Pasadena Star-News: The frequency of extremely high clouds in Earth’s tropics – the type associated with severe storms and rainfall – is increasing as a result of global warming, according to a study by scientists at NASA’s Jet Propulsion Laboratory in La Canada Flintridge. In a recent presentation at a meeting of the American Geophysical Union in San Francisco, JPL Senior Research Scientist Hartmut Aumann outlined the results of a study based on five years of data from the Atmospheric Infrared Sounder …