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The number of paleoprecipitation records from the South American Monsoon domain that cover the last millennium has increased substantially in past years. However, hitherto most studies focused only on regional aspects, thereby neglecting the role of large‐scale monsoon variability and the mechanisms that link proxy locations in space and time. Here we decompose the South American Monsoon into its main modes of variability by applying a Monte Carlo principal component analysis to a compilation of 11 well‐dated summer paleoprecipitation records from tropical South America. The first mode represents changes in precipitation over the core monsoon domain, while the second mode is characterized by high loadings along the fringes of the South American Monsoon over Southeastern South America and the northern monsoon limit. Composite analysis reveals an enhanced monsoon with a wider, rather than a southward displaced, South Atlantic Convergence Zone during the early Little Ice Age, in contrast to previous interpretations. Plain Language Summary: The South American Monsoon is responsible for more than 70% of the annual precipitation falling over tropical South America. Due to the lack of data prior to the middle of the twentieth century, the long‐term variability of the monsoon is poorly understood. Yet there are concerns that increasing greenhouse gas concentrations may significantly modify monsoon behavior in the 21st century. To better understand how the monsoon responds to such perturbations, detailed knowledge of how it varied in the past is crucial. This will facilitate improvements to Earth System Models that are used to project future rainfall changes in the region. Here 11 paleoprecipitation records that span the last millennium are analyzed using statistical techniques that allow extracting the shared variability from all records. Our result highlight how the monsoon responded in space and time to large‐scale perturbations of the climate system, associated with the Little Ice Age and the Medieval Climate Anomaly. Key Points: We use high‐resolution δ18O records to decompose the South American Monsoon into its main modes of variability during the last millenniumThe first mode shows an enhanced monsoon during the Little Ice Age and a weakening during the Medieval Climate AnomalyThe second mode represents monsoon variability along the fringes of the monsoon area and indicates periods of widening/contractions of the monsoon axis [ABSTRACT FROM AUTHOR]

Abstract: Most reconstructions of the South American Monsoon System (SAMS) over the last two millennia are based on δ18O records from locations at high‐elevation sites in the Andes, which are not influenced by the South Atlantic Convergence Zone (SACZ). Yet the SACZ is a key driver of SAMS variability over much of Brazil. Here we use two new δ18O records from speleothems sampled in the central and southwestern portions of the SACZ core to show that the SAMS was not varying in phase over the entire tropical continent during the last two millennia. In fact, speleothem records located to the northeast of the SACZ record precipitation variations that are antiphased with similar records on the opposite side of the SACZ, in particular during the Little Ice Age period, while records close to the core of the SACZ axis show no significant departure from the mean state during this period. [ABSTRACT FROM AUTHOR]

Background and Aims Modern viticulture requires robust, fast, non-destructive methods to assess berry composition. We tested a chlorophyll fluorescence screening method to estimate berry phenolic substances. Methods and Results We focused on anthocyanin and flavonol in red and white cultivars. The ANTH_RG index was dependent on the cultivar anthocyanin profile. In Nebbiolo, in which dihydroxylated anthocyanins prevail, ANTH_RG was 2.4 times higher than in Barbera, in which trihydroxylated anthocyanins prevail. Considering the profiles of the two cultivars at similar anthocyanin concentration and their relative in vitro absorbance, a bathochromic shift of 10 nm emerged, which can explain the different screening effect exerted by anthocyanin on chlorophyll fluorescence. As to flavanols, we propose the calibration of a new spectroscopic index, the FLAV_UV, in coloured and white berries, finding good correlation with flavonol concentration determined analytically ( R2 higher than 0.7). Conclusions Spectroscopic indices can estimate the concentration of anthocyanin and flavonol in grape berries. Significance of the Study A calibration curve for Nebbiolo, which has a distinctive anthocyanin profile, and the calibration of a new index, the FLAV_UV, able to estimate flavonol concentration in both red and white cultivars, are described for the first time. These indices can effectively be applied for non-destructive assessment of grape flavonoid. [ABSTRACT FROM AUTHOR]