MMS Physical Oceanography of Slope and Rise (POSAR) Workshop Results

Abstract

Abstract On September 12-14, 2000, the Minerals Management Service (MMS) sponsored the Physical Oceanography of the Slope and Rise (POSAR) Workshop. Its objective was to refine the experimental design of a study of currents in the deepwater (200–3,000 m) of the Central and Western Gulf of Mexico. The workshop generated wide interest with about 90 participants from academia, industry, and state and Federal agencies. Seven invited speakers set the tone of the workshop, followed by three breakout sessions addressing many oceanographic processes operating in deepwater, new observational technologies, and data needs. Workshop participants recommended four exploratory studies that are well focused and require reasonable funding. These studies should help the experimental design of POSAR by addressing information needs on topographic Rossby waves (TRWs), abyssal currents, Lagrangian observation of eddies, and climatology of currents over the slope and rise. Another recommendation was the continuation of current measurements by MMS south of the Mississippi Delta. Finally, MMS expects to complete a Request for Proposals in mid-2001 to address its deepwater physical oceanographic information needs. Introduction Deepwater leasing increased exponentially until 1997, then decreased to 1994 levels by 1999. Baud et al.2 discussed possible reasons for the trend change and that will not be reported here. Submission of deepwater exploration and development plans to the MMS also increased. Because of a time lag between leasing and actual submittal of plans, full impacts of this load increase did not start immediately in 1997. However, in-house deepwater plans cover a large area of the Central and Western Gulf of Mexico. MMS has responded to movement of OCS leasing into deepwater by reviewing the environmental database for the deepwater Gulf. Evaluation of existing information and identification of data gaps in the environmental and socioeconomic database were the major objectives of the "Workshop on Environmental Issues Surrounding Deepwater Oil and Gas Development."3 An outcome of that workshop was the conception and implementation of the "Deepwater Physical Oceanography Program" consisting of three major studies:Reanalysis and Synthesis of Historical Data;Study of Physical Processes over the Slope and Rise using Numerical Models;Physical Oceanography of the Slope and Rise (POSAR). The first two studies were straightforward and easily implemented. POSAR, however, was complex, ambitious, and expensive. New observations show strong currents (~ 90 cm/s) just 11 meters above the bottom and large bedforms, mega furrows, near the Sigsbee Escarpment. It became apparent that more planning was necessary. Thus, a workshop was conceived to discuss the objectives and finalize the experimental design of POSAR. The implementation and results of the POSAR Workshop are the topics of this article. The Workshop The original overall objective of the workshop was to "refine and finalize the experimental design for POSAR." The working design was conceived and delivered by the "Reanalysis and Synthesis of Histroical Data" study.