Effect of SST gradient caused by Typhoon-Generated Cold Wake on the Subsequent Typhoon Tembin in models of varying resolutions

Abstract

<p><span>The Weather Research and Forecast (WRF) models have been used to investigate the sensitivity of simulations of Typhoon Tembin (1214) to changes in three horizontal grid spacings of 12km, 8km, and 6km and the effect of the cold wake generated by the previous Typhoon Bolaven (1215). It was observed that Bolaven-</span><span>generated cold wakes cooled up to 7 °C in the sea around the Korean Peninsula. There are many previous studies on track dynamics influenced by sea surface temperature (SST) gradient due to the cold wakes. However, the intensity and precipitation of the following tropical cyclone (TC) is not yet certain. Here we show that the effect of SST gradient on the following TC are examined with WRF models of varying resolutions using modified SST from observed real-time data of the Ieodo Ocean Research Station and the Yellow Sea buoy in Korea. In the track of TC, a higher resolution showed the faster and more eastward movement of TCs in all SST conditions. TC tends to move more eastward at all resolutions particularly when the cold wake is generated in the western region of TC. When there is no cold wake, the intensity of TC is very sensitive to the resolution of the experiment. If a cold wake is maintained on the western (eastern) sides, the intensity of TC is weaker(stronger) than no cold wake experiment and is less sensitive to differences in resolution. The precipitation rate of TCs in the cold wake of the eastern (western) region is lower (higher) than when there is no wake. As the aspect of horizontal resolutions, the precipitation rate of TC in higher resolution shows stronger than lower resolution. The TC-generated cold wake significantly affects intensity and movement in cold wake cases in the western region, regardless of the horizontal grid, for various reasons. </span></p>