The Japanese Reanalysis for Three Quarters of a Century

The Japan Meteorological Agency is currently conducting the Japanese Reanalysis for Three Quarters of a Century (JRA-3Q), which covers the period from September 1947 onward to extend the current period of data coverage and improve the quality of long-term reanalysis. The project involves a sophisticated data assimilation system (based on the operational set-up as of December 2018) incorporating development results from the operational NWP system and sea surface temperature analysis achieved since the Japanese 55-year Reanalysis (JRA-55, based on the operational set-up as of December 2009). New datasets of past observations are also assimilated, including rescued historical observations and reprocessed satellite data supplied by meteorological and satellite centers worldwide. Many of the deficiencies of JRA-55 are alleviated in JRA-3Q, providing a high-quality homogeneous reanalysis dataset that covers the previous 75 years.

日本气象厅目前正在进行覆盖近三个半世纪的日本再分析项目（JRA-3Q），该项目始于1947年9月，旨在扩展现有数据覆盖范围并提升长期再分析数据的质量。该项目涉及一个复杂的数据同化系统（基于2018年12月为止的运行配置），该系统融合了自日本55年再分析（JRA-55，基于2009年12月为止的运行配置）以来在业务数值天气预报系统以及海表温度分析方面的研究成果。同时，还将新的历史观测数据集纳入其中，包括从全球气象和卫星中心抢救的历史观测数据以及重新处理的卫星数据。JRA-3Q在许多方面缓解了JRA-55的不足，提供了一组高质量、同质化的再分析数据集，覆盖了过去的75年。