Water temperature controls in low arctic rivers
Water temperature controls in low arctic rivers
复制标题
北极低水位河流的水温控制
DOI：
10.1002/2015wr017965
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发表时间：
2016
影响因子：
5.4
通讯作者：
D. Kane
中科院分区：
文献类型：
--
作者：
T. King;B. Neilson;L. D. Overbeck;D. Kane
了解热传递机制的动态对于预测气候变化对北极河流温度的影响至关重要。气候对北极河流温度的影响可能特别重要，因为相应的营养动态和生态响应的影响。据推测，同样的热量和质量通量影响北极和温带河流，但相对重要性和随时间和空间的变化不同。通过数据收集和应用的河流温度模型，占主要的热通量在温带气候相关，热通量估计了一个大的北极盆地在广泛的水文条件。热通量的影响类似于温带系统，主要包括短波辐射，从正到负的感热通量与下游距离的变化，以及更大的影响，在源头地区的横向流入。与许多温带系统不同的热通量包括持续的负净长波辐射和小的平均潜热通量。辐射热通量占总绝对热通量的88%，而所有其他热通量的贡献平均不到5%。横向流入（高达26%）和潜热通量（高达18%）在较低和较高的流阶部分的流域，分别定期的意义。来自大尺度流差和代表性支流的温度的分布横向流入为估计相关热负荷提供了数据有效的方法。低流量下的模型性能较差，表明需要进一步测试和数据收集，以支持包括额外的热通量。
Understanding the dynamics of heat transfer mechanisms is critical for forecasting the effects of climate change on arctic river temperatures. Climate influences on arctic river temperatures can be particularly important due to corresponding effects on nutrient dynamics and ecological responses. It was hypothesized that the same heat and mass fluxes affect arctic and temperate rivers, but that relative importance and variability over time and space differ. Through data collection and application of a river temperature model that accounts for the primary heat fluxes relevant in temperate climates, heat fluxes were estimated for a large arctic basin over wide ranges of hydrologic conditions. Heat flux influences similar to temperate systems included dominant shortwave radiation, shifts from positive to negative sensible heat flux with distance downstream, and greater influences of lateral inflows in the headwater region. Heat fluxes that differed from many temperate systems included consistently negative net longwave radiation and small average latent heat fluxes. Radiative heat fluxes comprised 88% of total absolute heat flux while all other heat fluxes contributed less than 5% on average. Periodic significance was seen for lateral inflows (up to 26%) and latent heat flux (up to 18%) in the lower and higher stream order portions of the watershed, respectively. Evenly distributed lateral inflows from large scale flow differencing and temperatures from representative tributaries provided a data efficient method for estimating the associated heat loads. Poor model performance under low flows demonstrated need for further testing and data collection to support the inclusion of additional heat fluxes.