Application of GPS Water Vapor Information to Interdisciplinary Studies

为了将日本地理调查研究所（GSI）在日本岛的全国GPS阵列GEONET上常规获取的GPS可降水量（PWV）信息应用于全球变暖对降水增加的影响、遥感水汽校正、大气污染研究等跨学科研究，(1)详细评价GEONET的GPS可降水量（PWV）；(2)对GPS PWV进行了独立于GSI常规分析的再分析；(B)建立了日本列岛GPS PWV信息数据库。结果如下：(1) GEONET的GPS PWV受海洋潮汐载荷的影响。(2)采用GIPSY软件对GPS PWV进行再分析时，有无大气延迟梯度模型，其精度与常规分析GPS PWV在GSI中的精度几乎相同，可靠性更高。针对(3)，构建可互联网访问的GPS PWV数据库，并向用户开放。通过GIPSY软件重新分析的GPS PWV数据也将通过数据库向用户开放。

In order to apply GPS precipitable water vapor (PWV information retrieved routinely from a nationwide GPS array called GEONET over the Japanese Island, conducted by the Geographical Survey Institute (GSI) of Japan, to interdisciplinary studies such as effects of the global warming on precipitation increase, the water vapor correction for remote-sensing, air pollution studies, etc., (1) detailed evaluation of GPS PWV from GEONET, (2) reanalysis of GPS PWV independent from the routine analysis in GSI, and (B) construction of internet accessible GPS PWV information data base over the Japanese Islands are done in this study. The results are as follows. Concerning (l), GPS PWV from GEONET have effects of ocean tidal loading. Concerning (2), reanalysis of GPS PWV by using GIPSY software with and without atmospheric delay gradient model show almost same accuracy and have higher reliability than the routinely analyzed GPS PWV in GSI. Concerning (3), internet accessible GPS PWV data base is constructed and will be opened to users. The reanalyzed GPS PWV data by GIPSY software will also be opened to users through the data base.