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It is located in central South America (Brazil), in the core of the SAMS domain (Fig.
1), at a location where hitherto no proxy records of similar resolution have been recovered. recently published a stable isotopic record derived from leaf waxes in lake sediments from a shallow lake located at the Brazil-Bolivia border, a few hundred kilometers to the northwest from our site.
The SACZ is defined as an elongated convective band, originating over the southeastern Amazon basin, and extending over southeastern Brazil into the southwest Atlantic (Fig. Previous studies have documented that both SACZ and ITCZ positions have shifted in the past in response to abrupt millennial-scale events, thereby significantly affecting SAMS precipitation over the SA continent0.3, highlighting the extent of the SAMS over the continent; contour interval is 0.05.
Wind data is from ERA-Interim and precipitation data from GPCC, with averages calculated over period 1979–2014.
Global area-averaged lower tropospheric temperature anomalies (departures from 30-year calendar monthly means, 1981-2010).
The 13-month centered average is meant to give an indication of the lower frequency variations in the data; the choice of 13 months is somewhat arbitrary…
Between September 2011 and December 2014 we monitored rainfall amount, isotopes in rainfall and air temperature in the region of Jaraguá cave.
Based on these data, we establish that the isotopic composition of rainfall (δO and δD measured in rainfall near our cave site also shows a good correspondence with the Global Meteoric Water Line (Supplementary Fig.
Similarly, our understanding of millennial-scale variability and abrupt changes in South American precipitation during this transition from glacial to interglacial conditions is still rudimentary. This link between tropical SA precipitation and high-latitude temperature is established through changes in the latitudinal position of the Inter-tropical Convergence Zone (ITCZ), which responds to changes in the inter-hemispheric energy balance.
Thus, the ITCZ is shifted southward in response to NH cooling and the resulting anomalous cross-equatorial temperature gradient.