TY - JOUR
T1 - How Does Air-Sea Wave Interaction Affect Tropical Cyclone Intensity? An Atmosphere-Wave-Ocean Coupled Model Study Based on Super Typhoon Mangkhut (2018)
AU - Li, Zhenning
AU - Tam, Chi Yung
AU - Li, Yubin
AU - Lau, Ngar Cheung
AU - Chen, Junwen
AU - Chan, S. T.
AU - Dickson Lau, Dick Shum
AU - Huang, Yiyi
N1 - Funding Information:
This work was supported by the National Key Research and Development Program of China (Ref. No. 2019YFC1510402). The Vice‐Chancellor's Discretionary Fund of The Chinese University of Hong Kong (CUHK, Project No. 4930744, 4930777) also supported this project. C.‐Y. Tam was supported by the CUHK Direct Grant (Project No. 4053427). The appointment of N.‐C. Lau at the CUHK was partially supported by the AXA Research Fund. Computing resource was provided by the CUHK Central Cluster. We also appreciate Dr. Mathieu Dutour Sikirić from Ruđer Bošković Institute providing the linear programming tool to modify the ocean bottom topography.
Publisher Copyright:
© 2022 The Authors.
PY - 2022/3
Y1 - 2022/3
N2 - Capturing TC intensity change remains a great challenge for most state-of-the-art operational forecasting systems. Recent studies found TC intensity forecasts are sensitive to three-dimensional ocean dynamics and air-sea interface processes beneath extreme winds. By performing a series of numerical simulations based on hierarchical atmosphere-wave-ocean (AWO) coupling configurations, we showed how atmosphere-ocean and atmosphere-sea wave coupling can affect the intensity of super typhoon Mangkhut (2018). The AWO coupled model can simulate TC-related strong winds, oceanic cold wake, and wind waves with high fidelity. With atmosphere-ocean (AO) coupling implemented, the simulated maximum surface wind speed is reduced by 7 m s−1 compared to the atmosphere-only run, due to TC-induced oceanic cold wakes in the former experiment. In the fully coupled AWO simulations, the wind speed deficit can be completely compensated by the wave-air coupling effect. Further analyses showed that, in the AWO experiment, two mechanisms contribute to the improvement of TC intensity. First, in the high wind scenario (>28 m s−1), the surface drag coefficient reaches an asymptotic level, assisting extreme wind speed to be maintained within the eyewall. Second, the wind speed distribution is modulated and becomes broader; higher wind within the TC area helps to offset the negative effect due to leveling off of the heat exchange coefficient as wind speed increases. Overall, the simulated TC in the AWO run can extract 8–9% more total heat energy from the ocean to maintain its strength, compared to that from the AO experiment.
AB - Capturing TC intensity change remains a great challenge for most state-of-the-art operational forecasting systems. Recent studies found TC intensity forecasts are sensitive to three-dimensional ocean dynamics and air-sea interface processes beneath extreme winds. By performing a series of numerical simulations based on hierarchical atmosphere-wave-ocean (AWO) coupling configurations, we showed how atmosphere-ocean and atmosphere-sea wave coupling can affect the intensity of super typhoon Mangkhut (2018). The AWO coupled model can simulate TC-related strong winds, oceanic cold wake, and wind waves with high fidelity. With atmosphere-ocean (AO) coupling implemented, the simulated maximum surface wind speed is reduced by 7 m s−1 compared to the atmosphere-only run, due to TC-induced oceanic cold wakes in the former experiment. In the fully coupled AWO simulations, the wind speed deficit can be completely compensated by the wave-air coupling effect. Further analyses showed that, in the AWO experiment, two mechanisms contribute to the improvement of TC intensity. First, in the high wind scenario (>28 m s−1), the surface drag coefficient reaches an asymptotic level, assisting extreme wind speed to be maintained within the eyewall. Second, the wind speed distribution is modulated and becomes broader; higher wind within the TC area helps to offset the negative effect due to leveling off of the heat exchange coefficient as wind speed increases. Overall, the simulated TC in the AWO run can extract 8–9% more total heat energy from the ocean to maintain its strength, compared to that from the AO experiment.
KW - air-wave-ocean interaction
KW - momentum and heat exchange
KW - structural improvement
KW - surface friction
KW - tropical cyclone
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U2 - 10.1029/2021EA002136
DO - 10.1029/2021EA002136
M3 - Article
AN - SCOPUS:85127256623
SN - 2333-5084
VL - 9
JO - Earth and Space Science
JF - Earth and Space Science
IS - 3
M1 - e2021EA002136
ER -