status and plans Shinya Kobayashi a , Yukinari Ota a , Yayoi Harada a - PowerPoint PPT Presentation

The Japanese 55-year Reanalysis (JRA-55): status and plans Shinya Kobayashi a , Yukinari Ota a , Yayoi Harada a , Ayataka Ebita a , Masami Moriya a , Hirokatsu Onoda a , Kazutoshi Onogi a , Hirotaka Kamahori b , Chiaki Kobayashi b , Hirokazu Endo b , Kiyotoshi Takahashi a , Kengo Miyaoka a , and Ryoji Kumabe a a Japan Meteorological Agency (JMA) b Meteorological Research Institute (MRI), JMA 7-11 October 2013 Sixth WMO Symposium on Data Assimilation 1

Outline • Outline of JRA-55 (nicknamed “JRA Go! Go!”) – Observational data – Data assimilation system • Basic performance of the data assimilation system • Early results of quality assessment • JRA-55 family • Release schedule • Future plans • Summary 7-11 October 2013 Sixth WMO Symposium on Data Assimilation 2

Outline of JRA-55 • The second Japanese global reanalysis conducted by JMA • The first comprehensive global atmospheric reanalysis that applies 4D-Var to the last half century • Aiming at providing a comprehensive atmospheric dataset that is suitable for studies of climate change and multi- decadal variability COMPLETED JRA-55 (4D-Var) JRA-25/JCDAS (3D-Var) Surface, radiosondes, tropical cyclone retrievals, windprofilers Aircraft Polar orbiting satellites Geostationary satellites IGY FGEE GNSS 1960 1970 1980 1990 2000 2010 7-11 October 2013 Sixth WMO Symposium on Data Assimilation 3

Observational data • The major data source – The ERA-40 observational dataset supplied by ECMWF • Homogenization – Radiosonde Observation Correction using Reanalyses (RAOBCORE) v1.4 (Haimberger 2008) • Reprocessed satellite observations – GMS, GOES-9 and MTSAT-1R (MSC/JMA) • Sustained, Coordinated Processing of Environmental Satellite Data for Climate Monitoring – METEOSAT (EUMETSAT), TMI (NASA Chronology of types of observational data and JAXA), AMSR-E (JAXA), QuikSCAT assimilated in JRA-55 (NASA/PO.DAAC), AMI (ESA), GNSS/RO (UCAR) 7-11 October 2013 Sixth WMO Symposium on Data Assimilation 4

Data assimilation system JRA-25/JCDAS JRA-55 Version Operational as of Mar 2004 Operational as of Dec 2009 T106L40 (~ 120 km) TL319L60 (~ 60 km) Resolution top layer at 0.4 hPa top layer at 0.1 hPa 3D-Var 4D-Var 6-hour time window 6-hour time window Assimilation T106 resolution T106 inner model scheme Background error covariances are inflated by 1.8 before 1972 Satellite radiance Adaptive but not variational Variational Bias Correction bias correction (Sakamoto and Christy 2009) (VarBC) (Dee 2005) Line absorption Line absorption Long-wave Statistical band model Table lookup + K-distribution Water vapor continuum Water vapor continuum radiation scheme e-type only e-type + P-type CO 2 only CO 2 , CH 4 , N 2 O, Green house gases (constant at 375 ppmv) CFC-11, CFC-12, HCFC-22 (historical concentrations) 7-11 October 2013 Sixth WMO Symposium on Data Assimilation 5

Basic performance of the data assimilation system Time series for the RMS errors of 5-day forecasts of geopotential height (gpm) at 500hPa verified against its own analysis 7-11 October 2013 Sixth WMO Symposium on Data Assimilation 6

Temporal consistency of temperature analysis JRA-55 (hPa) Time series of global mean ERA-Interim temperature anomalies JRA-25 ERA-40 Anomalies are calculated with respect to their own averages for the years from 1980 to 2001. (Year) 7-11 October 2013 Sixth WMO Symposium on Data Assimilation 7

A dry land surface problem in the Amazon basin Control No Ps over the Amazon basin Total Column Water Vapor flux (kg/m/s) & divergence (kg/m 2 ) for Nov 1979 Top: analysis Bottom: increment • Possible causes – bias in surface pressure observations – mis-specified station height Control No Ps over the Amazon basin – deficiencies in the diurnal cycle reproduced by the forecast model – lack of constraint on soil moisture • Quick fix for JRA-55 Surface pressure observations are simply discarded over the Amazon basin. 7-11 October 2013 Sixth WMO Symposium on Data Assimilation 8

JRA-55 family • JRA-55 (JMA) – Full observing system reanalysis • JRA-55C (MRI/JMA) – Fixed observing system reanalysis – Using conventional observations only • surface, radiosondes, tropical cyclone retrievals and windprofilers • JRA-55AMIP (MRI/JMA) – AMIP type run (with no observations assimilated) • Providing a range of products using the common base NWP system for investigating impact of changing observing systems and model biases 7-11 October 2013 Sixth WMO Symposium on Data Assimilation 9

Representation of the Quasi-Biennial Oscillation Time series for zonal wind (m/s) averaged for the equatorial band between 5S and 5N JRA-55 JRA-55C JRA-55AMIP (AGCM Simulation) • JRA-55 and JRA-55C provide a consistent representation of QBO, whereas JRA-55AMIP does not. • Upper observations are important for our system to represent QBO. Chiaki Kobayashi 7-11 October 2013 Sixth WMO Symposium on Data Assimilation 10

Product availability • Available for research purposes from – JMA Data Distribution System (JDDS) • http://jra.kishou.go.jp/JRA-55/index_en.html • A JRA-25 user account can be used to download the JRA-55 product as well. – Data Integration and Analysis System (DIAS) • http://dias-dss.tkl.iis.u-tokyo.ac.jp/acc/storages/filelist/dataset:204 – NCAR • in preparation, available soon • Release schedule – 1.25 degree latitude/longitude grid data from Oct 2013 – Near real-time product from Feb 2014 – Model grid data (TL319L60) from Mar 2014 • Provision of the JRA-25/JCDAS data will be ceased at the end of Feb 2014. 7-11 October 2013 Sixth WMO Symposium on Data Assimilation 11

Future plans • Production of JRA-55 will be continued on a near real-time basis. • Production of JRA-55C and JRA-55AMIP will be completed and release of basic products is planned in FY2014. • The JRA-55 papers are in preparation; – Part 1 general specification and basic characteristics • To be submitted by Nov 2013 – Part 2 reproducibility of atmospheric circulation and climate variability • To be submitted in mid 2014 • Production of a 5-km downscaling dataset over Japan is underway and will be completed in FY2015. • Examinations on issues identified in JRA-55, such as performance of data assimilation system under reduced observing systems, model biases and so on. 7-11 October 2013 Sixth WMO Symposium on Data Assimilation 12

Summary • Production of JRA-55 has been completed. Early results of quality assessment have suggested that many of deficiencies in JRA-25 have been diminished or reduced in JRA-55. • Temporal consistency of temperature analysis of JRA-55 has the best performance with few jumps among the reanalyses. • Inter-comparison among the “JRA -55 family” provides an opportunity for quantitative assessment regarding representation of climatic trends and low-frequency variations. • For further improvement of temporal consistency, issues such as performance of data assimilation system under reduced observing systems and model biases need to be addressed. 7-11 October 2013 Sixth WMO Symposium on Data Assimilation 13

Thank you! 7-11 October 2013 Sixth WMO Symposium on Data Assimilation 14

Backup slide 7-11 October 2013 Sixth WMO Symposium on Data Assimilation 15

Temporal consistency of temperature analysis (Part 2) JRA-55 (hPa) Time series of global mean MERRA temperature anomalies (NASA GMAO) CFSR (NOAA NCEP) NCEP/NCAR Anomalies are calculated with respect to their own averages for the years from 1980 to 2001. (Year) 7-11 October 2013 Sixth WMO Symposium on Data Assimilation 16