Satellite mapping the CCN and cloud vertical microphysical and precipitation profiles in and outside the Manaus plume by using clouds as CCN chambers

Abstract:

The newly acquired possibility of retrieving from the SUOMI/NPP satellite the cloud base drop concentrations and updrafts made it possible to calculate cloud base vapor super saturation (S) and thus the CCN(S) over the GOAmazon domain, and validate it against surface and aircraft measurements. This was used to map the Manaus air pollution plume and observe its impact on cloud drop effective radius, precipitation forming processes and glaciation temperatures. These observations allow completing and extending the patchy picture obtained by the aircraft measurements over the full domain of interest. The methodology will be shown, as well as the main findings. By the time of the writing of this abstract we have already documented that during pristine conditions the CCN(S) is nearly double in the Manaus plume with respect to the background of ~200 cm^-3 at S = 0.25 to 0.3%. The S of cloud base in the Manaus pollution plume is lower by about 0.05 to 0.1%. The cloud depth for initiation of warm rain increases by more than one km due to the decrease in cloud drop effective radius, as indicated by the increase in the isotherm level where it reaches the threshold of 14 micrometer. During smoky conditions, caused by distant biomass burning, the background CCN overwhelms the Manaus plume; CCN can exceed 1000 cm^-3 at S < 0.2%, and the height of rain initiation can exceed the 0° isotherm level. This means that the effects on clouds incurred by biomass burning dwarf the effects of the Manaus pollution plume.