NOAA/WDS Paleoclimatology - Central Andes composite 9 Tree ring width, PAGES LOTRED-SA Version

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年的南半球（Southern Hemisphere, SH）高分辨率古气候档案开展全面评估。我们从该半球范围内识别出174条分辨率从逐月至逐年的气候代用记录，涵盖树轮、珊瑚、冰芯、文献资料、石笋与沉积序列等类型。本研究评估了每条代用记录在20世纪期间对太平洋、印度洋及南大洋区域大型环流指数的年际与年代际敏感性。随后，我们分析了这一新扩展的古气候网络，能否共同表征气候重建中常用的预报变量：海表温度、海平面气压、地表气温与降水。热带印度洋-太平洋区域的关键动力作用中心被该古气候网络较好地捕捉，表明该区域具备可观的重建潜力，尤其在公元1600年之后的时段——此时已有多支长时序珊瑚记录可供使用。我们还讨论了当前数据覆盖存在的时空空白区域，以及未来具备代理记录采集潜力的重点区域。此外，我们强调了南半球关键动力区域亟需新增及延长现有代用记录的必要性。尽管南半球大型气候场重建仍处于起步阶段，但本研究表明，区域代用资料研究的长足进展，如今已使开展大陆至半球尺度的气候变异性合理估算成为可能。