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各主要流域的平均地表累积、净物质平衡、其变异性及其重要性的信息。为此目的，将利用水平分辨率为50公里、垂直高度为25层的区域气候模式HIRHAM，通过可靠的天气尺度气旋模拟来模拟水汽分布。最近的研究表明，在欧洲再分析资料的驱动下，HIRHAM模式能够很好地模拟南极的大气环流和地表过程。自欧洲气象中心业务数据质量提高以来，通过同化高分辨率红外辐射探测仪(HIRS)数据，推动HIRHAM的工作自1996年以来得到了改善。模拟结果将与卫星大地测量结果进行比较：即来自全球定位系统的水蒸气时间序列和GRACE重力场卫星飞行任务观测到的质量变化。这种对累积和质量变化的独立估计的比较将极大地提高我们对南极洲气候学和当今变化的了解。无论是基于区域气候模式HIRHAM的模拟，还是基于全球定位系统和GRACE任务的卫星大地观测，都将延长到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.