Through a study that explains how rain droplets attract aerosols out of the atmosphere, a group of atmospheric chemists at MIT have now determined just how effective rain is in cleaning the atmosphere. CEE and Atmospheric Chemistry Professor Dan Cziczo led a study in which he and his team calculated rain’s coagulation efficiency – the ability of a droplet to attract particles as it falls. They found that the smaller the droplet, the more likely it was to attract a particle. “Say you’re a modeler and want to figure out how a cloud in Boston cleans the atmosphere versus one over Chicago that’s much higher in altitude — we want you to be able to do that, with this coagulation efficiency number we produce,” Cziczo says. “This can help address issues such as air quality and human health, as well as the effect of clouds on climate.” Read the article here.