Climate diagnostics of three major drought events in the Amazon and illustrations of their seasonal precipitation predictions

Abstract

ABSTRACT:The Amazon has a well-defined wet austral summer monsoon and dry winter monsoon precipitation regime and experienced a sequence of drought events in the last 13 years. This study performs a comparative assessment of observed and predicted climate conditions during the three most recent drought events in the Amazon, in 1997Amazon, in -1998Amazon, in , 2004Amazon, in -2005Amazon, in and 2009Amazon, in -2010, with emphasis on how these events affected the regional monsoon-like precipitation regime. A century long Negro River level time series at Manaus is investigated, applying extreme values theory for estimating return periods of these major drought events. Possible teleconnections of river levels at Manaus and sea surface temperature at remote regions are explored. Large scale oceanic and atmospheric conditions are investigated to highlight the mechanisms associated with the observed drought conditions, particularly during the dry monsoon season. Satellite estimates are used for diagnosing biomass burning aerosol and discuss possible contributions to the observed precipitation deficits in the 2005 and 2010 drought events during the dry monsoon season. The study is concluded with an analysis of the performance of seasonal precipitation predictions for the dry monsoon seasons of July to September 1998September , 2005September and 2010 produced with the operational seasonal prediction system used at the Center for Weather Forecasts and Climate Studies (CPTEC) of the Brazilian National Institute for Space Research (INPE). This system was capable of producing 1 month in advance drought warning for the three investigated events, relevant for helping the government and local population make decisions for reducing drought impacts in the Amazon region.

Climatic characteristics of the 2010-2016 drought in the semiarid Northeast Brazil region

“…The meteorological and oceanic mechanisms that lead to circulation and rainfall changes responsible for drought in NEB have been reported elsewhere, and they refer to the occurrence of El Nino, or to an anomalously warm tropical North Atlantic, or a combination of both (Nobre et al 2016, Coelho et al 2012, 2015a, b, Marengo et al 2012, 2014, b, Silva et al 2013, Rodrigues and McPhaden 2014.…”

Recent Extremes of Drought and Flooding in Amazonia: Vulnerabilities and Human Adaptation

“…As described in [1,2,8,22,24], the 2005 drought in Amazonia was one of the worst on record there. Anecdotal evidence compiled in [8] indicates wide-ranging impacts of the drought on sectors such as fisheries, river and air transport, health and agriculture.…”

Droughts in the Amazon: Identification, Characterization and Dynamical Mechanisms Associated

“…The most vulnerable areas include the Amazon and Northeast Brazil, as demonstrated in recent studies [1]- [6]. In latest decades, the Amazon has experienced some extreme dry events; this attracted the attention of the scientists, not only because of the impact over local populations, but also because of the dry in the Amazon may have important impacts on the global climate [7] [8] [9].…”

“…The occurrence of drought and its consequences may require some time to be perceived by the socio-economic systems, because they tend to evolve slowly. In addition, the extreme dry events in the Amazon may be associated with the following factors: 1) the occurrence of intense El Niño events; 2) anomalous warming of sea surface temperatures in the tropical North Atlantic during the austral winter-spring; or 3) a combination of these two effects [9]- [14].…”