NOAA/WDS Paleoclimatology - Southern Hemisphere 2000 Year Proxy Correlation Maps

This study presents a comprehensive assessment of high-resolution Southern Hemisphere (SH) paleoarchives covering the last 2000 years. We identified 174 monthly to annually resolved climate proxy (tree ring, coral, ice core, documentary, speleothem and sedimentary) records from the Hemisphere. We assess the interannual and decadal sensitivity of each proxy record to large-scale circulation indices from the Pacific, Indian and Southern Ocean regions over the twentieth century. We then analyse the potential of this newly expanded palaeoclimate network to collectively represent predictands (sea surface temperature, sea level pressure, surface air temperature and precipitation) commonly used in climate reconstructions. The key dynamical centres-of-action of the equatorial Indo-Pacific are well captured by the palaeoclimate network, indicating that there is considerable reconstruction potential in this region, particularly in the post AD 1600 period when a number of long coral records are available. Current spatiotemporal gaps in data coverage and regions where significant potential for future proxy collection exists are discussed. We then highlight the need for new and extended records from key dynamical regions of the Southern Hemisphere. Although large-scale climate field reconstructions for the SH are in their infancy, we report that excellent progress in the development of regional proxies now makes plausible estimates of continental- to hemispheric-scale climate variations possible.

本研究针对覆盖过去2000年的高分辨率南半球（Southern Hemisphere, SH）古气候档案开展系统性评估。本研究从该半球范围内共甄别出174套时间分辨率为月至年尺度的气候代用资料，涵盖树轮、珊瑚、冰芯、文献记录、石笋与沉积记录共六大类。我们评估了20世纪期间，每套代用资料对太平洋、印度洋与南大洋区域大尺度环流指数的年际及年代际响应敏感性。随后，我们分析了这套最新扩充的古气候网络，在协同表征气候重建中常用的预报量（海表温度、海平面气压、地表气温与降水）方面的潜力。古气候网络可较好捕捉赤道印太区域的关键动力作用中心，表明该区域具备可观的气候重建潜力，尤其在公元1600年后的时段——此阶段已有多套长时序珊瑚记录可供使用。本研究还讨论了当前数据覆盖存在的时空空白区域，以及未来具备较大代用资料采集潜力的区域。随后我们强调，需在南半球关键动力区域获取新的或经延伸的古气候记录。尽管针对南半球的大尺度气候场重建仍处于起步阶段，但我们的研究表明，区域代用资料研究的长足进展，现已使得开展大陆至半球尺度气候变化的合理估算具备可行性。