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.