Late Medieval Climate in the Caribbean: Pacific vs. Atlantic control on interannual variability and mean state

中世纪气候异常(MCA)是1000年前的一个异常温暖的时期，紧随其后的是小冰期(LIA)，它代表了气候对辐射强迫变化的响应的一个可能的例子。以前的工作表明，热带印度洋-太平洋海面温度梯度的变化可能对MCA作出了贡献；然而，这种变化并不能完全解释这段时间内的气候扰动，大西洋的潜在作用尚未得到考虑。为了填补这一关键的知识空白，切萨皮克生物实验室的一名研究人员将使用保存在加勒比海珊瑚骨架中的同位素(锶/钙)生成MCA和LIA过渡的高分辨率古气候记录。加勒比地区特别适合进行这项研究，因为加勒比地区的表面温度与全球表面温度密切相关；此外，虽然模拟表明太平洋对加勒比气候有很大影响，但这种影响以前从未用古气候数据进行过检验。该项目产生的古气候记录将与热带太平洋先前存在的记录在时间上重叠，从而能够分析太平洋和大西洋盆地与短期(百年至年际)气候变化之间的关系。了解像MCA这样的异常短期事件对于评估长期气候预测的局限性具有重要意义。该项目将促进对大西洋热带人口稠密地区气候过程和可变性的了解。此外，该项目将支持研究生和本科生的培训，本科生由马里兰海洋助学金REU项目提供。一名熟悉研究地区(英属维尔京群岛阿内加达)的少数族裔女性学生将作为学生合作者参加，并鼓励波多黎各大学(一家为少数族裔服务的机构)的学生参加实地考察。该实地考察项目将为所有参与的学生提供国际经验。切萨皮克生物实验室正在进行的推广计划将纳入这项研究。

The Medieval Climate Anomaly (MCA), an unusually warm period ~1000 years ago that was followed immediately by the Little Ice Age (LIA), represents a possible example of climate response to changes in radiative forcing. Previous work indicates that a change in the tropical Indo-Pacific sea surface temperature gradient may have contributed to the MCA; however, this change does not fully explain climate perturbations during that time, and the potential role of the Atlantic Ocean has yet to be considered. To fill this critical knowledge gap, a researcher at Chesapeake Biological Laboratory will generate a high-resolution paleoclimate record for the MCA and LIA transition using isotopes (Sr/Ca, δ18O) preserved in coral skeletons from the Caribbean Sea. The Caribbean is particularly well-suited for this study because Caribbean surface temperatures are strongly correlated with global surface temperatures; furthermore, while modeling has suggested a strong Pacific influence on Caribbean climate, this influence has not previously been tested with paleoclimate data. The paleoclimate record produced by this project will overlap temporally with pre-existing records from the tropical Pacific, enabling analysis of the relationship between the Pacific and Atlantic ocean basins with respect to short-term (centennial to inter-annual) climate variability. Understanding anomalous, short-term events like the MCA has important implications for assessing the limitations of long-term climate predictions. This project will advance knowledge of climate processes and variability in the heavily populated region of the Atlantic tropics. In addition, the project will support student training at the graduate and undergraduate levels, with undergraduate students provided by the Maryland SeaGrant REU program. A female, underrepresented minority student familiar with the study area (Anegada, British Virgin Islands) will participate as a student collaborator, and students at the University of Puerto Rico (a minority-serving institution) have been encouraged to join the field expedition. The field program will provide international experience for all students involved. Ongoing outreach programs at Chesapeake Biological Laboratory will incorporate this research.