Nature Physics, published online 11 July 2010; doi: 10.1038/nphys1725
Scaling of tropical-cyclone dissipation
Álvaro Corral* (Centre de Recerca Matemàtica, Edifici Cc, Campus Universitari, E-08193 Bellaterra, Barcelona, Spain), Albert Ossó and Josep Enric Llebot (Grup de Física Estadística, Facultat de Ciències, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona, Spain)
Abstract
The influence of climate variability and global warming on the occurrence of tropical cyclones is a controversial issue1, 2, 3, 4, 5, 6, 7, 8, 9, 10. Existing historical databases on the subject are not fully reliable9, 11, 12, 13, but a more fundamental hindrance is the lack of basic understanding regarding the intrinsic nature of tropical-cyclone genesis and evolution14. It is known that tropical cyclones involve more than a passive response to changing external forcing15, but it is not clear which dynamic behaviour best describes them. Here we present an approach based on the application of the power dissipation index, which constitutes an estimation of released energy3, to individual tropical cyclones. A robust law emerges for the statistics of power dissipation index, valid in four different ocean basins and over long time periods. In addition to suggesting a description of the physics of tropical cyclones in terms of critical phenomena16, 17, the scaling law enables us to quantify their response to changing climatic conditions, with an increase in the largest power dissipation index values with sea surface temperature or the presence of El Niño phenomena, depending on the basin under consideration. In this way, we demonstrate that the recent upswing in North Atlantic hurricane activity does not involve tropical cyclones that are quantitatively different from those in other sustained high-activity periods before 1970.
*Correspondence e-mail: ACorral@crm.cat
Link: http://www.nature.com/nphys/journal/vaop/ncurrent/abs/nphys1725.html
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