Length of large leads in drifting ice of the sub-Atlantic part of the Arctic Basin with the use of satellite images

Abstract

Data on the extent of the large discontinuities of drifting ice in the Western part of the Arctic basin are ana‑ lyzed for the period from October 2005 to September 2012. The data were obtained as a result of decoding the low resolution images received from the NOAA satellites. Areas with the low, medium and high lengths of the leads were isolated. It was found that, during the entire ice cycle, areas with low lengths (less than 100 km) were the most numerous. Definite seasonal as well as inter‑annual variations were also determined in the changes of repeatability of the lead lengths in the ice cover, its relative value and the average values. They are manifested in changes of the mentioned parameters being calculated for both, the whole set of leads, and separately from data within each of the isolated areas. The seasonal variations of these parameters are shown to be consistent with the well‑known intra‑annual changes in the state of drifting ice, consisting in the development of the process of ice formation from October to March, and the subsequent destruction of the ice fields in April–June. Fluctuations with duration up to five years were revealed within the inter‑annual changes of characteristics of the lengths of leads. The presence of these inter‑annual changes may be explained by the development of the processes leading to «weakening» of drifting ice during the period under consideration. The assumption that the fluctuations in the length of discontinuities of the ice were related to the changes of the rate of the ice drift is grounded.

Keywords

• колебания протяжённости разрывов
• относительная протяжённость разрывов
• разрывы в ледяном покрове
• средняя протяжённость разрывов