Abstract

Abstract

This is the initial volume in a comparatively wide-ranging review of present knowledge of the circulation processes in the Gulf of Mexico. Volume I is focused on the large-scale low-frequency deep-water current structures in the Gulf, and on identifying in a preliminary way interactions of these circulation patterns (typically referred to as the general circulation) with the flow regimes on continental shelves (typically referred to as coastal circulations). Volume II is primarily concerned with coastal circulations, including their remote forcing and considering shelf-estuarine interactions. This review will attempt to expose and synthesize the physical oceanographic idea and publication base for the Gulf, as an aid in becoming familiar with what has been done, and not, what is known, and not known. The audience envisioned would include scientists and engineers and students who are specialists in other fields, perhaps especially marine scientists in other disciplines, as well as members of the general public with a technical inclination, and could be used as a supplemental text. The results discussed and synthesized and critiqued could also be of interest to professional physical oceanographers. I began to seriously examine publications connected to the oceanographic context for South Texas when I retired here in 1997, and to this end, the review is at its core a guide to material that I have found useful myself in becoming familiar with the Gulf, along with some new interpretation and suggestions and perspective on my part. My prior experience (A link to my resume is on this web site, please click on my name on the cover page) as an observational physical oceanographer was on large scale ocean currents and eddies, including participation in several inter-comparisons of observations with numerical model results, a topic that this review will emphasize. This volume is dedicated to the memory of Dana Thompson, a special friend, a scholar of the Gulf of Mexico, physical oceanographer and numerical modeler extraordinaire.

In summary, two review Volumes (I and II) will be devoted to a study of the open ocean and coastal circulations in and around the Gulf of Mexico, along with interactions between these flow regimes. The large-scale, deep-water, low-frequency circulation in the Gulf is dominated by the Loop Current and its eddy field, the latter composed of a diverse population of anticyclones and cyclones, including the collision products from eddy-topographic interactions and also involving eddy-eddy interactions. The reader should be advised that the data base for the deep open Gulf is sparse compared to many other locations. The coastal circulations are qualitatively characterized by wind (local and remote) and buoyancy forcing on the inner and middle continental shelves, and by interactions with the open Gulf on the outer shelf and shelf break. The continental slope and rise regimes are transition areas. Some of the shelf circulations are linked, and both downwelling and upwelling coastal regimes are involved. An effort is made to embed studies of the circulation of the Gulf of Mexico within the context of similar activities in other areas, especially within the framework of the circulation of the sub-tropical and tropical North Atlantic Ocean, a topic toward which Dr. J. Dana Thompson also made a significant contribution, along with his investigations of the physical oceanography of the Gulf of Mexico.

The topics to be covered and the approach used to pull this all together (please see Table of Contents) reflect my desire to develop ways for readers with a variety of backgrounds and interests to access this review in a way that is useful for them. The four chapters and six appendices are configured with this in mind. Chapter 1 is designed for readers with some scientific and technical background who want a quick introductory look at the characteristics of the General Circulation of the deep Gulf of Mexico. Chapter 2 is for those who are interested in the state of the art in research on the physical oceanography of the Gulf. One unique feature of Chapter 2 is an emphasis on the relation between observations and numerical model results. Chapter 3 is a reconnaissance of some topics related to the relationship between the general circulation of the Gulf and its coastal circulations, as an introduction to Volume II, which has coastal circulations as its priority. Chapter 4 is a summary and overview of the material presented in Volume I, containing suggestions for future work, presented for a general audience. Appendices A and B, which contain and discuss an extensive publication base, should be of general use but perhaps especially for graduate students. Appendix C will provide a state of the art look at how numerical models relate to the data base in an overview sense, but otherwise is primarily for specialists and experts. Appendix D is a very basic view of how the large scale circulation of the Gulf of Mexico fits into basin and global circulation perspectives, written for a general audience.