Modulation of Pacific Sea Surface Temperatures on the Late-Season Tropical Cyclone Tracks Over the Western North Pacific and its Implication for Seasonal Forecasting

Hua Yu,Xuyang Ge,Chao Wang

doi:10.3389/feart.2022.835001

Abstract

In this study, two leading modes of the late season (October–December) TC track frequency are identified with the empirical orthogonal function analysis. It is found that circulation anomalies associated with the two modes are linked to the concurrent El Niño-Southern Oscillation (ENSO), but with distinct locations of maximum sea surface temperature (SST). For the first mode, the maximum SST warming and the resulted heating can extend to the equatorial central Pacific, which emanates a cyclonic circulation extending to the east of the Philippines, and then generates an anti-cyclonic circulation to the west of the Philippines by dry advection and local air–sea interaction. In contrast, for the second mode, the maximum SST warming and the corresponding heating shift eastward to the equatorial eastern Pacific, the related cyclonic circulation, and the compensation descending motion migrate eastward and are confined to the east of 150°E. The associated suppressed heating then emanates an anti-cyclonic circulation to the west of 150°E. These anomalous circulations can modulate TC genesis and steering flow and thus contribute to variations in the two modes. A set of physics-based empirical models is further built, which shows a promising pathway for the seasonal forecasting of the two modes and the basin-wide total TC track frequency. The results highlight the importance of the location of ENSO maximum SST in understanding and seasonal prediction of the late-season TC tracks over the WNP.

Highlights

Understanding the climate variabilities in tropical cyclone (TC) track over the western North Pacific (WNP) is of great importance owing to enormous TC-generated disasters (Zhang et al, 2009; Peduzzi et al, 2012)
These results suggest a potential utility of our strategy for the seasonal forecasting of TC activity in the late season over the WNP
Two leading modes of the late-season TC track frequency are identified with the empirical orthogonal function analysis

Summary

INTRODUCTION

Understanding the climate variabilities in tropical cyclone (TC) track over the western North Pacific (WNP) is of great importance owing to enormous TC-generated disasters (Zhang et al, 2009; Peduzzi et al, 2012). The key for the distinct large-scale conditions associated with the two modes lies in their different zonal ranges of the anomalous cyclonic circulation, which is speculated to be linked to the distinct maximum centers of SST anomalies over the equatorial Pacific associated with the two modes (Figure 5). The standard deviation of the predicted (simulated) TC track frequency is less than that of the observed, the PEMs using the identified SST predictors can reasonably reproduce the temporal variability of the two modes of late-season TC track frequency (Figure 7). The correlation between the regressed TC track frequency and observation is 0.50, which is significant at 95% confidence level

CONCLUSION

Findings

DATA AVAILABILITY STATEMENT