A Major Initiative for the Investigation of

Meteorological Hazards in the Canadian Arctic

This project is concerned with the documentation, better understanding and prediction of meteorological and related hazards in the Arctic including their modification by local topography and land-sea transitions, their impact on the local communities, and an assessment as to whether these hazards will change with the climate.

To make progress on these critical issues, the proposed project will focus on extreme weather events in Nunavut .  The overall objective of this 5-year Major Initiative is:

To better understand severe Arctic storms, their associated hazardous conditions, and their potential change.

As a further focus, most of the special measurements will be made in the vicinity of Iqaluit although analyses will consider storms affecting other communities (in particular Rankin Inlet).  Iqaluit is considered as being representative of other coastal communities and Rankin Inlet, although on the coast, is predominantly subjected to continental climatic conditions.

This objective will be realized through a focus on three themes:

1.      Physical features of Arctic storms and extreme weather events and the identification of hazards

2.      Processes and feedbacks leading to such extremes

3.      Change in frequency, magnitude and location of such hazards under changing climatic conditions

More specifically, the main hazards we will investigate are:

1. Blizzards, blowing snow, severe wind chill and reduced visibility
2. Storms producing snow and mixed phase precipitation with significant accumulation

3. Storms, strong winds and their impact on sea ice

This objective will be realized through key tasks including:

1.      To assemble relevant datasets and assess observational and modelling capabilities with a particular focus being on the conduct of a major field experiment

2.      To determine the physical factors that generate hazardous Arctic storms

3.      To improve the simulation and prediction of such storms

4.      To better asses the likelihood of changes in the occurrence of such storms in the future

This 5-year plan represents an essential step towards our long-term goals which are:

1.      To better understand and predict atmospheric-related extremes in the Arctic

2.      To better assess whether the intensity and frequency of such extremes will change in the future

SCIENTIFIC RATIONALE

There are numerous atmospheric-related extremes in the Arctic .  These include harsh temperatures, strong winds, heavy precipitation, blowing snow, low visibility, freezing rain, and lightning.  Such extremes also produce major impacts on sea ice behaviour and can generate storm surges.  They also produce hardship on a daily scale and there is concern that they may become more frequent in the future.

Although predictions of extreme events are improving, there are still numerous issues that need to be addressed.  Our knowledge, technology and numerical guidance must be integrated to best predict hazardous wind and precipitation events over the complex Arctic terrain.  Special attention is needed for wind which, in the winter, leads to life threatening wind chill and blizzards, and, in the summer, to devastating impacts on small water craft.  A closely related issue is a blizzard, either associated with fresh snow or with clear-sky conditions.  Precipitation is an ongoing challenge and GEM model guidance is used to help predict, for example, mixed rain/snow and snow/rain events during the transition seasons.  The verification of such predictions is difficult because of the scarcity of data.  Lastly, a better understanding is needed of the location and influence of various moisture sources on fog and low level stratus cloud formation.  Collectively, these outstanding issues all point to the need for an improved understanding of the interaction between weather systems and the highly variable surface including nearby ocean and sea ice conditions and the need for more information. 

Our changing climate is also linked closely with extremes.  Recent model scenarios predict that globally averaged surface temperature will increase by approximately 1.4-5.8ºC over the period from 1990 to 2100.  Such simulations also indicate that these impacts will start in the Arctic where warming will be most intense. Climate change in the Arctic will have tremendous environmental, socio-economic and strategic consequences.  There is particular concern that the frequency, magnitude and location of weather extremes in the Arctic will change significantly in the future and Inuit observations indicate that this is already happening, with changes being most dramatic since the 1990s.  This includes, for example, temperature extremes, strong winds, storm surges, unusual ice conditions, heavy precipitation, blowing snow, freezing rain, and lightning.  It is expected that hazards may be more severe when occurring in certain sequences or seasons.

Because of the concern with a changing Arctic , ArcticNet was recently initiated in Canada as a new Network of Centres of Excellence.  The central objective of ArcticNet is "to develop impact assessments, national policies and strategies to help Northerners and northern governments and industries cope with the impacts associated with environmental and climate change.  Strategic objectives include building synergy between the natural, medical and social sciences; providing the research for decision- and policy-makers; contributing  to the training of the next generation of young scientists; and consolidating  international collaborations.”  Part of ArcticNet is concerned with meteorological-related extremes and their effects on local communities.

Despite the importance of Arctic meteorological-related extremes, only one field project has actually focused on them over Canada .  This occurred in 1994 within the Beaufort and Arctic Storms Experiment (BASE) and this effort only examined autumn storms in the southern Beaufort Sea and northern Mackenzie basin region.  Field projects focused on extremes in the Arctic are certainly called for.  Routine surface and upper air data are very sparse and no operational radars are present.  To adequately document and better understand such extremes, additional information must be a major consideration.   To complement ArcticNet activities with its focus on the central and eastern Arctic , the focus of our extremes studies will be on these regions as well.

Our focus will furthermore be on communities and in particular on Iqaluit and Rankin Inlet and their surrounding areas.  Differences in infrastructure and way of life between northern and southern communities lead to a more direct exposure of humans to extreme weather in the Arctic .  In addition, the dependence of people in the North on fishing and hunting makes them vulnerable to changing sea ice conditions and animal migration patterns (such as caribou).  A key issue to address in relation to these community and related challenges is the role of local characteristics (topography, surface type and coastal zones) on the nature of weather conditions.  With the high Coriolis factor, such influences can be accentuated especially in locations such as Iqaluit with its surrounding complex topography.