Inter-decadal variability in potential glacier surface melt energy at Vestari Hagafellsjokull (Langjokull, Iceland) and the role of synoptic circulation
The surface energy balance (SEB) of glaciers, although of considerable importance for understanding the melt response to climate change, is rarely analysed for more than a few melt seasons due to the logistical challenges of meteorological measurement campaigns on glaciers. Insight into low-frequency (inter-decadal) changes in the SEB in response to climate warming and variable atmospheric circulation patterns has thus been limited. Here this problem is addressed by using ERA-Interim reanalysis data to extend glacier-meteorological records at two locations on Vestari Hagafellsjökull (Iceland) for the period 1979–2012. Trend analysis is conducted for this series before the role of synoptic circulation in modulating surface energetics is investigated. The results indicate that potential melt energy has increased significantly throughout the period of simulation at both locations (by 19.7 and 32.4%), with the largest increase evident for the turbulent heat fluxes (36.3 and 93.1%). The synoptic conditions associated with the recent high melt rates on the proximate Greenland Ice Sheet (GrIS) do not result in similarly extreme melt conditions for our Icelandic location. We also find that the North Atlantic Oscillation Index is significantly correlated with the radiative and latent heat components of the SEB. This association remains hidden if the melt rate is assessed in isolation, highlighting the utility of the SEB approach presented here for assessing synoptic aspects of glacier-climate interactions.
History
School
Social Sciences
Department
Geography and Environment
Published in
INTERNATIONAL JOURNAL OF CLIMATOLOGY
Volume
35
Issue
10
Pages
3041 - 3057 (17)
Citation
MATTHEWS, T. ... et al., 2015. Inter-decadal variability in potential glacier surface melt energy at Vestari Hagafellsjokull (Langjokull, Iceland) and the role of synoptic circulation. International Journal of Climatology, 35 (10), pp. 3041 - 3057.
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/
Publication date
2015
Notes
Closed access. The authors of this paper are: T. Matthews, R. Hodgkins, S. Guðmundsson, F. Pálsson and H. Björnsson.