@InProceedings{GonzálezVeraLieb:2006:ChInVa,
               author = "Gonz{\'a}lez, Paula L. M. and Vera, Carolina S. and Liebmann, 
                         Brant",
          affiliation = "CIMA/DCAO, University of Buenos Aires-CONICET (Gonz{\'a}lez and 
                         Vera) and NOAA/CIRES Climate Diagnostics Center, Boulder, 
                         Colorado, USA (Liebmann)",
                title = "Characteristics of the intraseasonal variability of precipitation 
                         over eastern Argentina",
            booktitle = "Proceedings...",
                 year = "2006",
               editor = "Vera, Carolina and Nobre, Carlos",
                pages = "1063--1088",
         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 = "intraseasonal variability, precipitation, SACZ.",
             abstract = "An analysis of the intraseasonal variability of precipitation over 
                         central and eastern Argentina is presented. Daily precipitation 
                         data from Argentinean Weather Service stations that are 
                         representative of the different geographical regions have been 
                         used for the period 1976-2001. The climatological mean seasonal 
                         cycle was first removed from the timeseries. In order to retain 
                         the intraseasonal variability associated with the warm season (1 
                         Nov-31 Mar), the anomaly timeseries were normalized and filtered 
                         by a 20-90 day Lanczos filter. Daily OLR data for the period 
                         1979-2001 have also been used to compare its associated 
                         intraseasonal variability with that depicted by the precipitation 
                         data. Results show that intraseasonal variability observed in the 
                         daily precipitation over central and eastern Argentina explains a 
                         significant portion of the total summer variance. Moreover, the 
                         explained variance by the intraseasonal variability is largest 
                         over eastern Argentina, decreasing from subtropical to middle 
                         latitudes. OLR, typically used as summer precipitation proxy, is 
                         able to reproduce the basic characteristic of the precipitation 
                         intraseasonal variability, particularly when the amplitude of the 
                         intraseasonal oscillations (IO) in precipitation timeseries is 
                         relatively large. Although, when the IO amplitude is small, OLR 
                         variability only explains a small fraction of the precipitation 
                         variability. Furthermore, the OLR is not able to represent the 
                         precipitation variability on synoptic timescales. Positive 
                         (negative) events of precipitation intraseasonal variability were 
                         defined identifying the dates in which the filtered precipitation 
                         series exhibit values above (below) one standard deviation for at 
                         least 5 days. Around 50 events were identified for each category 
                         over the period considered, with around half of them exhibiting a 
                         mean length of 7 days and the others of 12 days. The date 
                         associated with the maximum (minimum) filtered precipitation value 
                         was identified for each positive (negative) event and was then 
                         considered as Day 0 in the computation of daily composites. 
                         Composite 200-hPa geopotential-height anomalies for positive 
                         precipitation events over subtropical eastern Argentina show a 
                         wave train evolving all along the South Pacific, over the 10-day 
                         period previous to the precipitation peak. The wave train is 
                         characterized by quasistationary anomaly centers and a relatively 
                         fast eastward wave energy progression. On the other hand, 
                         composites for positive precipitation events over extratropical 
                         eastern Argentina are associated with the evolution of long-life 
                         synoptic waves progressing eastward. Composites of OLR anomalies 
                         for positive precipitation events over both subtropical and 
                         extratropical eastern Argentina are associated with decreased 
                         convection in the SACZ region, in agreement with previous works. 
                         Nevertheless, differences in the location and timing of the OLR 
                         positive anomalies over the SACZ region were observed for both 
                         types of composites and will be further discussed in the 
                         Conference.",
  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/2005/10.31.19.28",
                  url = "http://urlib.net/ibi/cptec.inpe.br/adm_conf/2005/10.31.19.28",
           targetfile = "1063-1088.pdf",
                 type = "Monsoon systems and continental rainfall",
        urlaccessdate = "29 jun. 2024"
}