Slide 2:
Koeppen Key
B: PE > P
W: P < ½ PE
h: MAT >64º F
K: MAT < 64º F B climates are clearly the most extensive climate over land (35%) Map of Arid Lands Consider: Can h deserts receive > precip than k deserts and still be drier?
Slide 3:
General Characteristics of BW
1. Between 15º & 30º N/S
Subtropical H predominate
2. West coast
strong E subsidence Exceptions to general Characteristics
1. Great Basin/Patagonia (40º)
Rain Shadow
2. Taklamakan/Turkestan/Gobi
moisture-bearing air mass
3. N. East Africa & Somalia
Asia excludes maritime air
highlands & S. Asian monsoon
Slide 4:
Applied Regional Climatology: Living in the Sahel Human response to heat
1. The human thermostat
2. Dehydration (15-20% of body wt.) The Sahel is a region of & in transition (BSh) When over 100,000 people in the Sahel died , the human consequences of climate change became a reality. 3. Adaptation Acclimatization
- low body mass, long limbs,
long nose(humidify air)
- > in blood and sweat, < heat rate Loose cloths on a Tuareg, Algeria Animal adaptation, Thorny Devil
Slide 5:
Is the Sahel Experiencing Desertification Advancing Deserts
1. 50 m. ac. of lost productivity/yr (1970’s) or 30 mi/yr
2. Causes of desertification
- heavy settlement (>30 million)
- drought/southward shift in the ITCZ
- overgrazing = > albedo = absorb <
heat = < convection = stay desert
- less evapotranspiration
- fluctuations in global climate
- rainfall & revegetation
- tied to sea surface temperatures
- Sun spot cycle?? No one answer
Slide 7:
Is the Sahel Experiencing Desertification The Many Human Causes of Desertification Fossil water removal Barren circles/ year around grazing
Slide 8:
Is the Sahel Experiencing Desertification Center-pivot Armored soil Wind erosion
Slide 9:
Applied Regional Climatology: Living in the Sahel Desertification in Decline Between 1984 and 1991 the area of desert has declined by 270,000 sq mi