Japanese Reanalysis JRA-25 and JRA-55 H. Kamahori1, A. Ebita2, S. Kobayashi2, Y. Ota2, M. Moriya2, R. Kumabe2, K. Onogi2, Y. Harada2, S. Yasui2, K. Miyaoka2, K. Takahashi2, C. Kobayashi1, H. Endo1, M. Soma2, Y. Oikawa2, T. Ishimizu2 1MRI, 2JMA Overview of JRA-25 Japanese 25-years Reanalysis • Long range reanalysis based on JMA's operational global assimilation system • Joint Project by JMA and CRIEPI • Target Period : 1979-2004 • Completed in 2005 • Continued as operational JCDAS after 2005 Input Observation in JRA-25 1990 1980 2000 2004 02.08 Conventional (ERA-40 obs.) (JMA-archives) 84.5 Chinese Snow 03.12 CMV/AMV METEOSAT Reprocessed AMV GMS Reprocessed AMV 88.5 82.5 87.3 TOVS 1c 96.1 93.12 (HIRS,MSU 1d / SSU 1c used) 03.5 98.10 ATOVS 1c 98.11 SSM/I PW,snow ERS-1,2 QuikSCAT Wind Profiler 87.6 95.4 93.7 Fiorino TCR wind MODIS polar wind Translucent : available but not used White : not in JMA 01.1 01.10 Performance of JRA-25 • • • • Tropical Cyclones Global Temperature Forecast Score as initial state of JRA-25 Global Precipitation Impact of TC Wind Retrieval Data Hatsushika et al., 2005 Using TC wind data, tropical cyclones are properly represented 1200 UTC 15 September 1990 in the eastern North Pacific JRA-25 with TCR Control without TCR Norbert Marie 1800 UTC 19 September 1990 in the western North Pacific JRA-25 with TCR Control without TCR Flo Global Detection Rate of Tropical Cyclones Detection rate JRA-25 ~ 90% ERA-40 ~ 50% Grey：Observed TC (Best track) Blue : Detected TC The detecting method is based on 1. relative vorticity 2. sea level pressure 3. tropospheric thickness. Courtesy: H. Hatsushika Surface air temperature Trend JRA-25 and ERA-40 Global Temperature Anomaly JRA-25, ERA-40, CRU(Jones) Top : monthly mean, Bottom : 5-year moving avarage Distribution of tendency (K/decade) Courtesy: J. Tsutsui Global Temperature Anomaly Anomaly from averaged temperature of each level for each reanalysis Natural variability in troposphere with ENSO Artificial variability in stratosphere with Satellite data 8 Courtesy: J. Tsutsui and M. Sakamoto Forecast Score (Z500 FT=24 RMSE) Operational NH JRA NH JRA NH Operational NH year NH score is nearly constant homogenous quality in NH SH score is time dependent not homogenous in SH Global Precipitation GPCP vs. CMAP Observation uncertainty Score for JRA-25 is larger than others JRA-25 Products Available from 1. JMA http://jra.kishou.go.jp/JRA-25/index_en.html 2. NCAR http://dss.ucar.edu/datasets/ds625.0/ JRA-25 references • The JRA-25 Reanalysis J. Meteor. Soc. Japan, 85, 369-432. K. Onogi, J. Tsusui, H. Koide, M. Sakamoto, S. Kobayashi, H. Hatsushika, T. Matsumoto, N. Yamazaki, H. Kamahori, K. Takahashi, S. Kadokura, K. Wada, K. Kato, R. Oyama, T. Ose, N. Mannoji and R. Taira • JRA-25 : Japanese 25-year Reanalysis – progress and status – Onogi et al., QJRMS special issue of the WMO 4th DA workshop (April 2005), Vol.131, 3259-3268. Main Feature of JRA-25 • Good points 1. Better representation of global precipitation 2. Better representation of tropical cyclones 3. Stratus cloud in continental west-coast • Shortcomings 1. Relatively short target period 2. Dry bias in Amazon 3. Large bias in stratospheric temperature Outline of JRA-55 FY2009-FY2012 : calculation Global reanalysis(60km, 1958 - 2012) FY2013~ Product distributeded for Research communities New JCDAS with same system as JRA-55 Data assimilation system JRA-25/JCDAS JRA-55 Operational(2010) Tareget period 1979 - present 1958 - present - Assimilation 3D-VAR 4D-VAR 4D-VAR Resolution (Outer Model) T106L40 (Top : 0.4hPa) TL319L60 (Top : 0.1hPa) TL959L60 (Top : 0.1hPa) Resolution (Inner Model) T106L40 (Top : 0.4hPa) T106L60 (Top : 0.1hPa) T159L60 (Top : 0.1hPa) SST COBE v1.2 （~2000) 〃 v1.22 （2001~） (1-deg resolution) COBE v1.5 (1-deg resolution) MGDSST (0.25-deg resolution) Green house gases Constant CO2, CH4, N2O, CFC-11, CFC-12, HCFC-22 Constant Ozone Daily 3D historical (CTM T42L45) Daily 3D climatology (~1978) Daily 3D historical (1979~) (CTM T42L68) Daily 3D climatology (CTM T42L68) Green House Gases CO2(ppm) 1958:Ice Core(Etheridge et al.) 1989～1979：Keeling MLO 1980～：WDCGG CFC-11(ppt) 1958～2005:CMIP5 2006～：CMIP5 for 2005 CH4(ppb) N2O(ppb) 1958～1983:CMIP5 1984～：WDCGG 1958～1979:CMIP5 1980～：WDCGG CFC-12(ppt) CFC-22(ppt) 1958～2005:CMIP5 2006～：CMIP5 for 2005 1958～2005:CMIP5 2006～：CMIP5 for 2005 Input Observation in JRA-55 Conventional Satellite(Imager) Satellite(Reprocessed imager) Satellite(Sounder) Satellite(Other) First use in any reanalysis Utilized in JRA-55, but no use in JRA-25/JCDAS Improvements in Global Model RMSE(m) RMSE for 24hour 500hPa geopotential height in NH(m) Model for JRA-25 JMA ECMWF UKMO NCEP Model for JRA-55 RMSE : Root Mean Square Error Lower RMSE means higher quality reanalysis products. Available Reanalyses Name Organization target Assimilation Resolution Status R1 NCEP/NCAR 1948present 3D-Var T62L28(200km） Ongoing R2 NCEP/DOE 1979present 3D-Var T62L28(200km) Ongoing ERA-15 ECMWF 1979-1993 3D-OI T106L31(120km) Completed GEOS1 NASA/DAO 1980-1995 3D-OI + IAU 2×2.5deg L20 Completed ERA-40 ECMWF 1957-2002 3D-Var TL159L60(120km) Completed ERAinterim ECMWF 1979present 4D-Var TL255L60(80km) Ongoing JRA-25 JMA/CRIEPI 1979present 3D-Var T106L40(120km) Ongoing JRA-55 JMA 1958present 4D-Var TL319L60(60km) Processing Schedule of JRA-55 The target period is divided to 3 streams. ・ Stream A : 1958-1980 (pre-satellite era) ・ Stream B : 1979-2003 (developing-satellite era) ・ Stream C : 2002-2012 (full-satellite era) completed completed Preliminary Results of JRA-55 • Forecast Score • Global Temperature • Global Precipitation • Radiation Score of Extended Forecast Z500RMSE(GPM) 12-month running mean 48h forecast 120h forecast Northern Hemisphere Southern Hemisphere JRA-55 JRA-25 Operational Global Mean Surface Air Temperature Northern Hemisphere Southern Hemisphere Anomaly Difference from CRU Global Mean Precipitation All reanalyses overestimate global precipitation. Observation Anomaly Correlation against GPCC Global precipitation of JRA-55 has better quality than others. GPCC: Global Precipitation Climatology Project under WCRP is gridding observation with rain gauge data (1901~). Upward Short-wave on Top Upward Long-wave on Top Global Mean Radiation Flux Comparison with ERBE,or SRB 1988 Jun - Dec. Downward Short-wave Downward Long-wave on Bottom on Bottom ERBE : Earth Radiation Budget Experiment SRB : Surface Radiation Budget Black : Obs.(ERBE、SRB) Green : JRA-55 Red : JRA-25 Radiation flux is significantly Improved in JRA-55 JRA-55 Subsets • Conventional reanalysis utilize all available observations to aim at the higher quality as possible and is for all purpose. • Until now, we have to make such all purpose reanalysis due to limitation of computer resources and man powers. • Now, it is possible to make reanalysis subsets for specific purposes (not for all purpose). • Homogenous reanalysis available for climate change research. Global Temperature Anomaly Anomaly from averaged temperature of each level for each reanalysis Natural variability in troposphere with ENSO Artificial variability in stratosphere with Satellite data 28 Courtesy: J. Tsutsui and M. Sakamoto JRA-55C Reanalysis for climate change research S/N of conventional reanalysis is too large to study climate change. This is due to the dependency of reanalysis on observations (Satellite). Reanalysis specialized in climate change study. Only with no time change observations (SYNOPs, TEMPs) Reanalysis only with no time change Obs. JRA-55C Progress of the calculation Global mean precipitation (12 month running mean) AMIP RUN Reanalysis products = hybrid of observations and model --> model have some bias --> bias information is important “AMIP experiment with only boundary condition” Analysis increment in JRA-25 Temp. (Anl-Guess) Negative Bias Positive Bias Negative Bias Preliminary Result of AMIP Zonal mean temperature over 1958-1967 (JRA55-AMIP) ・ Negative bias in lower troposphere in high latitude ・ Positive bias in lower troposphere in tropics DJF JJA 東西風 Summary • JRA-55 improves many shortcomings in JRA-25. • Improved in JRA-55, precipitation, radiation fluxes,,, • JRA-55 is now processing, and a half of the period has been completed. • JRA-55 will be completed in 2013 spring, and be started distribution for research uses. • MRI has also been processing JRA-55 subset for climate studies. JRA-55C JRA-55AMIP Thank you very much JRA-25 and JCDAS JRA-25 (1979-2004) Joint project by JMA and CRIPIE JCDAS (2005-) JMA’s operational assimilation with same assimilation system as JRA-25 JRA-25 copyright by JMA and CRIPIE JCDAS copyright by JMA But, both are a series of things, and end users do not need to distinguish it.
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