Geoscience Reference
In-Depth Information
(a)
90°N
0
0
0
0
40
60°N
40
40
40
40
30°N
40
Equator
40
40
30°S
40
0
60°S
0
0
0
0
90°S
0°
30°E
60°E
90°E 120°E 150°E 180° 150°W 120°W 90°W 60°W 30°W 0°
(b)
90°N
40
0
60°N
40
80
40
40
40
80
120
80
40
30°N
80
120
40
80
40
80
120
120
80
Equator
120
120
120
160
120
80
40
120
120
30°S
80
80
80
40
80
40
40
60°S
40
0
0
0
0
0
90°S
0°
30°E
60°E
90°E 120°E 150°E 180° 150°W 120°W 90°W 60°W 30°W 0°
Figure 5.12 (a) Sensible and (b) latent heat fluxes from the surface to the atmosphere.
Contour intervals are 20 W/m
2
. Dashed contours indicate negative values.
Estimates of the turbulent heat flux climatologies from a reanalysis are
shown in
Figure 5.12.
The sensible heat flux (
Fig. 5.12a
) is generally larger
over land than over the oceans, except over the western boundary currents,
for example, the Kuroshio in the Pacific and the Gulf Stream in the Atlantic
(see
Figs. 2.15
and
2.22)
where warm water underlies cooler air (Eq. 5.20).
Negative values in Antarctica, the Arctic, and Greenland indicate a downward
(from atmosphere to surface) sensible heat flux, since the overlying air is often
warmer than the surface, especially during the winter. Ice and water on land
and ocean surfaces have an insulating effect, inhibiting the exchange of heat
between the atmosphere and ocean and suppressing the sensible heat flux.
