2014-05-14. Ground-breaking study: Hurricanes reaching peak strength farther north as globe warms, tropics expand.

posted May 15, 2014, 9:27 AM by Alan Gould

For GSS Climate Change chapter 8. Excerpt: ...Identifying a firm connection between hurricane activity and manmade global warming has proven elusive.  The 2013 Intergovernmental Panel on Climate Change report stated there was “low confidence” in any link between observed changes in tropical storms and human activity. But this poleward shift in the peak strength of tropical storms could be the smoking gun linking human-induced climate change and hurricane behavior. The study, to be published in the journal Nature Thursday, analyzed where tropical storms around the world reached peak intensity between 1982 and 2012. It finds this location of maximum storm strength leaped poleward about 33 miles per decade in the Northern Hemisphere and 38 miles per decade in the Southern Hemisphere. ...The author team of James Kossin of the National Oceanic and Atmospheric Administration (NOAA), MIT’s Emanuel, and Gabriel Vecchi of NOAA links the storm shift to an expansion of the Hadley Cell – a massive atmospheric circulation that transports heat from the tropics to the mid-latitudes and drives the easterly trade winds.   In other words, the tropics are occupying a larger area.  The expansion “is likely due largely to human influences” or the heating effect of increasing greenhouse gas concentrations, the study says....  http://www.washingtonpost.com/blogs/capital-weather-gang/wp/2014/05/14/ground-breaking-study-hurricanes-reaching-peak-strength-farther-north-as-globe-warms-tropics-expand/.  By Jason Samenow, Washington Post.