Abstract:
A relevant feature of the South American low-level circulation during the wet season is a poleward warm and moist current immediately to the east of the Andes often referred to as a low-level jet, because of its resemblance to the Great Plains low-level jet. Provided that the lack of observational data causes a great deal of uncertainty on the ability of analyses to describe diurnal fluctuations of sub-synoptic features like a low-level jet, this description has been carried out using the Eta regional model. Special emphasis has been given to the detection and characterization of a low-level jet (LLJ) east of the Andes, as a feature best developed at night and mesoscale cross-stream dimensions. This study describes the modeled northerly current east of the Andes during the 1997-1998 warm season, and progress on its mean characterization, including diurnal fluctuations and horizontal and vertical structure. From moisture budget calculations a net convergence of moisture flux is found over an area that includes the Del Plata basin, with a maximum southward flux through the northern boundary at low levels. While there are evidences to suggest that this model provides a realistic description of the local circulation, it is emphasized that observational data are needed to gain further understanding of the behavior of the South American low-level jet and its role upon the regional climate. © Springer-Verlag 2000.
Registro:
Documento: |
Artículo
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Título: | Model characterization of the South American low-level flow during the 1997-1998 spring-summer season |
Autor: | Saulo, A.C.; Nicolini, M.; Chou, S.C. |
Filiación: | Department of Atmospheric Sciences, University of Buenos Aires (UBA), Centro de Investigaciones del Mar y la Atmósfera (CIMA) - UBA/CONICET, Buenos Aires, Argentina Centro de Previsao de Tempo e Estudos Climaticos - CPTEC, Instituto Nacional de Pesquisas Espaciais - INPE, Cachoeira Paulista - SP, Brazil
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Palabras clave: | atmospheric circulation; jet flow; model analysis; atmospheric circulation; jet flow; low flow; model validation; troposphere; South America |
Año: | 2000
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Volumen: | 16
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Número: | 10-11
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Página de inicio: | 867
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Página de fin: | 881
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DOI: |
http://dx.doi.org/10.1007/s003820000085 |
Título revista: | Climate Dynamics
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Título revista abreviado: | Clim. Dyn.
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ISSN: | 09307575
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Registro: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09307575_v16_n10-11_p867_Saulo |
Referencias:
- Anthes, R., Regional models of the atmosphere in middle latitudes (1983) Mon Weather Rev, 111, pp. 1306-1335
- Berbery, E.H., Rasmusson, E.M., Mitchell, K.E., Studies of north american continental-scale hydrology using Eta model forecast products (1996) J Geophys Res, 101, pp. 7305-7319
- Berri, G., Berri, J.C., Inzunza, B., The effect of the low-level jet on the poleward water vapour transport in the central region of South America (1993) Atmos Env Part A, 27 A (3), pp. 335-341
- Black, T.L., NMC notes: The new NMC mesoscale Eta model: Description and forecast examples (1994) Weather Forecast, 9, pp. 256-278
- Blackadar, A.K., Boundary layer wind maxima and their significance for the growth of nocturnal inversions (1957) Bull Am Meteorol Soc, 38, pp. 283-290
- Bonner, W.D., Climatology of the low level jet (1968) Mon Weather Rev, 96, pp. 833-850
- Bonner, W.D., Paegle, J., Diurnal variations in boundary layer winds over the south-central United States in summer (1970) Mon Weather Rev, 98, pp. 735-744
- Bustamante, J.F., Regional numerical models for weather prediction: A comparison of FSU and Eta models performance over South America (in Portuguese) (1998) Master Thesis, Instituto Nacional de Pesquisas Espaciais. Sao Jose dos Campos, SP, Brazil
- Chou, S.C., Justi Da Silva, M.G.A., Objective evaluation of Eta model precipitation forecasts over South America (1999) Climanalise 1, , http://www.cptec.inpe.br/products/climanalise/artigos/artcien2.htm
- Douglas, M., Nicolini, M., Saulo, A.C., The low level jet at Santa Cruz, Bolivia, during January-March 1998 Pilot Balloon observations and model (1999) Proc 10th Symp Global Change, Dallas, USA, pp. 223-226
- Fernandez, A., Necco, G., Wind characteristics in the free atmosphere at argentinian radiosounding stations (in Spanish) (1982) Meteorologica, 13 (2), pp. 7-21
- Higgins, R.W., Yao, Y., Yarosh, E.S., Janowiak, J.E., Mo, K.C., Influence of the Great Plains low-level jet on summertime precipitation transport over the Central United States (1997) J Clim, 10, pp. 481-507
- Inzunza, B., Berri, J.C., Berri, G., Wind and water vapour transport behavior at the lower troposphere over northern (1990) Meteorologica, 17, pp. 17-25. , (in Spanish, abstract in English)
- James, I.N., Anderson, D.L.T., The seasonal mean flow and distribution of large-scale weather systems in the southern hemisphere: The effects of moisture transports (1984) Q J R Meteorol Soc, 110, pp. 943-966
- Janjic, Z.I., The step-mountain coordinate: Physical package (1990) Mon Weather Rev, 118, pp. 1429-1443
- Janjic, Z.I., The step-mountain eta coordinate model: Further developments of the convection, viscous sublayer, and turbulence closure chemes (1994) Mon Weather Rev, 122, pp. 927-945
- Mellor, G.L., Yamada, T., A hierarchy of turbulence closure models for planetary boundary layers (1974) J Atmos Sci, 31, pp. 1791-1806
- Mesinger, F., Improvements in quantitative precipitation forecast with the Eta regional model at the National Centers for Environmental Prediction: The 48-km upgrade (1996) Bull Am Meteorol Soc, 77, pp. 2637-2649
- Mesinger, F., Black, T.L., On the impact on forecast accuracy of the step-mountain (Eta) versus sigma coordinate (1992) Meteorol Atmos Phys, 50, pp. 47-60
- Mesinger, F., Janjic, Z.I., Nickovic, S., Gavrilov, D., Deaven, D.G., The step-mountain coordinate: Model description and performance for cases of Alpine lee cyclogenesis and for a case of Appalachian redevelopment (1988) Mon Weather Rev, 116, pp. 1493-1518
- Nicolini, M., Paegle, J., Altinger, M.L., Numerical simulation of convection and boundary layer convergence (1987) Preprints, 2nd Int Cong Meteorology, Buenos Aires, Argentina, Latin American Meteorological Federation and American Meteorological Society 8.5.1-8.5.7
- Nogues-Paegle, J., Mo, K.C., Alternating wet and dry conditions over South America during summer (1997) Mon Weather Rev, 125 (2), pp. 279-291
- Paegle, J., A comparative review of South American low level jets (1998) Meteorologica, 23, pp. 73-81
- Paegle, J., Ereno, C., Collini, E., Diurnal oscillations of convective weather and boundary layer flows in South America (1982) Preprints, 2nd Brazilian Meteorology Congr, pp. 132-146
- Rasmusson, E.M., Atmospheric water vapor transport and the water balance of North America, I, characteristics of the water vapor flux field (1967) Mon Weather Rev, 95, pp. 403-426
- Rasmusson, E.M., Mo, K.C., Large-scale atmospheric moisture cycling as evaluated from NMC global analysis and forecast products (1996) J Clim, 9, pp. 3276-3297
- Ropelewski, C.F., Halpert, M.S., Quantifying Southern Oscillation-precipitation relationship (1996) J Clim, 9, pp. 1043-1059
- Schwertdfeger, W., The atmospheric circulation over Central and South America (1976) World Survey of Climatology, 12, pp. 1-12. , In: Schwertdfeger W, Lansberg HE (eds); Elsevier, Amsterdam
- Seluchi, M.E., Chou, S.C., Tropical-extra-tropical air mass interchange over South America: Eta regional model validation (1999) Climanalise, 14 (4). , (in Spanish)
- Sugahara, S., Da Rocha, R.P., Low-level jet climatology during Southern Hemisphere summer over a South American region (in Portuguese) (1996) Proc IX Congr Brasileiro de Meteorologia, Campos do Jordao, SP, Brazil, pp. 1383-1387
- Sugahara, S., Da Rocha, R.P., Rodrigues, M.L., Atmospheric conditions associated with the South America low level jet (in Portuguese) (1994) Proc VIII Congr Brasileiro de Meteorologia, Spain, 2, pp. 573-577
- Virji, H., A preliminary study of summertime tropospheric circulation patterns over South America estimated from cloud winds (1981) Mon Weather Rev, 109, pp. 596-610
- Wang, M., Paegle, J., Impact of analysis uncertainty upon regional atmospheric moisture flux (1996) J Geophys Res, 101 (3), pp. 7291-7303
- Zhou, J., Lau, K.-M., Does a monsoon climate exist over South America? (1998) J Clim, 11, pp. 1020-1040
Citas:
---------- APA ----------
Saulo, A.C., Nicolini, M. & Chou, S.C.
(2000)
. Model characterization of the South American low-level flow during the 1997-1998 spring-summer season. Climate Dynamics, 16(10-11), 867-881.
http://dx.doi.org/10.1007/s003820000085---------- CHICAGO ----------
Saulo, A.C., Nicolini, M., Chou, S.C.
"Model characterization of the South American low-level flow during the 1997-1998 spring-summer season"
. Climate Dynamics 16, no. 10-11
(2000) : 867-881.
http://dx.doi.org/10.1007/s003820000085---------- MLA ----------
Saulo, A.C., Nicolini, M., Chou, S.C.
"Model characterization of the South American low-level flow during the 1997-1998 spring-summer season"
. Climate Dynamics, vol. 16, no. 10-11, 2000, pp. 867-881.
http://dx.doi.org/10.1007/s003820000085---------- VANCOUVER ----------
Saulo, A.C., Nicolini, M., Chou, S.C. Model characterization of the South American low-level flow during the 1997-1998 spring-summer season. Clim. Dyn. 2000;16(10-11):867-881.
http://dx.doi.org/10.1007/s003820000085