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.

中太平洋地区地面海洋的变暖会影响世界各地的天气模式。但是我们目前对该地区的过去温度历史知之甚少，这影响了未来天气的模型项目。该项目使用100年历史的热带珊瑚的骨骼阅读上个世纪的海洋温度。当海洋温度变化时，珊瑚骨骼的化学变化会发生变化，并且该信息存储在生长带中，就像树上的环一样。激光用于仔细采样珊瑚骨架，并在太平洋的主要位置建立新的温度历史。有了这些新记录，科学家可以评估大规模天气事件（例如厄尔尼诺现象）的规模和频率，并改善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，以及伍兹孔海洋学博士后学生的早期职业心理，赤道太平洋的海面温度（SSTS）对地球气候系统产生了巨大影响，但对nino 3.4 inino的陈旧阶层的陈旧记录，却是对纽约州的过度记录到卫星时代的开始。因此，在19世纪后期和20世纪的大部分时间里，ENSO的可变性和赤道太平洋SST的世俗趋势受到限制，对验证未来气候的模型项目的重要意义。该项目试图使用基于珊瑚的SR-U温度计，从中央平等的太平洋（CEP）的战略位置重建了代理SST的长期，连续的，每月的解决记录。开发和应用了一种新的激光消融方法，针对成功的每月散布之间接受的骨骼，以通过每月分辨率实现基于SR-U的SST重建。从西部，中央和东部等效太平洋收集的港口珊瑚的新的每月分辨记录将生成（1）（1）校准每月解决的SR-U与观察到的每月分辨SST在22度到32度至32 c至32 c和（2）的温度范围内，并（2）应用校准以产生两个世纪的SST SST SST记录。这些地点的位置是捕获CEP中20世纪SST趋势，20世纪ENSO事件的频率和放大器以及该时期中心与东太平洋埃尔尼诺尼诺相对频率的相对频率。新的数据集将有助于解决有关赤道太平洋平均状态和对人为强迫的可变性的响应的杰出问题。此外，该项目将开发新的方法，以从现代和化石珊瑚中生成准确的SST记录，并在此过程中改变对热带太平洋气候的知识。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子和更广泛的影响审查审查标准来通过评估来通过评估来支持的。