气候变化领域集成服务门户(CCPortal): Parameter and state estimation with a time-dependent adjoint marine ice sheet model

CCPortal

DOI	10.5194/tc-7-1659-2013
	Parameter and state estimation with a time-dependent adjoint marine ice sheet model
	Goldberg D.N.; Heimbach P.
发表日期	2013
ISSN	19940416
卷号	7 期号:6
英文摘要	To date, assimilation of observations into large-scale ice models has consisted predominantly of time-independent inversions of surface velocities for basal traction, bed elevation, or ice stiffness, and has relied primarily on analytically derived adjoints of glaciological stress balance models. To overcome limitations of such "snapshot" inversions-i.e., their inability to assimilate time-dependent data for the purpose of constraining transient flow states, or to produce initial states with minimum artificial drift and suitable for time-dependent simulations-we have developed an adjoint of a time-dependent parallel glaciological flow model. The model implements a hybrid shallow shelf-shallow ice stress balance, solves the continuity equation for ice thickness evolution, and can represent the floating, fast-sliding, and frozen bed regimes of a marine ice sheet. The adjoint is generated by a combination of analytic methods and the use of algorithmic differentiation (AD) software. Several experiments are carried out with idealized geometries and synthetic observations, including inversion of time-dependent surface elevations for past thicknesses, and simultaneous retrieval of basal traction and topography from surface data. Flexible generation of the adjoint for a range of independent uncertain variables is exemplified through sensitivity calculations of grounded ice volume to changes in basal melting of floating and basal sliding of grounded ice. The results are encouraging and suggest the feasibility, using real observations, of improved ice sheet state estimation and comprehensive transient sensitivity assessments. © 2013 Author(s).
学科领域	algorithm; basal melting; elevation; flow modeling; glaciology; ice sheet; marine environment; numerical model; parameterization; software; stiffness; time dependent behavior; velocity profile
语种	英语
scopus关键词	algorithm; basal melting; elevation; flow modeling; glaciology; ice sheet; marine environment; numerical model; parameterization; software; stiffness; time dependent behavior; velocity profile
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/120239
作者单位	Earth, Atmospheric and Planetary Sciences, M.I.T., Cambridge, United States
推荐引用方式 GB/T 7714	Goldberg D.N.,Heimbach P.. Parameter and state estimation with a time-dependent adjoint marine ice sheet model[J],2013,7(6).
APA	Goldberg D.N.,&Heimbach P..(2013).Parameter and state estimation with a time-dependent adjoint marine ice sheet model.Cryosphere,7(6).
MLA	Goldberg D.N.,et al."Parameter and state estimation with a time-dependent adjoint marine ice sheet model".Cryosphere 7.6(2013).