THE GLOBAL CLIMATE

WEATHER

CLIMATE

The condition of atmosphere at any particular time and place. It’s always changing

The synthesis of weather, the average weather of a region over a period of time

Precipitation, June 28 2010

Annual average precipitation

CLIMATE AND WEATHER IN MONGOLIA

Temp January(synthesis of 30 January: 1971-2000)

Temp Jan 2010(synthesis of weather of 30 days)

Weather

CLIMATE AND WEATHER IN CHINA

HEAVY RAINS IN SOUTHERN CHINA

•Rains from May 31st – June 2nd (> 230 mm)•June 13th -21st more rainfall (~ 1000 mm)•Landslides and floods•More than 200 deaths, thousands of homes destroyed

Precipitation June(synthesis of 30 Junes: 1971-2000)

Prec June 2010(weather of ~10 days)

948 mm ~430% above normal

June 2010: >1230 mmJune 1971-2000: 282 mm

Anomaly:

CLIMATE VARIABILITY

CLIMATE AND WEATHER IN ARKANSAS (US)

HEAVY RAINFALL IN SOUTHWEST ARKANSAS

•June 11, several inches of rainfall (~178 mm in one day)•Deadliest weather-related event in Arkansas since a tornado in 1997•River level rose as 2.4m an hour after heavy rains

Precipitation June(synthesis of 40 Junes: 1961-2000)

Prec June 11 (weather of 1 day)

above normalAnomaly:

CLIMATE VARIABILITY

CLIMATE IN THE PERUVIAN ANDES

1982-83 drought

1984 flood

Interanual variability of climate

Climatologies (Averages 1950-2000)

TEMPERATURE REGIMES

Based on:• Latitude•Landmass (continental, maritime)

1. EQUATORIAL: Uniform, very warm, no seasons (uniform insolation)

2. TROPICAL COAST Weak annual cycle(moderating effect of maritime location)3. MIDLATITUDE WEST COAST

5. MIDLATITUDE CONTINENTAL

6. SUBARTIC CONTINENTAL

4. TROPICAL CONTINENTALStrong annual temperature cycle

Strong annual temperature cycle, severe cold all year

7. ICE SHEET

GLOBAL PRECIPITATION

REGION RAINFALL FACTORS

Wet Equatorial Belt Heavy (more than 80 in.)

Warm temp and high moisture of mE air masses

Amazon Basin, Congo River, African Coast, Indonesia

Trade-Wind coast High (60-80in.) Trade winds bring moist mT air masses from warm oceans

Tropical deserts Very low (less than 10 in.)

Large stationary cells of high pressure; air mass is adiabatically warmed and dried

Mid latitude deserts and steppes

Very low (less than 4in.)

Rain shadows of coastal mountains North America, South America

Moist subtropical regions Moist mT air masses from ocean to land

SE North America, Asia, South America

Mid latitude west coast Prevailing westerlies, orographic precipitation

Arctic and polar deserts Low(less than 12in)

Cold and dry cP and cA air masses

CLIMATE CLASSIFICATION

1. LOW LATITUDE CLIMATES

2. MIDLATITUDE CLIMATES

3. HIGH LATITUDE CLIMATES

• Influence of cT, mT, mE air masses• Equatorial low pressure and subtropical high pressure belts, ITCZ• Tropical cyclones

• Interaction of mT and cP air masses (polar front)•Wave cyclones

• Influence of cP and cA air masses (Northern Hemisphere), mP and cAA air masses (Southern Hemisphere)

(CLASS EXERCISE)

KöPPEN CLIMATES OF THE WORLDOne of the most used climate classification. Based on the concept that native vegetation is the best expression of climate. Combines annual and monthly temperature and precipitation, and the seasonality of precipitation

LOW LATITUDE CLIMATES

1. Wet Equatorial2. Monsoon and trade-wind coast3. Wet-dry tropical4. Dry tropical5. High-elevation

WET EQUATORIAL (10°N to 10°S)

Amazon Basin (Iquitos, Peru)0

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• Heavy precipitation and uniform temperatures all months• ITCZ, mE, mT air masses

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RAINFOREST ENVIRONMENT

• Uniform temperature and high rainfall• Wet equatorial and monsoon trade-wind

• Dense forest vegetation• Thick soil rich in nutrients• Great diversity of plant and animal species: 3000 species of trees in ~ 4mi² 20,000 species of insects in ~6mi²

Issues:• Deforestation (climate change)• Slash/burn agriculture

MONSOON AND TRADE-WIND COASTAL CLIMATE (5° to 25°)

• Heavy precipitation with seasonal pattern• Warm all year, annual cycle

• mT and mE brought by trade winds• Rainfall intensifies when ITCZ is nearby (summer is close, winter: high pressure),

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Sao Paulo, Brasil

trade-wind

• Monsoon circulation brings mT air SW to NE (Western India)

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WET-DRY TROPICAL CLIMATE (5° TO 20° America, 10 to 20° in Asia)

• Very dry and warm season in winter. Very wet and cold during summer

• ITCZ produce stronger rainfall and temperature cycle

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Nagpur, India

SAVANNA ENVIRONMENT

• Plants bloom in rain period and have a dormant phase during dry season

• Vegetation: savanna woodland and grass savanna• Animals: large herbivores and predators

DRY TROPICAL (15° to 25°)

• Very low rainfall (only during unusual weather conditions)• High temperatures

• Found in the center and east side of subtropical high pressure cells (adiabatic warming no condensation)

HIGHLAND CLIMATES

• Mountains and plateaus• Cold climate (higher: colder)• Orographic rainfall

Lagunillas (Titicaca Lake Basin, Southern Peru)

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LOW LATITUDE CLIMATES

1. Wet Equatorial2. Monsoon and trade-wind coast3. Wet-dry tropical4. Dry tropical

CLIMATE PATTERNS FACTORS

WET EQUATORIAL Heavy precipitation, uniform temperature all months

ITCZ, mE, mT air masses

MONSOON TRADE WIND COAST

Heavy precipitation and warm temperatures, with annual cycle

mE and mT brought by trade winds; summer: ITCZ closer, winter: high pressure. Monsoon patterns (India)

WET-DRY TROPICAL Very dry and warm in winter, very wet and cold in summer

ITCZ proximity

DRY TROPICAL Very low rainfall and high temperatures

Subtropical high pressure cells (adiabatic warming)

HIGH ELEVATION Cold climate (higher: colder), annual cycle

Orographic rainfall; ITCZ influence