Differences Between Leads and Polynyas
Unlike polynyas, which tend to occur, and remain, at a given location, leads are transient features that can form anywhere in an ice-covered ocean. Moreover, while the origin of polynyas is linked with either warm air current circulation from the coastline or a warm water upwelling, the driving force behind lead formation is a state of stress, either wind- or current-induced, within the plane of the ice. Lead formation is therefore tied in with synoptic-scale weather patterns, typically lasting a few days. Also, because the open water within a lead tends to quickly refreeze, the contribution of leads to heat exchange and water vapour output to the atmosphere is significantly less than that of polynyas, where refreezing of the open water is prevented.
Read more about this topic: Lead (sea Ice)
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