Small fluctuations in the density and thickness of a dry firn column

被引:22
作者
Wingham, DJ [1 ]
机构
[1] UCL, Dept Space & Climate Phys, London W1CH 0AH, England
关键词
D O I
10.3189/172756500781833089
中图分类号
P9 [自然地理学];
学科分类号
0705 ; 070501 ;
摘要
It is of practical importance to have a description on time-scales of 1-100 years of the relationship between the mass imbalance of an ice sheet and its rate of change of thickness. In this paper, a linearized treatment off the relationship is described. Closed-form expressions are derived that relate the time-variant density in an isothermal firn layer to the fluctuations in accumulation rate and density that occur at the surface. These expressions are used to provide a spectral description of the contribution of surface accumulation and surface density fluctuations to the rate of change of thickness of an ice sheet. Using these, the contribution of firn densification to the variability of ice-sheet thickness is examined as a function of the time interval over which the ice sheet is observed. This contribution is illustrated for sites in Antarctica and Greenland. It is concluded that it is important to give greater attention than hitherto to the spatial scale of accumulation fluctuations if satellite observations of ice-sheet elevation change are to be used to estimate ice-sheet imbalance over short time intervals.
引用
收藏
页码:399 / 411
页数:13
相关论文
共 27 条
[1]   FIRN DENSIFICATION BY GRAIN-BOUNDARY SLIDING - A 1ST MODEL [J].
ALLEY, RB .
JOURNAL DE PHYSIQUE, 1987, 48 (C-1) :249-256
[2]  
[Anonymous], CHANGES SEA LEVEL CL
[3]  
[Anonymous], CLIMATE SCI AD 1500
[4]   The natural fluctuations of firn densification and their effect on the geodetic determination of ice sheet mass balance [J].
Arthern, RJ ;
Wingham, DJ .
CLIMATIC CHANGE, 1998, 40 (3-4) :605-624
[5]  
Bader H., 1954, J GLACIOL, V2, P319, DOI [10.3189/S0022143000025144, 10.3189/s0022143000025144]
[6]  
BADER H, 1960, 69 SIPRE
[7]   VARIATIONS OF NEAR-SURFACE FIRN DENSITY IN THE LOWER ACCUMULATION AREA OF THE GREENLAND ICE-SHEET, PAKITSOQ, WEST GREENLAND [J].
BRAITHWAITE, RJ ;
LATERNSER, M ;
PFEFFER, WT .
JOURNAL OF GLACIOLOGY, 1994, 40 (136) :477-485
[9]   FLUCTUATIONS OF SNOW ACCUMULATION IN THE ANTARCTIC AND SEA-LEVEL PRESSURE IN THE SOUTHERN-HEMISPHERE IN THE LAST 100 YEARS [J].
ENOMOTO, H .
CLIMATIC CHANGE, 1991, 18 (01) :67-87
[10]  
Giovinetto M. B., 1965, Archiv fur Meteorologie, Geophysik und Bioklimatologie, Serie A, V15, P227, DOI [10.1007/BF02246754, DOI 10.1007/BF02246754]