Snow cover evolution, on 2009-2014, at the Limnopolar Lake CALM-S site on Byers Peninsula, Livingston Island, Antarctica.

Abstract In February 2009, a new Circumpolar Active Layer Monitoring (CALM) site was established in the Limnopolar Lake drainage basin, in Byers Peninsula, Livingston Island (South Shetland Archipelago), Antarctica (62°38′59.1″S, 61°06′16.9″W). The first results from active layer thickness and thermal monitoring reported interannual variations, without relevant changes in the air temperature conditions, leaving the snow cover as the most suitable agent controlling the reported changes. Here we study in detail the snow cover evolution on thickness, timing and duration during the 2009–2014 period, by the analysis of mean daily air and ground surface temperature, as well as the snow depth monitored in a stake. Freezing indexes, n-factor, and snow indexes calculations were analyzed to establish the effects of snow cover on the ground thermal regime. The evolution of the snow cover during the 2009–2014 period resulted in about similar snow depths, with mean values of about 45 cm. The snow onset remained about constant with small variations of 10 days in early March. However, the snow offset had significant variations, increasing in more than 60 days in the last three years. This delay on the snow offset resulted in an increase in the snow cover duration from 267 (2011) to 338 (2014) days. Air temperature seems not to be strongly involved in this snow cover timing variation since the highest variation on this period of the maximum and mean annual temperatures only diminished, about 1.6° and 0.5° C respectively, but remaining constant the minimum temperatures (between − 12° and − 18 °C). In consequence, the surface temperature evolved to become less variable along the year directly related to the annual snow layer duration, trending to longer zero curtain periods. In conclusion, the increase in the snow duration is resulting in a reduction of the thaw period in the ground, but remaining similar snow cover onset dates. The consequent decrease in the snow-free period each year could result in a thinner active layer.

[1]  F. Ling,et al.  Impact of the timing and duration of seasonal snow cover on the active layer and permafrost in the Alaskan Arctic , 2003 .

[2]  Knut Stamnes,et al.  Impact of climatic factors on the active layer and permafrost at Barrow, Alaska , 1998 .

[3]  Corinne Le Quéré,et al.  Climate Change 2013: The Physical Science Basis , 2013 .

[4]  A. Lewkowicz.  Evaluation of miniature temperature‐loggers to monitor snowpack evolution at mountain permafrost sites, northwestern Canada , 2008 .

[5]  D. Campbell,et al.  Temporal and spatial variation in active layer depth in the McMurdo Sound Region, Antarctica , 2009, Antarctic Science.

[6]  G. P. Kershaw,et al.  Snow Ecology: An Interdisciplinary Examination of Snow-Covered Ecosystems , 2002 .

[7]  G. Leshkevich,et al.  Summary of Great Lakes weather and ice conditions, winter 1976-77 , 1978 .

[8]  Jerry Brown,et al.  PHYSICAL AND THERMAL DISTURBANCE AND PROTECTION OF PERMAFROST , 1979 .

[9]  N. Sharkhuu,et al.  Effects of Climate Warming and Vegetation Cover on Permafrost of Mongolia , 2012 .

[10]  F. Nelson,et al.  The circumpolar active layer monitoring (calm) program: Research designs and initial results , 2000 .

[11]  Miguel Ramos,et al.  Climate warming and permafrost dynamics in the Antarctic Peninsula region , 2013 .

[12]  Thomas Schmid,et al.  Periglacial processes and landforms in the South Shetland Islands (northern Antarctic Peninsula region) , 2012 .

[13]  Orlando B. Andersland,et al.  An Introduction to Frozen Ground Engineering , 1994 .

[14]  T. Davis.  Permafrost: A guide to Frozen Ground in Transition , 2001 .

[15]  Mauro Guglielmin,et al.  Ground surface temperature (GST), active layer and permafrost monitoring in continental Antarctica , 2006 .

[16]  Yuri Shur,et al.  Patterns of permafrost formation and degradation in relation to climate and ecosystems , 2007 .

[17]  F. Ling,et al.  Sensitivity of ground thermal regime and surface energy fluxes to tundra snow density in northern Alaska , 2006 .

[18]  M. Guglielmin,et al.  Permafrost thermal regime from two 30‐m deep boreholes in southern victoria land, antarctica , 2011 .

[19]  Stephan Gruber,et al.  Scale-dependent measurement and analysis of ground surface temperature variability in alpine terrain , 2011 .

[20]  M. Guglielmin.  Advances in permafrost and periglacial research in Antarctica: A review , 2012 .

[21]  M. Woo,et al.  RESPONSE OF THE CANADIAN PERMAFROST ENVIRONMENT TO CLIMATIC CHANGE , 1992 .

[22]  M. Smith,et al.  Climate and the limits of permafrost: a zonal analysis , 2002 .

[23]  M. Guglielmin,et al.  Influence of vegetation on the ground thermal regime in continental Antarctica , 2009 .

[24]  Mauro Guglielmin,et al.  Permafrost warming and vegetation changes in continental Antarctica , 2014 .

[25]  N. Matsuoka,et al.  Monitoring periglacial processes: Towards construction of a global network , 2006 .

[26]  Kenneth M. Hinkel,et al.  The N-factor in Natural Landscapes: Variability of Air and Soil-Surface Temperatures, Kuparuk River Basin, Alaska, U.S.A. , 2001 .

[27]  V. Romanovsky,et al.  Past and recent changes in air and permafrost temperatures in eastern Siberia , 2007 .

[28]  M. Ramos,et al.  Thermal characterization of the active layer at the Limnopolar Lake CALM-S site on Byers Peninsula (Livingston Island), Antarctica , 2014 .

[29]  P. Convey,et al.  Permafrost and snow monitoring at Rothera Point (Adelaide Island, Maritime Antarctica): Implications for rock weathering in cryotic conditions , 2014 .

[30]  Ole Humlum,et al.  Monitoring periglacial processes: new methodology and technology , 2003 .

[31]  Peter J. Williams,et al.  Pipelines and Permafrost: Science in a Cold Climate , 1986 .

[32]  D. Dixon,et al.  Recent climate and ice-sheet changes in West Antarctica compared with the past 2,000 years , 2013 .

[33]  M. Guglielmin,et al.  Permafrost and periglacial research in Antarctica: New results and perspectives , 2014 .

[34]  R. Assel.  Maximum Freezing Degree-Days as a Winter Severity Index for the Great Lakes, 1897–1977 , 1980 .

[35]  Observations on permafrost ground thermal regimes from Antarctica and the Italian Alps, and their relevance to global climate change , 2004 .

[36]  Lawson W. Brigham,et al.  Climate Change, Permafrost, and Impacts on Civil Infrastructure , 2003 .

[37]  Hugh M. French,et al.  The Periglacial Environment , 1977 .

[38]  J. Turner,et al.  Antarctic climate change during the last 50 years , 2005 .

[39]  D. Walker,et al.  The n‐factor of nonsorted circles along a climate gradient in Arctic Alaska , 2006 .

[40]  F. Hrbáček,et al.  Effect of Snow Cover on the Active‐Layer Thermal Regime – A Case Study from James Ross Island, Antarctic Peninsula , 2016 .

[41]  R. J. E. Brown,et al.  Distribution of permafrost in North America and its relationship to the environment; A review, 1963-1973 , 1973 .

[42]  L. Dyke,et al.  The physical environment of the Mackenzie Valley, Northwest Territories: a base line for the assessment of environmental change , 2000 .

[43]  L. Ravanel,et al.  Hazards related to permafrost and to permafrost degradation , 2011 .

[44]  C. Burn,et al.  The Thermal Regime, including a Reversed Thermal Offset, of Arid Permafrost Sites with Variations in Vegetation Cover Density, Wudaoliang Basin, Qinghai‐Tibet Plateau , 2015 .

[45]  L. Hinzman,et al.  Vegetation‐soil‐thaw‐depth relationships along a low‐arctic bioclimate gradient, Alaska: synthesis of information from the ATLAS studies , 2003 .

[46]  Howard E. Epstein,et al.  The thermoinsulation effect of snow cover within a climate model , 2008 .

[47]  Tingjun Zhang.  Influence of the seasonal snow cover on the ground thermal regime: An overview , 2005 .

[48]  B. Gądek,et al.  Influence of snow cover on ground surface temperature in the zone of sporadic permafrost, Tatra Mountains, Poland and Slovakia , 2010 .

[49]  M. Guglielmin,et al.  Spatial and temporal variability of ground surface temperature and active layer thickness at the margin of maritime Antarctica, Signy Island , 2012 .

[50]  Knut Stamnes,et al.  Effects of Climate on the Active Layer and Permafrost on the North Slope of Alaska, U.S.A. , 1997 .

[51]  David S. Hik,et al.  Responses of white spruce (Picea glauca) to experimental warming at a subarctic alpine treeline , 2007 .

[52]  M. Guglielmin,et al.  Interactions between climate, vegetation and the active layer in soils at two Maritime Antarctic sites , 2006, Antarctic Science.

[53]  F. Nelson,et al.  The Circumpolar Active Layer Monitoring (CALM) Workshop and THE CALM II Program , 2004 .

[54]  F. Chapin,et al.  Role of Land-Surface Changes in Arctic Summer Warming , 2005, Science.

[55]  M. Ramos,et al.  Interannual active layer variability at the Limnopolar Lake CALM site on Byers Peninsula, Livingston Island, Antarctica , 2013, Antarctic Science.

[56]  M. Guglielmin,et al.  A permafrost warming in a cooling Antarctica? , 2012, Climatic Change.

[57]  Miguel Ramos,et al.  Active layer dynamics in three topographically distinct lake catchments in Byers Peninsula (Livingston Island, Antarctica) , 2017 .

[58]  L. E. Goodrich,et al.  The influence of snow cover on the ground thermal regime , 1982 .

[59]  M. Guglielmin,et al.  Active layer thermal regime under different vegetation conditions in permafrost areas. A case study at Signy Island (Maritime Antarctica) , 2008 .

[60]  Miguel Ramos,et al.  Thermal state of permafrost and active‐layer monitoring in the antarctic: Advances during the international polar year 2007–2009 , 2010 .

[61]  Roger G. Barry,et al.  Spatial and temporal variability in active layer thickness over the Russian Arctic drainage basin , 2005 .

[62]  Sharon L. Smith,et al.  Climate and ground temperature relations at sites across the continuous and discontinuous , 2012 .