Glacier volume response time and its links to climate and topography based on a conceptual model of glacier hypsometry 1Centre for Air Transport and the Environment, Manchester Metropolitan University, Manchester, M1 5GD, UK
2School of Environment and Development, University of Manchester, Manchester M13 9PL, UK
Received: 12 Jan 2009 – Published in The Cryosphere Discuss.: 04 Mar 2009 Abstract. Glacier volume response time is a measure of the time taken for a glacier to
adjust its geometry to a climate change. It has been previously proposed
that the volume response time is given approximately by the ratio of glacier
thickness to ablation at the glacier terminus. We propose a new conceptual
model of glacier hypsometry (area-altitude relation) and derive the volume
response time where climatic and topographic parameters are separated. The
former is expressed by mass balance gradients which we derive from
glacier-climate modelling and the latter are quantified with data from the
World Glacier Inventory. Aside from the well-known scaling relation
between glacier volume and area, we establish a new scaling relation between
glacier altitude range and area, and evaluate it for seven regions. The
presence of this scaling parameter in our response time formula accounts for
the mass balance elevation feedback and leads to longer response times than
given by the simple ratio of glacier thickness to ablation at the terminus.
Volume response times range from decades to thousands of years for glaciers
in maritime (wet-warm) and continental (dry-cold) climates respectively. The
combined effect of volume-area and altitude-area scaling relations is such
that volume response time can increase with glacier area (Axel Heiberg
Island and Svalbard), hardly change (Northern Scandinavia, Southern Norway
and the Alps) or even get smaller (The Caucasus and New Zealand).
Revised: 20 Jul 2009 – Accepted: 10 Aug 2009 – Published: 14 Aug 2009
Citation: Raper, S. C. B. and Braithwaite, R. J.: Glacier volume response time and its links to climate and topography based on a conceptual model of glacier hypsometry, The Cryosphere, 3, 183-194, doi:10.5194/tc-3-183-2009, 2009.