气候变化领域集成服务门户(CCPortal): Impact of model developments on present and future simulations of permafrost in a global land-surface model

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DOI	10.5194/tc-9-1505-2015
	Impact of model developments on present and future simulations of permafrost in a global land-surface model
	Chadburn S.E.; Burke E.J.; Essery R.L.H.; Boike J.; Langer M.; Heikenfeld M.; Cox P.M.; Friedlingstein P.
发表日期	2015
ISSN	19940416
卷号	9 期号:4
英文摘要	There is a large amount of organic carbon stored in permafrost in the northern high latitudes, which may become vulnerable to microbial decomposition under future climate warming. In order to estimate this potential carbon-climate feedback it is necessary to correctly simulate the physical dynamics of permafrost within global Earth system models (ESMs) and to determine the rate at which it will thaw. Additional new processes within JULES, the land-surface scheme of the UK ESM (UKESM), include a representation of organic soils, moss and bedrock and a modification to the snow scheme; the sensitivity of permafrost to these new developments is investigated in this study. The impact of a higher vertical soil resolution and deeper soil column is also considered. Evaluation against a large group of sites shows the annual cycle of soil temperatures is approximately 25 % too large in the standard JULES version, but this error is corrected by the model improvements, in particular by deeper soil, organic soils, moss and the modified snow scheme. A comparison with active layer monitoring sites shows that the active layer is on average just over 1 m too deep in the standard model version, and this bias is reduced by 70 cm in the improved version. Increasing the soil vertical resolution allows the full range of active layer depths to be simulated; by contrast, with a poorly resolved soil at least 50 % of the permafrost area has a maximum thaw depth at the centre of the bottom soil layer. Thus all the model modifications are seen to improve the permafrost simulations. Historical permafrost area corresponds fairly well to observations in all simulations, covering an area between 14 and 19 million km2. Simulations under two future climate scenarios show a reduced sensitivity of permafrost degradation to temperature, with the near-surface permafrost loss per degree of warming reduced from 1.5 million km2 °C-1 in the standard version of JULES to between 1.1 and 1.2 million km2 °C-1 in the new model version. However, the near-surface permafrost area is still projected to approximately half by the end of the 21st century under the RCP8.5 scenario. © Author(s) 2015.
学科领域	bedrock; decomposition; environmental monitoring; global warming; land surface; moss; numerical model; organic carbon; organic soil; permafrost; simulation; soil column; soil temperature; vulnerability; United Kingdom; Bryophyta
语种	英语
scopus关键词	bedrock; decomposition; environmental monitoring; global warming; land surface; moss; numerical model; organic carbon; organic soil; permafrost; simulation; soil column; soil temperature; vulnerability; United Kingdom; Bryophyta
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/119844
作者单位	Earth System Sciences, University of Exeter, Laver Building, North Park Road, Exeter, EX4 4QE, United Kingdom; Met Office Hadley Centre, Fitzroy Road, Exeter, EX1 3PB, United Kingdom; Grant Institute, The King's Buildings, James Hutton Road, Edinburgh, EH9 3FE, United Kingdom; Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research (AWI), Potsdam, 14473, Germany; Laboratoire de Glaciologie et Géophysique de l'Environnement (LGGE), BP 96, St Martin d'Hères Cedex, 38402, France; Atmospheric, Oceanic and Planetary Physics, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom
推荐引用方式 GB/T 7714	Chadburn S.E.,Burke E.J.,Essery R.L.H.,et al. Impact of model developments on present and future simulations of permafrost in a global land-surface model[J],2015,9(4).
APA	Chadburn S.E..,Burke E.J..,Essery R.L.H..,Boike J..,Langer M..,...&Friedlingstein P..(2015).Impact of model developments on present and future simulations of permafrost in a global land-surface model.Cryosphere,9(4).
MLA	Chadburn S.E.,et al."Impact of model developments on present and future simulations of permafrost in a global land-surface model".Cryosphere 9.4(2015).