A multi‐sensor study of water vapour from radiosonde, MODIS and AERONET: a case study of Hong Kong
A multi‐sensor study of water vapour from radiosonde, MODIS and AERONET: a case study of Hong Kong
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DOI：
10.1002/joc.3412
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发表时间：
2013-01
期刊：
影响因子：
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通讯作者：
Zhizhao Liu;M. Wong;J. Nichol;P. W. Chan
中科院分区：
文献类型：
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作者：
Zhizhao Liu;M. Wong;J. Nichol;P. W. Chan
水汽是绿色温室气体之一，也是影响天气预报的关键参数。香港位于南中国海边缘，又受潮湿的亚洲季候风影响，比其他大部分城市都要多暴雨。香港是世界上人口密度最高的城市之一，准确观测水汽对预测恶劣天气有特别重要的意义。本文分析和交叉验证了过去6年的AERONET太阳光度计水汽观测、9年的中分辨率成像光谱仪（MODIS）TERRA卫星图像水汽观测和38年的无线电探空仪水汽观测。将空间分辨率分别为1公里和5公里的中分辨率成像分光仪水汽业务产品，即MOD 05和MOD 07，与无线电探空仪和AERONET数据进行了比较。MOD05和MOD07水汽产品与探空资料的相关系数分别为0.878和0.876，与AERONET资料的相关系数分别为0.822和0.976。结果还表明，无线电探空仪和AERONET水汽观测结果具有较好的一致性，相关性r = 0.988，平均绝对差（MAD）较小，均方根误差（RMS）分别为0.197和0.289 cm。虽然卫星数据（频率为每天一次）代表香港所有地区的水汽覆盖范围，但由于时间分辨率较低，无法满足短期天气预测的需求。每天两次的无线电探空仪观测在时间上也是不够的。这项研究表明，AERONET太阳光度计可以提供准确和高时间分辨率的水汽数据，可用于短期天气预报和长期气候变化研究。皇家气象学会
Water vapour is one of green house gases (GHG) and a key parameter affecting weather forecasting. Situated on the edge of the South China Sea and in the path of the wet Asian monsoon, Hong Kong experiences more rainstorms than most other cities. An accurate observation of water vapour has a special significance in severe weather prediction for Hong Kong, one of the cities with the highest density of population in the world. In this paper, water vapour observations over the last 6 years from an AErosol RObotic NETwork (AERONET) sunphotometer, 9 years from the MODerate resolution Imaging Spectroradiometer (MODIS) TERRA satellite images and 38 years from radiosonde were analysed and cross‐validated. The operational MODIS water vapour products, namely MOD05 and MOD07, with a spatial resolution of 1 and 5 km, respectively, were compared with both radiosonde and AERONET data. The correlation coefficients between MODIS water vapour products and radiosonde data are r = 0.878 and 0.876 for MOD05 and MOD07 products, and the correlations of those with AERONET data are r = 0.822, r = 0.976, respectively. The results also indicate that radiosonde and AERONET water vapour observations have a good agreement, with a correlation of r = 0.988 and a small mean absolute difference (MAD), and root mean square error (RMS) of 0.197 and 0.289 cm, respectively. Although the satellite data (with a frequency of once per day) represent water vapour coverage of all the territories of Hong Kong, they do not meet short‐term weather prediction demand due to their low temporal resolution. Radiosonde observations with a frequency of twice per day are also temporally inadequate. This study demonstrates that the AERONET sunphotometer can provide accurate and high temporal resolution water vapour data which can be used for short‐term weather prediction and long‐term climate change research. Copyright © 2011 Royal Meteorological Society