Ocean modelling activities in Japan(some of activities in China and Korea are inclu

ded in the report)

report to the CLIVAR Working Group for Ocean Model Development 7th session, August 2007

by Hiroyuki Tsujino (MRI-JMA)

1. Updates on oceanic components of global climate models for the next IPCC future climate projections

FRCGC and CCSR:

Centennial time-scale climate projection

with Earth System Model, NPZD ocean eco-system, 1-deg. resolution

CCSR, FRCGC, and NIES:

Decadal time-scale climate projection (prediction)

with high-resolution CGCM (60 km AGCM, 20 km OGCM)

updates on some schemes and physics (advection, ice-thermodynamics)

MRI-JMA:

Centennial time-scale climate projection

with Earth System Model, ocean bio-geochemical model, 1-deg. resolution

Emphases on assessment of regional impacts using “time-slice” runs

(regional climate model with 10 km ocean model)

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1. Updating oceanic components of global climate models for the next IPCC future climate projections

2. Developing systems for seasonal to inter-annual (or longer) climate predictions

3. Updating regional ocean models for use in regional marine environment forecasts

Activities are Focused on ...

• Two research centers in China (LASG, BCC) are preparing for IPCC AR5.

They are managing their own OGCM (eta-coordinate).• FIO couples wave model with existing OGCMs to obtain vertical diffusion

• There does not seem to be major institutional effort in Korea right now.

The APEC computer center will be build in Korea.

3. Updating regional ocean models for use in regional marine environment forecasts

FRCGC (POM), MRI-JMA(MRI.COM), RIAM (RIAMOM), Kyoto Univ.

Efforts to include additional processes (biogeochemistry)

to achieve higher resolution ...

Currently about 10 km grid spacing for relatively large region, physics only

2. Systems for seasonal to inter-annual (or longer) climate predictions

MRI-JMA ... ENSO (seasonal) forecast

TL95L50 and 1 degree Ocean, 3D-VAR ocean data assimilation

CGCM with on-line 3D-VAR data assimilated ocean

FRCGC and CCSR ... Decadal projection

60 km AGCM and 20 km OGCM, Ensemble Kalman Filter

data assimilation for ocean and surface wind

4. CORE

Inter-annual forcing run: FRCGC, CCSR

long-term variablity is reproduced well, mostly driven by wind stress anomalies

Normal year forcing: MRI-JMA

some would prefer using another re-analysis

(e.g., ERA, JRA (by JMA’s AGCM))

complaining about…

Equatorial thermocline (wind stress),

Hawaiian lee

precipitation (FRCGC-CCSR, per. comm.)

radiation in the Arctic region

Quasi-global ocean only model with 1/8º x 1/12º (10 km)

=> recently globalized

hierarchy of the North Pacific models differing in horizontal resolution

Need for the tracer advection scheme suitable to eddying simulations

… new advection scheme SOM, and/or tuning of the anisotropic GM

… SOM is recently introduced and implemented in Japan community

1/4x1/6 1/12x1/18 1/36x1/54

GrADS software option PDEF to quicklook on regular grid

Two-way nesting ocean in CGCM (CCSR and MRI-JMA)

data assimilation : robust diagnostic / semi prognostic

Low resolution model : predictor – corrector ?

conservation of volume, tracer, … in both models?

sustainable (not ad hoc) software (or run on separated CPUs)

Sharing of program codes

recently turned out to be too difficult to be united or shared …

Next generation code

C-grid, unstructured mesh, adaptive mesh, which should we choose?