| Creator |
N. Steiner, K. Azetsu-Scott, P. Galbraith, J. Hamilton, K. Hedges, X. Hu, M. Y. Janjua, N. Lambert, P. Larouche, D. Lavoie, J. Loder, H. Melling, A. Merzouk, P. G. Myers, W. Perrie, I. Peterson, R. Pettipas, M. Scarratt, T. Sou, M. Starr, R. F. Tallmann and A. van der Baaren |
| Summary |
Within the Aquatic Climate Change Adaptation Services Program (ACCASP), past trends and
future projections of key climatic variables such as air and water temperature, precipitation,
winds and storms, sea ice and biogeochemical variables are assessed. The assessment forms the
basis for the impact, vulnerabilities, and opportunities analysis needed to increase our
understanding of the impacts of climate change on the marine ecosystem and departmental
operations and enable adaptation in support of DFO’s strategic outcomes. This report
summarizes observed trends and projections on a 50-year timescale for the Arctic region,
including the four marine basins of the Beaufort Sea, Canadian Polar Shelf, Baffin Bay/Davis
Strait and Hudson Bay as well as the predominately terrestrial Mackenzie Basin. To evaluate
past trends, national and international data archives (which include land-based station data and
cruise data) as well as publications, reports, and earlier assessments have been used. Limited
observations in the Arctic, especially for ecosystem variables, lead to significant gaps and
limitations in the assessment. Future projections are mostly derived from global models, which
give a general tendency and range of expected future changes, but lack local details. Most
regional modelling efforts are limited to the atmosphere. Those have been included for higher
resolution projections of air temperature, precipitation and wind. Only a few models are
available on the aquatic basin scale that simulate ocean properties and sea ice. The main
outcomes of the assessment show significant increases in air temperature (0 - 3ºC in summer and
3 – 7ºC in winter over the next 50 years), a slight increase in precipitation and snow depth as
well as an intensification in extreme events (hot spells, extreme precipitation). With respect to
atmospheric circulation patterns, appreciable changes have been observed. Projections suggest
an increase in storm strength and size (storm surges and coastal erosion) as well as a slight
increase in wave heights with only small changes in windspeed. An Arctic-wide decrease in the
extent of multi-year ice has been observed, together with an increase in ice-free waters in
summer (longer time periods and larger areas). These observed sea ice trends are projected to
continue into the future. It can be anticipated that the longer open water period will allow wind and
storms to have a greater impact on the coast, i.e. erosion. Limited observations of ocean properties
show local freshening (e.g. Beaufort Sea) and summer warming (e.g. Baffin Bay). These trends
are projected to continue along with localized strengthening in stratification. Increased ocean
acidification has been observed and is projected to continue throughout the Canadian Arctic,
leading to decreased saturation states of calcium carbonate (aragonite and calcite). Within the
Mackenzie Basin, increased lake temperatures and stratification, as well as later freeze/earlier
break-up dates have been observed and are projected for lakes. A widespread warming of
terrestrial permafrost and thickening of the permafrost active layer has been observed, as well as
a slow warming of sub-sea permafrost. Again, this pattern is likely to continue in the future.
Changes expected for the next 10 years may in some cases be proportional to the 50-year
projections. However, in most instances, natural intra-decadal variability is expected to be at
least as important as the overall trends during the next decade. A continuation of the past
decade’s trends is expected in the case of ocean acidity, surface air temperature, multi-year ice
extent, first-year ice characteristics, storm waves, and permafrost. The assessment concludes that to improve our capability to assess and project climate change adaptation in aquatic
ecosystems, more consistent data sets are needed, especially over marine areas and for
biogeochemical variables. Higher resolution basin-scale ocean ecosystem models are also
required to provide locally applicable projections relevant for Arctic communities and DFO
management. |
| Local Relevance |
This report summarizes observed trends and projections on a 50-year timescale for the Arctic, including large parts of the NWT such as the Beaufort Sea and the Mackenzie River Basin. |
| Notes |
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| Tags |
Marine,Ocean,Trends,Projections,Beaufort Sea,Canadian Polar Shelf,Baffin Bay,Davis Strait,Hudson Bay,Mackenzie River Basin |
| Geographic Region |
NWT |
| Release Date |
2013-01-01 |
| Last Modified Date |
2013-01-01 |
| Funding Program |
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