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In-Situ Burning on Ice, Snow or in the Arctic
Published in Merv Fingas, In-Situ Burning for Oil Spill Countermeasures, 2018
Pack ice is a term used in a wide sense to include any area of sea ice other than fast ice no matter what form it takes or how it is disposed. Pack ice is often used when concentrations are high, that is, 7/10 or more. Burning in pack ice has taken place in the past and is one of the many situations with the possibility for burning with ice present.
Implications of Long-Term Climate Change for Biogeography and Ecological Processes in the Southern Ocean
Published in S. J. Hawkins, A. J. Evans, A. C. Dale, L. B. Firth, I. P. Smith, Oceanography and Marine Biology, 2018
The pack ice is a major characteristic of the Southern Ocean and undergoes enormous seasonal changes in extent, from a minimum of 4 × 106 km2 in summer to about 20 × 106 km2 in winter (Comiso et al. 1993), when it reaches to about 58°S in August–October (Longhurst 1998). The pack ice has important physical effects on the flux of heat and gases between the sea and the atmosphere and provides a unique habitat for a range of organisms including brine diatoms, krill and seals. Not only is the ice important in itself, it is important through its effects during ice retreat. The marginal ice zone represents an area of millions of square kilometres in which unique conditions of water column stability, salinity and epontic algae exist. Ice retreat triggers a spring bloom of production that follows water column stabilisation through the release of melt water. Ice melt also seeds the water column with algae released from the ice (El-Sayed 2005), and possibly releases iron (Sedwick et al. 2000). The net effect is to make a significant contribution to total annual primary production. Nevertheless, it has been suggested that a reduction in sea-ice cover would result in an overall increase in primary production (Holm-Hansen & Sakshaug 2002), and modelling exercises by both Sarmiento et al. (2004b) and Arrigo and Thomas (2004) support this. The models of Arrigo and Thomas predict that a drop of 25% in sea-ice cover would lead to an increase of 10% in total Southern Ocean primary production, as the relatively unproductive sea-ice habitat would be replaced by the more productive marginal ice zone habitat and permanently open ocean. However, sea-ice algae are important not only in terms of their contribution to total Southern Ocean production but because they provide food in places and at times when water column production is low (Lizotte 2001). A reduction in ice cover would have enormous consequences for species that depend on ice algae either directly or indirectly, which is effectively to say almost the entire food web.
Meteorology
Published in David House, Seamanship Techniques, 2019
This is sea ice which has become ‘fast’ to the shore, ice wall or other similar surface. It may be formed by the freezing of sea water close inshore or by pack ice freezing to the shore or other surfaces. Should its height extend more than 2 m, it would be referred to as an ‘ice shelf’.
On the Sturm–Liouville problem describing an ocean waveguide covered by pack ice
Published in Applicable Analysis, 2022
Boris P. Belinskiy, Don B. Hinton, Lakmali Weerasena, Mohammad M. Khan
Let the layered acoustic medium be located in the waveguide The derivation of the basic acoustic equations from fluid dynamics may be found in [14, 15]. The acoustic wave equation may be written in terms of a scalar potential : where the speed c is a function of . Since we consider a layered medium, we let Further, we suppose the bottom to be rigid, i.e. The ice cover is located at the surface Let be the vertical displacement of this surface. The continuity of the velocity on the boundary of the acoustic medium and ice cover results in the following condition: We consider the simplest model of ice, so-called pack ice in this paper. Physical Geography defines pack ice as a large area of floating ice, usually occurring in polar seas, consisting of separate pieces, which have become massed together. Newton's second law for the ice cover is used in [10] to derive the following boundary condition: where is the surface density of the ice cover, the ice density, h its thickness, the water density, g the gravitational constant. Equations (2), (3) and (4) represent the boundary conditions for the wave Equation (1).