1. Forecast system version

Identifier code:  JMA/MRI-CPS2

First operational forecast run: June 2015

2. Configuration of the forecast model

Is the model coupled to an ocean model?  Yes

Coupling frequency: 1 hour

2.1 Atmosphere and land surface

Horizontal resolution and grid


(approx. 110km)

Atmosphere vertical resolutionL60
Top of atmosphere0.1hPa
Soil levels

Soil temperature : 1

Soil moisture : 3

Time step30 minutes

Detailed documentation: JMA, 2013: Outline of the operational numerical weather prediction at the Japan Meteorological Agency, Appendix to WMO Technical Progress Report on the Global Data-processing and Forecasting System (GDPFS) and Numerical Weather Prediction (NWP) Research. Japan Meteorological Agency, Tokyo, Japan.

2.2 Ocean and cryosphere

Ocean modelMRI.COM v3
Horizontal resolution1ºx0.3º -0.5º on a tripolar grid
(See Toyoda et al. 2013 for more information on a tripolar grid)
Vertical resolutionL52 + Bottom Boundary Layer (BBL)
Time step20 minutes
Sea ice modelpart of MRI.COM v3
Sea ice model resolutionsame as ocean model
Sea ice model levels5 categories + open water
Wave modelNone
Wave model resolutionN/A

Detailed documentation: Tsujino, H., T. Motoi, I. Ishikawa, M. Hirabara, H. Nakano, G. Yamanaka, T. Yasuda, and H. Ishizaki, 2010: Reference manual for the Meteorological Research Institute Community Ocean Model (MRI.COM) version 3. Technical Reports of the Meteorological Research Institute, 59, 273pp.

3. Initialization and initial condition (IC) perturbations

3.1 Atmosphere and land

Atmosphere initialization
Japanese 55-year Reanalysis (JRA-55)Japanese 55-year Reanalysis (JRA-55)
Atmosphere IC perturbationsBreeding Growth Method (BGM)Breeding Growth Method (BGM)

Land Initialization

Land IC perturbationsNoneNone
Soil moisture initializationJRA-55JRA-55
Snow initializationJRA-55JRA-55
Unperturbed control forecast?NoneNone

Data assimilation method for control analysis: 4D-VAR (atmosphere) and 3D-VAR (ocean)

Horizontal and vertical resolution of perturbations:  TL159L60

Perturbations in +/- pairs: Yes

Detailed documentation: Kobayashi, S., Y. Ota, Y. Harada, A. Ebita, M. Moriya, H. Onoda, K. Onogi, H. Kamahori, C. Kobayashi, H. Endo, K. Miyaoka, and K. Takahashi, 2015: The JRA-55 reanalysis: General specifications and basic characteristics. J. Meteor. Soc. Japan, 93, 5-48.

3.2 Ocean and cryosphere

Ocean initialization

Multivariate Ocean Variational Estimation (MOVE)/MRI.COM Global 2 system


Multivariate Ocean Variational Estimation (MOVE)/MRI.COM Global 2 system


Ocean IC perturbationsMOVE/MRI-COM-G2 driven by JRA-55 with BGM perturbationMOVE/MRI-COM-G2 driven by JRA-55 with BGM perturbation
Unperturbed control forecast?NoneNone

Detailed documentation: Toyoda T., Y. Fujii, T. Yasuda, N. Usui, T. Iwao, T. Kuragano, and M. Kamachi, 2013: Improved analysis of seasonal-interannual fields using a global ocean data assimilation system. Theor Appl Mech Jpn, 61, 31-48.

4. Model Uncertainties perturbations:

Model dynamics perturbationsNone
Model physics perturbationsStochastically Perturbed Parametrization Tendencies (SPPT) scheme

If there is a control forecast, is it perturbed?


Detailed documentation: Yonehara, H. and M. Ujiie, 2011: A stochastic physics scheme for model uncertainties in the JMA one-week ensemble prediction system. CAS/JSC WGNE Res. Act. Atmos. Ocean Model/WMO, 41, 6.09–6.10.

5. Forecast system and hindcasts

Forecast frequencyEvery 5 days
Forecast ensemble size13
Hindcast years1981-2016
Hindcast ensemble size10 (5 members with 15-day Lagged Average Forecast)
On-the-fly or static hindcast set?static

6. Other relevant information

The available start dates are as follows:
(NOTE: hindcasts are just available for dates highlighted in bold and underlined)

Start MonthAvailable Start Days

1, 6, 11, 16, 21, 26 and 31

February5, 10, 15, 20 and 25
March2, 7, 12, 17, 22 and 27
April1, 6, 11, 16, 21 and 26
May1, 6, 11, 16, 21, 26 and 31
June5, 10, 15, 20, 25 and 30
July5, 10, 15, 20, 25 and 30
August4, 9, 14, 19, 24 and 29
September3, 8, 13, 18, 23 and 28
October3, 8, 13, 18, 23 and 28
November2, 7, 12, 17, 22 and 27
December2, 7, 12, 17, 22 and 27

7. Where to find more information

General information:

Takaya, Y., S. Hirahara, T. Yasuda, S. Matsueda, T. Toyoda, Y. Fujii, H. Sugimoto, C. Matsukawa, I. Ishikawa, H. Mori, R. Nagasawa, Y. Kubo, N. Adachi, G. Yamanaka, T. Kuragano, A. Shimpo, S. Maeda, and T. Ose, 2018: Japan Meteorological Agency/Meteorological Research Institute-Coupled Prediction System version 2 (JMA/MRI-CPS2): atmosphere–land–ocean–sea ice coupled prediction system for operational seasonal forecasting. Clim. Dyn., 50, 751-765.