飓风天气下机载SFMR与星载微波遥感海面风速的对比分析

Comparisons of SFMR and Satellite Microwave Remote Sensed Sea Surface Wind Speed in Hurricane Weather

飓风天气下多种探测技术提供的海面风速的一致性备受关注。飓风侦察机搭载的步进频率微波辐射计(SFMR)提供的海面高风速数据是海面风速最主要的现场观测数据源。本文旨在分析SFMR风速与星载微波散射计(C波段欧洲MetOp系列卫星散射计ASCAT,Ku波段中法海洋卫星散射计CSCAT和中国HY-2系列卫星散射计HSCAT)和微波辐射计(SMAP和SMOS)遥感风速的一致性。通过分析SFMR风速随空间尺度变化的关系,进而提出了SFMR与散射计和辐射计数据进行时空匹配的方法。结果表明,高风速(>15 m·s^(–1))辐射计比散射计风速与SFMR风速的一致性更好,风速高于25 m·s^(–1)时Ku波段散射计风速趋于饱和。高风速下降雨也是影响散射计风速误差的重要因素,但依赖于风速的误差显著高于降雨影响带来的误差。基于SFMR数据进一步揭示了星载微波散射计和辐射计提供海面风速的误差特征,为遥感数据应用提供参考。

The accuracy and consistency of sea surface wind speed measurements during hurricane conditions have garnered significant attention.Among the various techniques,the Stepping Frequency Microwave Radiometer(SFMR)provides crucial in-situ data on sea surface high wind speeds.This study aims to compare wind speed measurements obtained from SFMR with those from space-borne micro-wave scatterometers such as the C-band European MetOp series satellite Scatterometer ASCAT,the Ku-band China-France Oceanography Satellite(CFOSAT)Scatterometer CSCAT,and the Chinese HY-2 se-ries satellite Scatterometer HSCAT,as well as microwave radiometers such as SMAP and SMOS.We es-tablish the relationship between SFMR wind speed and spatial scale and propose a spatio-temporal matching method to align SFMR data with scatterometer and radiometer data.This method assumes that the spatial distribution of TC wind field is unchanged relative to the hurricane direction in a cer-tain time range.According to the TC center path information of IBTrACS,the trajectory of SFMR is transformed into the relative coordinates of storm movement,which effectively extending the matching time difference between SFMR,scatterometer and radiometer sea surface wind speed data to 3 hours.Our findings indicate that radiometer measurements of high wind speeds(>15 m·s^(–1))exhibit greater con-sistency with SFMR compared to scatterometer measurements,and Ku-band scatterometer measure-ments tend to saturate when wind speeds exceed 25 m·s^(–1).The spatio-temporal matching results of SMAP and HSCAT also showed the same distribution characteristics.However,the ASCAT wind speed of C-band scatterometer still shows the overall increasing distribution characteristics.Additionally,Rain-fall during high wind conditions significantly affects scatterometer wind speed error is still observed by us,although the error associated with wind speed is more pronounced.This study contributes to a bet-ter understanding of the error characteristics of sea surface wind speed measurements obtained from space-borne microwave scatterometers and radiometers,thereby offering valuable insights for the appli-cation of remote sensing data,subsequent research can analyze the contribution of different data sources in the physical meaning of wind speed to the consistency analysis results.