DOI: 10.5194/tc-12-145-2018
Scopus记录号: 2-s2.0-85040794795
论文题名: Characterizing permafrost active layer dynamics and sensitivity to landscape spatial heterogeneity in Alaska
作者: Yi Y ; , Kimball J ; S ; , Chen R ; H ; , Moghaddam M ; , Reichle R ; H ; , Mishra U ; , Zona D ; , Oechel W ; C
刊名: Cryosphere
ISSN: 19940416
出版年: 2018
卷: 12, 期: 1 起始页码: 145
结束页码: 161
语种: 英语
英文关键词: active layer
; climate feedback
; ecosystem response
; global warming
; heterogeneity
; in situ measurement
; landscape change
; permafrost
; radar
; remote sensing
; sensitivity analysis
; soil moisture
; soil organic matter
; spatial analysis
; trend analysis
; vertical distribution
; Alaska
; Arctic
; United States
英文摘要: An important feature of the Arctic is large spatial heterogeneity in active layer conditions, which is generally poorly represented by global models and can lead to large uncertainties in predicting regional ecosystem responses and climate feedbacks. In this study, we developed a spatially integrated modeling and analysis framework combining field observations, local-scale ( ∼ 50m resolution) active layer thickness (ALT) and soil moisture maps derived from low-frequency (Lband) airborne radar measurements, and global satellite environmental observations to investigate the ALT sensitivity to recent climate trends and landscape heterogeneity in Alaska. Modeled ALT results show good correspondence with in situ measurements in higher-permafrost-probability (PP ≥ 70%) areas (n Combining double low line 33; R Combining double low line 0.60; mean bias Combining double low line 1.58cm; RMSE Combining double low line 20.32cm), but with larger uncertainty in sporadic and discontinuous permafrost areas. The model results also reveal widespread ALT deepening since 2001, with smaller ALT increases in northern Alaska (mean trend Combining double low line 0.32±1.18cmyr-1) and much larger increases (> 3cmyr-1) across interior and southern Alaska. The positive ALT trend coincides with regional warming and a longer snow-free season (R Combining double low line 0.60±0.32). A spatially integrated analysis of the radar retrievals and model sensitivity simulations demonstrated that uncertainty in the spatial and vertical distribution of soil organic carbon (SOC) was the largest factor affecting modeled ALT accuracy, while soil moisture played a secondary role. Potential improvements in characterizing SOC heterogeneity, including better spatial sampling of soil conditions and advances in remote sensing of SOC and soil moisture, will enable more accurate predictions of active layer conditions and refinement of the modeling framework across a larger domain. © Author(s) 2018. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75439
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: Numerical Terradynamic Simulation Group, University of Montana, Missoula, MT, United States; Department of Electrical Engineering, University of Southern CaliforniaCA, United States; Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD, United States; Environmental Science Division, Argonne National Laboratory, Argonne, IL, United States; Department of Biology, San Diego State University, San Diego, CA, United States
Recommended Citation:
Yi Y,, Kimball J,S,et al. Characterizing permafrost active layer dynamics and sensitivity to landscape spatial heterogeneity in Alaska[J]. Cryosphere,2018-01-01,12(1)