Snowpack observations from a circumnavigation of the Greenland Ice Sheet (spring 2014).

J. I. López Moreno, M. Olivera-Marañón, J. Zabalza, R. H. de Larramendi

Abstract


We report the characteristics of the Greenland ice sheet snowpack, based on data collected during the first wind-propelled circumnavigation of the ice sheet, undertaken in spring 2014. The dataset included snow depth measurements made in 100 m2 plots, and data on the snow bulk density and snowpack temperature at 1 m depth at 25 sites distributed along the 4301 km route traveled during the 49 days of the circumnavigation. In addition, eight snow pits of 1 m depth were dug to measure the snow temperature and density at 10 cm intervals in the upper layer of the snowpack. All this information may help to better understand snow characteristics on this remote area, and provide data to validate and calibrate atmospheric and cryospheric models.

Snow depths exceeding 4 m were measured in the snow accumulation area, but in many cases the presence of an ice layer prevented penetration of the snow probe below 70 cm depth. This ice layer may be associated with the melting event that occurred in July 2012, and affected 98% of the ice sheet. Beyond the main snow accumulation zone, very constant snow depth values of approximately 1.5 m were measured. The snow temperature at 1 m depth generally ranged from –20°C to –10°C, and was highly correlated with the average atmospheric temperature during the 15 days prior to the snow temperature measurements. The snow bulk density was relatively homogeneous at the majority of sampling sites, ranging from 320 to 390 kg m–3. The snow temperature and density profiles measured in the snow pits indicated that the snowpack became progressively colder from the surface to 1 m depth. The temperature gradient measured in the snow pits was particularly steep (shallow) at the warmest (coldest) sampling sites. The snow density was characterized by denser snow at 60–80 cm depth, coinciding with the depth of the ice layer identified when depth was measured. A dense layer was also found close to the surface at the warmest snow pit sites, and it is likely that this corresponds to a more recent snow melt event.


Keywords


Greenland ice sheet; snow; snow density and temperature; snow pits

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References


Arctic Report Card: Update for 2014. http://www.arctic.noaa.gov/reportcard.

Bales, R.C., Mosley-Thompson, E., McConnell, J.R. 2001. Variability of accumulation in northwest Greenland over the past 250 years. Geophysical Research Letters 28 (14), 2679-2682.

Birger, U., Hansen, B., Elberling, N., Humlum, O., Nielsen, N. 2006. Meteorological trends (1991–2004) at Arctic Station, Central West Greenland (69°15'N) in a 130 years perspective. Geografisk Tidsskrift-Danish Journal of Geography 106 (1), 45-55. Doi: 10.1080/00167223.2006.10649544

Castellani, B.B., Shupe, M.D., Hudak, D.R., Sheppard, B.E. 2015. The annual cycle of snowfall at Summit, Greenland. Journal of Geophysical Research, Atmosphere 120 (13), 6654-6668. Doi: 10.1002/2015JD023072

Church, J.A., Gregory, J.M., Huybrechts, P., Kuhn, M., Lambeck, C., Nhuan, M.T., Qin, D., Woodworth, P.L. 2001: Changes in sea level. In: J.T Houghton, Y. Ding, D.J. Griggs, M. Noguer, P.J. Van der Linden, X. Dai, K. Maskell, C.A. Johnson (eds.), Climate Change 2001: The Scientific Basis: Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press (Cambridge, New York), 639-694.

Dibb, J. E., Fahnestock, M. 2004. Snow accumulation, surface height change, and firn densification at Summit, Greenland: Insights from 2 years of in situ observation. Journal of Geophysical Research 109, D24113. Doi:10.1029/2003JD004300

Fettweis, X., Tedesco, M., van den Broeke, M., Ettema, J. 2011 Melting trends over the Greenland ice sheet (1958–2009) from spaceborne microwave data and regional climate models. The Cryosphere 5, 359–375. Doi:10.5194/tc-5-359-2011

Fassnacht, S.R., Heun, C.M., López-Moreno, J.I., Latron J. 2010. Variability of snow density measurements in the Esera valley, Pyrenees mountains, Spain. Cuadernos de Investigación Geográfica 36 (1), 59-72.

Hansen, B.U., Elberling, B., Humlum, O., Nielsen, N. 2006. Meteorological trends (1991–2004) at Arctic Station, Central West Greenland (69°15'N) in a 130 years perspective. Geografisk Tidsskrift-Danish Journal of Geography 160 (1), 45-55.

Højlund Pedersen, S., Liston, G.E, Tamstorf MP, Westergaard-Nielsen A, Schmidt N.M. 2015. Quantifying episodic snowmelt events in Arctic ecosystems. Ecosystems, Doi: 10.1007/s10021-015-9867-8.

López Moreno, J.I., Fassnacht, S.R., Beguería, S., Latron, J. 2011. Variability of snow depth at the plot scale: implications for mean depth estimation and sampling strategies. The Cryosphere 5, 617-629.

López-Moreno, J.I., Fassnacht, S., Latron, J., Musselman, K., Morán-Tejeda, E., Jonas, T. 2013 Small scale spatial variability of snow density and depth over complex alpine terrain: implications for estimating snow water equivalent. Advances in Water Research 55, 40-52.

Morris, E.M., Wingham, D.J. 2014 Densification of polar snow: Measurements, modeling, and implications for altimetry. Journal of Geophysical Research, Earth Surface 119, 349–365. Doi: 10.1002/2013JF002898

Nghiem, S.V., Steffen, K., Neumann, G., Huff, R. 2005. Mapping of ice layer extent and snow accumulation in the percolation zone of the Greenland ice sheet. Journal of Geophysical Research 110, F02017. Doi:10.1029/2004JF000234

Shuman, N.E. DiGirolamo, L., Neumann, G. 2012. The extreme melt across the Greenland ice sheet in 2012. Geophysical Research Letters 39, L20502. Doi: 10.1029/2012GL053611

Shen, D., Liu,Y., Huang, S. 2012. Annual accumulation over the Greenland ice sheet interpolated from historical and newly compiled observation data. Geografiska Annaler, Series A, Physical Geography 94, 377-393.

Shupe, D. R. Hudak, L., Sheppard, B.E. 2015. The annual cycle of snowfall at Summit, Greenland. Journal of Geophysical Research Atmosphere 120, 6654–6668. Doi:10.1002/2015JD023072

Tedesco, M., Serreze, M., Fettweis, X. 2008. Diagnosing the extreme surface melt event over southwestern Greenland in 2007. The Cryosphere 2, 159–166. Doi:10.5194/tc-2-159-2008.

Wang, L., Sharp, M. Rivard, B., Steffen, K. 2007. Melt season duration and ice layer formation on the Greenland ice sheet, 2000–2004. Journal of Geophysical Research 112, F04013. Doi:10.1029/2007JF000760

Zwally, H.J., Giovinetto, M., Li, J. Cornejo, H., Beckley, M., Brenner, A., Saba, J., Yi, D. 2005. Mass changes of the Greenland and Antarctic ice sheets and shelves and contributions to sea-level rise: 1992 – 2002. Journal of Glaciology 51, 509-527.




DOI: http://dx.doi.org/10.18172/cig.2938

© Universidad de La Rioja, 2013

ISSN 0211-6820

EISSN 1697-9540