气候变化领域集成服务门户(CCPortal): Thaw processes in ice-rich permafrost landscapes represented with laterally coupled tiles in a land surface model

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DOI	10.5194/tc-13-591-2019
	Thaw processes in ice-rich permafrost landscapes represented with laterally coupled tiles in a land surface model
	Aas K.S.; Martin L.; Nitzbon J.; Langer M.; Boike J.; Lee H.; Berntsen T.K.; Westermann S.
发表日期	2019
ISSN	19940416
EISSN	13
起始页码	591
结束页码	609
卷号	13 期号:2 页码:591-609
英文摘要	Earth system models (ESMs) are our primary tool for projecting future climate change, but their ability to represent small-scale land surface processes is currently limited. This is especially true for permafrost landscapes in which melting of excess ground ice and subsequent subsidence affect lateral processes which can substantially alter soil conditions and fluxes of heat, water, and carbon to the atmosphere. Here we demonstrate that dynamically changing microtopography and related lateral fluxes of snow, water, and heat can be represented through a tiling approach suitable for implementation in large-scale models, and we investigate which of these lateral processes are important to reproduce observed landscape evolution. Combining existing methods for representing excess ground ice, snow redistribution, and lateral water and energy fluxes in two coupled tiles, we show that the model approach can simulate observed degradation processes in two very different permafrost landscapes. We are able to simulate the transition from low-centered to highcentered polygons, when applied to polygonal tundra in the cold, continuous permafrost zone, which results in (i) a more realistic representation of soil conditions through drying of elevated features and wetting of lowered features with related changes in energy fluxes, (ii) up to 2 °C reduced average permafrost temperatures in the current (2000-2009) climate, (iii) delayed permafrost degradation in the future RCP4.5 scenario by several decades, and (iv) more rapid degradation through snow and soil water feedback mechanisms once subsidence starts. Applied to peat plateaus in the sporadic permafrost zone, the same two-tile system can represent an elevated peat plateau underlain by permafrost in a surrounding permafrost-free fen and its degradation in the future following a moderate warming scenario. These results demonstrate the importance of representing lateral fluxes to realistically simulate both the current permafrost state and its degradation trajectories as the climate continues to warm. Implementing laterally coupled tiles in ESMs could improve the representation of a range of permafrost processes, which is likely to impact the simulated magnitude and timing of the permafrost-carbon feedback. © Author(s) 2019.
语种	英语
WOS研究方向	Physical Geography ; Geology
scopus关键词	climate change; climate modeling; land surface; landscape; landscape evolution; permafrost; soil water
来源期刊	The Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/93567
作者单位	Department of Geosciences, University of Oslo, Sem Sælands vei 1, Oslo, 0316, Norway; Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Telegrafenberg A45, Potsdam, 14473, Germany; Geography Department, Humboldt University of Berlin, Unter den Linden 6, Berlin, 10099, Germany; Bjerknes Centre for Climate Research, NORCE Norwegian Research Centre, Jahnebakken 5, Bergen, 5007, Norway
推荐引用方式 GB/T 7714	Aas K.S.,Martin L.,Nitzbon J.,et al. Thaw processes in ice-rich permafrost landscapes represented with laterally coupled tiles in a land surface model[J],2019,13(2):591-609.
APA	Aas K.S..,Martin L..,Nitzbon J..,Langer M..,Boike J..,...&Westermann S..(2019).Thaw processes in ice-rich permafrost landscapes represented with laterally coupled tiles in a land surface model.The Cryosphere,13(2),591-609.
MLA	Aas K.S.,et al."Thaw processes in ice-rich permafrost landscapes represented with laterally coupled tiles in a land surface model".The Cryosphere 13.2(2019):591-609.