|Title||Paleoclimatological assessment of the central Northwest Territories and implications for the long-term viability of the Tibbitt to Contwoyto winter ice road: a project overview|
|Author||Patterson, 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,
|Source||Northwest Territories Geoscience Office, Yellowknife Geoscience Forum Abstracts Volume 2013, 2013 p. 1 (Open Access)|
|Links||Online - En ligne|
|Alt Series||Earth Sciences Sector, Contribution Series 20130443|
|Meeting||41st Annual Yellowknife Geoscience Forum; Yellowknife; CA; November 19-21, 2013|
|Media||paper; on-line; digital|
|NTS||76D; 85I; 85P|
|Area||Tibbitt Lake; Contwoyto Lake|
|Lat/Long WENS||-114.0000 -109.0000 65.0000 62.0000|
|Subjects||paleontology; environmental geology; Nature and Environment; paleoclimates; Holocene; terrain sensitivity; climate change; Cenozoic; Quaternary|
|Program||Environmental Geoscience, environmental
impacts and adaptation in the northern environment|
|Abstract||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.
|Summary||(Plain Language Summary, not published)|
We studied biotic, physical, and chemical proxies of Holocene environmental change preserved in sediments of lakes located along the latitudinal gradient
of the Tibbitt to Contwoyto Winter Road, the sole overland route servicing mines in the mineral-rich Slave Geological Province. Our integration of high-resolution analyses of dendrochronology, sedimentary particle size, chironomids, isotopes,
diatoms, palynology, and arcellaceans has permitted recognition of cycles and trends that have impacted climate change at annual to centennial-scales for much of past 9000 years. With time series analysis on our multi-proxy dataset we determine that
well-known teleconnections influenced by the El Niño-Southern Oscillation (ENSO), the Pacific Decadal Oscillation, and solar cycles have impacted climate variability in the central Northwest Territories. Solar cycles appear to have influenced the
phase and magnitude of the Pacific Decadal Oscillation which in turn influence the penetration of ENSO events. Solar peaks generally resulted in warmer conditions, particular in northern latitudes.