Arctic evapotranspiration: A diagnostic synthesis and model assessment

北极蒸散量：诊断综合和模型评估

基本信息

批准号：
1830131
负责人：
John Walsh
金额：
$ 19.13万
依托单位：
University of Alaska Fairbanks Campus
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-04-15 至 2022-03-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1830131&HistoricalAwards=false
关键词：
Arctic evapotranspiration diagnostic synthesis model

项目摘要

In this study, the investigators will use available data and modeling tools to understand a key component of the water cycle in a changing Arctic terrestrial environment. Changes in the wetness of Arctic land surfaces can have consequences for vegetative stress, susceptibility to wildfires, and terrestrial release of greenhouse gases such as carbon dioxide and methane. Land surface wetness may also affect wildlife, as well as human activities such as subsistence hunting and fishing, overland travel, access to resources, and water availability. Global climate models are unanimous in projecting increases in Arctic precipitation and nearly so in projecting increases of runoff. Projections of net moisture flux, or the difference between precipitation and evapotranspiration, vary widely among models, especially during the warm season. Observational data point to recent decreases in soil moisture for at least some parts of the Arctic, consistent with increasing evapotranspiration in a warming climate, but increases in surface water in other areas. This study will synthesize different types of existing data to optimize model projections of anticipated changes to Arctic surface wetness. In addition to improved understanding of how a key Arctic process is represented in global models, the broader impacts of this project include training for a graduate student and dissemination of results to policy and stakeholder communities through the Scenarios Network for Alaska and Arctic Planning and Alaska Center for Climate Assessment and Policy programs. The investigators will synthesize three types of existing data on Arctic evapotranspiration (ET): in situ measurements from observing sites, remote-sensing-derived estimates of ET, and global climate model output. They will use these diverse data sources to: 1) clarify the drivers of ET variations over time in different vegetative types and 2) evaluate climate model simulations of terrestrial ET and its variability in the Arctic. The field sites will include various tundra and boreal vegetation types, both with and without permafrost, and observations will include incident radiation, humidity, and wind speed to assess the drivers of ET in the data and in climate models. Global climate model output will come primarily from the Coupled Model Intercomparison Project. Satellite remote-sensing-derived estimates will come from MODIS archives and will bridge the scale discrepancy between models and in situ measurements. Validation of model output against in situ and remote-sensing derived estimates will focus on variation in ET over timescales of days to years. Synthesis of the three types of information will assess key processes that climate models must capture to produce credible projections of Arctic terrestrial hydrology. Based on their ability to capture seasonal cycles and ET over various vegetation types, the investigators will identify the most realistic global models, along with their formulational and structural characteristics. Results will help set priorities for model improvement and model selection to enable more robust conclusions about the trajectory of Arctic terrestrial surface wetness.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.

在这项研究中，研究人员将使用现有的数据和建模工具来了解不断变化的北极陆地环境中水循环的关键组成部分。北极陆地表面湿度的变化可能会对植物胁迫、野火的易感性以及二氧化碳和甲烷等温室气体的陆地释放产生影响。地表湿度还可能影响野生动物以及人类活动，例如自给狩猎和捕鱼、陆路旅行、资源获取和水资源供应。全球气候模型一致预测北极降水会增加，并且几乎一致预测径流会增加。不同模型对净水分通量（即降水量与蒸散量之间的差异）的预测差异很大，尤其是在温暖的季节。观测数据表明，最近北极至少部分地区的土壤湿度有所下降，这与气候变暖导致蒸散量的增加相一致，但其他地区的地表水却有所增加。这项研究将综合不同类型的现有数据，以优化北极表面湿度预期变化的模型预测。除了加深对全球模型中如何体现北极关键过程的理解外，该项目的更广泛影响还包括对研究生进行培训，并通过阿拉斯加和北极规划情景网络以及阿拉斯加中心向政策和利益相关者社区传播结果气候评估和政策计划。研究人员将综合关于北极蒸散量（ET）的三类现有数据：观测地点的现场测量、遥感得出的蒸散量估计值以及全球气候模型输出。他们将使用这些不同的数据源来：1）阐明不同植被类型随时间的蒸散变化的驱动因素，2）评估陆地蒸散的气候模型模拟及其在北极的变化。实地地点将包括各种苔原和北方植被类型，有或没有永久冻土，观测将包括入射辐射、湿度和风速，以评估数据和气候模型中蒸散的驱动因素。全球气候模型的输出将主要来自耦合模型比对项目。卫星遥感估算将来自 MODIS 档案，并将弥合模型和现场测量之间的规模差异。根据实地和遥感得出的估计值验证模型输出将重点关注蒸散量在数天到数年时间尺度上的变化。这三种类型的信息的综合将评估气候模型必须捕获的关键过程，以产生北极陆地水文的可信预测。根据捕获各种植被类型的季节周期和蒸散的能力，研究人员将确定最现实的全球模型及其公式和结构特征。结果将有助于确定模型改进和模型选择的优先顺序，以便就北极陆地表面湿度的轨迹得出更可靠的结论。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。

项目成果

期刊论文数量（9）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Future Changes of Snow in Alaska and the Arctic under Stabilized Global Warming Scenarios

DOI：
10.3390/atmos13040541
发表时间：
2022-04-01
期刊：
ATMOSPHERE
影响因子：
2.9
作者：
Bigalke, Siiri;Walsh, John E.
通讯作者：
Walsh, John E.

Increasing contribution of peatlands to boreal evapotranspiration in a warming climate

DOI：
10.1038/s41558-020-0763-7
发表时间：
2020-05-11
期刊：
NATURE CLIMATE CHANGE
影响因子：
30.7
作者：
Helbig, Manuel;Waddington, James Michael;Zyrianov, Vyacheslav
通讯作者：
Zyrianov, Vyacheslav

Extreme weather and climate events in northern areas: A review

DOI：
10.1016/j.earscirev.2020.103324
发表时间：
2020-08
期刊：
Earth-Science Reviews
影响因子：
12.1
作者：
J. Walsh;T. Ballinger;E. Euskirchen;Edward Hanna;J. Mård;J. Overland;H. Tangen;T. Vihma;T. Vihma
通讯作者：
J. Walsh;T. Ballinger;E. Euskirchen;Edward Hanna;J. Mård;J. Overland;H. Tangen;T. Vihma;T. Vihma

Emerging Anthropogenic Influences on the Southcentral Alaska Temperature and Precipitation Extremes and Related Fires in 2019

2019 年新出现的人为因素对阿拉斯加中南部极端温度和降水以及相关火灾的影响

DOI：
10.3390/land10010082
发表时间：
2021
期刊：
Land
影响因子：
3.9
作者：
Bhatt, Uma S.;Lader, Rick T.;Walsh, John E.;Bieniek, Peter A.;Thoman, Richard;Berman, Matthew;Borries-Strigle, Cecilia;Bulock, Kristi;Chriest, Jonathan;Hahn, Micah
通讯作者：
Hahn, Micah

Diagnosis of Atmospheric Drivers of High-Latitude Evapotranspiration Using Structural Equation Modeling