongs to a) semi-arid or steppe b) humid subtropical with mild winter c) humid continental with severe winter d) moist tropical

Tropical Moist Climates tropical wet (Af): rainforest; small seasonal temperature variation; soil nutrients from dead tree decomposition tropical wet (Af): rainforest; small seasonal temperature variation; soil nutrients from dead tree decomposition tropical monsoon (Am): rainforest, tropical monsoon (Am): rainforest, with 1-2 dry months with 1-2 dry months

Tropical Moist Climates tropical wet and dry (Aw): savanna; distinct dry season; larger seasonal temperature variation tropical wet and dry (Aw): savanna; distinct dry season; larger seasonal temperature variation Q8: Why does max P occur in summer? a) ITCZ is located there in summer b) temperature is higher c) vegetation needs water in summer d) dust storm is less

Tropical Moist Climates tropical wet and dry (Aw): savanna; distinct dry season; larger seasonal temperature variation tropical wet and dry (Aw): savanna; distinct dry season; larger seasonal temperature variation Q9: Why does max T occur in March? a) ITCZ is located there in March b) solar heating is strong with minimal clouds c) dust storm is more frequent

Dry Climates In general, minimal P, large T seasonal variation, high T In general, minimal P, large T seasonal variation, high T arid (BW): most of the deserts in the world; arid (BW): most of the deserts in the world; few deserts are completely barren few deserts are completely barren Q10: What is the age of the cactus with arms in the figure? a) 0-20 yrs, b) yrs, c) yrs, d) > 60 yrs

Dry Climates semiarid (BS) or steppe: most of western U.S. (including Tucson); grass or shrubs semiarid (BS) or steppe: most of western U.S. (including Tucson); grass or shrubs Q11: is it possible to have coastal deserts with clouds and drizzles in the world? a) yes; b) no

Moist Subtropical Mid-Latitude Climates humid with mild winters; relatively large T variation humid subtropical (CfA): SE U.S.; small P seasonal variation humid subtropical (CfA): SE U.S.; small P seasonal variation (west coast) marine (CfB): cool summer (west coast) marine (CfB): cool summer

Moist Subtropical Mid-Latitude Climates Mediterranean (Cs): dry summer; western coast of U.S.; coastal areas of the Mediterranean Sea Mediterranean (Cs): dry summer; western coast of U.S.; coastal areas of the Mediterranean Sea coastal Cs interior Cs Q12: why is summer so dry in San Francisco? a) subtropical high; b) foggy weather, c) cold temperature, d) cloudy sky

Moist Subtropical Mid-Latitude Climates Mediterranean (Cs): Mediterranean (Cs): Vegetation type: chaparral (includes Chamise, manzanita, and foothill pine)

Moist Continental Climates with Severe Winter Hot summer Dfa Cool summer Subpolar Dfb Dfc

Polar Climates Polar Climates ice caps (EF) Tundra (ET)

Highland Climates altitude effects are similar to latitude effects: altitude effects are similar to latitude effects: 100 m elevation difference ~ 1 deg in horizontal distance 100 m elevation difference ~ 1 deg in horizontal distance Across central Sierra Nevada

Q13: Semi-arid regions usually have a) grassland and/or shrubland, b) forest, c) tundra Q14: Mediterranean climate usually has a) shrubland, b) grassland, c) chaparral, d) forest Q15: Humid continental climate with severe winter and cool summer usually has a) boreal forest, b) grassland, c) shrubs Q16: Subpolar or polar climate usually has a) forest, b) tundra