Mapping Saharan dust fluxes through the onset and termination of the African Humid Period in a transect of African margin cores

在11000年至5000年前的非洲潮湿时期，北非中部有大型湖泊，丰富的巨型动物和众多的人类定居点。从这一时期到过去五千年的干旱条件的转变标志着自末次冰期结束以来最戏剧性的区域气候变化之一，但目前可用的记录对转变的时间和时间不一致。这项研究从非洲西北部大陆边缘沿着的8个沉积物岩心的南北断面中记录了风吹尘埃沉积-大陆干旱和大气环流的敏感记录。这些记录将揭示非洲湿润期的开始和结束是否同步发生，并在整个北非地区具有类似的连续性。从岩芯中获得的河流沉积物通量和灰尘粒度数据将为降水和风强度的变化提供补充性的见解。除了阐明季风区气候突变的驱动机制外，该项目更广泛的影响还包括支持和指导一名新的博士后首席研究员，让本科生参与研究，以及调整项目研究结果，将其纳入哥伦比亚大学的本科地球科学课程和高中课程材料。

During the African Humid Period between 11 and 5 thousand years ago, central North Africa supported large lakes, abundant megafauna and numerous human settlements. The transition from this period to the dry conditions of the last 5 thousand years marks one of the most dramatic regional climate changes since the end of the last glacial period, but currently available records disagree over the timing and abruptness of the transition. This research develops records of wind-blown dust deposition-- a sensitive recorder of continental aridity and atmospheric circulation-- from a north-south transect of eight sediment cores from along the northwest African continental margin. These records will reveal whether the beginning and end of the African Humid Period occurred synchronously and with similar abruptness throughout North Africa. Fluvial sediment fluxes and dust grain size data from the cores will provide complementary insights into changes in precipitation and wind strength. In addition to elucidating the mechanisms driving abrupt climate changes in monsoonal regions, this project's broader impacts include support and mentoring for a new principal investigator in a postdoctoral position, involvement of undergraduate students in research, and adaptation of project findings for inclusion in undergraduate Earth science courses at Columbia University and in high school curricular materials.