The surface energy balance and its drivers in a boreal peatland fen of northwestern Russia
The surface energy balance and its drivers in a boreal peatland fen of northwestern Russia
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DOI：
10.1016/j.jhydrol.2014.01.056
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发表时间：
2014-04
影响因子：
6.4
通讯作者：
B. Runkle;C. Wille;M. Gažovič;M. Wilmking;L. Kutzbach
中科院分区：
文献类型：
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作者：
B. Runkle;C. Wille;M. Gažovič;M. Wilmking;L. Kutzbach
北方泥炭地能量平衡使用涡度协方差技术以前在阿拉斯加，加拿大，斯堪的纳维亚半岛，和西伯利亚西部，但不是在俄罗斯联邦的欧洲部分。俄罗斯欧洲部分有大约200，000平方公里的泥炭地，属于北方（亚北极）大陆性气候，影响着该地区的能源平衡。为了帮助填补这一研究空白，表面能量平衡确定了一个北方泥炭沼泽在俄罗斯科米共和国在2008-2009年的11个月期间使用涡度协方差法。总的测量期间的累积能量平衡关闭率为86%，在关键的夏季生长季节关闭较高。与其他北方泥炭地站点类似，仲夏短波辐射显示累积月基础上计算的Ekdo在0.13和0.19之间，而在降雪量最大的月份（2009年1月和2月），月Ekdo>0.9。仲夏鲍文比平均为0.20-0.25的累积基础上，每月平均的中午值在0.35-0.53的范围内的生长季节。潜热通量超过净辐射的70%和潜在蒸散的60%。在研究期间，总蒸散量（406毫米）略大于降雨量（389毫米），后来的降雪在大气水分收支中产生多余的水分。这些特征共同指向泥炭地，其能量平衡行为通常与其他北方沼泽的数据一致。LE通量主要受净辐射控制，冠层阻力小于其他北方沼泽，水汽压亏缺在能量平衡中的作用较轻。空气动力学和冠层传导条款是相似的幅度，无论是通过季节，并通过任何给定的日周期。因此，高解耦系数（0.65 ± 0.16在生长季节）允许进一步模拟沼泽在这一地区的参数化的表面电导项的不确定性及其对水位和蒸汽压力赤字变化的响应减少的影响。Priestley-Taylor方法提供了一个合理的方法来模拟蒸散，给出了一些假设网站的能量平衡关闭。这种对能源和水资源预算的当地驱动因素的理解对泥炭地生态和增长，区域碳动态和下游水文具有重要意义。
Boreal peatland energy balances using the eddy covariance technique have previously been made in Alaska, Canada, Scandinavia, and Western Siberia, but not in the European portion of the Russian Federation. European Russia contains approximately 200,000 km2of peatlands and has a boreal (subarctic), continental climate influencing the region’s energy balance. To help fill this research gap, the surface energy balance was determined for a boreal peatland fen in the Komi Republic of Russia for an 11-month period in 2008–2009 using the eddy covariance method. The total measurement period’s cumulative energy balance closure rate was 86%, with higher closure during the critical summer growing season. Similar to other boreal peatland sites, the mid-summer shortwave radiation demonstrated albedo between 0.13 and 0.19 as calculated on a cumulative monthly basis, whereas monthly albedo was >0.9 during the months with greatest snow (January, February 2009). Mid-summer Bowen ratios averaged 0.20–0.25 on a cumulative basis, with monthly averaged mid-day values in the range 0.35–0.53 during the growing season. Latent energy (LE) fluxes exceeded 70% of net radiation and 60% of potential evapotranspiration. During the study period, total evapotranspiration (406 mm) was slightly greater than rainfall (389 mm), with later snowfalls creating excess moisture in the atmospheric water budget. These characteristics together point to a peatland whose energy balance behavior is generally consistent with data from other boreal fens. The LE fluxes were dominantly controlled by net radiation, with less canopy resistance than at other northern fens and a lighter role for vapor pressure deficit to play in the energy balance. The aerodynamic and canopy conductance terms were of similar magnitude, both through the season and through any given diurnal cycle. The consequently high decoupling coefficient (0.65 ± 0.16 in the growing season) allows further modeling of fens in this region with reduced effects from the uncertainties of parameterizing surface conductance terms and their responses to water table and vapor pressure deficit changes. The Priestley–Taylor method provides a reasonable approach to modeling evapotranspiration, given some assumptions about the site’s energy balance closure. This understanding of the local drivers on the energy and water budgets has important implications for peatland ecology and growth, regional carbon dynamics, and downstream hydrology.