The Younger Dryas (YD, 12.9‐11.7 ka) is the most recent, near‐global interval of abrupt climate change with rates similar to modern global warming. Understanding the causes and biodiversity effects of YD climate changes requires determining the spatial fingerprints of past temperature changes. Here we build pollen‐ and branched glycerol dialkyl glycerol tetraether‐based temperature reconstructions in eastern North America (ENA) to better understand deglacial temperature evolution. YD cooling was pronounced in the northeastern United States (US) and muted in the north‐central US. Florida sites warmed during the YD, while other southeastern sites maintained a relatively stable climate. This fingerprint is consistent with an intensified subtropical high during the YD and demonstrates that interhemispheric responses were more complex spatially in ENA than predicted by the bipolar seesaw model. Reduced‐amplitude or antiphased millennial‐scale temperature variability in the southeastern US may support regional hotspots of biodiversity and endemism.

中文翻译：

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北美东部年轻树精降温和变暖的空间指纹

较年轻的树蛙（YD，12.9-11.7 ka）是最近的，接近全球的突变性气候变化区间，其变化速率与现代全球变暖相似。了解YD气候变化的原因和生物多样性影响需要确定过去温度变化的空间指纹。在这里，我们建立了北美东部（ENA）基于花粉和支链甘油二烷基甘油四醚的温度重建模型，以更好地了解冰期温度演变。YD冷却在美国东北部（US）明显，而在美国中北部则减弱。在本年末，佛罗里达州的站点变暖，而其他东南部站点则保持相对稳定的气候。该指纹与YD期间副热带高压的升高一致，表明ENA的半球间响应在空间上比双极跷跷板模型所预测的更为复杂。美国东南部的幅度减小或反相位的千年尺度温度变化可能支持生物多样性和地方性的区域热点。