No abstract

In response to increasing environmental and social changes in the past few decades, some Inuit hunters have been turning to scientific tools to help evaluate sea ice conditions. Simultaneously, there has been more scientific interest in understanding local scale processes through Inuit knowledge in order to develop a broader comprehension of dynamic sea ice conditions and implications of long‐term change. Building on several years of collaborative research with Inuit sea ice experts in Cape Dorset, Igloolik, and Pangnirtung, Nunavut, and local expressions of interest in increased access and availability of satellite imagery of sea ice, the Polar View Floe Edge Service was expanded to each community in the spring of 2007. Follow‐up workshops in November 2007 helped to evaluate and improve the service by considering previous local uses of satellite imagery and tailoring Floe Edge Service regions of interest to local areas of sea ice use. Through workshop discussions, several opportunities for the use of synthetic aperture radar (SAR) imagery emerged, including: seeing what is on (or within/under) the ice; monitoring seasonal and long‐term sea ice changes; hazards assessment; planning travel routes; and facilitating search and rescue operations. A number of challenges were also identified, such as: SAR image interpretation; image spatial resolution; frequency of image acquisition; SAR image representation capabilities; and technological limitations. The workshops also provided some insights into intercultural and intergenerational exchanges and led to a number of recommendations to continue expanding and improving the Floe Edge Service. This case study shows how remote sensing can be incorporated into the suite of traditional indicators and technological tools that hunters draw upon in their evaluations of complex human‐animal‐environment assessments. In the face of declining and unpredictable sea ice conditions, bridging scales and knowledge systems will be essential in developing integrated monitoring systems to respond to increased political and economic pressures as well as safety concerns for travelling on or within ice‐covered oceans.

No abstract

This paper describes the application of an automated cross-correlation technique to pairs of 85.5 GHz Special Sensor Microwave Imager (SSM/I) images to obtain Ice motion over the entire Arctic Basin for a contiguous two month period between December 1993 and January 1994. Although the surface ice information in the imagery is coarse and noisy, the area cross-correlation method is quite successful in picking up ice-motion information. The accuracy of 85.5 GHz SSM/I derived ice motions is evaluated by comparing results with Arctic buoy drift. Over 390 comparisons with buoy-drift estimates of ice displacement were made with an overall correlation of 0.75 and an average vector magnitude error in ice velocity of 3.5 km d−1. The main difficulty with the automated technique is the tendency to overestimate ice displacement compared to buoy data by about 14%. Two detailed examples of ice motion are presented. The first occurred in December 1993, when a major westward shift in the ice pack took place in the Canada Basin and opened up a very large lead off Banks and Prince Patrick Islands. The second example occurred in January 1994, when an intense anticyclone over the Canada Basin produced a strong Beaufort Gyre.

ABSTRACT. This paper descr ibes th e applicati on of a n auto mated cross-co rrel ati on tec hniqu e to pairs of 85.5 GHz Special Sensor Mi crowa\"C Im age r (SSM/I ) im ages to obta in ice motion over th e entire Arctic Basi n for a co nti guous two momh period betwee n December 1993 andJ anua ry 1994. Although the surface ice info rm ation in the imagery is coarse a nd noisy, the a rea cross-co rrelation method is quite successful in picking up icemotion inform ation. The accuracy of85.5 GHz SSM/I derived ice motions is evalu ated by com pa ring results with Arctic buoy drift. O ver 390 compa ri sons with buoy-dr ift estim ates of ice displacement were made with a n overall correl ation of 0.75 and an average vecto r magnitude error in ice velocity of3.5 km d I. The m ain difficulty with thc au tomated technique is the tendency to overest im ate ice displacemem compa red to buoy data by abo ut 14%. Two detailed exam pl es of ice motion a re presented. Th e fi rst occurred in D ecember 1993, when a major westward shift in the ice pack too k pl ace in the Canada Basin and opened up a very la rge lead off Ba nks a nd Prince Pa trick Isla nds. Th e second example occ urred in J a nua r y 1994, when an intense a nticyclone over the Canada Basin produced a strong Beaufort Gyre.