{'fraction_non_alphanumeric': 0.019343493552168817, 'fraction_numerical': 0.015240328253223915, 'mean_word_length': 5.345724907063197, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
The Northeast Greenland Sirius Water Polynya dynamics and variability inferred from satellite imagery

Abstract Geografisk Tidsskrift—Danish Journal of Geography 110(2):131–142, 2010 One of the most prominent polynyas in Northeast Greenland, already noted by the early expeditions in the area, is located around Shannon Ø and Pendulum Øer between 75° and 74°N in the transition zone between the fast ice and pack ice. This study names the polynya the ‘Sirius Water Polynya’, and examines its spatial and temporal dynamics by analysis of recent satellite imagery, modelled meteorological data and historical data covering the last decade. The dominating mechanisms to form and sustain the polynya are inferred and the persistence and inter-annual variability of the phenomenon are estimated. The polynya formation is predominantly governed by mechanical forcing caused by northerly gales, and it is classified as a wind-driven shelf water polynya. A marked seasonal difference in the surface wind field, together with the obvious seasonal cycle in insolation, creates distinct winter and summer regimes in the seasonal evolution of the polynya. During the winter regime, both the size of and the ice cover within the polynya varies significantly on a temporal and spatial scale. Intermittent wind-driven openings of the polynya alternate with periods of increasing ice cover. Some of the most persistent areas of open water in the polynya coincide with locations where significant concentrations of spring and summer settlements from the Thule Inuit culture (AD 1400–1850) are observed, indicating a connection between the presence of the polynya and the Thule Inuit living in the area in prehistoric times.