Blowing snow studies in the Canadian Arctic Shelf Exchange Study, 2003–04

2006 ◽  
Vol 20 (4) ◽  
pp. 817-827 ◽  
Author(s):  
S. A. Savelyev ◽  
M. Gordon ◽  
J. Hanesiak ◽  
T. Papakyriakou ◽  
P. A. Taylor
Keyword(s):  
Canadian Arctic ◽  
Arctic Shelf ◽  
Blowing Snow ◽  
Exchange Study

scholarly journals Adverse-Weather Trends in the Canadian Arctic

2005 ◽  
Vol 18 (16) ◽  
pp. 3140-3156 ◽  
Author(s):  
John M. Hanesiak ◽  
Xiaolan L. Wang
Keyword(s):  
Precipitation Amount ◽  
Canadian Arctic ◽  
Rate Of Change ◽  
Eastern Region ◽  
Blowing Snow ◽  
Homogenization Procedure ◽  
Almost Everywhere ◽  
Weather Events ◽  
Weather Observations ◽  
Adverse Weather

Abstract This study provides an assessment of changes in the occurrence frequency of four types of adverse-weather (freezing precipitation, blowing snow, fog, and low ceilings) and no-weather (i.e., no precipitation or visibility obscuration) events as observed at 15 Canadian Arctic stations of good hourly weather observations for 1953–2004. The frequency time series were subjected to a homogenization procedure prior to a logistic regression–based trend analysis. The results show that the frequency of freezing precipitation has increased almost everywhere across the Canadian Arctic since 1953. Rising air temperature in the region has probably resulted in more times that the temperature is suitable for freezing precipitation. On the contrary, the frequency of blowing snow occurrence has decreased significantly in the Canadian Arctic. The decline is most significant in spring. Changes in fog and low ceiling (LC) occurrences have similar patterns and are most (least) significant in summer (autumn). Decreases were identified for both types of events in the eastern region in all seasons. In the southwest, however, the fog frequency has increased significantly in all seasons, while the LC frequency has decreased significantly in spring and summer. The regional mean rate of change in the frequency of the four types of adverse weather was estimated to be 7%–13% per decade. The frequency of no-weather events has also decreased significantly at most of the 15 sites. The decrease is most significant and extensive in autumn. Comparison with the adverse-weather trends above indicates that the decline in no-weather occurrence (i.e., increase in weather occurrence) is not the result of an increase in blowing snow or fog occurrence; it is largely the result of the increasing frequency of freezing precipitation and, most likely, other types of precipitation as well. This is consistent with the reported increases in precipitation amount and more frequent cyclone activity in the lower Canadian Arctic.

scholarly journals Springtime CO2 exchange over seasonal sea ice in the Canadian Arctic Archipelago

2011 ◽  
Vol 52 (57) ◽  
pp. 215-224 ◽  
Author(s):  
Tim Papakyriakou ◽  
Lisa Miller
Keyword(s):  
Sea Ice ◽  
Sea Water ◽  
Canadian Arctic ◽  
Co2 Exchange ◽  
Critical Threshold ◽  
Canadian Arctic Archipelago ◽  
Blowing Snow ◽  
Net Radiation ◽  
Carbonate System ◽  
Wind Speeds

AbstractSpringtime measurements of CO2 exchange over seasonal sea ice in the Canadian Arctic Archipelago using eddy covariance show that CO2 was generally released to the atmosphere during the cold (ice surface temperatures less than about –6˚C) early part of the season, but was absorbed from the atmosphere as warming advanced. Hourly maximum efflux and uptake rates approached 1.0 and –3.0 μmol m–2 s–1, respectively. These CO2 flux rates are far greater than previously reported over sea ice and are comparable in magnitude to exchanges observed within other systems (terrestrial and marine). Uptake generally occurred for wind speeds in excess of 6 m s–1 and corresponded to local maxima in temperature at the snow–ice interface and net radiation. Efflux, on the other hand, occurred under weaker wind speeds and periods of local minima in temperature and net radiation. the wind speeds associated with uptake are above a critical threshold for drifting and blowing snow, suggesting that ventilation of the snowpack and turbulent exchange with the brine-wetted grains are an important part of the process. Both the uptake and release fluxes may be at least partially driven by the temperature sensitivity of the carbonate system speciation in the brine-wetted snow base and upper sea ice. the period of maximum springtime CO2 uptake occurred as the sea-ice permeability increased, passing a critical threshold allowing vertical brine movement throughout the sea-ice sheet. At this point, atmospheric CO2 would have been available to the under-ice sea-water carbonate system, with ramifications for carbon cycling in sea-ice-dominated polar waters.

scholarly journals An Empirical Blowing Snow Forecast Technique for the Canadian Arctic and the Prairie Provinces

2005 ◽  
Vol 20 (1) ◽  
pp. 51-62 ◽  
Author(s):  
David G. Baggaley ◽  
John M. Hanesiak
Keyword(s):  
Wind Speed ◽  
Canadian Arctic ◽  
High Impact ◽  
Probability Of Detection ◽  
The Arctic ◽  
Blowing Snow ◽  
Critical Success ◽  
Critical Success Index ◽  
Success Index ◽  
Prairie Provinces

Abstract Blowing snow has a major impact on transportation and public safety. The goal of this study is to provide an operational technique for forecasting high-impact blowing snow on the Canadian arctic and the Prairie provinces using historical meteorological data. The focus is to provide some guidance as to the probability of reduced visibilities (e.g., less than 1 km) in blowing snow given a forecast wind speed and direction. The wind character associated with blowing snow was examined using a large database consisting of up to 40 yr of hourly observations at 15 locations in the Prairie provinces and at 17 locations in the arctic. Instances of blowing snow were divided into cases with and without concurrent falling snow. The latter group was subdivided by the time since the last snowfall in an attempt to account for aging processes of the snowpack. An empirical scheme was developed that could discriminate conditions that produce significantly reduced visibility in blowing snow using wind speed, air temperature, and time since last snowfall as predictors. This process was evaluated using actual hourly observations to compute the probability of detection, false alarm ratio, credibility, and critical success index. A critical success index as high as 66% was achieved. This technique can be used to give an objective first guess of the likelihood of high-impact blowing snow using common forecast parameters.

Visually Induced Steering Errors From Simulated Blowing Snow Are Affected by Environmental Objects

2007 ◽  
Author(s):  
Roger Lew ◽  
Brian P. Dyre ◽  
Aaron Powers ◽  
Frank Yarbrough
Keyword(s):  
Blowing Snow ◽  
Environmental Objects
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