WebNov 16, 2024 · The problem. I have panel data (or longitudinal data or cross-sectional time-series data). I wish to identify systematically the first (or last) occurrences of a particular condition in each panel with an indicator variable that is 1 when an observation is the first (or last) occurrence in a panel and 0 otherwise. Coastal polynyas are formed through two main processes: A sensible heat polynya is thermodynamically driven, and typically occurs when warm water upwelling keeps the surface water temperature at or above the freezing point. This reduces ice production and may stop it altogether.A latent heat polynya is … See more A polynya is an area of open water surrounded by sea ice. It is now used as a geographical term for an area of unfrozen seawater within otherwise contiguous pack ice or fast ice. It is a loanword from the Russian полынья … See more Polynyas have also supported human populations throughout history. For example, the North Water Polynya, the largest and most biologically productive Arctic polynya, serves as a critical source of food in an otherwise barren region, enabling the … See more • Lead (sea ice) • North Water Polynya • Weddell Polynya See more Some polynyas, such as the North Water Polynya between Canada and Greenland, occur seasonally at the same time and place each year. Because animals can adapt their life strategies to this regularity, these types of polynyas are of special ecological research … See more When submarines of the U.S. Navy made expeditions to the North Pole in the 1950s and 1960s, there was significant concern about surfacing through the thick pack ice of the Arctic Ocean. … See more • Polar cyclones at the origin of the reoccurrence of the Maud Rise Polynya in austral winter 2024 (NOW) at agupubs.onlinelibrary.wiley.com (Error: unknown archive … See more
43-year-old mystery of Polynya in Antarctica unraveled
WebTranslations in context of "upwellings of nutrients" in English-French from Reverso Context: Forage is closely linked to upwellings of nutrients in currents and therefore may not be drastically affected by changes to sea ice cover. WebSep 27, 2024 · Arctic and Antarctic polynyas are crucial sites for deep-water formation, which helps sustain global ocean circulation. During glacial times, the occurrence of … bishops\\u0027 conference of scotland
Influence of total ozone column (TOC) on the occurrence of …
WebA study of polynya characteristics in East Antarctica was undertaken using ice concentrations derived from special sensor microwave/imager data for the period July 1987-August 1994. The areas of polynyas were defined as having an ice concentration ≤75%. The analysis revealed a total of 28 coastal polynyas within the study region. WebOct 4, 2024 · At most times, the areas of the different polynyas had synchronous variations, implying that the main driving factors of the opening of the four polynyas were the same. An obvious exception emerged after mid-September 2008, when the BaP remained closed while the other three polynyas reopened normally, after a long period of decline from mid … WebAug 13, 2024 · Generally, a polynya is defined as a persistent and recurrent area of open water and/or thin ice that occurs at times and under climatological conditions when one would expect a thicker or more consolidated ice cover (Smith et al., 1990; Tamura and Ohshima, 2011).Polynyas may be further categorized based on their mode of formation: … bishops\u0027 conference of england and wales