northern Atlantic Ocean, and this exchange is an important part of the heat budget and annual cycle of these waters. Were the Arctic Ocean ice free, quite different oceanic and climatic regimes would prevail in the Northern Hemisphere. Antarctica is a huge continent covered with a vast ice sheet, the earth's crust being pressed down by the weight of the ice to far below sea level. Should the deep southern oceans warm, or the circulation change, some of the antarctic ice sheet might be subject to catastrophic change. The breaking free and eventual melting of the West Antarctic Ice Sheet is one of these hypothesized catastrophes. The worldwide effect on sea level and on the oceans in general would be great. The torrid clime is the home of very large-scale and important oceanic phenomena, such as the great systems of low-latitude surface currents, under currents, and counter currents. They appear and disappear, perhaps in some relationship to atmospheric changes, resulting in oceanic conditions important to man, such as great changes in fish breeding conditions and recruitment of fish stocks. The changes in fishing grounds near Peru and off the east coast of Africa are a few of the important examples. Dark heaving boundless endless, says the poet. Byron was a sailor; he knew and loved the vagaries of the sea and respected its violence. His view, however, was restricted to the surface. Today, ships, buoys, bottom instruments, and submersible craft allow us to penetrate the darkness and to sample directly the chemical and physical processes of the sea. The geological, geochemical, and biological explorations of the sea bottom have led to incredible contemporary discoveries and new questions that the poet could not have imagined; the "living" sea floor to this day is hardly fathomed, hardly understood and explained. But the ocean is still rather dark, in the sense of yet withholding many details of its dynamics, its interaction with the earth below and the atmosphere above; the wide variety of life it contains still holds much to discover and understand. Its heavings and churnings are better understood than before, but are not yet satisfactorily predictable. Great storms brew up suddenly and wreak havoc on shipping, on fisheries, on human works along the ocean shores and pose sudden dangers to off-shore mineral and energy exploitation. Boundless and endless it no longer is, in the sense that we have the technology to explore all the depths, the remote niches, and even to observe its upper surface global and synoptically. Not many of these resources are at their optimum stage of development, nor are they satisfactorily cost-efficient-in fact, they are very costly indeed. The information they are capable of gathering, however, is cost-effective in terms of the need of mankind to know and understand the oceans and their vagaries. Sublime-what did the poet intend by this word of so many meanings and shades of color? Taking the ancient roots of the word, he may have meant "raised to a high level," perhaps unreachable, exalted in its mystery. Perhaps he meant to evoke the grandeur of its relationship to the human drive to explore, understand, conquer. One possible meaning is related to high intellectual worth. This is certainly a contemporary facet of the ocean sciences. Not only is knowledge of the oceans of great intellectual value, but the practical value cannot be minimized. Moreover, the intellectual and practical challenges are great and stimulating. The material in this report derives from a number of sources, first of which were the discussions of the NOSS Science Working Group, established to advise the National Aeronautics and Space Administration on what important ocean science programs could be accomplished or supported through a specific spacecraft program, the National Oceanic Satellite System (NOSS). The discussions grew to encompass remote sensing possibilities from other kinds of spacecraft and the use of spacecraft as communication links with drifting buoys. Direct shipboard, buoy, or other kinds of oceanographic and biological observations would be needed not only as validation. or quality control of spacecraft indirect observations, but also as observing partners of the satellite systems. The latter was seen as necessary to establish the composite observing technology needed to address the major ocean science problems. As time went on, it was also recognized that a broader survey would be needed of satellite observing possibilities to support a variety of ocean science needs. Many colleagues contributed special materials to this compilation, especially to Chapter 2, and special thanks are due them for their efforts. Chapter 2 has the appearance of a shopping list. It is intended to illustrate a variety of good scientific applications and only a limited attempt has been made to integrate material from diverse contributors, or to reduce overlap. Some useful and germane material from other published reports and studies has also been quoted or paraphrased. To provide a framework and a context for such material, some one person had to serve as organizer of the train of thought, editor of the material, and supervisor of the final production. The undersigned, in the capacity of staff support for the NOSS Science Working Group, assumed these tasks, and takes full and sole responsibility for the sins of omission and commission that the expert reader will discover. The report, however, has been reviewed by the NSWG and represents a consensus on what is needed, what can and should be done and, insofar as it is possible to specify, how. This report is addressed not only to those interested in the application of remote sensing to the ocean sciences, but also to colleagues in administrative and management positions in the federal agencies who have the unenviable task of deciding how to partition rather limited technical, human, and fiscal resources among the many worthy claimants for federal programs and support. Finally, the rules of the game have changed. NOSS has been deferred, probably permanently in the form discussed last year. The NOSS science planning exercise, however, has focussed attention on the important opportunities to oceanic sciences research of space-based remote sensing, as new tools, or as crucial complements to non-space technology. The Working Group, constrained to concern themselves with NOSS per se, however, also found it important to discuss some of the wider applications of remote sensing. Moreover, the compiler felt that it would be useful to express some thoughts concerning the continued development of space-based observing techniques for the ocean sciences. The final section of this report, then, is an attempt to set down some reasonable and realistic possibilities, based on the extensive recent experience with Seasat A, Nimbus 7, and the science planning efforts for NOSS. Stanley Ruttenberg Stanley Ruttenberg Executive Secretary NOSS Science WorkingGroup 1 July 1981 NCAR, Boulder, Colorado SUMMARY Satellite-borne observing and communication systems offer a variety of techniques to observe and/or map qualitatively, with high-resolution, many oceanic features of importance, and to make measurements that are the basis of quantitative information. Satellite techniques, however, are limited essentially to surface manifestations and hence there will continue to be a strong need for direct measurements using ships, buoys, bottom moorings, etc., as well as for subsurface remote sensing by acoustic methods. • The information derived from satellite observations is best used in close coordination with direct observations, for the latter are needed to provide the high time and space sampling needed, the highest accuracies, and also to serve as validation/control of the information inferred from satellite observations; the former provide the wide areal coverage, long-term and repeated observations necessary to build up valid statistical data series for such physical quantities as surface wind or stress fields, surface temperatures, ocean-atmosphere heat budget, and the time and space characteristics of the range of scales of oceanic circulation. Satellite techniques also facilitate widespread direct observations through the use of satellite-borne data collection and location systems, communicating with such platforms as drifting and pop-up buoys, ships of opportunity, and remote stations. There are several large-scale national and international experiments being planned in the context of the World Climate Research Program for which satellite techniques offer valuable and in some instances unique capability: a large-scale study of the heat budget in the North. Atlantic (Cage); a tropical ocean-atmosphere experiment with emphasis on the Southern Oscillation; and a general circulation experiment for which TOPEX (satellite radar altimeter topographic experiment) and extensive use of drifters tracked with satellite techniques would offer considerable unique contributions. There is a large variety of smaller-scale regional or site-specific oceanic processes that could be studied effectively with the use of satellite techniques in conjunction with direct observations. The color scanner has proven to be directly applicable to many studies of biological processes in the surface waters; the images have also proven to be valuable for mapping and studying some features of oceanic circulation. Color scanner information may also prove to be invaluable for some studies of atmospheric constituents, e.g., aerosols. Surface and subsurface drifters, tracked with satellites, which also collect direct measurements, are evolving to the point where substantial experiments seem possible in the near future to study important circulation models and features. Technical development is already under way and should continue, with the goal of deployment of advanced drifters for specific studies. The satellite data collection and platform location system (DCLS) requirements and designs need further study to ascertain what requirements could be met by existing systems (e.g., Argos and the systems on the geostationary satellites) and what further developments might be needed to serve oceanic needs even better. • There is much work to do in acquiring, editing, and formatting important historical data sets, such as winds from ships, and sea-surface temperatures, as well as extensive satellite data sets which have not yet been put into accessible form. Moreover, there is a great need to begin to compile a user-interactive data catalog for oceanic sciences to facilitate better use of the kinds of data fields just mentioned. One way to meet these needs is to establish a dedicated data system |