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Dependence of tropical cyclone intensification rate on sea‐surface temperature
Author(s) -
Črnivec Nina,
Smith Roger K.,
Kilroy Gerard
Publication year - 2016
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.2752
Subject(s) - tropical cyclone , diabatic , sea surface temperature , climatology , troposphere , atmospheric sciences , environmental science , latitude , cyclone (programming language) , hydrostatic equilibrium , lapse rate , adiabatic process , physics , geology , astronomy , field programmable gate array , quantum mechanics , computer science , computer hardware , thermodynamics
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.