水汽标高是一个反映水汽垂直分布特征的参数,也是全球导航卫星系统(global navigation satellite system,GNSS)对流层天顶湿延迟改正和GNSS水汽层析中的一个辅助参数.本文对2006—2012年水汽标高的时间序列进行频谱分析,发现水汽标高在时间上呈现出年周期和半年周期变化,因此利用包含年周期和半年周期的三角函数来表达水汽的时变规律,然后利用欧洲中尺度天气预报中心(European Centre for Medium-range Weather Forecasting,ECMWF)的数据在全球1°×1°的格网点上分别拟合了三角函数的系数.通过上述方法首次构建了一个全球适用的水汽标高模型GSH,该模型既体现了水汽标高的时变特性又考虑了其地理差异.以无线电探空数据为参考,GSH具有-0.19 km的偏差(bias)和1.81 km的均方根误差(root mean square error,RMSE);以ECMWF数据为参考,GSH具有0.04 km的bias和1.52 km的RMSE.GSH整体上表现出了比较稳定的精度,可服务于GNSS气象学研究,也可为其他相关气象研究提供水汽标高参考.
Water vapor scale height is an important parameter that reflects the vertical distribution of water vapor and also a key parameter that is usually used to make height correction in GNSS zenith wet delay and tropospheric tomography. Based on the spectral analysis of the time series of water vapor scale height from 2006 to 2012, it is found that the water vapor scale height shows an annual and a semi-annual variation in time. So, the trigonometric functions with an annual and a semi-annual cycle are used to express the time variation of water vapor scale height.And then the European Centre for Medium-range Weather Forecasting (ECMWF) data are used to fit the coefficients of the trigonometric functions at 1°×1° grid points on a global scale. By these methods,a global water vapor scale height model GSH is firstly established, which considers both the time and geographic variations of water vapor scale height. By taking radiosonde data as reference, the GSH model has bias of -0.19 km and rootmean square error (RMSE) of 1.81 km; by taking ECMWF data as reference, the GSH model has bias of 0.04 km and RMSE of 1.52 km. The GSH model shows a relatively even accuracy on a global scale, and could serve the study of GNSS meteorology and provide reference values of water vapor scale height for related meteorological researches.
[1] BEVIS M, BUSINGER S, HERRING TA, et al. GPS Meteorology: Remote Sensing of Atmospheric Water Vapor Using the Global Positioning System[J]. Journal of Geophysical Research: Atmospheres, 1992, 97(D14): 15787-15801.
[2] JACOB D. The Role of Water Vapour in the Atmosphere.A Short Overview from a Climate Modeller's Point of View[J]. Physics and Chemistry of the Earth, Part A: Solid Earth and Geodesy, 2001, 26(6-8): 523-527.
[3] CHEN Junyong. On the Error Analysis for the Remote Sensing of Atmospheric Water Vapor by Ground Based GPS[J]. Acta Geodaetica et Cartographica Sinica, 1998, 27(2): 113-118. (陈俊勇. 地基GPS遥感大气水汽含量的误差分析[J]. 测绘学报, 1998, 27(2): 113-118.)
[4] ZHANG Baocheng, OU Jikun, YUAN Yunbin, et al. Extracting Precise Atmospheric Propaganda Delays from Multiple Reference Station GPS Networks[J]. Acta Geodaetica et Cartographica Sinica, 2012, 41(4): 523-528. (张宝成, 欧吉坤, 袁运斌, 等. 多参考站GPS网提取精密大气延迟[J]. 测绘学报, 2012, 41(4): 523-528.)
[5] QIAN Chuang, HE Changyong, LIU Hui. Regional Precise Troposphere Delay Modeling Based on Spherical Cap Harmonic Analysis[J]. Acta Geodaetica et Cartographica Sinica, 2014, 43(3): 248-256. (钱闯, 何畅勇, 刘晖. 基于球冠谐分析的区域精密对流层建模[J]. 测绘学报, 2014, 43(3): 248-256.)
[6] KOU Leilei, XIANG Maosheng. Effect of Temporal Variation of Atmospheric Refraction on Geosynchronous Circular SAR Focusing Performance[J]. Acta Geodaetica et Cartographica Sinica, 2014, 43(9): 917-923. (寇蕾蕾, 向茂生. 大气折射率时间变化对地球同步轨道圆迹SAR聚焦性能的影响[J]. 测绘学报, 2014, 43(9): 917-923.)
[7] LI Chao, WEI Heli, WANG Zhenzhu, et al. Statistical Study on the Scale Height of Atmospheric Water Vapor in Hefei Region[J]. Journal of Atmospheric and Environmental Optics, 2008, 3(2): 115-120. (李超, 魏合理, 王珍珠, 等. 合肥地区大气水汽标高变化特征的统计研究[J]. 大气与环境光学学报, 2008, 3(2): 115-120.)
[8] ROCKEN C, VAN HOVE T, WARE R. Near Real-time GPS Sensing of Atmospheric Water Vapor[J]. Geophysical Research Letters, 1997, 24(24): 3221-3224.
[9] TOMASI C. Determination of the Total Precipitable Water by Varying the Intercept in Reitan's Relationship[J]. Journal of Applied Meteorology, 1981, 20(9): 1058-1069.
[10] REITAN C H. Surface Dew Point and Water Vapor Aloft[J]. Journal of Applied Meteorology, 1963, 2(6): 776-779.
[11] TOMASI C. Precipitable Water Vapor in Atmospheres Characterized by Temperature Inversions[J]. Journal of Applied Meteorology, 1977, 16(3): 237-243.
[12] ZHANG Xuewen. The Vertical Distribution Law of Vapor Pressure in Xinjiang, China[J]. Bimonthly of Xinjiang Meteorology, 2002, 25(4): 1-2, 14. (张学文. 新疆水汽压力的铅直分布规律[J]. 新疆气象, 2002, 25(4): 1-2, 14.)
[13] SCHVLER T. The TropGrid2 Standard Tropospheric Correction Model[J]. GPS Solutions, 2014, 18(1): 123-131.
[14] YU Shengjie, LIU Lintao, LIANG Xinghui. Influence Analysis of Constraint Conditions on GPS Water Vapor Tomography[J]. Acta Geodaetica et Cartographica Sinica, 2010, 39(5): 492-496. (于胜杰, 柳林涛, 梁星辉. 约束条件对GPS水汽层析解算的影响分析[J]. 测绘学报, 2010, 39(5): 492-496.)
[15] FLORES A, RUFFINI G, RIUS A. 4D Tropospheric [JP]Tomography Using GPS Slant Wet Delays[J]. Annales Geophysicae, 2000, 18(2): 223-234.
[16] FLORES A, DE ARELLANO J V G, GRADINARSKY L P,[JP] et al. Tomography of the Lower Troposphere Using a Small Dense Network of GPS Receivers[J]. IEEE Transactions on Geoscience and Remote Sensing, 2001, 39(2): 439-447.
[17] DAVIS J L, HERRING T A, SHAPIRO I I, et al. Geodesy[JP] by Radio Interferometry: Effects of Atmospheric Modeling Errors on Estimates of Baseline Length[J]. Radio Science, 1985, 20(6): 1593-1607.
[18] WEXLER A. Vapor Pressure Formulation [JP]for Water in the[JP] Range 0 to 100°C: A Revision[J]. Journal of Research of the National Bureau of Standards-A: Physics and Chemistry, 1976, 80A(5-6): 775-785.
[19] WEXLER A. Vapor Pressure Formulation for Ice[J]. Journal[JP] of Research of the National Bureau of Standards-A: Physics and Chemistry, 1977, 81A(1): 5-20.
[20] LAGLER K, SCHINDELEGGER M, BÖHM J, et al. [JP]GPT2: Empirical Slant Delay Model for Radio Space Geodetic Techniques[J]. Geophysical Research Letters, 2013, 40(6): 1069-1073.
[21] YAO Y B, ZHANG B, XU C Q, et al. Improved One-multi-parameter Models that Consider Seasonal and Geographic Variations for Estimating Weighted Mean Temperaturein Ground-based GPS Meteorology[J]. Journal of Geodesy, 2014, 88(3): 273-282.
[22] LI W, YUAN Y B, OU J K, et al. A New Global Zenith Tropospheric Delay Model IGGtrop for GNSS Applications[J]. Chinese Science Bulletin, 2012, 57(17): 2132-2139.
[23] YAO Yibin, HE Changyong, ZHANG Bao, et al. A New Global Zenith Tropospheric Delay Model GZTD[J]. Chinese Journal of Geophysics, 2013, 56(7): 2218-2227. (姚宜斌, 何畅勇, 张豹, 等. 一种新的全球对流层天顶延迟模型GZTD[J]. 地球物理学报, 2013, 56(7): 2218-2227.)
