Page 197 - Geosystems An Introduction to Physical Geography 4th Canadian Edition

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20˚
0˚
20˚
INDIAN
0˚
60° 70°
80°
60° West
East
130° 120°
(a) Average locations of the two jet streams over North America. ▲Figure 6.14 Jet streams.
Z
h
0
(a) Winter, dry monsoon.
December–January 120˚
J F M A M J J A S O N D 37.5 35.0
32.5 30.0 27.5 25 22.5 20.0 17.5 15.0 12.5 10.0 7.5 5 2.5 0
warmth in Verkhoyansk, Siberia, from Chapter 5). Mean­ while, subtropical high pressure dominates over the Indian Ocean, causing warming of sea­surface tempera­ tures (Figure 6.15b). Therefore, the pressure gradient is
110°
High pressure Dry
Nagpur
Dry
OCEAN
Tropic of Capricorn
80° 70°
80˚
100˚
0
(b) Summer, wet monsoon.
2000 KILOMETRES
2000 KILOMETRES 80˚ 100˚
(c) Precipitation at Nagpur,
India.
Precipitation (cm)
▲Figure 6.15 The Asian monsoons. (a and b) note the shifting location of the iTCZ, the changing pressures over the indian Ocean, and the different conditions over the asian landmass. (c) Seasonal precipitation graph for nagpur, india.
During the Northern Hemisphere summer, the ITCZ shifts northward over southern Asia, and the Asian continental interior develops low pressure associated with high average temperatures (remember the summer
Station: Nagpur, India
Lat/long: 21° 1′ N 79° 1′ E Total ann. precip.:
Dry
Tropic of Cancer
PACIFIC OCEAN
pressure
20˚
INDIAN
High pressure
20˚
June–July
Wet
Cherrapunji
Nagpur
OCEAN
Dry
Tropic of Capricorn
Wet
High pressure
Tropic of Cancer
PACIFIC OCEAN
Thermal low
Chapter 6 atmospheric and Oceanic Circulations 161
Idealized cross section of jet stream
900–2150 m
Depth
North America
160–480 km
Width
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(b) Width, depth, and altitude and core speed of an idealized polar jet stream.
7600–10 700 m
Altitude
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Elevation: 310 m 124.2 cm