author = "Zeri, Marcelo and Cunha-Zeri, Gisleine da Silva and Gois, 
                         Givanildo and Lyra, Gustavo B. and Oliveira J{\'u}nior, Jos{\'e} 
          affiliation = "{Centro Nacional de Monitoramento e Alertas de Desastres Naturais 
                         (CEMADEN)} and {Instituto Nacional de Pesquisas Espaciais (INPE)} 
                         and {Universidade Federal Fluminense (UFF)} and {Universidade 
                         Federal Rural do Rio de Janeiro (UFRRJ)} and {Universidade Federal 
                         do Alagoas (UFAL)}",
                title = "Exposure assessment of rainfall to interannual variability 
                         usingthe wavelet transform",
              journal = "International Journal of Climatology",
                 year = "2019",
               volume = "39",
               number = "1",
                pages = "jan.",
             abstract = "It is generally accepted that El NiņoSouthern Oscillation (ENSO) 
                         is the main modulator of rainfall variability over Northern South 
                         America in the interannual scale. Assuming that, an index is 
                         proposed to quantify this expected interannual variability in time 
                         series of rainfall. The result is the exposure assessment to the 
                         effects of droughts, measured with the Standardized Precipitation 
                         Index (SPI) for the monthly scale. The SPI is calculated from 
                         rainfall series, and wavelet analysis is used to estimate the 
                         variance for different frequencies present in the signal. The 
                         Wavelet Interannual Variability Index (WIVI) is calculated as the 
                         sum of the wavelet coefficients over a predetermined range of 
                         modes of variability (with periods longer than 2 year and shorter 
                         than 8 years). The index was tested using a dataset of rainfall 
                         records from Tocantins state, Central Brazil. Most of the series 
                         ranged from 1974 to 2012. On average, the series had 3.2% of gaps 
                         which were not filled to avoid the effect of artificial trends on 
                         the data. The state lies mostly over the Cerrado biome and is a 
                         new frontier of agricultural development in Brazil. According to 
                         the results, the Northern region is under higher exposure of 
                         interannual variability, with higher values of WIVI. The 
                         assessment is in agreement with large\‐scale features of 
                         South American climate, specifically considering the influences of 
                         the Pacific and Atlantic Oceans and their patterns of sea surface 
                         temperature (SST).",
                  doi = "10.1002/joc.5812",
                  url = "http://dx.doi.org/10.1002/joc.5812",
                 issn = "0899-8418",
             language = "en",
           targetfile = "zeri_exposure.pdf",
        urlaccessdate = "25 nov. 2020"