Canadian cryospheric response to an anomalous warm summer: A synthesis of the climate change action fund project "The state of the arctic cryosphere during the extreme warm summer of 1998"

As of 2003, the warmest year on record in Canada (and globally) was 1998. Extensive warming was observed over the Canadian Arctic during the summer of 1998. A collaborative, interdisciplinary project involving government, universities, and the private sector examined the effect of this unusual warmth on cryospheric conditions and documented the responses, placing them in a 30-40 year context. This paper represents a synthesis if these results. 1998 was characterized by a melt season of exceptional length, having both an unusually early start and late finish. Extremes were noted for cryospheric variables that included ground thaw penetration, snow-free season, lake-ice-free season, glacier melt, and the duration and extent of marine open water. The warm conditions contributed to the break-up of two long-term, multi-year ice plugs in the north-west Canadian Arctic Archipelago, which allowed floe ice into the Northwest Passage. Synoptic events and preconditioning were observed to play an important role in governing the response of some variables to the warming. It was also noted that response was not uniform in all regions. This study provided an opportunity to examine possible cryospheric response to future, warmer conditions. It also provided a chance to assess the capability of current cryospheric monitoring networks in the Canadian Arctic. This study has suggested the manner of cryospheric response to low frequency, high magnitude events occurring within the broader milieu of large-scale forcing.