RedOrbit: Weather extremes in the summer -- such as the record heat wave in the United States that hit corn farmers and worsened wildfires in 2012 -- have reached an exceptional number in the last ten years. Man-made global warming can explain a gradual increase in periods of severe heat, but the observed change in the magnitude and duration of some events is not so easily explained. It has been linked to a recently discovered mechanism: the trapping of giant waves in the atmosphere. A new data analysis now...