Page 190 - Geosystems An Introduction to Physical Geography 4th Canadian Edition

154
part I The energy–atmosphere System
120˚ 140˚ 160˚ E 180˚ W 160˚ 80˚ 1014 1018
140˚ 120˚
100˚
80˚
1014
60˚ 40˚ 20˚
20˚
40˚
1006
1022 1018
1014 1010
80˚
100˚ 120˚ 1014 80˚
1026 60˚ 1030
40˚
20˚ 1018
0˚
1006
20˚
40˚ 1014
60˚
80˚ 120˚
1006
Icelandic Low 998L
1002 1010
60˚
1022
Aleutian Low L998
1002
1010 1014
1010
January
990
994 998
1018
H
1018
990
140˚
1018
1018
W 0˚ E
1014 1010 1006
60˚
H
Z
C
T
I
C
T
I
Z
Z
I
T
Z
C
C
T
I
1014
986
140˚
L 982 986
1010 1014
1014 1010
1014 1018
1014 1010
L
1010 994
Azores High H
1018
10314030 40˚ 20˚
160˚ E 180˚ W 160˚
80˚
20˚
20˚ 40˚
20˚ 40˚
60˚
60˚
L
1026H
986
60˚
80˚
80˚
1006 1002
998
80˚ 100˚ 120˚
100˚ 120˚ 80˚
1010 H 1018
1014
H
60˚ July
998 994
982 998
990 994
998
80˚ 120˚
990
986
986 990 994
100˚ 80˚
982 L
140˚
160˚ E 180˚ W 160˚
140˚
60˚
40˚
W 0˚ E
20˚
40˚
80˚ 80˚ 100˚ 120˚
L
990
120˚
994 998
60˚ 40˚
990 994
(a) January average surface barometric pressures (millibars); dashed line marks the general location of the intertropical convergence zone (ITCZ).
120˚ 80˚
60˚ 1006 40˚
20˚
0˚
20˚
40˚
140˚ 160˚ E 180˚ W 160˚
140˚
1014 1018
120˚
100˚
80˚
1010
1018
60˚ 40˚ 20˚
W 0˚ E
1010
1018 1014
1010 1012
Bermuda High H
1010
Pacific High 1026 H
1022
1014 1002
1022 1014
1010 1014
H
1022
L
982
990
986
20˚
1018
120˚
1018
1014
1018 1022
H
986 L
100˚
1014 1018
L1006
1010
1006
(b) July average surface barometric pressures. Compare pressures in the North Pacific, the North Atlantic, and the central Asian landmass with the January map above.
▲Figure 6.10 Global barometric pressures for January and July.
[adapted by robert Christopherson and redrawn from national Climatic Data Center, Monthly Climatic Data for the World, 46 (January and July 1993), and WMO and nOaa.]
Animation
Global Patterns of Pressure
Satellite
Global Sea-Level Pressure
998
1010 40˚ 60˚
H
L
W 0˚ E
1014 1018 990
H
1010
60˚
40˚
1006 20˚ 1010 0˚
1014 1018 20˚
40˚ L 60˚
994
1010
0˚ 20˚