1. 1 JRA-55 the Japanese 55-year reanalysis project - status and plan - Climate Prediction Division Japan Meteorological Agency

2. 2 JMA’s current Climate Data Assimilation System JRA-25 (1979~2004) production finished in 2006 –jointly conducted by JMA and Central Research Institute of Electric Power Industry (CRIEPI) –freely available for research purposes http://jra.kishou.go.jp/JRA-25/index_en.html –A full copy of the JRA-25 data set provided to NCAR http://dss.ucar.edu/datasets/ds625.0/http://dss.ucar.edu/datasets/ds625.0/ continued as JCDAS (2005~) –available 2 days behind the real time Over 1,300 registered users and 100 cited references as of Sep 2009 –The JRA-25 paper (Onogi et al., 2007, JMSJ) http://www.jstage.jst.go.jp/article/jmsj/85/3/85_369/_article extensively used for many activities at JMA –real-time climate monitoring, verification of seasonal forecasts, atmospheric forcing fields for the ocean data assimilation, chemical transport simulations and so on

3. 3 Overview of JRA-55 providing a fundamental data set for  researches on climate change and decadal variability in the last half century  real-time climate monitoring  verification of seasonal forecast and climate models  atmospheric forcing fields for ocean data assimilations  chemical transport simulations  carbon cycle simulations  water resource management  estimation of renewable energy resources  severe weather risk assessment and much more Phase 1 (2009~2012) JRA-55 (1958~2012) Reanalysis of past observations using a constant state-of-the-art data assimilation system Phase 2 (2013~2015) Regional downscaling over Japan (1958~2012) Details to be determined Boundary fields 60-km resolution global climate data set High-resolution (~5 km) climate data set over Japan

4. 4 Observations for JRA-55 First time for reanalyses Improved from or added to JRA-25

5. 5 Specifications of data assimilation system JRA-25 (1979~2004)JRA-55 (1958~2012) Resolution T106L40 (~120km) (top layer at 0.4 hPa) TL319L60 (~60km) (top layer at 0.1 hPa) Time integration EularianSemi-Lagrangian Long-wave radiation Line absorption Statistical band model Water vapor continuum e-type Line absorption Table lookup + K-distribution Water vapor continuum e-type + p-type Assimilation scheme 3D-Var 4D-Var (with T106 inner model) B matrix Constant Different B matrices for pre-satellite and satellite eras Bias correction (radiosonde) Radiation bias only (Andrae et al., 2004) RAOBCORE v1.4 (Haimberger, 2007, J. Climate) Bias correction (radiances) For satellite OfflineVariational Bias Correction

6. 6 Other changes from the JRA-25 system Revised short-wave radiation scheme –Retuned absorption coefficients for O 3, CO 2 and O 2 –Added more bands for CO 2 and O 2 Enhanced QC for conventional data –Application of thorough QC procedures for conventional data –Revised QC thresholds for conventional data Improved treatment of cloud effects in the radiation scheme –Revised treatment of vertically overlapping clouds –Retuned cloud radiative properties Introduction of a convective triggering scheme into the deep convective parameterization Updated radiative transfer model for satellite radiances –Introduction of RTTOV-9 (Saunders et al., 2008)

7. 7 Boundary and forcing fields JRA-25 (1979~2004)JRA-55 (1958~2012) Radiatively active gases H 2 O, CO 2, O 3 H 2 O, CO 2, O 3, CH 4, N 2 O, CFC-11, CFC-12, HCFC-22 GHG concentrations Constant at 375 ppmv (CO 2 ) vary over time Ozone Daily 3-D ozone (produced by AED/JMA) (-1978) Monthly climatology (1979-) New daily 3-D ozone (produced using a revised CTM) Aerosols Annual climatology for continental and maritime aerosols Monthly climatology for continental and maritime aerosols SST Sea ice COBE SST (Ishii et al., 2005, I.J.Clim.) COBE SST (Same as JRA-25)

8. 8 JRA-55 production schedule Jul 2010start of Stream B Sep 2010start of Stream A Early 2013completion of production Mid 2013product release –Production will be continued as a new JCDAS

9. 9 Summary JRA-55 improves upon JRA-25 in many respects, –a longer reanalysis period, extending back in 1958, –much better forecast performance than JRA-25, –significantly reduced cold bias in the lower stratosphere, and –reduced dry bias over the Amazon basin. Quality of analysis changes inevitably due to changes in observing systems, but there is a good prospect that a reasonably homogeneous analysis will be produced in the northern hemisphere troposphere. –Quality of analysis is reasonablely high over the regions that radiosondes cover even if no satellite data is available. –On the other hand, it is anticipated that analyses of the pre-satellite era would degrade seriously in the southern hemisphere troposphere.

10. 10 Summary (cont.) There is a considerable possibility that quality of analysis in the pre- satellite era will improve by tuning the background error. –An experiment with a global constant scaling factor showed a small but positive result in the southern hemisphere. The JRA-55 production is planned to start in Jun 2010 and expected to complete by early 2013.