NOAA/WDS Paleoclimatology - EPICA Dome C Ice Core 800KYr Dust Flux Data at 25yr Resolution

Ice core data from Antarctica provide detailed insights into the characteristics of past climate, atmospheric circulation, as well as changes in the aerosol load of the atmosphere. We present high-resolution records of soluble calcium (Ca2+), non-sea-salt soluble calcium (nssCa2+), and particulate mineral dust aerosol from the East Antarctic Plateau at a depth resolution of 1 cm, spanning the past 800 000 years. Despite the fact that all three parameters are largely dust-derived, the ratio of nssCa2+ to particulate dust is dependent on the particulate dust concentration itself. We used principal component analysis to extract the joint climatic signal and produce a common high-resolution record of dust flux. This new record is used to identify Antarctic warming events during the past eight glacial periods. The phasing of dust flux and CO2 changes during glacial-interglacial transitions reveals that iron fertilization of the Southern Ocean during the past nine glacial terminations was not the dominant factor in the deglacial rise of CO2 concentrations. Rapid changes in dust flux during glacial terminations and Antarctic warming events point to a rapid response of the southern westerly wind belt in the region of southern South American dust sources on changing climate conditions. The clear lead of these dust changes on temperature rise suggests that an atmospheric reorganization occurred in the Southern Hemisphere before the Southern Ocean warmed significantly.

来自南极的冰芯数据可为过去气候特征、大气环流以及大气气溶胶载荷变化提供详尽的科学解析。本研究公开了东南极高原（East Antarctic Plateau）过去80万年以来的高分辨率观测记录，涵盖可溶性钙（Ca²+）、非海盐可溶性钙（nssCa²+）以及颗粒态矿物粉尘气溶胶三类参数，其深度分辨率可达1厘米。尽管上述三类参数均主要源自粉尘，但非海盐可溶性钙与颗粒态粉尘的比值本身取决于颗粒态粉尘的浓度。我们采用主成分分析（Principal Component Analysis）提取联合气候信号，并构建了一套统一的高分辨率粉尘通量记录。这套全新的记录被用于识别过去8个冰期期间的南极暖事件。冰期-间冰期转换阶段粉尘通量与二氧化碳（CO₂）浓度变化的相位关系表明，过去9次冰消期内南大洋的铁质施肥并非驱动二氧化碳浓度在冰消期上升的主导因素。冰消期与南极暖事件期间粉尘通量的快速变化显示，南美南部粉尘源区周边的南半球西风带对气候条件变化存在快速响应。这些粉尘变化明显早于温度上升，这表明在南大洋显著增暖之前，南半球已发生了大气环流重组。