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Theoretical and Applied Climatology

, Volume 100, Issue 1–2, pp 207–220 | Cite as

Sensitivity of the simulated African monsoon of summers 1993 and 1999 to convective parameterization schemes in RegCM3

  • L. A. Djiotang TchotchouEmail author
  • F. Mkankam Kamga
Original Paper

Abstract

In this study, the International Center for Theoretical Physics Regional Climate Model version 3 (RegCM3) was used to investigate the sensitivity of the simulation of the West African monsoon using four different cumulus and closures parameterization schemes of Anthes Kuo (AK), Grell and Fristish Chappell (GFC), Grell and Arakawa Schubert (GAS), and MIT-Emmanuel (EM) while maintaining other physical packages unchanged. The contrasting monsoon years of 1993 and 1999, which were dry and wet years, respectively, were simulated. The model was integrated from a period of 5 months, starting from May 1 to September 30 of each year using the European Centre for Medium-Range-Weather Forecast (ECMWF) Reanalysis data (ERA40) as input boundary conditions. The 6-hourly reanalysis data were used to provide the lateral boundary conditions, and the observed weekly Reynolds Sea Surface Temperature interpolated to 6 h was used as the lower boundary forcing. The results show that in West Africa, monsoon precipitations are sensitive to the choice of cumulus parameterization and closure schemes. None of the schemes is able to simulate the monsoon rainfall accurately, and furthermore, there is little difference in behavior among schemes between dry and wet years. The spatial features of precipitation are not identical among schemes, although they all show a northward shift of the rain bands, giving a very wet Sahel and dry Guinean Coast. The GFC and EM schemes are able to capture the diurnal cycle of precipitation and the zonal averages of stratiform rain fractions as observed in the Tropical Rainfall Measuring Mission (TRMM), although they overestimated rainfall amounts. The most important deficiencies, however, cannot be attributed to the schemes. In particular, the northward shift of both the rain band and the AEJ in RegCM3 is the result of unrealistic soil moisture resulting from the way albedo is parameterized, leading to an excessive northward penetration of monsoon flow. A sensitivity study showed that an adjustment of initial albedo values over the Sahel improved the simulation, and in particular the position of rain bands and of the AEJ.

Keywords

Tropical Rainfall Measure Mission Climate Research Unit NCEP Reanalysis West African Monsoon Rain Band 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgements

The International Centre for Theoretical Physics (ICTP) Trieste Italy, through the Associate Scheme provided support during preparation of the revised version of this work. The careful review and detailed comments by anonymous reviewers substantially helped the authors to improve the final version of the paper.

References

  1. Afiesimama EA, Pal J, Abiodun BJ, Gutowski J, Adedoyin A (2006) Simulation of West African monsoon using the RegCM3. Part I: model validation and interannual variability. Theor Appl Climatol 86:23–37CrossRefGoogle Scholar
  2. Anthes RA (1977) A cumulus parameterization scheme utilizing a one-dimensional cloud model. Mon Wea Rev 105:270–286CrossRefGoogle Scholar
  3. Charney J, Quirk W, Chow S, Korneld J (1977) A comparative study of the effects of albedo change on drought in semi-arid regions. J Atmos Sci 34:1356–1385CrossRefGoogle Scholar
  4. Collier JC, Kenneth PB (2004) Diurnal cycle of tropical precipitation in a general circulation model. J Geophy Res 109:D17105. doi: 10.1029/2004JD004818 CrossRefGoogle Scholar
  5. Cook KH (1999) Generation of the African easterly jet and its role in determining West African precipitation. J Clim 12:1165–1184CrossRefGoogle Scholar
  6. Dickinson R, Henderson-Sellers A, Kennedy P (1986) Biosphere-Atmosphere Transfer Scheme (BATS) for the near Community Climate Model. NCAR Tech. Note, NCAT/TN-275+STR, 69 ppGoogle Scholar
  7. Dickinson RE, Henderson-Sellers A, Kennedy P (1993) Biosphere-Atmosphere Transfer Scheme (BATS) version 1e as coupled to the near Community Climate Model, Tech Rep., National Center for Atmospheric Research (NCAR), Boulder, CO, USAGoogle Scholar
  8. Druyan L, Fulakeza M, Lonergan P (2002) Dynamic downscaling of seasonal climate predictions over Brazil. J Climate 15:3411–3426CrossRefGoogle Scholar
  9. Druyan L, Fulakeza M, Lonergan P (2004) Land surface influences on the West African summer monsoon: implications for synoptic disturbances. Meteorol Atmos Phys 86:261–273. doi: 10.1007/s00703-003-0025-z CrossRefGoogle Scholar
  10. Druyan L, Fulakeza M, Lonergan P (2006) Mesoscale analyses of West African summer climate: focus on wave disturbances. Clim Dyn 27:459–481. doi: 10.1007/s00382-006-0141-9 CrossRefGoogle Scholar
  11. Druyan L, Fulakeza M, Lonergan P (2007) Spatial variability of regional model simulated June-September mean precipitation over West Africa. Geophys Res Lett 34:L18709. doi: 10.1029/2007/GL031270 CrossRefGoogle Scholar
  12. Emanuel KA (1991) A scheme for representing cumulus convection in large-scale models. J Atmos Sci 48(21):2313–2335CrossRefGoogle Scholar
  13. Emanuel KA, Zivkovic-Rothman M (1999) Development and evaluation of a convection scheme for use in climate models. J Atmos Sci 56:1766–1782CrossRefGoogle Scholar
  14. Fritsch JM, Chappell CF (1980) Numerical prediction of convectively driven mesoscale pressure systems. Part I: convective parameterization. J Atmos Sci 37:1722–1733CrossRefGoogle Scholar
  15. Fulakeza M, Druyan L, Krishnamurti T (2002) A simple soil moisture scheme for climate simulations in the tropics. Meteorol Atmos Phys 79:105–126CrossRefGoogle Scholar
  16. Gallée H, Moufouma-Okia W, Bechtold P, Dupays I, Marbaix P, Messager R, Ramel R, Lebel T (2004) A high-resolution simulation of a West African rainy season using a regional climate model. J Geophys Res 109:D05108. doi: 10.1029/2003JD004020 CrossRefGoogle Scholar
  17. Giorgi F (1990) Simulation of regional climate using a limited area model nested in a general circulation model. J Clim 3:941–963CrossRefGoogle Scholar
  18. Giorgi F, Marinucci M (1996) An investigation of the sensitivity of simulated precipitation to model resolution and its implication for climate studies. Mon Weather Rev 124:148–166CrossRefGoogle Scholar
  19. Giorgi F, Mearns L (1999) Introduction to special section: regional climate modeling revisited. J Geophys Res 104:6335–6352CrossRefGoogle Scholar
  20. Giorgi F, Bates GT, Nieman SJ (1993a) Development of a second-generation regional climate model (RegCM2). Part I: boundary layer and radiative transfer processes. Mon Weather Rev 112:2794–2813CrossRefGoogle Scholar
  21. Giorgi F, Marinucci M, Bates G, De Canio G (1993b) Development of a second-generation regional climate model (RegCM2). Part II: convective processes and assimilation of lateral boundary conditions. Mon Weather Rev 121:2814–2832CrossRefGoogle Scholar
  22. Grell G (1993) Prognostic evaluation of assumptions used by cumulus parameterizations. Mon Weather Rev 121:764–787CrossRefGoogle Scholar
  23. Grell GA, Dudhia J, Stauffer DR (1994) Description of the fifth-generation Penn State/NCAR Mesoscale Model (MM5). Tech. Rep. TN-398+STR, NCAR, Boulder, CO, USA, pp.121Google Scholar
  24. Holtslag A, de Bruijn E, Pan H (1990) A high-resolution air mass transformation model for short-range weather forecasting. Mon Weather Rev 120:2814–2832Google Scholar
  25. Jenkins GS (1997) The 1988 and 1990 summer season simulations for West Africa using a regional climate model. J Clim 10:1255–1272CrossRefGoogle Scholar
  26. Jenkins GS, Mikovitz JC (2003) Examining climate variability over West Africa during the 1979–1993 period: observations and CCM3 comparisons. Clim Dyn 20:503–522. doi: 10.1007/s00382-002-0287-z Google Scholar
  27. Kalnay E, Kanamitsu M, Kistler R, Collins W, Deaven D, Gandin L, Irdell M, Saha S, White G, Woollen J, Zhu Y, Chelliah M, Ebisuzaki W, Higgins W, Janowiak J, Mo KC, Ropelewski C, Wang J, Leetmaa A, Reynolds R, Jenne R, Joseph D (1996) The NCEP/NCAR 40-year reanalysis project. Bull Amer Meteor Soc 77:437–471CrossRefGoogle Scholar
  28. Kiehl J, Hack J, Bonan G, Boville B, Breigleb B, Williamson D, Rasch P (1996) Description of the near Community Climate Model (ccm3). NCAR Tech. Note NCAR/TN-420+STR 152ppGoogle Scholar
  29. Lamb PJ, Peppler RA (1992) Further case studies of tropical Atlantic surface atmospheric and oceanic patterns associated with Sub-Saharan drought. J Clim 5:476–488CrossRefGoogle Scholar
  30. Landsea CW, Mielke PW, Berry KJ (1992) Long-term variations of western Sahelian monsoon rainfall and intense U.S. landfalling hurricanes. J Clim 5:1528–1534CrossRefGoogle Scholar
  31. Lebel T, Delclaux F, Lebel T, Polcher J (2000) From GCM scales to hydrological scales: rainfall variability in West Africa. Stoch Environ Res Risk Asses 14:275–295CrossRefGoogle Scholar
  32. Mitchell T, Carter T, Jones P, Hulme M, New M (2003) A comprehensive set of high-resolution grids of monthly climate for Europe and the globe: the observed record (1901–2000) and 16 scenarios (2001–2100). Tyndall Centre for Climate Change Research, Norwich, UK, Working Paper 55Google Scholar
  33. Newell RE, Kidson JW (1984) African mean wind changes between Sahelian wet and dry periods. J Climatol 4:27–33CrossRefGoogle Scholar
  34. Nicholson S (2005) On the question of the “recovery” of the rains in the West African Sahel. J Arid Environ 63:615–641CrossRefGoogle Scholar
  35. Nicholson SE, Some B, Kone B (2000) An analysis of recent rainfall conditions in West Africa, including the rainy seasons of the 1997 El Niño and the 1998 La Niña years. J Clim 13:2628–2640CrossRefGoogle Scholar
  36. Pal JS, Eltahir EAB (2001) Pathways relating soil moisture conditions to future summer rainfall within a model of the land-atmosphere system. J Clim 14(6):1227–1242. doi:10.1175/1520-0442(2001) 014<1227:PRSMCT>2.0.CO;2CrossRefGoogle Scholar
  37. Pal JS, Small EE, Eltahir AB (2000) Simulation of regional-scale water and energy budgets: representation of subgrid cloud and precipitation processes within RegCM. J Geophys Res 105(D24):29579–29594CrossRefGoogle Scholar
  38. Pal J, Giorgi F, Bi X, Elguindi N, Solmon F, Grimm A, Sloan L, Syed A, Zakey F (2005) The ICTP Regional Climate Model version 3 (RegCM3). Benchmark simulations over tropical regions. Bull Amer Meteor Soc (submitted)Google Scholar
  39. Poccard J, Janicot S, Camberlin P (2000) Comparison of rainfall structures between NCEP/NCAR reanalyses and observed data over tropical Africa. Clim Dyn 16:897–915CrossRefGoogle Scholar
  40. Ramel R, Gallée H, Messager C (2006) On the northward shift of the West African monsoon. Climate Dyn Res 26:429–440. doi: 10.1007/s00382-005-0093-5 CrossRefGoogle Scholar
  41. Rowell DP, Folland CK, Maskell K, Ward MN (1995) Variability of summer rainfall over tropical North Africa (1906–1992): observations and modeling. Quart J Roy Meteor Soc 121:669–704Google Scholar
  42. Schumacher C, Robert AHJ (2003) Stratiform rain in the tropics as seen by TRMM precipitation radar. J Clim 16:1739–1756CrossRefGoogle Scholar
  43. Semazzi FHN, Lin YL, Giorgi F (1993) A nested model study of the Sahelian climate response to sea-surface temperature anomalies. Geophys Res Lett 20:2897–2900CrossRefGoogle Scholar
  44. Simmons AJ, Gibson JK (2000) The ERA-40 project plan. ERA-40 Project Report, series No. 1, 63 ppGoogle Scholar
  45. Steiner AL, Pal JS, Raucher SA, Bell JL, Diffenbaugh NS, Boone A, Sloan LC, Giorgi F (2009) Land surface coupling in regional climate simulations of the West African monsoon. Clim Dyn, doi  10.1007/s00382-009-0543-6
  46. Thiaw WM, Kingtse CM (2005) Impact of sea surface temperature and soil moisture on seasonal rainfall prediction over the Sahel. J Clim 18:5330–5343CrossRefGoogle Scholar
  47. Thorncroft CD, Rowell DP (1998) Interannual variability of African wave activity in a general circulation model. Int J Climatol 18:1305–1323CrossRefGoogle Scholar
  48. Uppala SM et al (2005) The ERA-40 re-analysis part B. Quart J Roy Meteor Soc 131:2961–3012. doi: 10.1256/qj.04.176 CrossRefGoogle Scholar
  49. Vanvyve E, Hall N, Messager C (2007) Internal variability in a regional climate model over West Africa. Clim Dyn, doi  10.1007/s00382-007-0281-6
  50. Xie P, Arkin P (1997) Global precipitation: a 17-year monthly analysis based on gauge observations, satellite estimates and numerical outputs. Bull Amer Meteor Soc 78:2539–2558CrossRefGoogle Scholar
  51. Xue Y, Shukla J (1993) The influence of land surface properties on Sahel climate. Part I: desertification. J Clim 6:2232–2245CrossRefGoogle Scholar
  52. Xue Y, Shukla J (1997) Model simulation of the influence of global SST anomalies on Sahel rainfall. Mon Weather Rev 126:2782–2792CrossRefGoogle Scholar
  53. Zheng X, Eltahir E (1998) The role of the vegetation in the dynamics of West African monsoons. J Clim 11:2078–2098Google Scholar

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  1. 1.Department of Physics, Faculty of Sciences, Laboratory for Environmental Modelling and Atmospheric PhysicsUniversity of Yaoundé IYaoundéCameroon

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