Modeling the large-scale effects of surface moisture heterogeneity on wetland carbon fluxes in the West Siberian Lowland
Modeling the large-scale effects of surface moisture heterogeneity on wetland carbon fluxes in the West Siberian Lowland
复制标题
模拟西西伯利亚低地表面水分异质性对湿地碳通量的大规模影响
DOI：
10.5194/bg-10-6559-2013
复制
发表时间：
2013
期刊：
影响因子：
4.9
通讯作者：
D. Lettenmaier
中科院分区：
文献类型：
--
作者：
T. Bohn;E. Podest;R. Schroeder;N. Pinto;K. McDonald;M. Glagolev;I. V. Filippov;Shamil Maksyutov;M. Heimann;Xiaodong Chen;D. Lettenmaier
我们使用一个基于过程的模型来研究1948-2010年西西伯利亚低地湿地碳收支中地表和次表层水的空间异质性所起的作用。我们发现，虽然表层非均质性(饱和分数面积)对该区域碳通量估算的总体影响很小，但次表层非均质性(地下水位深度的空间变化)对该区域碳通量估算值的总体大小和空间分布都起着重要作用。特别是，为了再现通过密集的现场观测记录的整个区域CH4排放的空间模式，其中CH4在60°N以北排放很少，有必要(A)考虑非饱和湿地的CH4排放，和(B)使用空间变化的甲烷模型参数，以减少区域北部(永冻层)估计的CH4排放(和/或考虑淹没条件下较低的CH4排放)。我们的结果表明，之前对这些湿地对永久冻土融化的反应的估计，可能高估了未来永久冻土区甲烷排放的增加。
We used a process-based model to examine the role of spatial heterogeneity of surface and sub-surface water on the carbon budget of the wetlands of the West Siberian Lowland over the period 1948–2010. We found that, while surface heterogeneity (fractional saturated area) had little overall effect on estimates of the region's carbon fluxes, sub-surface heterogeneity (spatial variations in water table depth) played an important role in both the overall magnitude and spatial distribution of estimates of the region's carbon fluxes. In particular, to reproduce the spatial pattern of CH 4 emissions recorded by intensive in situ observations across the domain, in which very little CH 4 is emitted north of 60° N, it was necessary to (a) account for CH 4 emissions from unsaturated wetlands and (b) use spatially varying methane model parameters that reduced estimated CH 4 emissions in the northern (permafrost) half of the domain (and/or account for lower CH 4 emissions under inundated conditions). Our results suggest that previous estimates of the response of these wetlands to thawing permafrost may have overestimated future increases in methane emissions in the permafrost zone.