The Japanese 55-year Reanalysis using conventional data only with high resolution SST(JRA-55CHS)

The Meteorological Research Institute of the Japan Meteorological Agency, under support of the Japanese “Hotspot project” (Nakamura et al. 2015), is constructing an additional product of the Japanese 55-year Reanalysis (JRA-55) family. The product, named “JRA-55CHS”, utilizes high-resolution (quarter-degree) sea-surface temperature (SST) as lower-boundary condition with the same data assimilation system as the JRA-55 Conventional (JRA-55C), into which no satellite data is assimilated (Masunaga et al. 2018). The dataset is intended to be suitable for diagnosing small-scale oceanic influence (such as the one from the western boundary currents) on atmosphere, which is not necessarily well represented in JRA-55 and JRA-55CHS. The reanalysis period of the JRA-55CHS is from 1985 through 2012. We recommend to use together with the JRA-55C data.