LA JOLLA – To explore the link between climate change and air pollution, a La Jolla scientist and his colleagues will launch a trans-Pacific journey Tuesday with an unusual goal: to maneuver the nation's most advanced environmental research plane into the middle of a giant cloud of dust and soot. This and other plumes of polluted air from Asia can be the size of California. Their increasingly frequent appearance in recent years has generated substantial scientific scrutiny. But the latest venture is believed to be the first in which researchers will follow a plume across the Pacific and take air...