Rapid intensification of Super Typhoon Haiyan: the important role of a warm-core ocean eddy

Super Typhoon Haiyan devastated portions of Southeast Asia, particularly the Philippines, on November 8, 2013. In this paper, observational data are used to analyze the intensification process of Super Typhoon Haiyan. Observational data showed that Typhoon Haiyan intensified and the maximum sustained winds increased to 59 ms(-1) after it encountered a double warm-core ocean eddy, while the central pressure of the typhoon dropped from 970 hPa to 920 hPa. Numerical simulations and observational data show that the presence of the warm-core eddy combined with SST increases due to climate change led to the rapid intensification of Super Typhoon Haiyan. Comparing these two factors, the warm-core ocean eddy, which brings significantly more heat into the upper ocean, plays the leading role in the intensification, with climate warming making a lesser contribution. Moreover, due to the increased thickness of the mixed layer associated with the warm-core ocean eddy, Super Typhoon Haiyan did not significantly decrease the sea surface temperature to the east of the Philippines, as is typical of typhoons, and the largest decrease was approximately 1 degrees C.