Relationship between ocean climatic variability and rain-fed agriculture in northeast Brazil

Abstract

The statistical relationship between sea-surface temperature variability over tropical oceans and the 1952 to 2000 crops of maize and beans in the state of Ceará, Brazil, was investigated. This region mainly receives precipitation from February to May. The climatic indices used were the Niño-3 for the Pacific and the dipole index for the Atlantic. In a first series of diagnostic analyses, the climatic precursor variables were examined from November to January (Years 0 to 1) for the Niño-3 index and from February to April (Year 1) for the Atlantic dipole components. The agronomic variables were the planted area, annual production, yield (which showed a negative linear trend during the study period), price, and aggregate value (price/yield) for Year 1. A more robust statistical weight was obtained with the Atlantic dipole. The Pacific weight added to, or decreased, the Atlantic effect, depending on the sign of the index. Ocean climatic conditions that generate drought episodes in the Nordeste region of Brazil are generally associated with bad harvests. However, the reverse (i.e. wet weather episodes) does not necessarily produce good harvests. In a second series of prognostic analyses, a statistical model used the ocean climatic information available before the rainy season to forecast the yields of maize and beans. The model gave some relevant data in terms of yield tendencies, and was more sensitive when the climatic conditions were neutral or dry. Remarkably good yield forecasts were noted at the end of the study period. Harvests depend on complex combinations of multiple climatic criteria related, not only to quantitative, but also qualitative factors connected with the rainy season.KEY WORDS: Climate variability · Northeast Brazil ('Nordeste') · Climatic impact · Rain-fed agriculture Resale or republication not permitted without written consent of the publisher

Predictive Potential of Maize Yield in the Mesoregions of Northeast Brazil

“…The combination of positive DIP and neutral Pacific (Figure 19b) already showed most of the central-eastern NEB with negative deviations in production, with the notable exception of mesoregions in Maranhão and the Sudoeste piauiense. The combination of positive DIP and positive Pacific represented the most damaging situation for maize production, exceeding This fact has already been investigated, and the results for this last combination are in line with the results obtained by [66], when they investigated the influence of the different phases of the Pacific and Atlantic on maize and bean production in Ceará between 1952 and 2000.…”

Long‐term variation of precipitation indices in Ceará State, Northeast Brazil

“…Crops may also be affected by the increase in dry spells in January and February. The increased length of dry spells may lead to reduced plant growth or even compromise the harvest itself, as they are more affected by duration of dry spells than total amount of rain in the season (Alves et al, 2009, Menezes et al, 2010. Rainfed crops which have their initial stage at the beginning of the wet season may be affected by the increase in CDD of January and February.…”

“…When SATL and NATL SST have lower than normal values, they lead to an increase in the southeast trade winds and a weakening of the northeast trade winds. This anomaly results in a delay of the ITCZ movement on the Southern Hemisphere with a resulting decrease in precipitation over the state of Ceará (Uvo et al, 1998;Alves et al, 2009). From June to August, a positive tendency may be observed, expressing an increase in the number of very wet days, although not statistically significant at the 5% level.…”

“…The state of Ceará is in the semiarid region of north-eastern part of Brazil, with high spatial and temporal variability of precipitation (Chu, 1983;Haylock et al, 2006;Alves et al, 2009). In some regions, it is not uncommon that 70% of the annual precipitation occurs in only 1 month (Andrade et al, 2010).…”

Influenza (H1N1) e a Síndrome Respiratória Aguda Grave (SRAG) no Ceará: Relações com as Variáveis Meteorológicas

“…Em relação ao Estado do Ceará, menciona-se que o clima é classificado como tropical quente semiárido, com período chuvoso observado no primeiro semestre do ano, com as chuvas concentradas, em geral, no período de fevereiro a maio (Alves e Repelli, 1992). Os fatores do clima dessa região são os mesmos que caracterizam as condições meteorológicas da região semiárida do nordeste brasileiro (Alves et al, 2009;Silva et al, 2020).…”