Journal cover Journal topic
The Cryosphere An interactive open-access journal of the European Geosciences Union
The Cryosphere, 9, 971-988, 2015
https://doi.org/10.5194/tc-9-971-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
11 May 2015
Numerical simulation of extreme snowmelt observed at the SIGMA-A site, northwest Greenland, during summer 2012
M. Niwano1, T. Aoki1, S. Matoba2, S. Yamaguchi3, T. Tanikawa4, K. Kuchiki1, and H. Motoyama5 1Meteorological Research Institute, Japan Meteorological Agency, Tsukuba, Japan
2Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
3Snow and Ice Research Center, National Research Institute for Earth Science and Disaster Prevention, Nagaoka, Japan
4Earth Observation Research Center, Japan Aerospace Exploration Agency, Tsukuba, Japan
5National Institute of Polar Research, Tachikawa, Japan
Abstract. The surface energy balance (SEB) from 30 June to 14 July 2012 at site SIGMA (Snow Impurity and Glacial Microbe effects on abrupt warming in the Arctic)-A, (78°03' N, 67°38' W; 1490 m a.s.l.) on the northwest Greenland Ice Sheet (GrIS) was investigated by using in situ atmospheric and snow measurements as well as numerical modeling with a one-dimensional multi-layered physical snowpack model called SMAP (Snow Metamorphism and Albedo Process). At SIGMA-A, remarkable near-surface snowmelt and continuous heavy rainfall (accumulated precipitation between 10 and 14 July was estimated to be 100 mm) were observed after 10 July 2012. Application of the SMAP model to the GrIS snowpack was evaluated based on the snow temperature profile, snow surface temperature, surface snow grain size, and shortwave albedo, all of which the model simulated reasonably well. Above all, the fact that the SMAP model successfully reproduced frequently observed rapid increases in snow albedo under cloudy conditions highlights the advantage of the physically based snow albedo model (PBSAM) incorporated in the SMAP model. Using such data and model, we estimated the SEB at SIGMA-A from 30 June to 14 July 2012. Radiation-related fluxes were obtained from in situ measurements, whereas other fluxes were calculated with the SMAP model. By examining the components of the SEB, we determined that low-level clouds accompanied by a significant temperature increase played an important role in the melt event observed at SIGMA-A. These conditions induced a remarkable surface heating via cloud radiative forcing in the polar region.

Citation: Niwano, M., Aoki, T., Matoba, S., Yamaguchi, S., Tanikawa, T., Kuchiki, K., and Motoyama, H.: Numerical simulation of extreme snowmelt observed at the SIGMA-A site, northwest Greenland, during summer 2012, The Cryosphere, 9, 971-988, https://doi.org/10.5194/tc-9-971-2015, 2015.
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Short summary
A physical snowpack model SMAP and in situ meteorological and snow data obtained at site SIGMA-A on the northwest Greenland ice sheet are used to assess surface energy balance during the extreme near-surface snowmelt event around 12 July 2012. We determined that the main factor for the melt event observed at the SIGMA-A site was low-level clouds accompanied by a significant temperature increase, which induced surface heating via cloud radiative forcing in the polar region.
A physical snowpack model SMAP and in situ meteorological and snow data obtained at site SIGMA-A...
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