Tropical Cyclone Center Automatic Determination Model Based on HY-2 and QuikSCAT Wind Vector Products

摘要

Tropical cyclones (TCs) are weather systems with vast destructive power. A key element in issuing warnings for TCs approaching land is the accurate and timely knowledge of the location of the circulation center. Current procedures are usually performed with manual input from a human analyst. Since subjective elements are involved in this process, analysts could disagree on the results even when multiple factors are considered. In this paper, we propose a new method for the automatic determination of the center of TCs using HY-2 and Quick Scatterometer wind vector products. First, we calculate the high-wind speed zone from the wind speed map. Next, we extract the vortexlike zone using the wind direction map. Finally, we automatically determine the center from the vortexlike zone. Six representative TCs (Haikui, Saola, Usagi, Florence, Ioke, and Gordon) and seventeen TCs in the 2013-2016 seasons are used to validate the TC center automatic determination (TCCAD) method. The results show that 1) the accuracy of the TCCAD method is close to that of the human expert method for most TCs and 2) the standard deviation in the TCCAD method is much smaller than that in the human expert method, which indicates that the TCCAD method is more efficient and reliable. Although the TCCAD method has some limitations because of the quality of scatterometer products and problems with the structure of TC eyes, it can automatically provide the practical, independent, and objective identification of TC centers.