Satellite photo of a tropical cyclone with a graph overlaying it.
The spatial distribution of drag coefficient CD in the motion-relative quadrants of a tropical cyclone (TC). The spatial distribution of CD on the periphery of a TC is asymmetric. CD in the right rear quadrant (reddish dots) are much larger than those in the right front quadrant (bluish dots), which is attributable to different ocean wave properties in different locations. Credit: Sheng Chen and Fangli Qiao
Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: Journal of Geophysical Research: Oceans

The air-sea flux is an essential and complex turbulent process which controls the momentum, energy, and mass exchanges between the ocean and the atmosphere. The drag coefficient is a key parameter for surface wind stress, and it is known to have a non-monotonous dependence on surface wind speed.

Based on turbulent flux observations, Chen et al. [2022] find that the drag coefficient has an asymmetric spatial distribution in different quadrants of a tropical cyclone which is attributable to the asymmetry of ocean waves during a tropical cyclone. The results highlight the importance of the ocean waves for air-sea fluxes. They also present a new challenge and a new avenue for a better simulation of ocean-tropical cyclone interactions, and the climate system.

Citation: Chen, S., Qiao, F., Zhang, J. A., Xue, Y., Ma, H., & Chen, S. (2022). Observed drag coefficient asymmetry in a tropical cyclone. Journal of Geophysical Research: Oceans, 127, e2021JC018360.

—Lei Zhou, Editor, Journal of Geophysical Research: Oceans

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