scholarly journals Supplementary material to "Characterization of Canadian High Arctic glacier surface albedo from MODIS C6 data, 2001–2016"

Author(s):  
Colleen A. Mortimer ◽  
Martin Sharp
2017 ◽  
Author(s):  
Colleen A. Mortimer ◽  
Martin Sharp

Abstract. Inter-annual variations and longer-term trends in the annual mass balance of glaciers in Canada's Queen Elizabeth Islands (QEI) are largely attributable to changes in summer melt. The largest source of melt energy in the QEI in summer is net shortwave radiation, which is modulated by changes in glacier surface albedo. We used measurements from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors to investigate large scale spatial patterns and temporal trends and variability in the summer surface albedo of QEI glaciers and their relationship to observed changes in glacier surface temperature from 2001 to 2016. Mean summer black-sky shortwave broadband albedo (BSA) decreased at a rate of 0.029 ± 0.025 decade-1 over that period. Larger reductions in BSA occurred in July (−0.050 ± 0.031 decade-1). No change in BSA was observed in either June or August. Most of the decrease in BSA, which was greatest at lower elevations around the margins of the ice masses, occurred between 2007 and 2012 when mean summer BSA was anomalously low. The First Principal Component of the 16-year record of mean summer BSA was well correlated with the mean summer North Atlantic Oscillation Index, except in 2006, 2010, and 2016. During this 16-year period, the mean summer LST increased by 0.046 ± 0.036 °C yr-1 and the BSA record was negatively correlated (−0.64, p 


2017 ◽  
Author(s):  
Franziska Köllner ◽  
Johannes Schneider ◽  
Megan D. Willis ◽  
Thomas Klimach ◽  
Frank Helleis ◽  
...  

2016 ◽  
Author(s):  
Dan Weaver ◽  
Kimberly Strong ◽  
Matthias Schneider ◽  
Penny M. Rowe ◽  
Chris Sioris ◽  
...  

2009 ◽  
Vol 6 (1) ◽  
pp. 2697-2721 ◽  
Author(s):  
M. Stibal ◽  
A. M. Anesio ◽  
C. J. D. Blues ◽  
M. Tranter

Abstract. Arctic glacier surfaces harbor abundant microbial communities consisting mainly of heterotrophic and photoautotrophic bacteria. The microbes must cope with very low concentrations of nutrients and with the fact that both the dissolved and debris-bound nutrient pools are dominated by organic phases. Here we provide evidence that phosphorus (P) is deficient and limiting in the supraglacial environment on a Svalbard glacier, we show how the microbial community responds to the P stress and we quantify the contribution of the microbes to the cycling of the dominant organic P in the supraglacial environment. Incubation of cryoconite debris revealed significant phosphatase activity in the samples (19–67 nmol MUP g−1 h−1), which was controlled by the concentration of inorganic P during incubations and had its optimum at around 30°C. The phosphatase activity rates measured at near-in situ temperature and substrate concentration imply that the available dissolved organic P can be turned over by microbes within ~3–11 h on the glacier surface. By contrast, the amount of potentially bioavailable debris-bound organic P is sufficient for a whole ablation season. However, it is apparent that some of this potentially bioavailable debris-bound P is not accessible to the microbes.


2016 ◽  
Vol 7 ◽  
Author(s):  
Sara M. E. Rassner ◽  
Alexandre M. Anesio ◽  
Susan E. Girdwood ◽  
Katherina Hell ◽  
Jarishma K. Gokul ◽  
...  

Polar Biology ◽  
2015 ◽  
Vol 38 (12) ◽  
pp. 1983-1992 ◽  
Author(s):  
Melissa P. Galicia ◽  
Gregory W. Thiemann ◽  
Markus G. Dyck ◽  
Steven H. Ferguson

Sign in / Sign up

Export Citation Format

Share Document