四川盆地及川西高原地区FY-3D/VASS温湿度廓线检验

Validation of FY-3D/VASS Retrieved Temperature and Humidity Profiles in Sichuan Basin and Western Sichuan Plateau

利用2020—2021年探空站及ERA5再分析资料,对FY-3D大气垂直探测系统(VASS)温湿度廓线在四川盆地及川西高原地区的精度进行检验。结果表明:与ERA5数据相比,FY-3D/VASS温度在盆地和高原地区不同季节的平均偏差分别为-0.631~0.500℃和-2.230~-1.234℃,均方根误差分别为2.117~3.222℃和3.077~3.460℃,高原比盆地地区大,在垂直高度上,盆地地区的精度在800~700 hPa较低,高原地区的精度随高度的减小逐渐降低;FY-3D/VASS比湿呈现一致的负偏差,平均偏差在盆地和高原地区分别为-0.775~-0.525 g·kg^(-1)和-1.096~-0.347 g·kg^(-1),均方根误差分别为1.251~2.367 g·kg^(-1)和0.696~1.991 g·kg^(-1),在700~600 hPa的精度较低;通过将两组检验的平均偏差相加,间接建立FY-3D/VASS基于探空温湿度数据的检验结果,其中FY-3D/VASS温度在盆地地区的平均偏差较小,高原地区平均偏低2.440℃左右,比湿在盆地和高原地区平均偏低0.612 g·kg^(-1)左右。上述结果可提升FY-3D/VASS温湿度反演产品在四川盆地及川西高原地区的天气气候应用能力。

FY-3D Vertical Atmospheric Sounding System(VASS)temperature and humidity profile products are evaluated using radiosonde observations and ERA5 reanalysis dataset in Sichuan Basin and Western Sichuan Plateau.The results show that relative to ERA5 data,the average bias of FY-3D/VASS temperature in different seasons is from-0.631 to 0.500℃and from-2.230 to-1.234℃respectively,and the root mean square error is from 2.117 to 3.222℃and from 3.077 to 3.460℃in the basin and the plateau area respectively.Vertically,the accuracy of temperature is low at 800-700 hPa in the basin area and gradually decreases as the height decreases in the plateau area.The average bias of FY-3D/VASS specific humidity relative to ERA5 data is generally negative,while the average bias in different seasons is from-0.775 to-0.525 g·kg^(-1)and from-1.096 to-0.347 g·kg^(-1)respectively,and the root mean square error is from 1.251 to 2.367 g·kg^(-1)and from 0.696 to 1.991 g·kg^(-1)at the basin and the plateau area respectively.The accuracy of specific humidity is relatively low at 700-600 hPa.In consideration of the small diurnal difference in the accuracy of FY-3D/VASS temperature and humidity,the average biases of the two groups of evaluations are properly added.As a result,the average biases of FY-3D/VASS temperature and specific humidity can be indirectly obtained based on the radiosonde observations.Relative to radiosonde observations,the average bias of FY-3D/VASS temperature in the basin area is relatively small and the average bias in the plateau area is lower by about 2.440℃.The average bias of FY-3D/VASS specific humidity in the basin and plateau area is lower by about 0.612 g·kg^(-1).The above-mentioned results are significant for improving the weather and climate application ability of FY-3D/VASS temperature and humidity profile products in Sichuan Basin and Western Sichuan Plateau.