Maps of global wind-driven upwelling/downwelling:
Climatological wind-induced upwelling/downwelling at the base of the
surface Ekman layer over the global ocean has been computed from the COADS
(Comprehesive Ocean-Atmosphere Data Set) monthly wind stress data
(Xie and Hsieh, 1995). The computation has been repeated using the longer
data record from Jan.1950 to Apr.1999 (Wong, Xie and Hsieh, 2007).
In the following global maps prepared by
Liusen Xie, besides the colour coding (with red
representing the strongest upwelling and purple, the strongest downwelling),
contour lines of +/-
5, 10, 20, 50, 100, 200 cm/day are also plotted for the upwelling/downwelling velocity, and the
zero contour is drawn as a thicker line. Higher resolution images for colour
printers are provided for the annual mean, January and July.