Glaciers as Indicators of Climatic Change - Background and Tools for Modelling

Oerlemans J (1993). Glaciers as Indicators of Climatic Change - Background and Tools for Modelling. IIASA Working Paper. IIASA, Laxenburg, Austria: WP-93-032

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Abstract

Glaciers may be used as indicators of climatic change. This paper presents data from six glaciers with records of glacier length greater than 200 years. All show a strong retreat since 1850. The paper discusses past work to model these glaciers based on climatological time series from nearby station. Studies performed until now have not produced good results and have only partially described the retreats of the past 100 years.

A new, two-step modelling approach is presented here. The first component relates climate conditions to glacier mass balance followed by a second which calculates ice flow as a response to imposed mass balance.

The mass balance approach uses an energy balance on the glacier surface, explicitly accounting for turbulent fluxes in the atmospheric boundary layer above the glacier surface and for the changes in albedo in the modelling of radiation. Meteorological data needed to run the mass balance module are temperature and humidity, cloudiness, and precipitation.

A one-dimensional flow model based on equations of the continuity and motion is used to compute the dynamics of a glacier along the centerline down the surface slope. It takes into account varying lateral geometry, sliding and deformation of the glacier and changes in ice thickness.

The coupled, two-component model system is solved using an explicit scheme for time integration. Various numerical techniques to improve computational efficiency are discussed.

Preliminary results of this approach have been promising and will be discussed by a follow-up paper.

Item Type: Monograph (IIASA Working Paper)
Depositing User: IIASA Import
Date Deposited: 15 Jan 2016 02:02
Last Modified: 13 Aug 2016 16:37
URI: http://pure.iiasa.ac.at/3781

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