Recurring polynyas in the coastal lagoons of the Northern hemisphere

• Published in: Estuarine, coastal and shelf science coastal and shelf science, 2021-06, Vol.254, p.107353, Article 107353
• Main Authors: Zhelezova, E.V., Chubarenko, B.V.
• Format: Article
• Language: English
• Subjects: Ice cover; Lagoons; Polynya; Satellite images
• ISSN: 0272-7714; 1096-0015
• DOI: 10.1016/j.ecss.2021.107353

After visual analysis of more than 3000 satellite images for 2013–2020, it was found that the presence of recurring (stationary or stable) polynyas in coastal lagoons in the Northern Hemisphere of the boreal and polar climate zones of the Atlantic, Pacific and Arctic Oceans was quite common. At least 115 out of 246 lagoon-type coastal objects demonstrated this (47%). Polynyas were primitively classified into two types: the flowing polynya (due to a river inflow in a lagoon), and the inlet polynya (with three subtypes: the inward, outward and «window» ones) attached to the lagoon inlet. The geographical distribution of the lagoons with polynyas was discussed. Some comments on different mechanisms (thermal and mechanical) that guided the polynyas’ appearance in the lagoons were presented. It was noted that statistical distributions of the number of the polynyas by polynya areas or relative size of polynya areas (ration of polynya areas to lagoon areas) could be expressed by lognormal distribution function. •Recurring polynyas in coastal lagoons were quite common, at least 115 out of 246 lagoons demonstrate this (47% of lagoons).•Typology: the inlet polynya with three subtypes – the inward, outward, «window» polynyas and the flowing polynya.•Zoning by the presence of the recurring polynyas were made for coasts of the Atlantic, Pacific and Arctic Oceans.•Recurring polynyas are the manifestations of thermal or mechanical mechanisms guided the polynya origin and support.•Statistical distributions of the normalized areas and relative sizes of the polynyas are expressed by lognormal function.