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

1. 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

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

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

4. 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)

5. 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

6. CO2 Concentration 370 311 2001 1951

7. 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/

8. Land surface Temperature, Annual Mean, Global MeanAnomaly from 1961-1990 climatology OBSERVATION MODEL Ensemble Average

9. Land surface Temperature Global Mean Trend (C/Decade) OBS Model

10. Land surface Temperature NH Mean Trend (C/Decade) OBS Model

11. Land surface Temperature SH Mean Trend (C/Decade) Model OBS

12. Annual Mean Trend (C/Decade) Observation Model

13. Summer (JJA) Trend (C/Decade) Observation Model

14. Winter (DJF) Trend (C/Decade) Observation Model

15. Land surface Temperature, Annual Mean, Global MeanAnomaly from 1961-1990 climatology OBSERVATION MODEL Ensemble Average

16. Land surface Temperature, Temporal correlation between observation and model SH Global NH

17. Land surface Temperature, Temporal correlation between observation and modelAnnual mean, 1951-2001

18. Land surface Temperature, Temporal correlation between observation and modelSummer , 1951-2001

19. Land surface Temperature, Temporal correlation between observation and modelWinter , 1951-2001

20. Precipitation, Land only Annual Mean, Global MeanRatio to 1961-1990 climatology OBSERVATION MODEL Ensemble Average

21. Precipitation, Land only Global Mean Trend (%/century) Model OBS

22. Precipitation, Land only NH Mean Trend (%/century) OBS Model

23. Precipitation, Land only SH Mean Trend (%/century) OBS Model

24. Annual Mean Trend (%/century) Observation Model

25. Summer Trend (%/century) Observation Model

26. Winter Trend (%/century) Observation Model

27. Precipitation, Land only Annual Mean, Global MeanRatio to 1961-1990 climatology OBSERVATION MODEL Ensemble Average

28. Precipitation, Land only, Temporal correlation between observation and model SH Global NH

29. Precipitation, Land only, Temporal correlation between observation and modelAnnual mean, 1951-1997

30. Precipitation, Land only, Temporal correlation between observation and modelSummer, 1951-1997

31. Precipitation, Land only, Temporal correlation between observation and modelWinter, 1951-1997

32. Summary :Land Surface TemperatureTrend ・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.

33. Summary :Land Surface TemperatureYear-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.

34. Summary : Land-only PrecipitationTrend ・Model generally well simulates trends of global, NH, SH mean precipitation for annual and seasonal mean. ・ Model generally well reproduces geographical distributions of trends.

35. Summary : Land-only PrecipitationYear-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.

36. 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

37. Land surface Temperature Trend (C/decade), Global mean, Annual mean, 1951-2001 Observation Model

38. Land surface Temperature, Temporal Correlation (%), Annual mean, 1951-2001 Global NH SH

39. Precipitation, Trend (%/Century), Global mean, Annual mean, 1951-2001 Observation Model

40. Precipitation, Temporal Correlation (%), Annual mean, 1951-2001 Global NH SH