Regime shifts in Arctic terrestrial hydrology manifested from impacts of climate warming
Regime shifts in Arctic terrestrial hydrology manifested from impacts of climate warming
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DOI：
10.5194/tc-18-1033-2024
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发表时间：
2024-03
期刊：
影响因子：
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通讯作者：
M. Rawlins;A. Karmalkar
中科院分区：
文献类型：
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作者：
M. Rawlins;A. Karmalkar
抽象。北极地区的人为变暖正在导致水文循环加剧和永久冻土融化，对陆地生物群落向沿海地区的水、碳和能源流动产生影响。为了更好地了解这些变化可能产生的影响，我们使用了一个水文模型，该模型由大气再分析的气象数据和两个全球气候模型驱动，适用于1980-2100年。水文模型考虑了土壤冻融过程，并在泛北极流域应用。模拟结果表明，在永久冻土覆盖的盆地最北部地区和北极西部，变化更大。在最近的过去，模拟河流流量的加速与从观察得出的趋势和其他研究报告是相称的。在本世纪初（2000-2019年）和本世纪末（2080-2099年）期间，模型模拟表明年总径流量增加了17%-25%，而来自地下通道的径流量预计将增加13%-30%，夏季和秋季以及永久冻土区的变化最大。最值得注意的是，径流对河流排放的贡献转移到北极盆地的北方地区，那里含有更多的土壤碳。每个季节的地下径流量都会增加;春季是地表径流量占主导地位的唯一季节，总径流量增加，夏季尽管地下径流量增加，但总径流量下降。在永久冻土存在的地区看到的更大的变化支持了这样一种观点，即土壤解冻的增加正在将水文作用转移到更多的地下水流中。气候变暖、水文循环加剧和永冻层融化的现象将通过改变河流及其运输的物质影响北极陆地和沿海环境。
Abstract. Anthropogenic warming in the Arctic is causing hydrological cycle intensification and permafrost thaw, with implications for flows of water, carbon, and energy from terrestrial biomes to coastal zones. To better understand the likely impacts of these changes, we used a hydrology model driven by meteorological data from atmospheric reanalysis and two global climate models for the period 1980–2100. The hydrology model accounts for soil freeze–thaw processes and was applied across the pan-Arctic drainage basin. The simulations point to greater changes over northernmost areas of the basin underlain by permafrost and to the western Arctic. An acceleration of simulated river discharge over the recent past is commensurate with trends drawn from observations and reported in other studies. Between early-century (2000–2019) and late-century (2080–2099) periods, the model simulations indicate an increase in annual total runoff of 17 %–25 %, while the proportion of runoff emanating from subsurface pathways is projected to increase by 13 %–30 %, with the largest changes noted in summer and autumn and across areas with permafrost. Most notably, runoff contributions to river discharge shift to northern parts of the Arctic Basin that contain greater amounts of soil carbon. Each season sees an increase in subsurface runoff; spring is the only season where surface runoff dominates the rise in total runoff, and summer experiences a decline in total runoff despite an increase in the subsurface component. The greater changes that are seen in areas where permafrost exists support the notion that increased soil thaw is shifting hydrological contributions to more subsurface flow. The manifestations of warming, hydrological cycle intensification, and permafrost thaw will impact Arctic terrestrial and coastal environments through altered river flows and the materials they transport.