机器学习和基于过程的模拟在阿拉斯加州的活性层厚度的时空变化
Sagar Gautam1, Umakant Mishra2, Sarah N Scott3
1Bioscience Division, Sandia National Laboratory, Livermore, CA, 94550, USA. sgautam@sandia.gov.
Scientific reports
|November 27, 2025
概括
阿拉斯加的永久土退化正在加速,增加了活跃层厚度 (ALT). 机器学习模型显示未来的ALT增加比传统方法要小,这对于北极适应战略至关重要.
科学领域:
- 地球和环境科学 地球和环境科学
- 气候科学 气候科学
- 地质物理学 地质物理学
背景情况:
- 北极的永久土退化对基础设施和生态系统构成重大风险,原因是加快变暖.
- 活动层厚度 (ALT) 是永久土融化及其相关影响的关键指标.
研究的目的:
- 在预测的气候变化场景下,调查阿拉斯加各地ALT的时空动态.
- 为了比较物理模型 (Stefan) 与机器学习 (ML) 技术的性能,用于ALT预测.
- 评估ALT对未来天气条件的敏感性,使用合模型相互比较项目第6阶段 (CMIP6) 的预测.
主要方法:
- 综合现场观测,环境数据集,斯蒂芬模型和随机森林 (RF) ML技术.
- 根据共享社会经济路径 (SSP 2-4.5和SSP 5-8.5) 的CMIP6天气预测用于未来的气候场景.
- 分析的变量重要性 (年平均温度,斜率角度,沉积物运输指数,流动功率指数) 对于ALT预测.
主要成果:
- 与Stefan模型 (R2 = 0.53训练,R2 = 0.54测试) 相比,RF模型在训练数据上表现更好 (R2 = 0.84),但在测试数据上概括性较低 (R2 = 0.24).
- 年平均温度和斜率角度是ALT的最重要的预测因素.
- 预计到2100年ALT的增加为ML模型的3.3厘米 (SSP 2-4.5) 和5.9厘米 (SSP 5-8.5),而Stefan模型的13厘米 (SSP 2-4.5) 和28厘米 (SSP 5-8.5),在阿拉斯加北部增幅最大.
结论:
- 结合物理和机器学习技术的混合建模方法为复杂的ALT动态提供了宝贵的见解.
- 与斯蒂芬模型相比,ML模型表明ALT增加更为保守,这突显了模型选择对北极适应的重要性.
- 加快永久土融化需要提高预测能力,以减轻对北极基础设施,生态系统和碳排放的风险.
更多相关视频
09:19Measuring the Structure, Composition, and Change of Underwater Environments with Large-area Imaging
Published on: April 18, 2025
1.3K
09:06Removal of Exogenous Materials from the Outer Portion of Frozen Cores to Investigate the Ancient Biological Communities Harbored Inside
Published on: July 3, 2016
8.5K
相关概念视频
Precipitation Processes
4.6K
The experimental conditions in a gravimetric analysis should be optimized to maximize the particle size and purity of the obtained precipitate. Ideally, the concentration of the precipitating reagent should be low with effective stirring to maintain low relative supersaturation for the growth of large crystals. In homogeneous precipitation, the precipitant is slowly generated by a chemical reaction in the solution to avoid local reagent excesses. For example, urea decomposes gradually to...
4.6K
Thematic Layering in GIS
304
In the past, planning projects such as schools or public facilities required extensive manual effort to gather and compile data. Information such as property boundaries, soil characteristics, road networks, zoning regulations, and flood zones had to be sourced individually from courthouses, utility providers, and registry offices. Assembling these datasets into a coherent format often took several months, delaying project timelines.The introduction of Geographic Information Systems (GIS)...
304
Global Climate Change
28.6K
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
28.6K
Mechanistic Models: Compartment Models in Algorithms for Numerical Problem Solving
264
Mechanistic models play a crucial role in algorithms for numerical problem-solving, particularly in nonlinear mixed effects modeling (NMEM). These models aim to minimize specific objective functions by evaluating various parameter estimates, leading to the development of systematic algorithms. In some cases, linearization techniques approximate the model using linear equations.
In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a...
In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a...
264
Boundary Layer Characteristics
514
When a fluid encounters a solid surface, a boundary layer forms due to the interaction between the fluid's motion and the stationary surface. This phenomenon is characterized by a thin region adjacent to the surface where viscous forces dominate, influencing the fluid's velocity profile. The development of the boundary layer begins at the leading edge of the surface and evolves as the fluid moves downstream.As the fluid flows over the surface, friction between the fluid and the wall slows down...
514
Precipitation Gravimetry
13.1K
Precipitation gravimetry is based on converting an analyte into a sparingly soluble precipitate, which is separated by filtration and weighed. An ideal precipitate should be pure, insoluble, of known composition, and easily filtered from the reaction mixture.
In determining nickel by gravimetric analysis, a precipitant of ethanolic dimethylglyoxime is added to a hot nickel salt solution. This is quickly followed by the dropwise addition of dilute ammonia solution until precipitation occurs. A...
In determining nickel by gravimetric analysis, a precipitant of ethanolic dimethylglyoxime is added to a hot nickel salt solution. This is quickly followed by the dropwise addition of dilute ammonia solution until precipitation occurs. A...
13.1K
