Atmospheric total water vapour and mass accumulation in Antarctica: Regional climate model simulations versus satellite obser vations

该项目的目的是改进关于南极洲主要流域的平均地表积累、净质量平衡、变率及其重要性的资料。为此，我们将采用HIRHAM区域气候模式，以50公里的水平分辨率和25个垂直高度，模拟水汽分布，并可靠地模拟天气尺度的气旋。最近的研究表明，HIRHAM模式在欧洲再分析数据的驱动下，能够以足够的精度代表南极的大气环流和地表过程。由于ECMWF运行数据的质量，自1996年以来，通过同化高分辨率红外辐射测深仪（HIRS）数据，驱动HIRHAM的工作得到了改善。该项目重点开发1996年至2008年期间的数据集。模拟结果将与卫星大地测量观测结果进行比较：即GPS的水汽时间序列和GRACE重力场卫星任务观测到的质量变化。这种对累积量和质量变化的独立估计的比较将大大提高我们对气候学和现今南极洲变化的认识。基于HIRHAM区域气候模式的模拟和基于GPS和GRACE任务的卫星大地测量观测将延长到2008年，涵盖国际极地年的时间。

The aim of this project is an improved information on the mean surface accumulation respectively net mass balance, its variability and its importance for the main drainage basins in Antarctica. For this aim, simulations of the water vapour distribution with a reliable simulation of synoptic-scale cyclones will be done by applying the regional climate model HIRHAM with 50 km horizontal resolution and 25 vertical levels. It was shown recently that the HIRHAM model represents the atmospheric circulation and surface processes of Antarctica with sufficient accuracy if driven by the European Reanalyses data. Since the quality of the ECMWF operational data, driving HIRHAM has been improved from 1996 by assimilation of High-resolution Infrared Radiation Sounder (HIRS) data the project focuses on developing data sets for the period from 1996 until 2008. The simulation results will be compared to satellite geodetic observations: namely water vapour time series from GPS and mass variations observed by the GRACE gravity field satellite mission. This comparison of independent estimates on accumulation and mass changes will significantly improve our knowledge on climatology and present-day changes in Antarctica. Both the simulations based on the regional climate model HIRHAM and satellite geodetic observations based on GPS and the GRACE mission will be extended until 2008 covering the time of the International Polar Year.