Dependence of tropical cyclone intensification rate on sea‐surface temperature. (29th April 2016)

• Record Type: Journal Article
• Authors: Črnivec, Nina; Smith, Roger K.; Kilroy, Gerard
• Is Part Of: Quarterly journal of the Royal Meteorological Society. Volume 142:Number 697(2016)
• Page Start: 1618
• Page End: 1627
• Publication Date: 2016-04-29
• Subjects: tropical cyclones -- hurricanes -- typhoons -- intensity -- rapid intensification -- sea‐surface temperature; Meteorology -- Periodicals; 551.5
• DOI: 10.1002/qj.2752
• Languages: English
• ISSNs: 0035-9009

Abstract

Abstract : The dependence of tropical cyclone intensification rate on the sea‐surface temperature (SST) is examined in the prototype problem for tropical cyclone intensification on an f ‐plane using a three‐dimensional, non‐hydrostatic numerical model. The effects of changing the SST are compared with those of changing the latitude examined in a recent article. It is found that the dependence of intensification rate on latitude is largest when the SST is marginal for tropical cyclone intensification (26 °C) and reduces in significance as the SST is increased. Further, at a given latitude, intensification begins earlier and the rate of intensification increases with increasing SST, on account of a significant increase of surface moisture fluxes from the warmer ocean. These higher fluxes result in higher values of near‐surface moisture and equivalent potential temperature, leading to a larger radial gradient of diabatic heating rate in the low to middle troposphere above the boundary layer. This larger radial gradient leads to a stronger overturning circulation, which in turn leads to a stronger radial import of absolute angular momentum surfaces and therefore more rapid spin‐up. These arguments invoke the classical axisymmetric spin‐up mechanism. Non‐axisymmetric issues are touched upon briefly.