Ocean current observations near McMurdo Station, Antarctica, 1993 to 1994: Relation to wastewater discharge dispersal

• Main Author: Barry, J.P.
• Other Authors: United States. Department of Energy., National Science Foundation (U.S.)
• Format: Report
• Language: English
• Published: EG & G, Inc. 1995
• Subjects: Waste Management; Liquid Wastes; Ground Release; 58 Geosciences; Antarctica; 54 Environmental Sciences; Waste Disposal; Plumes; Water Currents; Sewage; McMurdo Sound; McMurdo Station; Antarc*
• Online Access: https://doi.org/10.2172/130648; http://digital.library.unt.edu/ark:/67531/metadc627256/

This report presents analyses of current measurements from McMurdo Sound, Antarctica during December, 1993 to November, 1994, in relation to dispersal of the McMurdo Station wastewater plume. Data collected from 1991 to 1993 are also discussed here. Six current meters were deployed near McMurdo Station, Antarctica, from December 1993 to November 1994. Five functioned properly throughout the observation period, and one failed. Analyses of 5 data series include: (1) summaries of current speed and direction, (2) directional analyses of flow, (3) time series current vectors averaged over 1, 3, 6, 12, and 24 h, (4) principal axes of flow, (5) maps of mean seasonal flow, (6) progressive vector plots, (7) spectral analyses, and (8) low-pass filtered (30h) time series of currents at McMurdo Station. Observations of flow near McMurdo Station during 1994 were generally similar to 1993. Short term variation in flow was related principally to diurnal tidal motions. Longer period oscillations in flow such as seasonal shifts, and non-periodic changes in current speed and direction were likely related to changes in ice cover and wind stress in the vicinity of McMurdo Station or over much larger scales or both. Three distinct oceanographic {open_quote}seasons{close_quote} were apparent in time series from 1992 to 1994, from stations furthest offshore, where the effects of local topography are minimal. The spring-summer (Oct.-Jan.) period of both years was dominated by regional southward flow, which generates a counter-clockwise eddy (McMurdo Gyre) adjacent to McMurdo Station. With regard to dispersal of the wastewater plume from McMurdo Station, observations of currents during 1994 generally corroborate those from 1993, and the recommendation that the outfall pipe should be repositioned offshore of the McMurdo Gyre is supported.