12
NET AIR-SEA HEAT FLUX AND MERIDIONAL HEAT TRANSPORT
12
10
~ 8
I~
"-6
I~ 4
2
0
0
+
+
50
a,: -0.0572
ao: 11.322
150
200
Figure 14: Relative error of the wind
speed as a function of squared wind speed
ww. Individual crosses depict monthly
50 x 100 averages. A linear fit of ao +
al WW is applied.
-:0
.:3- rn a
()
1.0
0.9
0.8
0.7
0
+
at:
ao:
50
WW
0.003313 at: 0.000582
0.69952
ao: 0.83717
100
150
200
[m 2 s- 2 ]
Figure 15: Asfig.14, butfor the wind direction. Two linear fits for WW less than
and greater than 50m 2 8- 2 are applied
error cos l1d (fig.15). For weak winds, corresponding to mean squared wind speeds of less
than 50 m 2 8- 2 , the directional error is
cosl1d = 0.700 + c WW
(18)
and for stronger winds
cos l1d = 0.837 + c WW
, c = 0.00058 8 2 m- 2
(19)
Summarizing both, strength and steadiness error, the latter dominates, so that the wind stress
is underestimated by 5% (for WW = 150 m 2 8- 2 ) to 10% (for WW = 40 m 2 8- 2 ).
4 Net Air-Sea Heat Flux and Meridional Heat Transport
The net heat gain of the ocean is determined by summing the fluxes of shortwave (SR) and
longwave radiation (LR) and the turbulent fluxes of sensible (H) and latent heat (LE) at the
sea surface.
NHF = SR+LR+LE +H
(20)
The annual average of net heat flux (NHF) is small in most parts of the Atlantic (fig.16).
Of course, the Gulf Stream region is an exeption where the ocean looses large amounts of
energy mainly due to strong evaporation. Also the warm water of Agulhas Current provides
NET AIR-SEA HEAT FLUX AND MERIDIONAL HEAT TRANSPORT
12
10
~ 8
I~
"-6
I~ 4
2
0
0
+
+
50
a,: -0.0572
ao: 11.322
150
200
Figure 14: Relative error of the wind
speed as a function of squared wind speed
ww. Individual crosses depict monthly
50 x 100 averages. A linear fit of ao +
al WW is applied.
-:0
.:3- rn a
()
1.0
0.9
0.8
0.7
0
+
at:
ao:
50
WW
0.003313 at: 0.000582
0.69952
ao: 0.83717
100
150
200
[m 2 s- 2 ]
Figure 15: Asfig.14, butfor the wind direction. Two linear fits for WW less than
and greater than 50m 2 8- 2 are applied
error cos l1d (fig.15). For weak winds, corresponding to mean squared wind speeds of less
than 50 m 2 8- 2 , the directional error is
cosl1d = 0.700 + c WW
(18)
and for stronger winds
cos l1d = 0.837 + c WW
, c = 0.00058 8 2 m- 2
(19)
Summarizing both, strength and steadiness error, the latter dominates, so that the wind stress
is underestimated by 5% (for WW = 150 m 2 8- 2 ) to 10% (for WW = 40 m 2 8- 2 ).
4 Net Air-Sea Heat Flux and Meridional Heat Transport
The net heat gain of the ocean is determined by summing the fluxes of shortwave (SR) and
longwave radiation (LR) and the turbulent fluxes of sensible (H) and latent heat (LE) at the
sea surface.
NHF = SR+LR+LE +H
(20)
The annual average of net heat flux (NHF) is small in most parts of the Atlantic (fig.16).
Of course, the Gulf Stream region is an exeption where the ocean looses large amounts of
energy mainly due to strong evaporation. Also the warm water of Agulhas Current provides