Using Amazonian Aerosols to Understand Preindustrial Aerosol Impacts
The Amazon is one of the few continental regions where atmospheric aerosol particles and their effects on climate are not dominated by anthropogenic sources. In the Amazonian Aerosol Characterization Experiment 2008 (AMAZE-08), during the Amazonian wet season, DOE-funded scientists studied the composition, physical characteristics, and cloud-nucleating ability of the local aerosols under ambient conditions, conditions that approach those of the pristine pre-industrial era. As reported in a recent Science article, the authors measured aerosol that was very dilute and primarily limited to primary biological fragments and to secondary biogenic aerosol largely unmixed with typical inorganic products of human activity. Further, they found that the aerosol-cloud-precipitation system there was “distinctly different” from that over land regions impacted by human activity or even pristine ocean regions. These results are highly relevant to reliable modeling of the atmosphere in the preindustrial period to investigate the human perturbations that impact current and future climate regimes.
U. Poeschl, et al. 2010. “Rainforest Aerosols as Biogenic Nuclei of Clouds and Precipitation in the Amazon,” Science, 329, 1513-1516.