飓风中卫星臭氧总柱观测与位涡相关性和在飓风中心定位中的应用

Correlation between satellite total column ozone observations and potential vorticity in hurricane and the application of hurricane center positioning

本文使用搭载于极轨气象卫星S-NPP(Suomi National Polar-orbiting Partnership)的臭氧成像廓线仪(Ozone Mapping and Profiler Suite,OMPS)观测的臭氧总柱(Total Column Ozone,TCO)资料对大西洋飓风“Maria”(2017)进行研究。针对对流区域TCO与气柱平均位涡(Mean column-integrated Potential Vorticity,MPV)的低相关性构建了分区域线性回归模型,不仅能同时提高大尺度和对流尺度上TCO和MPV的相关性,还能提高对流区域S-NPP OMPS TCO观测资料的利用率(95.5%)。TCO观测资料可以清晰地反映出飓风的顶部结构,据此可得到对流层顶附近的飓风中心位置。卫星总柱臭氧资料对飓风Maria中心定位结果与最佳路径的距离相差58.1 km,略大于使用S-NPP先进技术微波探测仪(Advanced Technology Microwave Sounder,ATMS)、MetOp-A微波湿度计(Microwave Humidity Sounder,MHS)和FY-3B微波湿度计(MWHS)亮温观测资料得到的Maria中心定位结果与最佳路径的距离(47.5 km)。臭氧定位结果与垂直风切变(Vertical Wind Shear,VWS)具有一定关系,垂直风切变越强,臭氧资料定位中心偏离最佳路径越大。本研究构建的分区域线性回归模型可作为间接同化卫星TCO资料的观测算子,也可应用到涡旋初始化中,以改进飓风路径和强度预报水平。

Applications of Total Column Ozone(TCO)observations from the Ozone Mapping and Profiler Suite(OMPS)onboard the polar-orbiting meteorological satellite Suomi National Polar-orbiting Partnership(S-NPP)to Hurricane“Maria”(2017)were studied.To address the issue of low correlation between TCO and Mean column-integrated Potential Vorticity(MPV)in convective regions,this paper constructs two regime-dependent linear regression models.The division of TCO data into two regimes not only improves the correlation between TCO and MPV at both large-and convective scales,but increases the utilization rate(95.5%)of the S-NPP OMPS TCO data in convective regions.TCO observations can clearly reflect the top structure of hurricane,and accordingly locate the center of the hurricane near the top of the tropopause.The distance difference between the satellite ozone center and the best track for Hurricane Maria is 58.1 km,which is slightly larger than the distance(47.5 km)between the best track and the center positioning based on the brightness temperature observations from the Advanced Technology Microwave Sounder(ATMS)onboard S-NPP,the Microwave Humidity Sounder(MHS)onboard MetOp-A,and the Microwave Humidity Sounder(MWHS)onboard FY-3B.The ozone positioning results have a dependence on the Vertical Wind Shear(VWS).The stronger the VWS,the greater the deviation of the ozone data positioning center from the best track.The regime-dependent linear regression models constructed in this study can be used as an observational operator for indirectly assimilating satellite TCO observations and for vortex initialization to improve hurricane track and intensity forecasting.