Abstract Changes in monsoon precipitation governed agricultural practices and production, health risks, competition and conflict level of preindustrial human societies in South Asia. To understand monsoon shifts and their implication to the South Asian societies, we produced a sub-decadal scale multiproxy record of monsoon variability from the Rewalsar lake, India encompassing the past ~3200 years. Our multi-proxy data from this lake indicate a long, strong Indian monsoon interval during ~1200 BCE to 450 AD with intermittent short-lived dry phases, the latter half is coinciding with the Roman Warm Period. A moderately wet summer monsoon characterizes the Medieval Climate Anomaly during ~950–1300 AD. The Rewalsar lake experienced hypertrophic conditions across the transition from the Medieval Climate Anomaly to the Little Ice Age (~1250 to 1400 AD) marked by severe depletion in δ15N ratio (0 to −5‰). The monsoon was weak during the Little Ice Age cold interval and has intensified during the past four centuries in the study region. We find an evidence of the coincidence between increased summer precipitation and economic boom in South Asia with flourishing dynasties during the last three millennia.

中文翻译：

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过去三千年印度夏季风的突然变化

摘要 季风降水的变化控制着南亚工业化前人类社会的农业实践和生产、健康风险、竞争和冲突水平。为了了解季风变化及其对南亚社会的影响，我们制作了印度 Rewalsar 湖在过去约 3200 年间的季风变化的亚年代际尺度多代理记录。我们来自该湖的多代理数据表明，在公元前 1200 年至公元 450 年期间，印度季风间隔时间长且强度大，具有间歇性的短暂干旱期，后半期与罗马暖期重合。中等潮湿的夏季风是公元 950-1300 年中世纪气候异常的特征。Rewalsar 湖在从中世纪气候异常到小冰河时代（公元 1250 年到 1400 年）的过渡期间经历了肥厚条件，其特征是 δ15N 比率（0 到 -5‰）的严重枯竭。季风在小冰河期寒冷间隔期间很弱，并在研究区域的过去四个世纪中增强。我们发现了一个证据，证明在过去的三千年里，夏季降水增加与南亚经济繁荣与王朝繁荣之间存在巧合。