Sea surface height evidence for long-term warming effects of tropical cyclones on the ocean.
Tropical cyclones have been hypothesized to influence climate by pumping heat into the ocean, but a direct measure of this warming effect is still lacking. We quantified cyclone-induced ocean warming by directly monitoring the thermal expansion of water in the wake of cyclones, using satellite-based sea surface height data that provide a unique way of tracking the changes in ocean heat content on seasonal and longer timescales. We find that the long-term effect of cyclones is to warm the ocean at a rate of 0.32 ± 0.15 PW between 1993 and 2009, i.e., ∼23 times more efficiently per unit area than the background equatorial warming, making cyclones potentially important modulators of the climate by affecting heat transport in the ocean-atmosphere system. Furthermore, our analysis reveals that the rate of warming increases with cyclone intensity. This, together with a predicted shift in the distribution of cyclones toward higher intensities as climate warms, suggests the ocean will get even warmer, possibly leading to a positive feedback.
Department of Earth System Science, University of California, Irvine, CA 92697.
Wei
W
Mei
François
F
Primeau
James C
JC
McWilliams
Claudia
C
Pasquero
D055867:Cyclonic Storms / Q000706:statistics & numerical data*; D057232:Global Warming / Q000706:statistics & numerical data*; D008962:Models, Theoretical; D019370:Observation; D009792:Oceans and Seas; D013696:Temperature; D014872:Water Movements