Contrasting patterns of the extreme drought episodes of 2005, 2010 and 2015 in the Amazon Basin

Abstract

Future climate scenarios point to an increase in the frequency of extreme droughts events, even in humid biomes. Throughout the 21st century, large areas of the Amazon basin experienced the most severe droughts ever recorded with special emphasis on the 2005 and 2010 events due to their severity and extent. Currently, there is an increased demand to understand the geographic extent and seasonal variability of climate variables during drought events, especially with respect to the social and environmental impacts. In this study, we aim to compare the observed climate conditions during the drought episodes of 2005, 2010 and 2015. We perform a detailed assessment of the measured precipitation, land-surface temperature (LST) and solar radiation anomalies. We provide evidence that the anomalous precipitation deficit during 2015 exceeded the amplitude and spatial extent of the previous events, affecting more than 80% of Amazon basin, particularly the eastern portion. The pronounced lack of rainfall availability during late spring and early summer, coincident with radiation and temperature surpluses during these years are significant and notable. Changed meteorological spatial patterns were observed, with precipitation and radiation being the most prominent parameters in 2005, whereas precipitation and LST were most relevant in 2010. Understanding the behaviour and interactions of pertinent meteorological variables, as well as identifying similar or divergent patterns over the region during distinct extreme events, is essential for the improvement of our knowledge of Amazon forest vulnerability to climate fluctuation changes.

<strong>Extreme drought events over Amazon basin: the perspective from regional reconstruction of South American hydroclimate</strong>

“…For the 2010 event, the spatial distribution of the SRDAS anomaly fields exhibits negative patterns of precipitation and integrated soil moisture over most of the Amazon basin (Figures 4a and 4d), and anomalously positive near-surface temperature values concentrate in the southeastern part of the river basin (Figure 4b), as well as the negative anomalous values of near-surface relative humidity (Figure 4c), in agreement with [6] results.…”

“…Extreme drought events have occurred in the Amazon basin for thousand years [1], and several of these historical events since last century, as in 1906, 1912, 1916, 1925, 1936, 1948, 1957/58, 1963/64; 1970; 1982/83, 1987, 1997/98, 2005, 2010 and 2015 [2][3][4][5][6]. It was also detected that these events were more frequently in the past decades, as well as more intense [1].…”

“…It was also detected that these events were more frequently in the past decades, as well as more intense [1]. Each extreme drought event of the 21 st century was considered more powerful than the last one [6].…”

Spatial and Temporal Variations in Aboveground Woody Carbon Storage for Cerrado Forests and Woodlands of Mato Grosso, Brazil

“…While interactions between hydrology and nutrient availability appeared to have little influence on Δ C w , annual rates of Δ C w were linearly related with annual rainfall, with similar trends for both upland and hyperseasonal cerrado (Figures b and ). Notably, the lowest rates of Δ C w were observed in 2015–16 (Figure a), which coincided with an intense El Niño event that brought drought and high temperatures to the southern Amazon Basin (Panisset et al, ). Drought that normally occurs during the dry season in the southern Amazon Basin causes limitations to leaf photosynthesis (Dalmagro et al, ; Dalmolin et al, ) and net CO 2 exchange (Vourlitis et al, ; Zanella De Arruda et al, ), but during El Niño, drought stress becomes more intense and/or prolonged (Panisset et al, ).…”

Climatic and synoptic characterization of heat waves in Brazil

“…The exceptional high NHWD values recorded since the beginning of 21st century and especially for the years of 2005 and 2010 regarding the city of Manaus are representative of the abnormally hot and dry periods that have been observed in this region. The extreme 2005 and 2010 Amazon droughts events resulted in part from the warming of the Tropical North Atlantic SST and of the co‐occurrence of an El Niño in the particular case of 2010 (Marengo and Espinoza, ; Panisset et al, ).…”