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，研究人员将使用可用的数据和建模工具来了解北极陆地环境中水周期的关键组成部分。北极土地表面湿度的变化可能会对营养应激，对野火的敏感性以及陆地释放温室气体（如二氧化碳和甲烷）产生后果。地表湿度也可能影响野生动植物，以及人类活动，例如狩猎和捕鱼，陆上旅行，资源的获取和水的供应。全球气候模型在预测北极降水增加以及几乎预测径流增加时是一致的。在模型之间，尤其是在温暖的季节，净水分通量的投影或降水与蒸发之间的差异差异很大。观察数据表明，至少在北极的某些部分，最近的土壤水分最近减少，这与在温暖的气候下蒸散量的增加一致，但在其他地区的地表水增加。这项研究将合成不同类型的现有数据，以优化对北极表面湿度的预期变化的模型预测。除了对全球模型中如何代表关键的北极进程的了解更加了解外，该项目的更广泛影响还包括对研究生的培训以及通过阿拉斯加的情景网络和阿拉斯加气候评估和政策计划中的情景网络将结果传播给政策和利益相关者社区。研究人员将综合三种类型的有关北极蒸散液（ET）的现有数据：从观察站点，ET的遥感衍生估计值和全球气候模型输出来测量的原位测量。他们将使用这些多样化的数据源来：1）在不同的营养类型中阐明随时间变化的驱动因素，2）评估陆地ET的气候模型模拟及其在北极的可变性。野外地点将包括有或没有多年冻土的各种苔原和北方植被类型，观察结果包括入射辐射，湿度和风速，以评估数据和气候模型中ET的驱动因素。全球气候模型输出将主要来自耦合模型对比项目。卫星遥感衍生的估计将来自MODIS档案，并将弥合模型和原位测量之间的规模差异。验证模型输出对原位和遥感衍生估计值的验证将集中于几天到几年的时间标准的ET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学的可靠预测。基于他们在各种植被类型上捕获季节性周期和ET的能力，研究人员将确定最现实的全球模型以及它们的形式和结构特征。结果将有助于设定改进模型和模型选择的优先级，以实现有关北极陆地表面湿度轨迹的更强大的结论。该奖项反映了NSF的法定任务，并认为通过基金会的智力优点和更广泛的影响来通过评估来获得支持。

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