B Climates - METC 331 Exam 3 pt. 4

What percentage of land area do B-climates comprise?

35% of land area

What are BW climates?

True desert

How much precipitation do BW climates receive

Very dry: less than 12’’ annually

What are the two types of BW climates

BWh – “Hot” – low latitudes (~25-40 N), BWk – “Cold” – mostly Asia (~35-45 N)

What causes BW Climates?

Subtropical high (30 N)
Rain shadows (Asia, N. Amer.)
Far from water (Asia)

Where are BWh climates located?

Southwest US and nearby Mexico, Middle East, Pakistan

What are characteristics of BWh climates?

Big daily and annual temp ranges
Lack of water vapor
Lack of clouds
Lots of insolation
Summer temps often >100 F

Where are BWk climates located

Kazakh-, Uzbeki-, Turkmeni- stan
Gobi Desert: N. China, Mongolia
Intermountain west, ABQ

Characteristics of BWk climates

Still very dry, annual mean temp <64F

What is the water balance in BWh climates

Giant summer deficits, always dry, but some summer monsoon rain

Vegetation found in BWh climates

Scattered shrubs with dramatic drought adaptations, succulence, allelopathy, small leaves, Herbaceous annuals

life cycle of herbaceous annuals

seeds → rain → germinate → flowers → seeds

Water balance in BWk climates?

big summer deficits, water must be carefully managed

Vegetation in BWk climates

Contiguous cover, enough moisture for shrubland, small leaves, gaps in drier area

What are BS climates

steppe

How are BS climates positioned relative to other climates

Transition from BW to C or A

How much precipitation do BS climates receive?

Not so dry: 10-30” precip.

What are the two types of BS climates?

BSh – “Hot”
BSk – “Cold”

What causes BS climates

rain shadows, continentality

Where are BSh climates located

Mexico (northern half) Iraq, Afghanistan, Middle East, Pakistan

What are characteristics of BSh Climates

Large temp ranges, but the edge is gone

Where are BSk climates located?

Intermountain west, High Plains, AB, SK
Turkey, central Asia, Mongolia, southern Russia

What are characteristics of BSk climates?

Annual mean temp <64 F
Water can be highly variable
Great Plains 20 year droughts
Fire!
Dust!

water balance BSh climates

summer deficits

Vegetation in BSh climates

desert to dry grassland

Water balance in BSk climates

More water available further north
Less hot
Mid-latitude jet
Some recharge, some withdrawal
Maybe a surplus
There can be snowstorms!

Vegetation in BSk

grasses and shrubs, drought tolerant, small trees near water

what is BWh

subtropical hot desert

what is BWk.

Mid latitude cold desert

what is BSk

Cold steppe

what is BSh

hot steppe