American Geophysical Union Become an AGU Member
Subscribe to AGU Journals		 AGU Home AGU Publications

Read Full Article (file size: 211562 bytes)    Cited by

GEOPHYSICAL RESEARCH LETTERS, VOL. 32, L02804, doi:10.1029/2004GL021369, 2005

On smoke suppression of clouds in Amazonia

Graham Feingold

NOAA Environmental Technology Laboratory, Boulder, Colorado, USA


Hongli Jiang

Cooperative Institute for Research in the Atmosphere/National Oceanic and Atmospheric Administration, Fort Collins, Colorado, USA


Jerry Y. Harrington

Department of Meteorology, Pennsylvania State University, University Park, Pennsylvania, USA


Abstract

We use large eddy simulations of smoke-cloud interactions to demonstrate the relative importance of various factors responsible for cloud suppression in the biomass burning regions of Amazonia. The model includes unprecedented treatment of coupled smoke aerosol-cloud-radiative feedbacks in a 3-dimensional model that resolves scales of ∼100s m. It is shown that the vertical distribution of smoke aerosol in the convective boundary layer is crucial to determining whether cloudiness is reduced; Smoke aerosol emitted at the surface in a daytime convective boundary layer may reduce or increase cloudiness whereas smoke aerosol residing in the layer where clouds tend to form will reduce cloudiness. On the other hand, the reduction in surface latent and sensible heat fluxes associated with biomass burning is sufficient by itself to substantially reduce cloudiness.

Received 30 August 2004; accepted 17 December 2004; published 19 January 2005.

Index Terms: 3307 Atmospheric Processes: Boundary layer processes; 3310 Atmospheric Processes: Clouds and cloud feedbacks; 3311 Atmospheric Processes: Clouds and aerosols; 3314 Atmospheric Processes: Convective processes.

Read Full Article (file size: 211562 bytes)    Cited by

Citation: Feingold, G., H. Jiang, and J. Y. Harrington (2005), On smoke suppression of clouds in Amazonia, Geophys. Res. Lett., 32, L02804, doi:10.1029/2004GL021369.