Japanese ReanalysisJRA-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-25Japanese 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-251980 1990 2000 2004

Translucent : available but not usedWhite : not in JMA

95.4 01.101.10

82.5

87.3

88.5

03.12

98.11

98.10

87.6

84.5

03.5

(HIRS,MSU 1d / SSU 1c used)

93.7

93.12 96.1

Conventional(ERA-40 obs.) (JMA-archives)

CMV/AMVMETEOSAT Reprocessed AMV

GMS Reprocessed AMV

TOVS 1c

ATOVS 1c

ERS-1,2QuikSCAT

Chinese Snow

SSM/I PW,snow

MODIS polar wind

Wind Profiler

Fiorino TCR wind

02.08

Performance of JRA-25

• Tropical Cyclones

• Global Temperature

• Forecast Score as initial state of JRA-25

• Global Precipitation

1200 UTC 15 September 1990 in the eastern North Pacific

1800 UTC 19 September 1990 in the western North Pacific

Impact of TC Wind Retrieval Data Hatsushika et al., 2005

Flo

Control without TCR

Norbert

Marie

Control without TCR

Using TC wind data, tropical cyclones are properly represented

JRA-25 with TCR

JRA-25 with TCR

GlobalDetection

Rate of

Tropical Cyclones

Grey ： Observed TC (Best track)Blue : Detected TC

Courtesy: H. Hatsushika

The detecting method is based on 1. relative vorticity 2. sea level pressure 3. tropospheric thickness.

Detection rate JRA-25 ~ 90% ERA-40 ~ 50%

Surface air temperature Trend

Global Temperature AnomalyJRA-25, ERA-40, CRU(Jones)Top : monthly mean, Bottom : 5-year moving avarage

Distribution of tendency (K/decade)

JRA-25 and ERA-40

Courtesy: J. Tsutsui

8

Anomaly from averaged temperature of each level for each reanalysis

Natural variability in troposphere with ENSO

Artificial variability in stratosphere with Satellite data

Courtesy: J. Tsutsui and M. Sakamoto

Global Temperature

Anomaly

year

Forecast Score (Z500 FT=24 RMSE)

JRA NHOperational NH

Operational NHJRA NH

NH score is nearly constant homogenous quality in NHSH score is time dependent not homogenous in SH

Global Precipitation

Score for JRA-25 is larger than others

GPCP vs. CMAPObservation uncertainty

JRA-25 ProductsAvailable 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 points1. Better representation of global precipitation

2. Better representation of tropical cyclones

3. Stratus cloud in continental west-coast

• Shortcomings1. 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)

SSTCOBE v1.2 （ ~2000)

〃 v1.22 （ 2001~ ）(1-deg resolution)

COBE v1.5(1-deg resolution)

MGDSST(0.25-deg resolution)

Green house gases

ConstantCO2, CH4, N2O, CFC-11,

CFC-12, HCFC-22Constant

OzoneDaily 3D historical

(CTM T42L45)

Daily 3D climatology (~1978)Daily 3D historical (1979~)

(CTM T42L68)

Daily 3D climatology(CTM T42L68)

N2O(ppb)N2O(ppb)CH4(ppb)CH4(ppb)

CFC-22(ppt)CFC-22(ppt)CFC-12(ppt)CFC-12(ppt)

1958 ～ 1983:CMIP51984 ～： WDCGG

1958 ～ 1979:CMIP5 1980 ～： WDCGG

1958:Ice Core(Etheridge et al.)1989 ～ 1979 ： Keeling MLO 1980 ～： WDCGG

1958 ～ 2005:CMIP52006 ～： CMIP5 for 2005

1958 ～ 2005:CMIP52006 ～： CMIP5 for 2005

1958 ～ 2005:CMIP52006 ～： CMIP5 for 2005

CO2(ppm)CO2(ppm)

CFC-11(ppt)CFC-11(ppt)

Green House Gases

Input Observation in JRA-55

First use in any reanalysis

Utilized in JRA-55, but no use in JRA-25/JCDAS

ConventionalSatellite(Imager)Satellite(Reprocessed imager)Satellite(Sounder)Satellite(Other)

JMAECMWFUKMONCEP

Improvements in Global Model

Model for JRA-25

Model for JRA-55

RMSE : Root Mean Square Error

RM

SE(m

)

Lower RMSE means higher quality reanalysis products.Lower RMSE means higher quality reanalysis products.

RMSE for 24hour 500hPa geopotential height in NH(m)

Available ReanalysesName Organization target

AssimilationResolution

Status

R1 NCEP/NCAR1948-

present3D-Var

T62L28(200km ） Ongoing

R2 NCEP/DOE1979-

present3D-Var

T62L28(200km) Ongoing

ERA-15 ECMWF 1979-19933D-OI

T106L31(120km) Completed

GEOS1 NASA/DAO 1980-19953D-OI + IAU

2×2.5deg L20 Completed

ERA-40 ECMWF 1957-20023D-Var

TL159L60(120km) Completed

ERA-interim ECMWF

1979-present

4D-VarTL255L60(80km) Ongoing

JRA-25 JMA/CRIEPI1979-

present3D-Var

T106L40(120km) Ongoing

JRA-55 JMA1958-

present4D-Var

TL319L60(60km) Processing

Schedule of JRA-55The 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 ForecastZ500RMSE(GPM) 12-month running mean

Northern HemisphereNorthern Hemisphere

Southern HemisphereSouthern Hemisphere

48h forecast48h forecast 120h forecast120h forecast

JRA-25JRA-55 Operational

Global Mean Surface Air Temperature

Difference from CRUDifference from CRU

Northern HemisphereNorthern Hemisphere Southern HemisphereSouthern Hemisphere

AnomalyAnomaly

Global Mean Precipitation

Observation

All reanalyses overestimate global precipitation.

Anomaly Correlation against GPCC

GPCC: Global Precipitation Climatology Project under WCRP is gridding observation with rain gauge data (1901~).

Global precipitation of JRA-55 has better quality than others.

Global Mean Radiation Flux Comparison with

ERBE,or SRB

1988 Jun - Dec.ERBE : Earth Radiation Budget Experiment

SRB : Surface Radiation Budget

Black : Obs.(ERBE 、 SRB)

Green : JRA-55

Red : JRA-25

Radiation flux is significantlyImproved in JRA-55

Upward Short-waveon Top

Upward Long-waveon Top

Downward Short-waveon Bottom

Downward Long-waveon Bottom

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.

28

Anomaly from averaged temperature of each level for each reanalysis

Natural variability in troposphere with ENSO

Artificial variability in stratosphere with Satellite data

Courtesy: J. Tsutsui and M. Sakamoto

Global Temperature

Anomaly

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-55CReanalysis for climate change research

JRA-55CProgress of the calculation

Global mean precipitation (12 month running mean)

AMIP RUNReanalysis 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

東西風DJF JJA

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 JCDASJRA-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 CRIPIEJCDAS copyright by JMABut, both are a series of things, and end users do not need to distinguish it.