Recovery of Tropical Cyclone Induced SST Cooling Observed by Satellite in the Northwestern Pacific Ocean

Zheng Ling,Hailun He,Changlin Chen,Guihua Wang,Zhifeng Chen

doi:10.3390/rs13183781

Abstract

Based on the satellite observed sea surface temperature (SST), the recovery of SST cooling induced by the tropical cyclones (TCs) over the northwestern Pacific Ocean is investigated. The results show that the passage of a TC induces a mean maximum cooling in the SST of roughly −1.25 °C. It was also found that most of this cooling (~87%) is typically erased within 30 days of TC passage. This recovery time depends upon the degree of cooling, with stronger (weaker) SST cooling corresponding to longer (shorter) recovery time. Further analyses show that the mixed layer depth (MLD) and the upper layer thermocline temperature gradient (UTTG) also play an important role in the SST response to TCs. The maximum cooling increases ~0.1 °C for every 7 m decrease in the MLD or every 0.04 °C/m increase in the UTTG. The combined effects of MLD and TC intensity and translation speed on the SST response are also discussed.

Highlights

Gaining insight into the tropical cyclone (TC) induced sea surface temperature (SST) cooling is important for both improving tropical cyclones (TCs) prediction and understanding the atmospheric and oceanic circulation, which influences the number, path, and intensity of the TCs [1,2,3,4,5,6,7] and affects the large-scale atmospheric circulation [6] and oceanic thermohaline circulation [8,9,10]
This result shows that the maximum SST cooling occurs most frequently on D1 after passage (Figure 2a), with the corresponding mean maximum cooling on each day ranging from −0.58 ◦ C on
The results show that the passage of a TC induces SST

Summary

Introduction

Gaining insight into the tropical cyclone (TC) induced SST cooling is important for both improving TC prediction and understanding the atmospheric and oceanic circulation, which influences the number, path, and intensity of the TCs [1,2,3,4,5,6,7] and affects the large-scale atmospheric circulation [6] and oceanic thermohaline circulation [8,9,10]. The maximum SST cooling generally occurs to the right of the TC track in the northern hemisphere [15,20,21,22], it can be observed to the left of the TC track [23,24] or exactly along the track [25]. The magnitude of SST cooling induced by the passage of TCs has been reported to range from 1 ◦ C to 10 ◦ C [14,26,27,28,29]. After the passage of a TC, there is a recovery period reported in previous studies to range from several days to more than a month. Hazelworth [31] found that the recovery time ranged from 1 to 36 days with an average duration of about 20 days

Methods

Results

Discussion

Conclusion