观测系统模拟和评估:进展及展望

An Overview on the Development of the Observing System Simulation Experiments (OSSEs)

开发、维护和使用新的天基观测系统非常昂贵,并且从仪器发展和配置的完成到业务应用通常有明显的时间延迟(6~12个月)。因此需要事先对现有和未来观测系统的影响和应用技术进行定量评估,以优化包括仪器指标确定、轨道选取、星座布局和数值天气预报(Numerical Weather Prediction-NWP)等应用。观测系统模拟试验(Observing System Simulation Experiments,OSSEs)是一种敏感性试验,旨在回答新的观测系统或是对旧观测系统的重新部署带来的影响和价值的问题,通常指在数值天气预报和气候预测中的影响。OSSEs还为在数值天气预报中应用新的数据类型以及优化已有数据类型提供支撑。数值天气预报模式和卫星资料同化系统的快速发展(例如全天侯、全地表覆盖资料的同化等)以及未来大量的新型观测系统的部署(例如静止卫星上的红外高光谱及微波大气探测仪等)对OSSEs试验的同步发展带来挑战和机遇。未来的OSSE试验采用更高时空分辨率分析场、耦合系统分析场等来模拟更加逼近真实状态的自然场景(Nature Run,NR),并采用更先进的辐射传输模式和同化系统来进行观测系统的模拟和影响试验等。同时基于数值天气预报模式的OSSEs将拓展到短时临近OSSEs,气候OSSEs等多种形式的观测和模拟评估系统。

The development,maintenance and use of a new space-based observing system is very expensive.There is usually a significant time delay (around 6 months to 1 year) from the completion of the instrument development and configuration to operational applications.It is very important to quantitatively evaluate the impacts and applications of the current and future observing system in advance to deploy it.The evaluation of the observing systems includes the instrument determination,orbit selection,constellation configuration,the applications to the numerical prediction and etc.The Observing System Simulation Experiments (OSSEs) is a sensitive experiment to study the value of new or proposed observing systems and the impacts of their data.An OSSE is designed to use the data assimilation method to investigate the potential impact of the future observing systems.In an OSSE,a nature run (NR) is generated by a very high temporal and spatial resolution numerical weather prediction (NWP) model output.The rapid development of NWP models and satellite data assimilation bring challenges as well opportunities to the development of OSSEs.Quick-OSSE,Hybrid OSSE and other forms of OSSE are extended to effectively evaluate future observing systems.