# Presentation: 883089

## 51-year simulation of the period from 1951 to 2001 by the JMA AGCM

- By _Shoji KUSUNOKI_, Keiichi MATSUMARU, Toshiyuki NAKAEGAWA, Isamu YAGAI and Osamu ARAKAWA

*Climate Research Department Meteorological Research Institute Japan Meteorological Agency *

## Contents

- Purpose
- Model
- 3.   Experimental design
- 4.   Verification of land surface temperature and land-only precipitation
- 5.   Summary

## Purpose

- Investigate model’s ability to reproduce trend and year-to-year variability of  land surface temperature and land-only precipitation.

## Model : MJ98

**Resolution**: T42, 270km grid spacing, 30 levels, 0.4 hPa top
**Radiation: **Delta-two-stream approximation for short-wave,** **Multi-parameter random model for long-wave
**Deep convection**: Prognostic of Arakawa-Schubert
**Land surface**: Simple Biosphere (SiB) model
**Vertical diffusion**: Mellor and Yamada (1974), level 2 closure
**Gravity wave drug**: Iwasaki et al. (1989)

## Experimental Design

**External forcing**
-   Sea Surface Temperature: HadISST1.1
-   Sea Ice: HadISST1.0
-   CO2: GISS data by Hansen et al. (2002)
-   N2O=306 ppbv, CH4=1650 ppbv by AMIP2
**  **NO volcanic forcing, Solar constant unchanged
**Ensemble size**:  6,  Initial conditions are generated from preliminary AMIP type long run
**Target period**: 1951-2001, 51 years

## CO2 Concentration

- 311

- 370

- 1951

- 2001

## Observational Data for Verification

**Land surface temperature**
-        Source: Jones et al. (2001)
-        Target period: 1951~2001
-         Resolution: Monthly, 5 degree grid
**Precipitation, Land only**
-        Source: Hulme et al. (1998)
-        Target period: 1951~1997
-         Resolution: Monthly, 5 degree grid

- http://www.cru.uea.ac.uk/cru/data/

## Land surface Temperature, Annual Mean, Global MeanAnomaly from 1961-1990 climatology

- OBSERVATION

- MODEL Ensemble Average

## Land surface Temperature Global Mean Trend (C/Decade)

- OBS

- Model

## Land surface Temperature NH Mean Trend (C/Decade)

- OBS

- Model

## Land surface Temperature SH Mean Trend (C/Decade)

- Model

- OBS

## Annual Mean Trend (C/Decade)

- Observation

- Model

## Summer (JJA) Trend (C/Decade)

- Observation

- Model

## Winter (DJF) Trend (C/Decade)

- Observation

- Model

## Land surface Temperature, Annual Mean, Global MeanAnomaly from 1961-1990 climatology

- OBSERVATION

- MODEL Ensemble Average

## Land surface Temperature, Temporal correlation between observation and model

- SH

- NH

- Global

## Land surface Temperature, Temporal correlation between observation and modelAnnual mean, 1951-2001

## Land surface Temperature, Temporal correlation between observation and modelSummer , 1951-2001

## Land surface Temperature, Temporal correlation between observation and modelWinter , 1951-2001

## Precipitation, Land only Annual Mean, Global MeanRatio to 1961-1990 climatology

- Precipitation, Land only Annual Mean, Global MeanRatio to 1961-1990 climatology

- OBSERVATION

- MODEL Ensemble Average

## Precipitation, Land only Global Mean Trend (%/century)

- OBS

- Model

## Precipitation, Land only NH Mean Trend (%/century)

- OBS

- Model

## Precipitation, Land only SH Mean Trend (%/century)

- Model

- OBS

## Annual Mean Trend (%/century)

- Observation

- Model

## Summer Trend (%/century)

- Observation

- Model

## Winter Trend (%/century)

- Observation

- Model

## Precipitation, Land only Annual Mean, Global MeanRatio to 1961-1990 climatology

- Precipitation, Land only Annual Mean, Global MeanRatio to 1961-1990 climatology

- OBSERVATION

- MODEL Ensemble Average

## Precipitation, Land only, Temporal correlation between observation and model

- SH

- Global

- NH

## Precipitation, Land only, Temporal correlation between observation and modelAnnual mean, 1951-1997

## Precipitation, Land only, Temporal correlation between observation and modelSummer, 1951-1997

## Precipitation, Land only, Temporal correlation between observation and modelWinter, 1951-1997

## Summary :Land Surface TemperatureTrend

- ・Model well simulates positive trends of global, NH, SH mean temperature for annual and seasonal mean, but underestimates their magnitude of global and NH mean.
- ・ Model fails to reproduce wintertime large positive trend over Eurasia, Alaska and Canada.

## Summary :Land Surface TemperatureYear-to-year Variability

- ・Model generally well reproduces variability of global, NH, SH mean temp. for annual and some seasonal mean, but reproducibility is low in boreal winter of global and NH mean.
- ・ Reproducibility is high in the tropics and coastal areas, but low in the central Eurasia.

## Summary : Land-only PrecipitationTrend

- ・Model generally well simulates trends of global, NH, SH mean precipitation for annual and seasonal mean.
- ・ Model generally well reproduces geographical distributions of trends.

## Summary : Land-only Precipitation Year-to-year Variability

- ・Model’s reproducibility is lower in NH than in SH. In boreal summer, model’s reproducibility is low for both hemisphere.
- ・ Model’s reproducibility is generally  lower than that of temperature. Skillful regions are tends to be restricted to the tropics.

## Future Plan

-  Extend the target period from 1872
- 2.Study the reproducibility of  teleconnection patterns such as SO, PNA, NAO, AO, AAO.
- 3.  Analyze results by separating external forced variability and atmospheric internal variability
- 4.  Study the influence of volcanic forcing, solar constant change

## Land surface Temperature Trend (C/decade), Global mean, Annual mean, 1951-2001

- Observation

- Model

## Land surface Temperature, Temporal Correlation (%), Annual mean, 1951-2001

- Global

- SH

- NH

## Precipitation, Trend (%/Century), Global mean, Annual mean, 1951-2001

- Precipitation, Trend (%/Century), Global mean, Annual mean, 1951-2001

- Observation

- Model

## Precipitation, Temporal Correlation (%), Annual mean, 1951-2001

- Global

- SH

- NH