AJCC> Vol.1 No.3, September 2012

Climate Fields over South America and Variability of SACZ and PSA in HadGEM2-ES

DownloadDownload as PDF (Size:4458KB)  HTML    PP. 132-144  

ABSTRACT

Historical simulations (present climate) and projections under RCP8.5 scenario (future climate) by HadGEM2-ES of temperature and precipitation are analyzed during the four seasons in South America. Projections of precipitation are discussed in terms of atmospheric circulation. The South Atlantic Convergence Zone (SACZ) and the Pacific South America (PSA) patterns are analyzed in simulations of present climate and in future climate projections. The model shows small systematic errors over South America, larger close to the northern South American coast in DJF and MAM. The seasonal variability of precipitation, temperature and wind fields is very well reproduced, mainly the summer/winter differences. The SACZ and the Intertropical Convergence Zone (ITCZ) are well simulated. The good model performance to reproduce the precipitation, temperature and wind fields, in the present climate, gives confidence in the projection results subject to the future scenarios. Changes from the present time to the future indicate increased precipitation over southern and southeastern Brazil and areas nearby and the tropical western South American coast. Reduced precipitation is projected over eastern Amazonia, northern South America and southern Chile. The changes are related to changes in the low level wind flow over the tropical North Atlantic, which reduces the advection of moisture to the continent and also to the increased low level flow over central South America southwards, which increases the humidity in the southern regions. The upper level flow changes are also consistent with the precipitation changes. There is a weakening of the Bolivian High and a strengthening of the subtropical jet over the continent. The SACZ dipole pattern is well simulated and in the future projections the southern center anomalies are more intense than in the present time. The PSA1 and PSA2 patterns are well represented in the present climate, but in the future projection only one dominant mode is identified as the typical teleconnection over the Pacific and South America.

Cite this paper

I. Cavalcanti and M. Shimizu, "Climate Fields over South America and Variability of SACZ and PSA in HadGEM2-ES," American Journal of Climate Change, Vol. 1 No. 3, 2012, pp. 132-144. doi: 10.4236/ajcc.2012.13011.

References

[1] K. E., Taylor, R. J. Stouffer and G. A Meehl, “An Overview of CMIP5 and the Experiment Design,” Bulletin of the American Meteorological Society, Vol. 93, No. 4, 2011, pp. 485-498. doi:10.1175/BAMS-D-11-00094.1
[2] K. E. Taylor, R. J. Stouffer and G. A. Meehl, “A Summary of the CMIP5 Experiment Design,” 2009. http://cmip-pcmdi.llnl.gov/cmip5/docs/Taylor_CMIP5_design.pdf
[3] I. F. A. Cavalcanti, “Large scale and Synoptic Features Associated with Extreme Precipitation over South America: A Review and Case Studies for the First Decade of the 21st Century,” Atmospheric Research, Vol. 118, 2012, pp. 27-40. doi:10.1016/j.atmosres.2012.06.012
[4] Solomon, et al., “Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change,” Working Group I Report, The Physical Science Basis, Cambridge University Press, Cambridge and New York, 2007.
[5] C. Vera, G. Silvestri, B. Liebmann and P. Gonzalez, “Climate Change Scenarios for Seasonal Precipitation in South America from IPCC-AR4 Models,” Geophysical Research Letters, Vol. 33, No. L13707, 2006, 4 pp.? doi:10.1029/2006GL025759
[6] A. Seth, M. Rojas and S. A. Rauscher, “CMIP3 Projected Changes in the Annual Cycle of the South American Monsoon,” Climatic Change, Vol. 98, No. 3-4, 2010, pp. 331-357. doi:10.1007/s10584-009-9736-6
[7] R. J. Bombardi and L. M. V. Carvalho, “IPCC Global Coupled Model Simulations of the South America monsoon system,” Climate Dynamics, Vol. 33, No. 7-8, 2009, pp. 893-916. doi:10.1007/s00382-008-0488-1
[8] J. Nogues-Paegle and K. C. Mo, “Alternating Wet and Dry Conditions Over South America during Summer,” Monthly Weather Review, Vol. 125, No. 2, 1997, pp. 279291. doi:10.1175/1520-0493(1997)125<0279:AWADCO>2.0.CO;2
[9] F. C. Vasconcellos and I. F. A. Cavalcanti, “Extreme Precipitation over Southeastern Brazil in the Austral Summer and Relations with the Southern Hemisphere Annular Mode,” Atmospheric Science Letters, Vol. 11, No. 1, 2010, pp. 21-26.
[10] C. A. C. Cunningham and I. F. A. Cavalcanti, “Intraseasonal Modes of Variability Affecting the South Atlantic Convergence Zone,” International Journal of Climatology, Vol. 26, No. 9, 2006, pp. 1165-1180. doi:10.1002/joc.1309
[11] L. M. V. Carvalho, C. Jones and B. Liebmann, “The South Atlantic Convergence Zone: Intensity, Form, Persistence, and Relationships with Intraseasonal to Interannual Activity and Extreme Rainfall,” Journal of Climate, Vol. 17, No. 1, 2004, pp. 88-108. http://dx.doi.org/10.1175/1520-0442(2004)017<0088:TSACZI>2.0.CO;2
[12] B. Liebmann, G. N. Kiladis, J. A. Marengo, T. Ambrizzi and J. D. Glick, “Submonthly Convective Variability over South America and the South Atlantic Convergence Zone,” Journal of Climate, Vol. 12, No. 7, 1999, pp. 1877-1891. doi:10.1175/1520-0442(1999)012<1877:SCVOSA>2.0.CO;2
[13] K. C. Mo and R. W. Higgins, “The Pacific-South American Modes and Tropical Convection During the Southern Hemisphere Winter,” Monthly Weather Review, Vol. 126, No. 6, 1998, pp. 1581-1596. doi:10.1175/1520-0493(1998)126<1581:TPSAMA>2.0.CO;2
[14] J. M. Wallace and D. S. Gutzler, “Teleconnections in the Geopotential Height Field during the Northern Hemisphere winter,” Monthly Weather Review, Vol. 109, No. 4, 1981, pp. 784-812. doi:10.1175/1520-0493(1981)109<0784:TITGHF>2.0.CO;2
[15] I. F. A. Cavalcanti, “Teleconnection Patterns Orographically Induced in Model Results and from Observational Data in the Austral Winter of the Southern Hemisphere,” International Journal of Climatology, Vol. 20, No. 10, 2000, pp. 1191-1206. doi:10.1002/1097-0088(200008)20:10<1191::AID-JOC523>3.0.CO;2-G
[16] J. A. Marengo, T. Ambrizzi, G. Kiladis and B. Liebmann, “Upper-Air Wave Trains over the Pacific Ocean and Wintertime Cold Surges in Tropical-Subtropical South America Leading the Freezes in Southern and Southeastern Brazil,” Theoretical and Applied Climatology, Vol. 73, No. 3-4, 2002, pp. 223-242. doi:10.1007/s00704-001-0669-x
[17] C. Vera and G. Silvestri, “Precipitation Interannual Variability in South America from the WCRP-CMIP3 MultiModel Dataset,” Climate Dynamics, Vol. 32, No. 7-8, 2009, pp. 1003-1014. doi:10.1007/s00382-009-0534-7
[18] C. Junquas, C. Vera, L. Li and H. Le Treut, “Summer Precipitation Variability over Southeastern South America in a Global Warming Scenario,” Climate Dynamics, Vol. 38, No. 9-10, 2011, pp. 1867-1883. doi:10.1007/s00382-011-1141-y
[19] R. F. Adler, et al., “The Version 2 Global Precipitation Climatology Project (GPCP) Monthly Precipitation Analysis (1979 Present),” Journal of Hydrometeorology, Vol. 4, No. 6, 2003, pp. 1147-1167. doi:10.1175/1525-7541(2003)004<1147:TVGPCP>2.0.CO;2
[20] D. P. Dee, et al., “The ERA-Interim Reanalysis: Configuration and Performance of the Data Assimilation system,” Quarterly Journal of Royal Meteorological Society, Vol. 137, No. 656, 2011, pp. 553-597. doi:10.1002/qj.828
[21] T. C. Johns, et al., “The New Hadley Centre Climate Model (HadGEM1): Evaluation of Coupled Simulations,” Journal of Climate, Vol. 19, No. 7, 2006, pp. 1327-1353. doi:10.1175/JCLI3712.1
[22] G. M. Martin, M. A. Ringer, V. D. Pope, A. Jones, C. Dearden, and T. J. Hinton, “The Physical Properties of the Atmosphere in the New Hadley Centre Global Environmental Model (HADGEM1), Part I: Model Description and Global Climatology,” Journal of Climate, Vol. 19, No. 7, 2006, pp. 1274-1301. doi:10.1175/JCLI3636.1
[23] W. G. Collins, et al., “Hadley Centre, Evaluation of the HadGEM2 Model,” Technical note 74 at Hadley Centre, 2008, 47 pp.
[24] W. G. Collins, et al., “Development and Evaluation of an Earth-System Model—HadGEM2,” Geoscientific Model Development, Vol. 4, 2011, pp. 997-1062. doi:10.5194/gmdd-4-997-2011
[25] C. D. Jones, et al., “The HadGEM2-ES Implementation of CMIP5 Centennial Simulations,” Geoscientific Model Development, Vol. 4, 2011, pp. 689-763. doi:10.5194/gmdd-4-689-2011
[26] I. F. A. Cavalcanti, et al., “Global Climatological Features in a Simulation Using CPTEC/COLA AGCM,” Journal of Climate, Vol. 15, No. 21, pp. 2965-2988. doi:10.1175/1520-0442(2002)015<2965:GCFIAS>2.0.CO;2
[27] A. Raia and I. F. A. Cavalcanti, “The Life Cycle of the South American Monsoon System,” Journal of Climate, Vol. 21, No. 23, 2008, pp. 6227-6246. doi:10.1175/2008JCLI2249.1
[28] J. A. Marengo, W. Soares, C. Saulo and M. Nicolini, “Climatology of the LLJ East of the Andes as Derived from the NCEP Reanalyses,” Journal of Climate, Vol. 17, 2004, pp. 2261-2280.

comments powered by Disqus

Copyright © 2014 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.