Multi-sensor study of precipitable water vapor and atmospheric profiling from microwave radiometer, GNSS/MET, radiosonde, and ECMWF reanalysis in Beijing
Multi-sensor study of precipitable water vapor and atmospheric profiling from microwave radiometer, GNSS/MET, radiosonde, and ECMWF reanalysis in Beijing
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DOI：
10.1117/1.jrs.14.044514
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发表时间：
2020-10
影响因子：
1.7
通讯作者：
Heng Hu;Rongkang Yang;Wen-Chau Lee;Yunchang Cao;Jiajia Mao;Lina Gao
中科院分区：
文献类型：
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作者：
Heng Hu;Rongkang Yang;Wen-Chau Lee;Yunchang Cao;Jiajia Mao;Lina Gao
抽象的。我们比较了用国产地面微波辐射计(MWR PWV)测定的可降水量(PWV)与无线电探空仪(RS PWV)、全球导航卫星系统(GNSS PWV)和欧洲中期天气预报中心(ECMWF)(EC PWV)的再分析所测得的PWV。MWR PWV受降水的影响，与其他三次观测有很大的不同。水利枢纽脉冲量与卫星脉冲量的相关系数为0.934(0.933)，均方根误差为17.19 mm(16.05 mm)，卫星脉冲量与卫星脉冲量的相关系数为0.989(0.986)，均方根误差为17.04 mm(15.83 mm)。MWR PWV和其他观测的散射分布显示出与地面气温负相关的系统偏差。经多项式拟合和校正后，最大水流量与最大风速和最小风速的相关系数分别提高到0.993和0.99，均方根误差分别减小到14.13和15.86 mm。温度和水汽密度廓线是由亮温反演得到的，能够反映亮温的质量。由于从地面微波辐射计反演的PWV与亮温具有线性关系，因此可以根据亮温的质量来分析PWV的精度。我们发现，2000m以下的温度廓线差异较小，而2000m以下的水汽密度廓线差异最大。这一发现反映了亮温的差异，这可能是PWV观测不准确的原因。
Abstract. We compare the precipitable water vapor (PWV) determined using a domestic ground-based microwave radiometer (MWR PWV) with PWV measurements from radiosondes (RS PWV), the Global Navigation Satellite System (GNSS PWV), and reanalysis from the European Centre for Medium-Range Weather Forecasts (ECMWF) (EC PWV). The MWR PWV is affected by precipitation, and thus it differs greatly from the other three observations. The correlation coefficient between the MWR PWV and RS PWV (EC PWV) is 0.934 (0.933), and the root mean square error (RMSE) is 17.19 mm (16.05 mm), whereas the correlation coefficient between the GNSS PWV and RS PWV (EC PWV) is 0.989 (0.986), and the RMSE is 17.04 mm (15.83 mm). The scatter distributions of the MWR PWV and the other observations show a systematic deviation that is negatively correlated with the surface air temperature. After polynomial fitting and corrections are applied, the correlation coefficients between the MWR PWV and the RS PWV and EC PWV increase to 0.993 and 0.99, and the RMSEs decrease to 14.13 and 15.86 mm, respectively. The temperature and water vapor density profiles are retrieved from the bright temperature and can reflect the quality of the bright temperature. Because the PWV retrieved from the ground-based MWR has a linear relationship with the brightness temperature, the accuracy of the PWV can be analyzed in terms of the quality of the brightness temperature. We found that the differences in the temperature profile below 2000 m are smaller, whereas those in the water vapor density profile below 2000 m show the largest difference. This finding reflects the differences in the brightness temperature, which may be the cause of the inaccurate PWV observations.