权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Resolving 20th Century Sea Surface Temperatures in the Central Equatorial Pacific with Laser Sr-U

利用激光 Sr-U 解析 20 世纪中赤道太平洋海面温度

基本信息

批准号：
2016133
负责人：
Anne Cohen
金额：
$ 55.06万
依托单位：
Woods Hole Oceanographic Institution
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-01 至 2022-12-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2016133&HistoricalAwards=false
关键词：
Resolving 20th Century Sea Surface

项目摘要

Warming of the surface ocean in the central Pacific affects weather patterns all over the world. But we currently know little about the past temperature history of this region which affects model projections of future weather. This project uses skeletons of 100-year old tropical corals to read ocean temperatures for the last century. The chemistry of coral skeletons changes when the ocean temperature changes and this information is stored in growth bands, much like rings in a tree. Lasers are used to carefully sample the coral skeleton and build new temperature histories at key locations across the Pacific Ocean. With these new records scientists can evaluate the size and frequency of large-scale weather events like El Niño and improve climate models used to predict future weather conditions. This project supports research experiences and training for undergraduate students as well as early career mentoring for a postdoctoral student at Woods Hole Oceanographic Institute.Sea surface temperatures (SSTs) of the equatorial Pacific exert an outsize influence on Earth’s climate system yet the observational record of equatorial Pacific SSTs, in particular the Nino 3.4 region that is used to define El Nino-Southern Oscillation (ENSO), is sparse prior to the start of the satellite era. Consequently, ENSO variability and the secular trend in equatorial Pacific SSTs are poorly constrained over much of the late 19th and 20th centuries with important implications for validating model projections of future climate. This project seeks to reconstruct century long, continuous, monthly resolved records of proxy SST from strategic locations in the central equatorial Pacific (CEP) using the coral-based Sr-U thermometer. A new laser ablation method is developed and applied, targeting skeleton accreted between successive monthly dissepiments, to enable Sr-U based SST reconstruction with monthly resolution. New monthly-resolved records from Porites coral collected in the western, central, and eastern equatorial Pacific will be generated to (1) calibrate monthly-resolved Sr-U versus observed monthly-resolved SST over a temperature range of 22 deg to 32 deg C and (2) apply the calibration to generate two century-long SST records at sites in the Nino 3.4 and Nino 4.0 regions. These sites are strategically located to capture the 20th century SST trend in the CEP, the frequency and amplitude of ENSO events over the 20th century, and the relative frequency of central versus east Pacific El Niño over this time period. The new datasets will help to resolve outstanding questions regarding the response of the equatorial Pacific mean state and variability to anthropogenic forcing. Additionally, the project will develop new methods for generating accurate monthly records of SST from modern and fossil corals and, in doing so, transform knowledge of the climate of the tropical Pacific.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

太平洋中部海洋表层变暖影响着世界各地的天气模式。但我们目前对该地区过去的温度历史知之甚少，而这会影响未来天气的模型预测。该项目使用 100 年历史的热带珊瑚骨骼来读取上个世纪的海洋温度。当海洋温度变化时，珊瑚骨骼的化学成分会发生变化，这些信息存储在生长带中，就像树的年轮一样。使用激光对珊瑚骨架进行仔细采样，并在太平洋的关键地点建立新的温度历史记录。借助这些新记录，科学家可以评估厄尔尼诺等大规模天气事件的规模和频率，并改进用于预测未来天气状况的气候模型。该项目支持本科生的研究经验和培训，以及伍兹霍尔海洋研究所博士后的早期职业指导。赤道太平洋的海面温度（SST）对地球气候系统产生巨大影响，但赤道太平洋海表温度的观测记录，特别是用于定义厄尔尼诺南方涛动（ENSO）的尼诺 3.4 区域，之前却很少。到卫星时代的开始。因此，ENSO 的变化和赤道太平洋海温的长期趋势在 19 世纪末和 20 世纪的大部分时间里受到的限制很弱，这对于验证未来气候的模型预测具有重要意义。该项目旨在使用基于珊瑚的 Sr-U 温度计重建中赤道太平洋 (CEP) 战略位置的长达一个世纪的、连续的、每月解析的代理海表温度记录。开发并应用了一种新的激光烧蚀方法，针对连续每月分配之间积累的骨骼，以实现基于 Sr-U 的 SST 重建，具有每月分辨率。将生成从赤道西部、中部和东部太平洋收集的滨珊瑚的新月分辨记录，以 (1) 校准月分辨 Sr-U 与 22 ℃ 至 32 ℃ 温度范围内观测到的月分辨 SST，以及 (2) 应用该校准在 Nino 3.4 和 Nino 4.0 区域生成长达两个世纪的 SST 记录。这些站点的位置具有战略意义，可以捕获 CEP 中的 20 世纪海温趋势、20 世纪 ENSO 事件的频率和幅度，以及这段时间内中太平洋与东太平洋厄尔尼诺现象的相对频率。新的数据集将有助于解决有关赤道太平洋平均状态的响应和人为强迫变化的悬而未决的问题。此外，该项目还将开发新方法，从现代珊瑚和化石珊瑚中生成准确的海表温度月度记录，从而改变对热带太平洋气候的认识。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。