Interrelationship and ENSO relationship of Fortaleza rainfall in different seasons

Abstract

The rainfall series at Fortaleza, Ceara, NE Brazil for the four seasons DJF, MAM (main rainy season), JJA, SON were poorly intercorrelated (correlation 0.45 or less, common variance only ~20%). The relationship with El Niños was poor, with only about half of the El Niños associated with droughts. Among the El Niños, Unambiguous ENSOW had a better affinity for droughts, more so for DJF. But some droughts occurred in the abscence of El Niños and even during La Niña years, and some excess rains occurred during El Niño years. A large interference from other factors (mostly Atlantic SST etc.) unrelated to the ENSO phenomenon is obvious. The media seems to be giving undue importance to El Niño and La Niña only, which needs to be diluted.Key words: El Niño; Fortaleza; Rainfall. INTERCORRELAÇÕES E RELAÇÕES COM A ENSO DA PRECIPITAÇÃO EM FORTALEZA EM DIFERENTES ESTAÇÕES -As séries de precipitação em Fortaleza, Ceará, nordeste do Brasil para as quatro estações DJF, MAM (principal estação chuvosa), JJA, SON estão pobremente intercorrelacionadas (correlação de 0,45 ou menos, variância comum de apenas ~20%). A relação com os El

Understanding Drought Dynamics during Dry Season in Eastern Northeast Brazil

“…Our findings suggest an unclear interannual relationship between ENSO and anomalous precipitation events in ENEB during the dry season, as wet episodes may occur during El Niño years and dry ones during La Niña years. Such unexpected association between ENSO and OND precipitation in ENEB may be explained either by the influence of other factors (e.g., Tropical Atlantic SST condition) on OND precipitation anomalies, which may disrupt this interannual relationship (Kane, 2001), or due to the most prominent long-term relationship (Kane, 1999). Indeed, we only could find few years with strong ENSO anomalies (e.g., 1982 and 1999) in which Pacific conditions seem to have overcome the effect of Tropical Atlantic conditions on anomalies of precipitation in ENEB.…”