Efficient Representation of the Hydrographic Structure of the North Atlantic Ocean and Aspects of the Circulation from Objective Methods

• Main Author: Fukumori, Ichiro
• Other Authors: WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
• Format: Text
• Language: English
• Published: 1989
• Subjects: Physical and Dynamic Oceanography; *OCEANOGRAPHIC DATA; *OCEAN MODELS; *SEA WATER; *HYDROGRAPHY; EFFICIENCY; THESES; NUTRIENTS; DEGREES OF FREEDOM; OXYGEN; PROFILES; VERTICAL ORIENTATION; SCALE; MATHEMATICAL ANALYSIS; INVERSION; MEDITERRANEAN SEA; SALINITY; CIRCULATION; NORTH ATLANTIC OCEAN; BASINS(GEOGRAPHIC); SILICATES; ORTHOGONALITY; FUNCTIONS(MATHEMATICS); EAST(DIRECTION); PHOSPHATES; MARINE GEOPHYSICS; STRUCTURAL PROPERTIES; TEMPERATURE; NITRATES; SPATIAL DISTRIBUTION; METHODOLOGY; *OCEAN CIRCULATION; INVERSE METHODS; ORTHOGONAL FUNCTIONS; OCEAN BASINS; North Atlantic
• Online Access: http://www.dtic.mil/docs/citations/ADA218606; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA218606

This dissertation systemmatically studies mathematical techniques for determining ocean circulation from classical hydrographic data. The first aspect analyzed is finding an efficient representation of hydrographic structure to make it most useful and informative. The second is application of inverse methods to the data to determine ocean circulation. The efficient representation is examined in terms of empirical orthogonal functions (EOFs) among the variations in vertical hydrographic profiles. The data used are of a new set of high quality hydrography, all obtained in the early 1980s. Common EOFs are examined among temperature, salinity, oxygen, phosphate, silicate, and nitrate. The EOFs identify a fundamental simplicity in the spatial distributions of these properties. Although the volume of numbers involved in the raw data is large, the significant degrees of freedom are only six in space and two among the six properties; temperature and salinity are represented by one mode, while the nutrients by another. The modal structure reflects some underlying simplicity in ocean physics. Two applications of inverse methods are explored on small regional scales. The first problem addressed concerns the circulation inside a 12 deg square located in the eastern basin over the axis of the Mediterranean Water tongue. The study is based on an ocean model constructed by mapping the modes identified in the first half of the thesis over the entire North Atlantic Ocean. Theses. Prepared in cooperation with Massachusetts Institute of Technology.