Effects of the Cold Core Eddy on Tropical Cyclone Intensity and Structure under Idealized Air–Sea Interaction Conditions

Abstract

The impacts of ocean feedback on tropical cyclones (TCs) are investigated using a coupled atmosphereocean model under idealized TC and cold core eddy (CCE) conditions. Results reveal negative impacts of the ocean coupling on TC development. The cold wake induced by a TC not only weakens the TC intensity but also limits the expansion of the storm circulation. The presence of CCE has boosted the TC-induced sea surface temperature cooling, which conversely inhibits the TC development. The TC appears to be weakened as it encounters the CCE edge. The intensity reduction attains a maximum shortly after the TC passes over the CCE center, and simultaneously the CCE-induced asymmetry of the storm structure is most significant as well. The TC undergoes a period of recovery after departure from the CCE, lasting about 36-48 h. During this time the residual asymmetry caused by the CCE is smoothed gradually by storm axisymmetrization. The CCE has induced smaller TC size throughout the simulation even after the TC intensity has completely recovered, an indication of longer recovery time for the TC size. Notably cooler and moister eye air in the lower troposphere, just under the warm-core height, is found in the experiment with CCE. The water vapor mixing ratio budget analysis indicates that it is primarily attributed to changes in vertical advection that occurred in the eye, that is, the undermined eye subsidence associated with the suppressed eyewall convection. The horizontal patterns of vertical motion in the boundary layer are also distinctly changed by the CCE.

Sensitivity of the Simulated Tropical Cyclone Intensification to the Boundary‐Layer Height Based on a K‐Profile Boundary‐Layer Parameterization Scheme

“…Note that there are some important differences among these schemes, including the handling of the turbulent Prandtl number, diffusion above the boundary layer, and specification of the critical bulk‐Richardson number (Bu et al, ). Although the K‐profile parameterization scheme has its limitations as cautioned by Kepert (), it has been proved to work well in modeling the intensity and structure of tropical cyclones (e.g., Ma et al, ; Ma, Fei, Huang, et al, ; Ma, Fei, Cheng, et al, ; Nolan, Zhang, et al, ; Nolan, Stern, et al, ; Zhang et al, ), and performs satisfactorily in the HWRF model (Gopalakrishnan et al, ; Zhang et al, , ). As a typical K‐profile parameterization scheme, the YSU scheme is chosen to parameterize boundary‐layer processes in this study.…”

The effects of ocean feedback on tropical cyclone energetics under idealized air‐sea interaction conditions

“…With this aim, the air‐sea coupling numerical simulations by Ma et al . [] are used, but with the time intervals of model output improved from 1 h to 10 min. Section 2 describes briefly the model setup.…”

Impact of Major Typhoons on Sea Surface Environment in the Northwestern Pacific Derived from Satellite Remote Sensing

“…By analyzing four typical tropical cyclones in the South China Sea, Zhang et al concluded that the stronger the intensity of a tropical cyclones, the slower the movement speed, the shallower the mixed layer depth, and the greater the reduction in SST [24]. On the other hand, pre-existing cold eddies would enhance the SSC caused by the typhoons [8,26,27], whereas the SST drop in a warm-eddy-controlled region might not be very obvious [24,25].…”