|Titre||Variability and change in the Canadian Cryosphere
|Auteur||Derksen, C; Smith, S L; Sharp, M; Howell, S; Mueller, D; Copland, L; Gautier, Y; Fletcher, C; Walker, A|
|Source||Program and abstracts, International Polar Year (IPY) 2012 conference; par IPY 2012 Committee; 2012 p. 1|
|Séries alt.||Secteur des sciences de la Terre, Contribution externe 20110193|
|Réunion||International Polar Year (IPY) 2012 Conference - From Knowledge to Action; Montréal; CA; avril 22-27, 2012|
|Media||en ligne; numérique|
|Province||Colombie-Britannique; Alberta; Saskatchewan; Manitoba; Ontario; Québec; Nouveau-Brunswick; Nouvelle-Écosse; Île-du-Prince-Édouard; Terre-Neuve-et-Labrador; Territoires du Nord-Ouest; Yukon;
|SNRC||1; 2; 3; 10; 11; 12; 13; 14; 15; 16; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48; 49; 52; 53; 54; 55; 56; 57; 58; 59; 62; 63; 64; 65;
66; 67; 68; 69; 72; 73; 74; 75; 76; 77; 78; 79; 82; 83; 84; 85; 86; 87; 88; 89; 92; 93; 94; 95; 96; 97; 98; 99; 102; 103; 104; 105; 106; 107; 114O; 114P; 115; 116; 117; 120; 340; 560|
|Lat/Long OENS||-141.0000 -50.0000 90.0000 41.7500|
|Sujets||effets climatiques; climat arctique; fluctuations climatiques; températures au sol; temperature; pergélisol; géologie de l'environnement; géologie des dépôts meubles/géomorphologie|
|Programme||Gestionn aire de programme - sciences de changements climatiques, Géosciences de changements climatiques|
|Liens||IPY 2012 |
|Résumé||(disponible en anglais seulement)|
Through its influence on the surface energy balance of the Earth, and on moisture and gas (including greenhouse gas) fluxes within the Earth system, the polar
cryosphere plays an important role in Arctic and global climate, ocean circulation, and freshwater hydrological systems. During the International Polar Year, Canadian cryospheric scientists conducted comprehensive observational research programs
aimed at increasing our understanding of the Canadian polar cryosphere response to a changing climate. Cryospheric components considered were snow, permafrost, sea ice, freshwater ice, glaciers and ice shelves. Enhancement of conventional observing
systems and retrieval algorithms for satellite measurements facilitated development of a snapshot of current cryospheric conditions, providing a baseline against which future change can be assessed. Key findings include that:
1. a consistent
response to warming air temperatures at the surface and in the lower troposphere is evident through the analysis of longer-term cryospheric data sets. The pan-Arctic, pan-cryosphere response to spring temperature anomalies underscore the close
relationship between the cryosphere and surface air temperatures over the Arctic region in June when albedo feedback potential is at a maximum.
2. the IPY period marked an acceleration of trends observed over the previous decades including warming
permafrost, reduction in snow cover extent and duration, reduction in summer sea ice extent, increased mass loss from glaciers, and thinning and break-up of the remaining Canadian ice shelves. These changes illustrate both a reduction in the spatial
extent and mass of the cryosphere (such as sea ice area/volume and negative glacier mass balance) as well as an increase in the temporal persistence of melt related parameters.
3. the strength of the snow-albedo feedback (SAF), as determined from
a suite of global climate model simulations, is an excellent predictor of SAF strength under climate change. Model simulations also projected an earlier lake ice break-up date by up to 25 days, with a reduction in mean ice thickness of up to 40
4. the observed changes in the cryosphere have important implications for human activity including the vulnerability of northern residents and their traditional lifestyles, access to northern regions for natural resource development, and the
integrity of northern infrastructure.
Sustained efforts to comprehensively observe all elements of the cryosphere are necessary to understand the response to a changing global climate system, understand how these changes will affect
terrestrial and marine ecosystems, and reduce the vulnerability of northern residents and northern development to climate-induced uncertainty.