The overall lack of activity was due to a strong Walker circulation over Indonesia, which increased convection over the Australian region, but suppressed convection over the Indian Ocean.
12.
During non-El Ni�o conditions, the Walker circulation is seen at the surface as easterly trade winds that move water and air warmed by the sun toward the west.
13.
The Walker circulations of the tropical Indian, Pacific, and Atlantic basins result in westerly surface winds in northern summer in the first basin and easterly winds in the second and third basins.
14.
Meanwhile, in the Atlantic, fast-blowing upper level Westerlies of the Hadley cell, which would ordinarily be blocked by the Walker circulation and unable to reach such intensities, form.
15.
There are projected increases of wind shear in the tropical Atlantic and East Pacific associated with the deceleration of the Walker circulation, as well as decreases of wind shear in the western and central Pacific.
16.
When the Walker circulation weakens or reverses, an " El Ni�o " results, causing the ocean surface to be warmer than average, as upwelling of cold water occurs less or not at all.
17.
Changes in ocean currents would also affect local sea levels, as is the case in the Pacific where the sea levels are around half a meter higher in the west than in the east due to the Walker circulation and cold Humboldt Current.
