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DOI	10.1016/j.epsl.2020.116518
	Improving the estimate of the secular variation of Greenland ice mass in the recent decades by incorporating a stochastic process
	Zhang B.; Liu L.; Yao Y.; van Dam T.; Abbas Khan S.
发表日期	2020
ISSN	0012821X
卷号	549
英文摘要	The irregular interannual variations observed in the Greenland ice sheet (GrIS) mass balance can be interpreted as stochastic. These variations often have large amplitudes, and, if not accounted for correctly in the mass change model parameterization, could have profound impacts on the estimate of the secular trend and acceleration. Here we propose a new mass trajectory model that includes both the conventional deterministic components and a stochastic component. This new model simultaneously estimates the secular rate and acceleration, seasonal components, and the stochastic component of mass changes. Simulations show that this new model improves estimates of model parameters, especially accelerations, over the conventional model without stochastic component. Using this new model, we estimate an acceleration of −1.6 ± 1.3 Gt/yr2 in mass change (minus means mass loss) for 2003-2017 using the Gravity Recovery and Climate Experiment (GRACE) data and an acceleration of −1.1 ± 1.3 Gt/yr2 using the modeled surface mass balance plus observed ice discharge. The corresponding rates are estimated to be −288.2 ± 12.7 Gt/yr and −274.9 ± 13.0 Gt/yr. The greatest discrepancies between the new and the conventional model parameter determinations are found in the acceleration estimates, −1.6 Gt/yr2 vs. −7.5 Gt/yr2 from the GRACE data. The estimated accelerations using the new method are apparently smaller than those estimated by other studies in terms of mass loss. Our quantitative analysis elucidates that the acceleration estimate using the conventional method is the lower bound (i.e., −7.5 Gt/yr2 for 2003–2017) while the acceleration estimated by the new method lies in the middle of the possible ranges. It is also found that these discrepancies between the new and the conventional methods diminish with sufficiently long (>20 yr) observation records. © 2020 The Author(s)
关键词	Greenland interannual variations secular mass changes stochastic process
英文关键词	Acceleration; Climate change; Climate models; Glacial geology; Gravitation; Ice; Parameter estimation; Random processes; Stochastic systems; Conventional methods; Conventional modeling; Deterministic component; Gravity recovery and climate experiment datum; Greenland Ice Sheet; Interannual variation; Stochastic component; Surface mass balance; Stochastic models; acceleration; discharge; estimation method; GRACE; ice sheet; mass balance; quantitative analysis; satellite data; secular variation; stochasticity; Arctic; Greenland; Greenland Ice Sheet
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202999
作者单位	School of Geodesy and Geomatics, Wuhan University, Wuhan, 430079, China; Earth System Science Programme, The Chinese University of Hong Kong, Shatin, Hong Kong; Faculty of Science, Technology, and Communication, University of Luxembourg, Luxembourg City, Luxembourg; DTU Space-National Space Institute, Technical University of Denmark, Department of Geodesy, Kgs. Lyngby, Denmark
推荐引用方式 GB/T 7714	Zhang B.,Liu L.,Yao Y.,et al. Improving the estimate of the secular variation of Greenland ice mass in the recent decades by incorporating a stochastic process[J],2020,549.
APA	Zhang B.,Liu L.,Yao Y.,van Dam T.,&Abbas Khan S..(2020).Improving the estimate of the secular variation of Greenland ice mass in the recent decades by incorporating a stochastic process.Earth and Planetary Science Letters,549.
MLA	Zhang B.,et al."Improving the estimate of the secular variation of Greenland ice mass in the recent decades by incorporating a stochastic process".Earth and Planetary Science Letters 549(2020).