GEOSCAN, résultats de la recherche


TitreVariability and change in the Canadian Cryosphere
AuteurDerksen, C; Smith, S L; Sharp, M; Howell, S; Mueller, D; Copland, L; Gautier, Y; Fletcher, C; Walker, A
SourceProgram and abstracts, International Polar Year (IPY) 2012 conference; par IPY 2012 Committee; 2012 p. 1
LiensIPY 2012
Séries alt.Secteur des sciences de la Terre, Contribution externe 20110193
RéunionInternational Polar Year (IPY) 2012 Conference - From Knowledge to Action; Montréal; CA; avril 22-27, 2012
Mediaen ligne; numérique
ProvinceColombie-Britannique; Alberta; Saskatchewan; Manitoba; Ontario; Québec; Nouveau-Brunswick; Nouvelle-Écosse; Île-du-Prince-Édouard; Terre-Neuve-et-Labrador; Territoires du Nord-Ouest; Yukon; Nunavut
SNRC1; 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
Sujetseffets climatiques; climat arctique; fluctuations climatiques; températures au sol; temperature; pergélisol; géologie de l'environnement; géologie des dépôts meubles/géomorphologie; Nature et environnement
ProgrammeGestionaire de programme - sciences de changements climatiques, Géosciences de changements climatiques
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 cm.
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.