Multi-scale satellite observations of Arctic sea ice: new insight into the life cycle of the floe size distribution

This study provides a new conceptional framework to understand the life cycle of the floe size distribution of Arctic sea ice and the associated processes. We derived the floe size distribution from selected multi-scale satellite imagery data acquired from different locations and times in the Arctic. Our study identifies three stages of the floe size evolution during summer - 'fracturing', 'transition' and 'melt/wave fragmentation'. Fracturing defines the initial floe size distribution (N similar to d(-alpha), where d is floe size) formed from the spring breakup, characterized by the single power-law regime over d= 30-3000 in with alpha approximate to 2. The initial floe size distribution is then modified by various floe fragmentation processes during the transition period, which is characterized by 'selective' fragmentation of large floes (d > 200-300 m) with variable alpha = 2.5-3.5 depending on the degree of fragmentation. As ice melt intensifies, the melt fragmentation expands the single power-law regime into smaller floes (d = 70 m) with alpha = 2.4-3.8, while a significant reduction of small floes (d < 30-40 m) occurs due to lateral melt. The shape factor shows an overall progression from elongated floes into rounded floes. The effects of scaling and wave-fracture are also discussed. This article is part of the theme issue 'Theory, modelling and observations of marginal ice zone dynamics: multidisciplinary perspectives and outlooks'.

Automated summary

This study presents a new conceptual framework for understanding the life cycle of floe size distribution and associated processes in Arctic sea ice. It identifies three stages of floe size evolution during summer and discusses the effects of scaling and wave fracture. The study provides valuable insights into the dynamics of Arctic sea ice.