Impact of land-surface processes on tropical climate variability - WP1300

Partners involved: CNRM (lead contractor), ICTP, MPI, UB

PROMISE aims to investigate the role of land surface processes and of anomalies in land surface conditions in determining the predictability and variability of monsoon climates.

Key achievements so far:

• sensitivity experiments have demonstrated the importance of land-surface processes in influencing monsoon variability on daily to interannual timecales. Global AGCM experiments confirm that realistic oil moisture boundary conditions are necessary for simulating the mid-latitude stationary waves with a significant impact on both extratropical and tropical precipitation

• an analysis of the relationship between Eurasian snow-depth anomalies and indices of the Asian monsoon circulation has been carried out using data from numerical simulations performed in the context ofthe PRISM project

• a selection of multi-linear regressors have been studied to demonstrate their effectiveness in predicting Sahelian June-September rainfall. It was found that April to June meridonal patterns of near surface MSE content control the amplitude and the timing of the Sahelian July-to-September rainy season. Wet Sahelian seasons are usually preceded by stronger than normal MSE gradients during Boreal spring.

• the necessity of modelling the dynamic vegetation processes for accurate simulation of interdecadal changes in Sahelian rainfall has been demonstrated using atmospheric GCMs coupled to a simple dynamic vegetation model

Publications on this topic arising from PROMISE

Cox P.M., Betts R.A., Jones C.D., Spall S.A., Totterdell I.J. 2002 Modelling vegetation and the carbon cycle as interactive elements of the climate system. pp 259-279 in Meteorology at the millennium (Ed Pearce R.P.) Academic Press

Cramer W., Bondeau A., Woodward F.I., Prentice I.C., Betts R.A., Brovkin, V., Cox P.M., Fisher V., Foley J.A., Friend A.D., Kucharik C., Lomas M.R., Ramankutty N., Stitch S., Smith B., White A. and Young-Molling C. 2001
Global response of terrestrial ecosystem structure and function to CO2 and climate change. Results from six dynamic global vegetation models Global Change Biology 7 357-374

Fontaine B. and N. Philippon 2002 The relationship between the Sahelian and previous 2nd Guinean rainy seasons : a monsoon regulation by soil wetness? Annales Geophysicae 20 575-582

Fontaine B. and N. Philippon 2000 Seasonal evolution of boundary layer heat content in the West african monsoon from the NCEP/NCAR reanalysis (1968-1998) International Journal of Climatology 20 1777-1790

Fontaine B., P. Roucou P. and S.Trzaska 2003 Atmospheric water cycle and moisture fluxes in the West African monsoon: mean annual cycles and relationship using NCEP/NCAR reanalyses Geophysical Research Letters 30 10.1029-10.1032

Lawrence, D.M. and J.M. Slingo 2003 An annual cycle of vegetation in a GCM. Part II: Global impacts on climate and hydrology Climate Dynamics Submitted

Lawrence, D.M. and J.M. Slingo 2003 An annual cycle of vegetation in a GCM. Part I: Implementation and impact on evaporation Climate Dynamics Submitted

Maynard K. and J.F. Royer 2003 Sensitivity of a General Circulation Model to land surface parameters. Climate Dynamics Submitted

Maynard K. and J.F. Royer 2003 The influence of surface roughness on African afforestation experiments Journal of Climate Submitted

Schnitzler, K.-G., N. Zeng, M. Latif, W. Knorr, and M. Scholze 2003 Impact of vegetation feedback on climate variability in a coupled GCM land-vegetation model in preparation

Publications related to this topic by PROMISE partners

Douville H. and J-F. Royer (1996): Sensitivity of the Asian summer monsoon to an anomalous Eurasian snow cover within the METEO-FRANCE GCM, Climate Dynamics, 12, 441-448

Douville H, Chauvin F (2000): Relevance of soil moisture for seasonal climate predictions: a preliminary study. Climate Dynamics 16, 719-736

Douville H, Chauvin F, Broqua H (2001): Influence of soil moisture on the Asian and African monsoons. Part I: Mean monsoon and daily precipitation. J Climate (in press)

Douville H (2001): Influence of soil moisture on the Asian and African monsoons. Part II: interannual variability. J Climate (submitted)

Ferranti, L. and F. Molteni, 1999: Ensemble simulations of Eurasian snow-depth anomalies and their influence on the summer Asian monsoon. Quaterly Journal of the Meteorological Society, 125, 2597-2610

Corti, S., F. Molteni and C. Brankovic, 2000: Predictability of snow-depth anomalies over Eurasia and associated circulation patterns. Quaterly Journal of the Meteorological Society, 126, 241-262

Further information

see:
Work package description in the proposal
First annual report (available to PROMISE partners or with the permission of the lead contractor)
Second annual report (available to PROMISE partners or with the permission of the lead contractor)
Third annual report (available to PROMISE partners or with the permission of the lead contractor)
Final report

or:
contact Emily Black (emily@met.reading.ac.uk)