Decadal Variation of the Number of El Nino Onsets and El Nino-Related Months and Estimating the Likelihood of El Nino Onset in a Warming World

[摘要] Examination of the decadal variation of the number of El Nino onsets and El Nino-related months for the interval 1950-2008 clearly shows that the variation is better explained as one expressing normal fluctuation and not one related to global warming. Comparison of the recurrence periods for El Nino onsets against event durations for moderate/strong El Nino events results in a statistically important relationship that allows for the possible prediction of the onset for the next anticipated El Nino event. Because the last known El Nino was a moderate event of short duration (6 months), having onset in August 2006, unless it is a statistical outlier, one expects the next onset of El Nino probably in the latter half of 2009, with peak following in November 2009-January 2010. If true, then initial early extended forecasts of frequencies of tropical cyclones for the 2009 North Atlantic basin hurricane season probably should be revised slightly downward from near average-to-above average numbers to near average-to-below average numbers of tropical cyclones in 2009, especially as compared to averages since 1995, the beginning of the current high-activity interval for tropical cyclone activity.

[发布日期] 2009-06-01

[学科分类] 大气科学