A Geometric Model for the Beaufort/Chukchi Sea Thermohaline Structure

• Main Authors: Chu, Peter C., Wang, Qianqian, Bourke, Robert H.
• Other Authors: NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF OCEANOGRAPHY
• Format: Text
• Language: English
• Published: 1999
• Subjects: Physical and Dynamic Oceanography; *THERMOCLINES; REPRINTS; OCEAN SURFACE; MODELS; STATISTICAL TESTS; SEASONAL VARIATIONS; GEOMETRIC FORMS; CHUKCHI SEA; BEAUFORT SEA; MIXED LAYER(MARINE); SALINITY; SURFACE TEMPERATURE; STRATIFICATION; SEA WATER; GEOMETRIC MODEL; Chukchi Sea; Beaufort Sea; Chukchi
• Online Access: http://www.dtic.mil/docs/citations/ADA479869; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA479869

A geometric model has been developed for analyzing observed Beaufort/Chukchi Sea temperature and salinity profiles based on their geometric features. It contains four major components: (a) a nonhomogeneous mesh difference scheme for second derivatives partial derivative 2T(Zk)/partial derivative Z2 and partial derivative 2S(Zk)/partial derivative Z2 at each data point (Zk, Tks, Sk); (b) a set of key depths (depths of mixed layer, upper and lower thermoclines and haloclines, and deep layers) determined mostly by the geometric features of profiles, such as depths of minimum and maximum of partial derivative 2T(Zk)/partial derivative Z2 and partial derivative 2S(Zk)/partial derivative Z2 for shelf water and upper portion deep water; (c) modeled profiles T (Zk) and (Zk), which are linearly interpolated from observed T, S values at the key depths; and (d) statistical tests for accepting [T(Zk), (Zk)] as a good representative of (Zk, Tk, Sk). The output of this geometric model is a set of major characteristics of each profile: sea surface temperature (salinity), mixed layer depth, upper- and lower-thermocline (halocline) depths, thermocline (halocline) temperature (salinity) gradient, and deep layer stratification. Analyzing 3562 Beaufort/ Chukchi Sea historical (1970-93) temperature and salinity profiles from the Naval Oceanographic Office's Master Oceanographic Observation Data Set by this geometric model, the Beaufort/Chukchi Sea thermohaline field reveals a dual structure: one layer (vertically uniform) on the continental shelf (depth less than 150 m) during winter and multiple layers (mixed layer, thermocline/halocline, sublayer) during summer. Strong seasonal variations were also found in mixed layer depth, upper thermocline/halocline depth, and strength. Pub. in Jnl. of Atmospheric and Oceanic Technology, v16 p613-632, June 1999.