美国布朗大学的
研究人员利用有机地球化学指标对厄瓜多尔Laguna Llaviucu的沉积物岩心进行了研究，得到了热带安第斯山脉近16,800年来的高分辨率温度和水文气候记录。水文气候记录与亚马逊西部和安第斯山脉东部和中部的记录一致，表明了变化的夏季日照对南美夏季风强度的主要长期影响。
温度记录显示，在冰期结束时，温度上升了约4°C，在全新世早期至中期气候保持稳定，自约6,000年前以来，气温逐渐上升。
重要的是，研究人员观察到与ACR一致的约1.5°C的冷反转。这些数据记录了热带安第斯山脉在冰川消融期间的温度变化模式，该模式类似于南半球高纬度地区的温度变化，被认为是由大气温室气体的辐射作用力和大西洋经向翻转环流引起的海洋热输送变化所控制的。
据了解，末次冰期终止期间的全球变暖被新仙女木期和南极寒流逆转期(ACR)等千年尺度的降温间隔所中断。虽然这些事件在高纬度地区具有明显的特征，但它们在低纬度地区的影响鲜为人知。
附：英文原文
Title: Tropical Andean climate variations since the last deglaciation
Author: Zhao, Boyang, Russell, James M., Blaus, Ansis, Nascimento, Majoi de Novaes, Freeman, Aaron, Bush, Mark B.
Issue&Volume: 2024-8-12
Abstract: Global warming during the Last Glacial Termination was interrupted by millennial-scale cool intervals such as the Younger Dryas and the Antarctic Cold Reversal (ACR). Although these events are well characterized at high latitudes, their impacts at low latitudes are less well known. We present high-resolution temperature and hydroclimate records from the tropical Andes spanning the past ~16,800 y using organic geochemical proxies applied to a sediment core from Laguna Llaviucu, Ecuador. Our hydroclimate record aligns with records from the western Amazon and eastern and central Andes and indicates a dominant long-term influence of changing austral summer insolation on the intensity of the South American Summer Monsoon. Our temperature record indicates a ~4 °C warming during the glacial termination, stable temperatures in the early to mid-Holocene, and slight, gradual warming since ~6,000 y ago. Importantly, we observe a ~1.5 °C cold reversal coincident with the ACR. These data document a temperature change pattern during the deglaciation in the tropical Andes that resembles temperatures at high southern latitudes, which are thought to be controlled by radiative forcing from atmospheric greenhouse gases and changes in ocean heat transport by the Atlantic meridional overturning circulation.
DOI: 10.1073/pnas.2320143121
Source: https://www.pnas.org/doi/abs/10.1073/pnas.2320143121