@InProceedings{BorqueVidSalGarNic:2006:CaSt,
               author = "Borque, Paloma Celina and Vidal, Ricardo and Salio, Paola and 
                         Garcia Skabar, Yanina and Nicolini, Matilde",
          affiliation = "Departamento de Ciencias de la Atm{\'o}sfera y los Oc{\'e}anos. 
                         Universidad de Buenos Aires. Buenos Aires. Argentina (Borque, 
                         Vidal, Salio, Nicolini) and Centro de Investigaciones del Mar y la 
                         Atm{\'o}sfera. CONICET/UBA (Salio, Nicolini)",
                title = "Previous conditions associated to a development of a mesoscale 
                         convective system under South American Low-Level Jet event: A case 
                         study",
            booktitle = "Proceedings...",
                 year = "2006",
               editor = "Vera, Carolina and Nobre, Carlos",
                pages = "1677--1682",
         organization = "International Conference on Southern Hemisphere Meteorology and 
                         Oceanography, 8. (ICSHMO).",
            publisher = "American Meteorological Society (AMS)",
              address = "45 Beacon Hill Road, Boston, MA, USA",
             keywords = "mesoscale convective system - low-level jet -.",
             abstract = "The objective of the present work is to study the prestorm 
                         environment prior to the development of a group of subtropical 
                         mesoscale convective systems (MCSs) during a South American 
                         Low-Level Jet (SALLJ) event. The evolution of the kinematics and 
                         thermodynamic structure of the atmosphere is studied in order to 
                         understand the gradual building of optimal conditions for the 
                         formation of organized convection during an intensive observation 
                         period. The work is centered in the study of a situation that 
                         occurs on 5 7 February 2003 included in SALLJEX (SALLJ 
                         Experiment). This case is characterized by an intense pre-frontal 
                         MCS and the presence of SALLJ conditions that penetrates up to 
                         subtropical latitudes during the whole period. IR satellite images 
                         with high temporal and horizontal resolution are used to detect 
                         subtropical convection, and determine the initiation, maximum 
                         extent and decay times. The environment associated with the 
                         systems is described using operational analyses (GDAS - Global 
                         Data Assimilation System) with 1 degree horizontal and 6-hours 
                         temporal resolution. SALLJEX data enhance the operational pibal 
                         and sounding network generating a unique dataset to study 
                         mesoscale processes. The period of study is included in a long 
                         intensive observation period, where in some stations soundings 
                         were launched every 6 hours, and pibal observation every 3 hours 
                         in the whole network. The subtropical area was dominated by a 
                         northerly flux that advected Humidity and high temperature values 
                         on February 5. The convection developed in the central area of 
                         Argentina and it moved towards the northeast of this country. Due 
                         to this movement, the northerly flux retreated up to 27S. At the 
                         beginning of Feb 6 the northerly flux developed close to the slope 
                         of the Andes, and propagated to the east during the following 
                         hours, this is observed in GDAS dataset as well as in the wind 
                         profiles. February 6 was characterized by the absence of 
                         convection in all the area south of 20S and between just to the 
                         east of the Andes to 55W, in spite of showing SALLJ conditions in 
                         all the region. A new convective cell developed at 32S-64W at 18 
                         Z, this system grew up to an enormous size that reached 350.000 
                         km2 and it dissipated while moving northward. A convective 
                         regeneration was observed north ahead of the dissipation area. New 
                         isolated developments grow up mainly in northern Argentina and 
                         Uruguay 600 km away from the baroclinic zone. Sounding 
                         observations show the building of the environment generated by 
                         SALLJ conditions, this is evident by an increase in humidity and 
                         temperature values at low levels. Once maximum in specific 
                         humidity is attained close to the surface the changes by the 
                         low-level jet centers in an increase in the height of the mixing 
                         layer with an extreme constant specific humidity value. Santiago 
                         del Estero soundings display a deep mixing layer, that evolves 
                         from 2000 m to 3500 m (between Feb 6 18Z to Feb 7 6Z) before the 
                         passage of MCS.",
  conference-location = "Foz do Igua{\c{c}}u",
      conference-year = "24-28 Apr. 2006",
             language = "en",
         organisation = "American Meteorological Society (AMS)",
                  ibi = "cptec.inpe.br/adm_conf/2005/10.31.19.56",
                  url = "http://urlib.net/ibi/cptec.inpe.br/adm_conf/2005/10.31.19.56",
           targetfile = "1677-1682.pdf",
                 type = "Weather analysis and forecasting",
        urlaccessdate = "11 maio 2024"
}