Over the past 70 years, hurricane frequency in the Atlantic basin is up, but the strength of the storms have remained relatively constant. Those are the conclusions of a new study conducted by Clemson University researchers. Clemson Professor of Mathematical Sciences Robert Lund participated in the study that looked at changes in the tropical cycle record in the North Atlanticbetween 1851 and 2008. Lund says he knows global warming is a hot button issue and many researchers have maintained that warming waters of the Atlantic are increasing the strengths of these storms. We do not see evidence for this at all, however we do find that the number of storms has recently increased.”
“We took a look at the record from 1851 to 2008 and we did find a lot of changes besides recent changes. For instance, we found that around 1935 the count radically increased and that was probably do to aircraft reconnaissance, being able to fly out into the ocean and see these storms.”
Also participating in the study were Michael Robbins and Colin Gallagher of Clemson along with Mississippi State University Mathematics professor Dr. QIQi ( pronounced, chi-chi) Lu.
Lund says the increase in the frequency of hurricanes and some measurable increase in strength of the storms was first observed from data from the beginning of the 20th century. Lund attributes the observations from better and more sophisticated technological devices used to monitor the storms. “We saw them from about 1900 which makes sense because most of the data recorded before 1900 was guesstimated and not very consistent. We also found small changes in the strengthof the storms around 1960 which coincides with the onset of satellites.”
Lund says in a number of studies involving the analysis of years and years of data, the study of probabilities is best conducted by mathematicians.”We have to play by the rules of probability and the laws of random chance. As statisticians and probabilists, we are not allowed to distort the conclusion nor are we invested in any particular outcome or inference from the data. We’re just going to crunch the numbers as best we can with rigorous probability assessments and tell you what we find.”
Lund says the study he and his colleagues just concluded opens up avenues for more questions yet to answered. “Are the storms changing in terms of duration in terms of how long they last? Are they occurring in more northern latitudes? There are a lot of small issues that still need to be tied down, but we sort of felt that at least given the data that we’ve seen recently that this pretty much answers the question of are changes happening?”