Modelling the evolution of Djankuat Glacier, North Caucasus, from 1752 until 2100 CE

We use a numerical flow line model to simulate the behaviour of the Djankuat Glacier, a World Glacier Monitoring Service reference glacier situated in the North Caucasus (Republic of Kabardino-Balkaria, Russian Federation), in response to past, present and future climate conditions (1752–2100 CE). T...

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Bibliographic Details
Published in:The Cryosphere
Main Authors: Y. Verhaegen, P. Huybrechts, O. Rybak, V. V. Popovnin
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2020
Subjects:
geo
Online Access:https://doi.org/10.5194/tc-14-4039-2020
https://tc.copernicus.org/articles/14/4039/2020/tc-14-4039-2020.pdf
https://doaj.org/article/b4a5f7302d37456b81e53fe908b08c54
Description
Summary:We use a numerical flow line model to simulate the behaviour of the Djankuat Glacier, a World Glacier Monitoring Service reference glacier situated in the North Caucasus (Republic of Kabardino-Balkaria, Russian Federation), in response to past, present and future climate conditions (1752–2100 CE). The model consists of a coupled ice flow–mass balance model that also takes into account the evolution of a supraglacial debris cover. After simulation of the past retreat by applying a dynamic calibration procedure, the model was forced with data for the future period under different scenarios regarding temperature, precipitation and debris input. The main results show that the glacier length and surface area have decreased by ca. 1.4 km (ca. −29.5 %) and ca. 1.6 km2 (−35.2 %) respectively between the initial state in 1752 CE and present-day conditions. Some minor stabilization and/or readvancements of the glacier have occurred, but the general trend shows an almost continuous retreat since the 1850s. Future projections using CMIP5 temperature and precipitation data exhibit a further decline of the glacier. Under constant present-day climate conditions, its length and surface area will further shrink by ca. 30 % by 2100 CE. However, even under the most extreme RCP 8.5 scenario, the glacier will not have disappeared completely by the end of the modelling period. The presence of an increasingly widespread supraglacial debris cover is shown to significantly delay glacier retreat, depending on the interaction between the prevailing climatic conditions, the debris input location, the debris mass flux magnitude and the time of release of debris sources from the surrounding topography.