Ocean mediation of tropospheric response to reflecting and absorbing aerosols Institutional Repository Document uri icon

abstract

  • Abstract. Radiative forcing by reflecting (e.g., sulfate, SO4) and absorbing (e.g., black carbon, BC) aerosols is distinct: the former cools the planet by reducing solar radiation at the top of the atmosphere and the surface, without largely affecting the atmospheric column, while the latter heats the atmosphere directly. Despite the fundamental difference in forcing, here we show that the structure of the tropospheric response is remarkably similar between the two types of aerosols, featuring a deep vertical structure of temperature change (of opposite sign) in the Northern Hemisphere (NH) mid-latitudes. The deep temperature structure is anchored by the slow response of the ocean, as large meridional sea surface temperature (SST) gradient drives an anomalous inter-hemispheric Hadley circulation in the tropics and induces atmospheric eddy adjustments in the NH mid-latitudes. The robust tropospheric response is unique to aerosol forcing and absent in the CO2 response, which can be exploited for climate change attribution. The tropospheric warming in response to projected future decline in reflecting aerosols poses additional threats to the stability of mountain glaciers in NH.

author list (cited authors)

  • Xu, Y., & Xie, S.

citation count

  • 2

complete list of authors

  • Xu, Y||Xie, S-P

Book Title

  • EGUsphere

publication date

  • February 2015