@InProceedings{ObregonNobr:2004:HyVaOv,
               author = "Obregon, Guilhermo O. and Nobre, Carlos Afonso",
          affiliation = "{CPTEC-INPE-Cachoeira Paulista-12630-000-SP-Brasil}",
                title = "Hydrologic variability over the Amazon basin and its ip with ENOS 
                         and NAO relationship",
                 year = "2004",
         organization = "International Clivar Science Conference, 1.",
             abstract = "The availability of long-term streamflow records of the Amazon 
                         river at Manacapur{\'u} station, representative of the rainfall 
                         integrate over the western portion of the basin, is useful as a 
                         proxy for precipitation. Since this data provides a natural 
                         integration of the hidroclimatic variations, it will allow us a 
                         better understanding of the relationship between the hydrologic 
                         processes over Amazonia and the large-scale circulation, which 
                         drives the variability of the precipitation. Past studies found 
                         that the rainfall over Amazonia is strong related to ENSO 
                         phenomena (e. g. Marengo 1992), and it explains part of the 
                         interannual variance of the river discharge (Amarasekera et al. 
                         1997) with significant coherency at the period of 2-3 year 
                         (Richlet et al. 1989). The rainfall (Nobre and Shukla 1996) and 
                         the hydrologic trends (Costa and Foley 1999) over Amazonia are 
                         also linked to the Tropical Atlantic SST. Besides it, there is a 
                         relationship between the Tropical North Atlantic SST and the North 
                         Atlantic Oscillation (NAO) at times scales of 8 - 20 year 
                         (Rajagopalan et al. 1998), and model evidence that there is some 
                         dependency between the NAO and the tropical Atlantic SST 
                         (Robertson et al. 2000) Thus, the goals of this work are twofold: 
                         first to reveal structures of a characteristic scale of monthly 
                         river discharge using wavelet transform. Secondly, search for 
                         relationship between the discharges and both the SOI and NAO 
                         through the cross wavelet analyses, because they depict part of 
                         the variability of the global climatic system and appear to be 
                         independent manifestations of climate variability (Giannini at al. 
                         2001). The use of the wavelet transform analysis offers 
                         significant advantages over other techniques for analysis of 
                         streamflow records because periodic and non-periodic events are 
                         precisely located in time, permitting transient or time-dependent 
                         features to be detected, that may otherwise be obscure.",
  conference-location = "Baltimore",
      conference-year = "21-25 jun.",
           copyholder = "SID/SCD",
             language = "en",
           targetfile = "4Obregon.G.pdf",
        urlaccessdate = "01 maio 2024"
}