Abstract
The characteristics of the main components of the water cycle over Equatorial Central Africa (ECA) were analysed using the 32-year period, spanning from 1968 to 2000, of the National Centers for Environmental Prediction-National Censearch (NCEP-) reanalysis project database. A special emphasis was given to identifying the causes of annual and interannual variability of water vapor flux and precipitation recycling. The results suggest that the first maximum of moisture convergence, during the rainy season MAM, comes from upper level moisture flux, related to the north component of the African Easterly Jet (AEJ-N). The second, and greatest, maximum in SON is found to be a consequence of low level moisture advection from the Atlantic Ocean. AEJ-N also drive the seasonal spatial pattern of moisture flux. The interannual variability of moisture flux is contributed mainly by the low level moisture advected from the Atlantic Ocean, underlying its crucial role for the regional climate. Studying the recycling ratio in ECA as a whole shows a low annual cycle whereas subregional scale analysis reveals high amplitude of the seasonal variation. Seasonal variability of the spatial gradient of precipitation recycling is regulated by both moisture flux direction and strength. The annual cycles of recycling ratio in the North and the South of ECA are regulated by both moisture transport and evapotranspiration.
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References
Bosilovich MG, Schubert SD (2001) Precipitation Recycling over the Central United States Diagnosed from the GEOS-1 Data Assimilation System. J Hydrometeorol 2:26–35
Bosilovich MG, Chern JD (2006) Simulation of water sources and precipitation recycling for the Mackenzie, Mississipi, and the Amazon River Basins. J Hydrometeorol 7:312–329
Brubaker KL, Entekhabi D, Eagleson PS (1993) Estimation of continental precipitation recycling. J Clim 6:1077–1089
Budyko MI (1974) Climate and life. Academic Press, Waltham
Burde GI (2006) Bulk recycling models with incomplete vertical mixing, Part I: conceptual framework and models. J Clim 19:1461–1472
Burde GI, Gandush C, Bayarjargal Y (2006) Bulk recycling models with incomplete vertical mixing, Part II: precipitation recycling in the Amazon Basin. J Clim 19:1473–1489
Burde GI, Zangvil A (2001) The estimation of regional precipitation recycling. Part I: reviews of recycling models. J. Climate 14:2497–2508
Burde GI, Zangvil A (2001) The estimation of regional precipitation recycling. Part II: a new recycling model. J Clim 14:2509–2527
Burde GI, Zangvil A, Lamb PJ (1996) Estimation of the role of local evaporation in precipitation for a two-dimensional region. J Clim 9:1328–1338
Dirmeyer PA, Brubaker KL (1999) Contrasting evaporative moiture sources during the drought of 1988 and flood of 1993. J Geo Res 104(D16):19383–19397
Dirmeyer P, Zeng F, Ducharne A, Morrill J, Koster R (2000) The sensitivity of surface fluxes to soil water content in three land surface schemes. J Hydrometeorol 1:121–134
Dirmeyer PA, Brubaker KL (2006) Evidence for trends in the Northern Hemisphere water cycle. Geophys Res Lett 33:L14712. doi:10.1029/2006GL026359
Dirmeyer PA, Schlosser CA, Brubaker KL (2008) Precipitation, recycling and land memory: An integrated analysis. J Hydrometeorol 10:278–288. doi:10.1175/2008JHM1016.1
Drozdov OA, Grigore’eva AS (1965) The Hydrological cycle in the atmosphere. Israel Program for Scientific Translation, Israel
Eltahir EAB, Bras LB (1996) Precipitation recycling. Rev Geophys 34:367–378
Eltahir EAB, Bras RL (1994) Precipitation recycling in the Amazon basin. Q J R Meteor Soc 120:861–880
Fitzmaurice JA (2007) A critical analysis of bulk precipitation recycling models. Ph.D. thesis, M. I. T. Dept. Civil and Environmental Engineering
Fontaine B, Roucou P, Trzaska S (2003) Atmospheric water cycle and moisture fluxes in the West African monsoon: mean annual cycles and relationship using NCEP/NCAR reanalysis. Geophys Res Lett 30(3):1117. doi:10.1029/2002GL015834
Gat JR, Matsui E (1991) Atmospheric water balance in the Amazon Basin: an isotropic evapotranspiration model. J Geophys Res 91:13179–13188
Hulme M (1992) A 1954-80 global land precitation climatology for the evaluation of general circulation models. Clim Dyn 7:57–72
Hulme M (1994) Validation of large-scale precipitation fields in general circulation models. Global precipitation, climatechange. In: Desbois M, Desalmand F (eds) NATO ASI series., Springer, Berlin, pp 387–406
Jackson B, Nicholson SE, Kloster D (2009) Mesoscale convective system over Western Equatorial Africa and their relation to large-scale circulation. Mon Weather Rev 137:1272–1294
Kalnay E et al (1996) The NCEP-NCAR 40 year Reanalysis Project. Bull Am Meteorolo Soc 77:437–471
Karam HN, Bras RL (2008) Estimates of net atmospheric moisture flux convergence over the Amazon Basin: a comparison of reanalysis products. J Hydrometeorol 9:1035–1047
Koster RD (1988) Tracer water transport and subgrid precipitation variation within atmospheric general circulation models. ScD thesis, MIT Dept. Civil Engineering
Labraga JC, Frumento O, López M (2000) The atmospheric water vapor cycle in South America and the troposperic circulation. J Clim 13:1899–1915
Lettau H, Lettau K, Molion LCB (1979) Amazonian’s hydologic cycle and the role of atmospheric recycling in assessing deforestation effects. Mon Weather Rev 107:227–238
Long M, Enthekabi H, Nicholson SE (2000) Interannual variability in rainfall, water vapor flux and vertical motion over west Africa. J Clim 13:3827–3841
Matsuyama H, Oki T, Shinoda M, Masuda K (1994) The seasonal change of the water budget in the Congo River Basin. J Meteor Soc Jpn 32:281–299
McCollum JR, Gruber A, Ba MB (2000) Discrepancy between gauges and satellite estimates of rainfall in equatorial Africa. J Appl Meteor 39:666–679
Mo KC, Higgins RW (1996) Large-scale atmospheric moisture transport as evaluated in the NCEP/NCAR and NASA/DAO reanalyses. J Clim 9:1531–1545
Nesbitt SW, Cipelli R, Rutledge SA (2006) Storm morphology and rainfall characteristics of TRMM precipitation features. Mon Weather Rev 134:2702–2721
Newell, RE, Kidson, JW, Vincent, DG, Boer, GJ (eds) (1972) The general circulation of the tropical atmosphere. The MIT Press, Cambridge
Nicholson SE, Grist JP (2003) The seasonal evolution of the Atmospheric Circulation over West Africa and Equatorial Africa. J Clim 16:1013–1030
Numaguti A (1999) Origin and recycling processes of precipitation water over the Eurasian continent: experimental using an atmospheric general circulation moadel. J Geophys Res 104:1957–1972
Poccard L, Janicot S, Camberlin P (2000) Comparaison of rainfall structure between NCEP/NCAR reanalyses and observed data in tropical Africa. Clim Dyn 16:897–915
Salati E, Dall’Olio A, Matsui E, Gat JR (1979) Recycling of water in the Amazon basin: an isotopic study. Water Resourc Res 15:1250–1258
Shem WO (2006) Biosphere-atmosphere interaction over the Congo Basin and its influence on the regional hydrologycal cycle. PhD thesis, Georgia Institute of Technology, Sc. Earth and Atmospheric Sciences
Starr VP, Peixoto JP (1958) On the global balance of water vapor and hydrology of deserts. Tellus 10:189–194
Stohl A, James P (2004) A Lagrandian analysis of the atmospheric branch of the global water cycle. Part I: method description, validation and demonstration for the August 2002 flooding in central Europe. J Hydrometeorol 5:656–678
Stohl A, James P (2005) A Lagrandian analysis of the atmospheric branch of the global water cycle. Part I: moisture transports between earth’s ocean basins and river catchments. J Hydrometeorol 5:961–984
Szeto KK (2002) Moisture recycling over the Mackenzi Basin. Atmos Ocean 40(2):191–197
Trenberth KE (1999) Atmospheric moisture recycling: role of advection and local evaporation. J Clim 12:1368–1381
Trenberth KE, Guillemot CJ (1996) Evaluation of the atmospheric moisture and hydrological cycle in the NCEP reanalysis. NCAR Tech. Note NCAR/TN-340+STR
Trenberth KE, Guillemot CJ (1998) Evaluation of the atmospheric moisture and cycle in NCEP reanalysis. Clim Dyn 14:213–231
Trenberth KE, Stepaniak DP, Hurrell WJ (2001) Quality of reanalysis in the tropics. J Clim 14:1499–1510
Zangvil A, Lamb PJ, Portis DH, Jin F, Malka S (2010) Comparative study of atmospheric water vapor budget associated with precipitation in Central US and eastern Mediterranean. Adv Geosci 23:3–9
Zangvil A, Portis DH, Lamb PJ (2004) Investigation of the large-scale atmospheric moisture field over the Midwestern United States in relation to summer precipitation. Part II: recycling of local evapotranspiration and association with soil moisture and crop yields. J Clim 17:3283–3301
Zheng X, Eltahir EAB (1998) The role of vegetation in the dynamic of West African monsoons. J Clim 11(8):2078–2096
Zeng N (1999) Seasonal cycle and interannual variability in the Amazon hydrologic cycle. J Geophys Res 104:9097–9106
Acknowledgments
The authors would like to express their gratitude to Prof. S.E. Nicholson of Florida State University for providing Jackson et al. (2009), Prof. G. I. Burde of Ben-Gurion University of the Negev for assessing to Burde et al. (2006, 2006); They wish to acknowledge very fruitful discussions with Prof. P.J. Lamb of the University of Oklahoma, and for providing Zangvil et al. (2004). We also acknowledge the helpful comments provided by the reviewers.
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An erratum to this article is available at http://dx.doi.org/10.1007/s00382-013-1977-4.
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Pokam, W.M., Djiotang, L.A.T. & Mkankam, F.K. Atmospheric water vapor transport and recycling in Equatorial Central Africa through NCEP/NCAR reanalysis data. Clim Dyn 38, 1715–1729 (2012). https://doi.org/10.1007/s00382-011-1242-7
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DOI: https://doi.org/10.1007/s00382-011-1242-7