Why do the maximum intensities in modeled tropical cyclones vary under the same environmental conditions?
Tao, D., Bell, M., Rotunno, R., & Leeuwen, P. J. (2020). Why do the maximum intensities in modeled tropical cyclones vary under the same environmental conditions? Geophysical Research Letters, 47, e2019GL085980. doi:10.1029/2019GL085980
In this study w e explored why the different initial tropical cyclone structures can result in different steady-state maximum intensities in model simulations with the same environmental conditions. We discovered a linear relationship between the radius of maximum wind (r(m)) and the absolute ang... Show moreIn this study w e explored why the different initial tropical cyclone structures can result in different steady-state maximum intensities in model simulations with the same environmental conditions. We discovered a linear relationship between the radius of maximum wind (r(m)) and the absolute angular momentum that passes through r(m) (M-m) in the model simulated steady-state tropical cyclones that r(m) = aM(m)+b. This nonnegligible intercept b is found to be the key to making a steady-state storm with a larger M-m more intense. The sensitivity experiments show that this nonzero b results mainly from horizontal turbulent mixing and decreases with decreased horizontal mixing. Using this linear relationship from the simulations, it is also found that the degree of supergradient wind is a function of M-m as well as the turbulent mixing length such that both a larger M-m and/or a reduced turbulent mixing length result in larger supergradient winds. Show less