Eos, Transactions American Geophysical Union

Global cyclone activity historically low



[1] A new research study shows that overall global tropical cyclone activity has decreased to historically low levels during the past 5 years. Maue analyzed global tropical cyclone data from 1970 through May 2011 to examine the considerable interannual variability of the accumulated cyclone energy (ACE) metric. Since 2006, global and Northern Hemisphere ACE have decreased significantly, reaching their lowest levels since the late 1970s. Also, during 2010–2011, the overall global frequency of tropical cyclones reached a historic low. The author demonstrated that much of the variability in tropical cyclone energy during the past 40 years is clearly associated with natural large-scale climate oscillations such as the El Niño—Southern Oscillation and the Pacific Decadal Oscillation. (Geophysical Research Letters, doi:10.1029/2011GL047711, 2011)