959 resultados para Moreton-bay
Resumo:
Basal melt of ice shelves may lead to an accumulation of disc-shaped ice platelets underneath nearby sea ice, to form a sub-ice platelet layer. Here we present the seasonal cycle of sea ice attached to the Ekström Ice Shelf, Antarctica, and the underlying platelet layer in 2012. Ice platelets emerged from the cavity and interacted with the fast-ice cover of Atka Bay as early as June. Episodic accumulations throughout winter and spring led to an average platelet-layer thickness of 4 m by December 2012, with local maxima of up to 10 m. The additional buoyancy partly prevented surface flooding and snow-ice formation, despite a thick snow cover. Subsequent thinning of the platelet layer from December onwards was associated with an inflow of warm surface water. The combination of model studies with observed fast-ice thickness revealed an average ice-volume fraction in the platelet layer of 0.25 +/- 0.1. We found that nearly half of the combined solid sea-ice and ice-platelet volume in this area is generated by heat transfer to the ocean rather than to the atmosphere. The total ice-platelet volume underlying Atka Bay fast ice was equivalent to more than one-fifth of the annual basal melt volume under the Ekström Ice Shelf.
Meteorological observations during PENELOPE cruise from Delgada Bay to Halifax started at 1809-07-20
Resumo:
Distribution of Cd and Pb in sea ice and in under-ice water of the Amur Bay at the end of February 1998 is considered. The metals were determined by technique of inversion voltammetry. Contribution of Cd and Pb from atmospheric precipitation and from under-ice water to sea ice examined is discussed. On the basis of analysis of vertical distribution in ice, atmospheric fluxes supplying metals to the aquatic area of the bay are estimated at 100 and 2000 µg/m**2/year for Cd and Pb, respectively. Concentrations of Cd and Pb found in middle and lower parts of ice cores allow to suggest that their accumulation relative to main ions of seawater occurs in the ice. Estimated enrichment factors of Cd and Pb in sea ice relative to seawate are ~9 and ~5. A possible mechanism of relative metal accumulation in sea ice is considered.
Resumo:
Data on chlorophyll a concentration and phytoplankton primary production in the south Kola Bay in 2004-2005 are given.