May 4, 2006

Weakening of tropical Pacific atmospheric circulation due to anthropogenic forcing

Gabriel A. Vecchi, Brian J. Soden, Andrew T. Wittenberg, Isaac M. Held, Ants Leetmaa, Matthew J. Harrison
  • Explores changes in tropical Pacific circulation since the mid-nineteenth century using observations and a suite of global climate model experiments
  • States that observed Indo-Pacific sea level pressure reveals a weakening of the Walker circulation
  • States that the size of this trend is consistent with theoretical predictions, is accurately reproduced by climate model simulations and, within the climate models, is largely due to anthropogenic
  • Finds that the climate model indicates the weakened surface winds have altered the thermal structure and circulation of the tropical Pacific Ocean
  • These results support model projections of further weakening of tropical atmospheric circulation during the twenty-first century