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TitrePaleoclimatological assessment of the central Northwest Territories and implications for the long-term viability of the Tibbitt to Contwoyto winter ice road: a project overview
AuteurPatterson, R T; Clark, I A; Crann, C; Falck, H; Galloway, J M; Gammon, P R; Griffith, F; Macumber, A L; Muise, P; Mullan, D J; Pisaric, M F J; Roe, H M; Sulphur, K C; Swindles, G T; Upiter, L M; Vermaire, J C
SourceNorthwest Territories Geoscience Office, Yellowknife Geoscience Forum Abstracts Volume 2013, 2013 p. 1
Année2013
Séries alt.Secteur des sciences de la Terre, Contribution externe 20130443
Réunion41st Annual Yellowknife Geoscience Forum; Yellowknife; CA; Novembre 19-21, 2013
Documentpublication en série
Lang.anglais
Mediapapier; en ligne; numérique
Formatspdf
ProvinceTerritoires du Nord-Ouest
SNRC76D; 85I; 85P
Lat/Long OENS-114.0000 -109.0000 65.0000 62.0000
Sujetspaléoclimats; Holocène; sensitivité de terrain; Changement climatique; paléontologie; géologie de l'environnement; Cénozoïque; Quaternaire
Programmeadaptation et impacts sur l'environnement, environnement du nord, Géosciences de l'environnement
LiensOnline - En ligne
Résumé(disponible en anglais seulement)
Our multi-disciplinary research on a series of cores collected along, and adjacent to, the length of the TCWR was mandated to provide high-resolution information on climate variability and its affects on aquatic and terrestrial environments in the central NWT and NU. Our methodology has permitted us to recognize cycles and trends that have impacted climate change at annual to centennial scales through not only the mandated past 3500 years, but for much of the Holocene. In addition to analyzing the available instrumental record that exists from 1942 onward for the region, additional climate sensitive proxies utilized included dendrochronology (annual resolution), grain-size analysis (subdecadal resolution), chironomids (decadal resolution), isotopic analysis (decadal oscillation), diatoms (decadal resolution), palynology (decadal resolution), arcellaceans (decadal resolution). Through use of time series analysis techniques on our multi-proxy data set we have been able to determine that well-known teleconnections influenced by El Niño-Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO) and solar cycles, all influenced climate variability in this region. Their influence has been cyclic and has followed predictable patterns. The overarching influence has been solar cycles of varying period. These seem to have influenced the phase and magnitude of Pacific Decadal Oscillations, which in turn influence the penetration of ENSO events into the north. Solar peaks generally result in warmer conditions, particularly at northerly latitudes. In the past positive PDO¿s have been associated with warmer winters and negative PDO¿s cooler winter conditions. For example, following the great PDO regime shift of 1976-77 there was a significant step-wise increase in winter temperatures in the NWT. El Niño events coupled with PDO+ events generally result in particularly warm winters.
With the recent shift to PDO- conditions and a projection of very weak solar activity in the next decades winter conditions should be colder than in recent years resulting in conditions ideal for construction of ice roads. Possibly offsetting this cooling trend is the potential impact of increased atmospheric CO2 on regional climate. An ensemble of global circulation models using the statistical down-scaling approach have been developed by members of our team, which suggest that the observed increased CO2 levels may have overarching implications for the long-term viability of the TCWR. Our results will be of interest to stakeholders (e.g., industry, government, non-government organizations, and First Nations groups) as they strive to strategically manage northern ecosystem and to inform policy makers and planners of potential climatic conditions that may prevail in the coming decades.
Résumé(Résumé en langage clair et simple, non publié)
Nous avons étudié les indicateurs biotiques, physiques et chimiques du changement environnemental de l'Holocène préservés dans les sédiments des lacs situés le long du gradient latitudinal de la route d'hiver qui relie Tibbitt à Contwoyto, la seule route terrestre qui dessert les mines dans la province géologique des Esclaves, riche en minéraux. Notre intégration des analyses à haute résolution de la dendrochronologie, de la taille des particules des sédiments, des chironomidés, des isotopes, des diatomées, de la palynologie et des Arcellinida nous a permis d'observer des cycles et des tendances qui se sont répercutés sur le changement climatique à l'échelle de l'année ou du siècle pendant la plus grande partie des 9 000 dernières années. L'analyse des séries chronologiques, nous avons déterminé que des téléconnexions bien connues influencées par le phénomène El Niño-oscillation australe (ENSO), l'Oscillation décennale du Pacifique et les cycles solaires se sont répercutées sur la variabilité climatique dans le centre des Territoires du Nord-Ouest. Les cycles solaires semblent avoir influencé la phase et l'ampleur de l'Oscillation décennale du Pacifique qui, elle, a influencé la pénétration des événements ENSO. Les pics d'activité solaire se sont généralement traduits par un réchauffement, en particulier sous les latitudes nordiques.
GEOSCAN ID293586