Changes in equatorial atmospheric zonal circulations in recent decades

Abstract

The equatorial zonal circulation is characterized by the atmospheric mass flux, and is calculated using the NCEP-NCAR and ERA-40 reanalysis products. A speed-up of the equatorial circulations over the Atlantic and Indian oceans is found in recent decades in both reanalyses, in conjunction with a slow-down of the Pacific Walker circulation. These changes in the equatorial circulations are consistent with changes in dynamically related heating in the tropics, and with observed changes in precipitation. Copyright © 2010 by the American Geophysical Union.