author = "Parise, Claudia Klose and Farina, L",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and Mathematics 
                         Institute, UFRGS, Porto Alegre, Brazil",
                title = "Short-scale wave variability in the South Atlantic ocean based on 
                         empirical orthogonal function and singular value decomposition",
            booktitle = "Posters",
                 year = "2010",
         organization = "The Meeting of the Americas.",
            publisher = "AGU",
             keywords = "ocean predictability, prediction.",
             abstract = "The availability of observational ocean wave data in the South 
                         Atlantic Ocean (SAO) is still very limited. Due to this shortage 
                         of data obtained in situ, numerical modeling has become the most 
                         used tool for the investigation of wave climate in whole world. 
                         Here, the global model WAM was used to simulate waves from June 
                         2006 to July 2007 in order to better understand the wave 
                         variability in short-scale. For this was applied the EOF and SVD 
                         analysis which have found the leading modes of the significant 
                         wave height (Hs), swell, velocity of the wind at height 10 meters 
                         (U10) and peak period (Tp) in the SAO. The large share of wave 
                         variability was explained by the first four modes, where a strong 
                         correlation was found between Tp and swell (68%) and also that 
                         with Hs (61%). The cross-correlation functions of the 1st and 2nd 
                         PCs time series were calculated and compared to Southern Annular 
                         Mode (SAM). The results have led us to conclude that the leading 
                         potential mechanism that drives the short-scale variability of 
                         ocean surface wave in the SAO is the extratropical cyclone amount 
                         variability. It could be noticed that the first modes of U10 and 
                         Hs were significantly related, as well as their second modes. The 
                         spatial pattern of the EOF3 of U10 started appearing in the EOF3 
                         of Hs, but became really similar to the fourth mode of the Hs, 
                         what outpoint the known time lag of ocean surface response to the 
                         atmospheric forcing. The EOF1 of swell has exhibited positive 
                         anomalies in southeast of grid and lowering of them toward 
                         northeast, showing that there is a correspondence between the 
                         propagation directions of swell and the dominant directions of 
                         storms. From spatial patterns were noticed contributions of swell 
                         from Pacific, Indian and North Atlantic Oceans. The anomalies (+) 
                         observed in the first and second Hs modes showed a contribution of 
                         swell from the Indic Ocean modifying the wave climate in the SAO. 
                         The application of cross-correlation function of PCs time series 
                         has provided the information that one maximum oscillation happened 
                         in each two day. We guess that this short and synoptic scale can 
                         have some relation to the extratropical cyclone variability. A 
                         clear seasonal fluctuation could be noted, particularly for the 
                         summer months, but the period studied is much short for a deep 
                         seasonal analyze. The negative tendency of SAM added with its also 
                         negative correlation coefficient with all variables analyzed 
                         indicate that the storms have shifted toward midlatitudes, and, 
                         consequently, larger is the chance to occur swell events. In this 
                         way, the results obtained here lead us to conclude that the 
                         leading potential mechanism that drives the short-scale 
                         variability of Hs and swell in the SAO is the extratropical 
                         cyclone amount variability. The application of EOF and SVD methods 
                         for obtaining leading modes of short-scale spatial temporal 
                         variability of oceanic waves, apart from appearing pioneer in the 
                         South Hemisphere, provided a better understanding of the ocean 
                         waves behavior in the South Atlantic Ocean and the relationship to 
                         local process, to other Oceans and to the high latitudes 
  conference-location = "Foz do Igua{\c{c}}u",
      conference-year = "8-12 Aug. 2010",
             language = "en",
           targetfile = "AGU_Parise\&Farina.pdf",
        urlaccessdate = "24 jan. 2021"