ABSTRACT

The seven simulations were performed to investigate the role of the sea surface temperature (SST) in numerical prediction of tropical cyclones (TCs). The TC Gonu, formed over the Arabian Sea in 2007, was selected for this study. The first five simulations were performed using WRF model. In the first simulation as control simulation (CTL), the SST derived from NCEP-MMAB was used. In the second simulation, 1°C was added to input SST, and in the third simulation, 1°C was subtracted to input SST. It was found that the deviation between the simulated track of simulation SST +1 and CTL is more significant than that between simulation SST −1 and CTL. For the fourth simulation, a homogeneous SST field over the entire basin was used. For the fifth simulation, SST anomaly was calculated, and its values were added to the entire domain. Removing the temperature gradient caused TC intensity to decrease and deviation of the track to the northeast; the increasing temperature gradient had a lower impact on the TC intensity but with a significant deviation of the track to the north with respect to the CTL simulation. In the sixth simulation to consider cyclone-induced SST cooling, a one-dimensional oceanic mixed layer scheme was applied. Results showed no significant reduction in TC intensity. In the seventh simulation, the COAWST modelling system was used. The simulated SST of the COAWST model was consistent with the satellite observations, which finally led to improve the simulation of track and intensity of TC Gonu.

摘要

进行了七次模拟，以研究海面温度 (SST) 在热带气旋 (TC) 的数值预测中的作用。2007 年在阿拉伯海形成的 TC Gonu 被选中用于这项研究。前五次模拟是使用 WRF 模型进行的。在作为控制模拟 (CTL) 的第一次模拟中，使用了从 NCEP-MMAB 派生的 SST。在第二次模拟中，输入 SST 增加 1°C，在第三次模拟中，输入 SST 减去 1°C。发现模拟SST +1 和CTL 的模拟轨迹之间的偏差比模拟SST -1 和CTL 之间的偏差更显着。对于第四次模拟，使用了整个盆地的均匀 SST 场。第五次模拟计算了海温异常，并将其值添加到整个域中。去除温度梯度导致台风强度减弱，路径偏东北；增加的温度梯度对 TC 强度的影响较小，但相对于 CTL 模拟，北向轨迹有显着偏差。在考虑气旋引起的 SST 冷却的第六次模拟中，应用了一维海洋混合层方案。结果显示 TC 强度没有显着降低。在第七次模拟中，使用了COAWST建模系统。COAWST模式模拟的SST与卫星观测结果一致，最终导致了对TC Gonu的路径和强度模拟的改进。增加的温度梯度对 TC 强度的影响较小，但相对于 CTL 模拟，北向轨迹有显着偏差。在考虑气旋引起的 SST 冷却的第六次模拟中，应用了一维海洋混合层方案。结果显示 TC 强度没有显着降低。在第七次模拟中，使用了COAWST建模系统。COAWST模式模拟的SST与卫星观测结果一致，最终导致了对TC Gonu的路径和强度模拟的改进。增加的温度梯度对 TC 强度的影响较小，但相对于 CTL 模拟，北向轨迹有显着偏差。在考虑气旋引起的 SST 冷却的第六次模拟中，应用了一维海洋混合层方案。结果显示 TC 强度没有显着降低。在第七次模拟中，使用了COAWST建模系统。COAWST模式模拟的SST与卫星观测结果一致，最终导致了对TC Gonu的路径和强度模拟的改进。在第七次模拟中，使用了COAWST建模系统。COAWST模式模拟的SST与卫星观测结果一致，最终导致了对TC Gonu的路径和强度模拟的改进。在第七次模拟中，使用了COAWST建模系统。COAWST模式模拟的SST与卫星观测结果一致，最终导致了对TC Gonu的路径和强度模拟的改进。