Global ClimatesGlobal Climates

►Weather:Weather: short-term condition of the short-term condition of the atmosphereatmosphere

►ClimateClimate: long-term conditions of the : long-term conditions of the atmosphere, including averages and atmosphere, including averages and extremesextremes

►3 general climate types:3 general climate types:

1. Low latitude1. Low latitude

2. Mid-latitude2. Mid-latitude

3. High latitude3. High latitude

3 general climate groups3 general climate groups

1. Low latitude1. Low latitude

►High temperaturesHigh temperatures Consistently long days, high solar angleConsistently long days, high solar angle

Low latitudes (20°N – 20°S)Low latitudes (20°N – 20°S)

ITCZITCZ

1. Wet equatorial1. Wet equatorial

Wet, HotWet, Hot►High ppt all months; High ppt all months;

little temperature little temperature variationvariation

ITCZ dominatesITCZ dominates

Tropical Rain forest Tropical Rain forest vegetationvegetation

2. Monsoon and trade-wind 2. Monsoon and trade-wind coastalcoastal

►North and south of wet equatorialNorth and south of wet equatorial

►Windward coasts in tropicsWindward coasts in tropics

►Wet and dry seasonsWet and dry seasons►1-3 months < 2.5 inches rain1-3 months < 2.5 inches rain►WetWet when ITCZ dominates when ITCZ dominates►DryDry when ITCZ leaves; High pressure when ITCZ leaves; High pressure

3. Wet-Dry Tropical3. Wet-Dry Tropical

►surrounds 1, 2 on mapsurrounds 1, 2 on map

►3-6 months < 2.5 inches3-6 months < 2.5 inches

►hot dry winter; hot wet summerhot dry winter; hot wet summer

►semiarid to aridsemiarid to arid

4. Dry Tropical4. Dry Tropical

►Low ppt.; high daily range in Low ppt.; high daily range in temperaturetemperature

3 general climate groups3 general climate groups

2. Mid-latitude Climates (Table 7.4)2. Mid-latitude Climates (Table 7.4) Range from dry to moistRange from dry to moist

Mild wintersMild winters

MidlatitudesMidlatitudes►Most in Northern hemisphereMost in Northern hemisphere

►SeasonalitySeasonality►Shifting air masses (mT,mP,cP); High and Low pressure Shifting air masses (mT,mP,cP); High and Low pressure

centerscenters

1. Dry subtropical1. Dry subtropical

►Cool/cold seasonCool/cold season►Low ppt all monthsLow ppt all months►Dominated by cTDominated by cT

2. Moist Subtropical2. Moist Subtropical

►Winters above Winters above freezingfreezing

►High temp rangeHigh temp range

► Abundant rain from Abundant rain from mTmT

3. Mediterranean3. Mediterranean

► hot / warm summerhot / warm summer

►west side of west side of continentscontinents

►Wet, mild winterWet, mild winter

► dry summerdry summer

4. Marine west-coast4. Marine west-coast

► Poleward of Mediterranean climate zonePoleward of Mediterranean climate zone

► precipitation all months; winter max (mP)precipitation all months; winter max (mP)

► small temp. range (moderated by proximity small temp. range (moderated by proximity to ocean)to ocean)

► humidhumid

5. Dry midlatitude5. Dry midlatitude

►Very large range in tempVery large range in temp

►Low ppt with Summer max Low ppt with Summer max

6. Moist continental6. Moist continental

►Warm summers, cold winters Warm summers, cold winters (3 mos. < freezing)(3 mos. < freezing)

►Large temp. range (continental)Large temp. range (continental)

►Plenty of ppt (summer max)Plenty of ppt (summer max)

►Polar front zone (cP and mT)Polar front zone (cP and mT)

3 general climate groups3 general climate groups

3. High-latitude Climates (Table 7.5)3. High-latitude Climates (Table 7.5)

• northern hemisphere (except for ice northern hemisphere (except for ice sheet)sheet)

• frequent midlatitude cyclonesfrequent midlatitude cyclones• low temps and low ppt.low temps and low ppt.

1. Boreal Forest Climate1. Boreal Forest Climate

►Cool, short summerCool, short summer

►Long, severely cold wintersLong, severely cold winters►6-7 mos. < 326-7 mos. < 32ooFF

►high annual temp. rangehigh annual temp. range

►drydry

2. Tundra2. Tundra

►predominantly N. Hemispherepredominantly N. Hemisphere► long periods of light and darklong periods of light and dark►short summer (<40short summer (<40ooF)F)►drydry►treelesstreeless

3. Ice Sheet3. Ice Sheet

►Poleward of 32Poleward of 32oo F isotherm F isotherm►every month < 32every month < 32oo F F

►glacial iceglacial ice

►extremely dryextremely dry