ne EVEN Rese arc h «O n Research ALIS Ws Arctic Studies Be ‘ ,_- CEAoRtE X 88-89 /EMERALD “' 7 /@ 82 wl 2, oe. a 9”Y -FRAM8 1 : 7af PAM 20 @cearex 0" 89 . @\cEAREX “A" 89 — VERAM79 | MIZEX 83, 84, 87 . e EGC 79, 80 | ~~ 7 Ea \ / CANBARKK ~ Ys 78 » @laiovex 73% / LEADEX 26 A AIDJEX yf @ 6175/7 / y ne cm hasin 93-54 arame® S . AIDJEX 71 % C-130 lancings ®@ c-130 ar drops Office of Naval Research (ONR) sponsored a program of manned ice camps in the late 1940’s where scientists worked and lived for long periods of time. Initially the camps were situated on thick pieces of glacial ice (100 or more feet thick) which were stable and lasted for decades. Such ice islands were rare because very few glaciers drift into the Arctic Ocean. Starting in the 1970's, ONR shifted to manned camps on thinner mobile sea ice. Logistic and support techniques have been perfected to the point that such camps are now routine for Arctic research and are used to support under-ice naval operations. Ice camps are the research and equipment platforms for studying large scale sea ice in its environment. Up-to-date information on the extent, position, thickness and break up characteristics of sea ice are vital for Arctic naval missions. An understanding of the large scale response of sea ice to its environment is needed for solving many important practical and theoretical problems ranging from the interaction between the ice cover and global circulation to navigation on and under the ice-covered sea. Picture courtesy ofA . Heiberg. PAE TT A A ERA PRO IT a Office of Naval Research One/1998 eEVIEWS pr 2 23 History of the ONR Chair in Sea Ice Thickness Arctic Marine Science Distribution as a State R. H. Bourke Variable A. Thorndike 6 Historical Perspectives on 25 the Arctic Program at the Project SPINNAKER; Office of Naval Research ICESHELF 1988 -1996 and T. B. Curtin Beyond J. L. Newton 9 Arctic Climate Variability: 29 Observations and Model Interdisciplinary Interaction Simulations in Arctic Research J. E. Walsh H. J. Niebauer 13 Bottom Water Formation and Distribution in the Weddell Departments Sea A. L. Gordon 12 17 Profiles in Science Sea Ice Growth in Antarctic 32 Leads: Top Freezing vs. List of papers from the Bottom Melting CHIEF OF NAVAL RESEARCH S. F. Ackley American Geophysical Union RADM Paul G. Gaffney, II, USN Meeting dedicated to the 19 ONR Arctic Marine Science DEPUTY CHIEF OF NAVAL RESEARCH TECHNICAL DIRECTOR Modeling Sea Ice Behavior Chair 20th Anniversary Dr. Fred Saalfeld R. S. Pritchard CHIEF WRITER/EDITOR William J. Lescure About the cover Finger rafting is a common phenomenon in ice covered regions. Individual fingers range in scale SCIENTIFIC EDITOR from centimeters to hundreds of meters, and usually occur in regular patterns. The finger shown here Dr. Robert H. Bourke is about three meters long. The precise mechanism for finger rafting is not well understood Dr. Thomas B. Curtin Naval Research Reviews publishes articles about research conducted by the laboratories and contractors of the MANAGING EDITOR Office of Naval Research and describes important naval experimental activities Manuscripts submitted for Norma Gerbozy publication, correspondence concerning prospective articles, and changes of address, should be directed to Code OOPA, Office Naval Research, Arlington, VA 22217-5660. Requests for subscriptions should be directed to the ART DIRECTION Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20403 Naval Research Cynthia Nishikawa Reviews is published from appropriated funds by authority of the Office of Naval Research in accordance with Jorge Scientific Corporation Navy Publications and Printing Regulations. NAVSOP-35 One/1998 istory of the ONK air in Arctic Marine cience Robert H. Bourke, Department of Oceanography, Naval Postgraduate School, Monterey, CA The polar marine science community is a small seg- Today this diverse group, encompassing members from ment of the much larger and broader U.S. and international a broad spectrum of the geophysical sciences, is gathered to marine science community. It is a close knit community as honor both the U.S. Navy, in particular the Office of Naval attested that most of us gathered in this room this afternoon Research, for having the wisdom and foresight to establish a know a considerable number of the attendees. We may be research Chair in Arctic Marine Science and the scientists small in numbers but we are truly global in our interests as who have occupied the Chair. In 1976, 20 years ago, the many of us study phenomena and processes associated with Chair was founded through the efforts of Warren Denner and both the Arctic and Antarctic polar regions. The polar ocean- Ron McGregor. Twenty years later the occupants of the Chair ography community is truly international in its make up with read like a who’s who in polar marine science with repre- most U.S., Canadian and European scientists having worked sentatives from universities, government and research labo- together over the years. In the past 15 years this interna- ratories, a variety disciplines and five different countries tional cooperation has flourished with meetings and work- (Table 1). Today we will hear from 13 of these Chair alumni. shops being held in the U.S. and Europe and attended by Before I introduce our honored colleagues and speak- members from many countries including colleagues from ers, let me digress and tell you of the early history of the Asia. As an example, think back and recall how many dif- Chair, its formation and evolution. ferent countries were represented on the Polarstern during In the years after WWII during the 1950s and 1960s, the MIZEX experiments. Another example is to note that the U.S. Navy exhibited little interest in the Arctic region, over 15 countries had scientists present at the Nansen Cen- i.e., the Navy didn’t expect to conduct war fighting opera- tennial Symposium in Bergen in 1993. tions there. However, scientists from various universities Naval Research Reviews Table 1: Occupants of the ONR Arctic Marine Sciences Chair 1976-77 PROFESSOR WARREN W. DENNER 1983-84 PROFESSOR WALKER O. SMITH 1990-91 PROFESSOR JOHN L. NEWTON Naval Posigraduate School University of Tennessee Consulting Scientist (Ice Dynamics/Mechanics) (Ice Edge Biology) (Arctic ASW) 1977-78 PROFESSOR ALLAN M. BEAL 1984-85 PROFESSOR H. JOSEPH NIEBAUER 1991-92 PROFESSOR ALAN S. THORNDIKE Arctic Sub Lab University of Alaska University of Puget Sound (Sea Floor Bathymetry) (Ice Dynamics) (Sea Ice Physics) 1978-79 PROFESSOR WILFORD F. WEEKS 1985-86 PROFESSOR STEPHEN A. ACKLEY 1992-94 PROFESSOR JAMES H. WILSON CRREL CRREL Consulting Scientist (Ice Mechanics) (Ice Mechanics) (Arctic Ambient Noise and ASW) 1979-80 PROFESSOR ALLAN R. MILNE 1986-87 PROFESSOR JOHN E. WALSH 1994-95 PROFESSOR ARNOLD L. GORDON IOS (CANADA) University of Illinois Lamont-Doherty Earth Observatory (Ambient Noise) (Sea Ice Variability) (Antarctic Circulation) 1980-81 PROFESSOR PETER WADHAMS 1987-88 PROFESSOR ROBERT S. PRITCHARD 1996-97 PROFESSOR LAWSON W. BRIGHAM Scott Polar Research Institute Consulting Scientist Cambridge University, USCG (Ret) (Ice-Wave Interaction) (Arctic Sea-Ice Dynamics) (Remote Sensing, Ice Operations) PROFESSOOLRA M. JOHANNESSEN 1988-89 PROFESSOR ARNE FOLDVIK University of Bergen University of Bergen (Marginal Ice Zone) (Ocean-Ice Shelf Interaction) PROFESSOR MILES G. MCPHEE 1989-90 PROFESSOR JAMES H. MORISON Private Consultant University of Washington (Ice-Water Boundary Layer) (Under-Ice Boundary Layer Dynamics) were interested in studying a broad range of topics related to When Warren Denner returned to NPS in 1976, he the Arctic environment. In 1947 the Naval Arctic Research convinced the NPS administration to establish a research Laboratory (NARL) was established at Pt Barrow in Alaska Chair supported by ONR. This was no easy task as Chairs to provide a base of operations for these scientists. When were a new entity to NPS at that time. Warren was the first Warren Denner joined the faculty of NPS in 1963, he inher- Chairholder and worked to establish its foundations of pro- ited and expanded a course in Polar Oceanography based viding a means to make the civilian polar science commu- mainly on the venerable Russian work of Zubov. Warren nity aware of the Navy’s needs and capability to conduct recognized the need to get these naval officer students into operations in, above and beneath ice-covered waters. The the field to experience the harsh realities of the polar envi- objectives of the Chair, as defined 20 years ago, are still valid ronment so he arranged to have the class taught at NARL in today: (1) the Chairholders are to conduct polar research 1964/65. The class continued to be offered twice a year at and assist in translating basic knowledge into operational NARL until the lab closed in 1978. products and (2) to inculcate a love of polar science in NPS During the late 60s, early 70s, when the ARLIS and students and students from their own institutions in order to T-3 ice camps were in operation, Warren got to know Ron provide the Navy with a cadre of officer and civilian polar McGregor who was the Polar Program Manager at ONR. In experts. 1973 Warren was selected to be the Director of NARL where In 1977-78 Alan Beal held the Chair. Alan had a long, he remained until 1976. It was during these years that War- illustrious career at the Arctic Submarine Laboratory work- ren and Ron recognized the need to increase the Navy’s ing with its founder, Waldo Lyon. He served as Chief Scien- awareness of polar science. The reluctance to consider po- tist on many of the icebreaker cruises that my colleague, Bob lar operations as a potential warfare theater was one mainly Paquette, and I participated in. Alan passed away several borne of ignorance, with the important exception of the sub- years ago, the only deceased Chairholder among the Chair marine force who recognized its significance after the suc- alumni. cessful trans-Arctic voyage of NAUTILUS in 1958. In 1978, when Warren left NPS, Bob Paquette took One/1998 over the duties of Chair Administrator during which time he Table 2 recruited Willy Weeks, Allen Milne, Peter Wadhams, Ola Technological Advances Johannessen and Miles McPhee to the Chair. I took over as the Chair Administrator in 1983/4 upon the retirement of GPS Bob Paquette and have had the good fortune to recruit and - provides precise navigational accuracy work with 12 more Chairholders since then. As I said earlier, the Chairholders represent a broad Satellites spectrum of countries, universities and labs and disciplines. - visual, infrared, microwave, radar Four have come from other countries: Allen Milne from - frequent, wide area remotely sensed observation Canada, Peter Wadhams from England, Ola Johannessen and Arne Foldvik from Norway. Government labs are represented Arctic Buoy Program - surface pressure/winds and temperature throughout Arctic basin by Alan Beal from ASL, Willy Weeks and Steve Ackley from CRREL, and John Newton from NRAD. Private consulting SUBICEX/SCICEX companies are represented by Miles McPhee, Bob Pritchard - submarine science measurement programs and Jim Wilson. When categorized by scientific discipline, the largest Icebreakers preponderance is, perhaps not surprisingly, associated with - deep penetration into Arctic Ocean sea ice, the all pervasive medium that defines the polar re- - North Pole and Trans-Arctic voyages “routine” gime. In this category I have included Warren Denner, Willy CTD Weeks, Peter Wadhams, Steve Ackley, Bob Pritchard and - continuous observations in the vertical, increased speed and Alan Thorndike. Their studies mainly concern ice mechan- accuracy ics, its properties, strength, thickness and temporal and spa- tial distribution. The study of the ocean underlying the ice ADCP cover, i.e., its physical oceanography has been conducted on - ship/moored current observations over large segments of the micro to macro scales by Arnold Gordon, Arne Foldvik, Joe water column Niebauer, Jamie Morison, Miles McPhee and, if we fold in the specialty of remote sensing, we include Ola Johannessen Computer Power and Lawson Brigham. The Navy has long had an interest in - in situ data processing/analysis - high resolution forecast/simulation models developed acoustic propagation and noise generation in the polar seas tied to submarine operations in ice-covered waters and the Acoustic Sensors conduct of ASW missions to counter the submarine threat. - horizontal and vertical directionality This group of applied scientists includes John Newton (who - upward looking sonars for ice draft observations has ridden on most of the SUBICEX boats and participated in many ice camps), Jim Wilson, Allen Milne, Alan Beal and Data Sets Warren Denner - longer records, higher quality We have two remaining Chairholders whose specialty is not in either of these three preceding groups. Walker Smith is the lone biological oceanographer but is well known for My initial intent was to include some anecdotal re- his interaction with the physical oceanographers. Indeed, marks for each Chairholder relative to their stay in Monterey. he and Joe Niebauer have teamed up over the years in large However, the compacted schedule prevents me from doing part because their tenure in the Chair overlapped and opened this. I can say that all have enthusiastically enjoyed their the door for a shared view of the oceanography near the ice time at NPS and found it highly productive. Most finally edge. Our lone mid-westerner and atmospheric scientist, John found time to complete long over due manuscripts, thought- Walsh, has shown how climate variability affects the ice dis- fully examine old and recent data sets or participate in plan- tribution on seasonal, annual and longer time scales. ning for future field projects. In this latter regard, ONR Although the Chair was initially set up to further our actively involved the Chairholders in much of the early plan- knowledge and understanding of the processes affecting the ning for the MIZEX series of experiments and follow on Arctic Ocean and its peripheral seas, it soon broadened to experiments such as CEAREX and LEADEX. Many acted polar seas in general. Like many of you in the room today, as thesis advisors for our Naval Officer students; their ex- many of our Chairholders have conducted research in Ant- pertise was highly sought after by both our faculty and stu- arctic waters, notably Arnold Gordon, Steve Ackley, Willy dents. One of the side benefits of the Chair has been the Weeks, Arne Foldvik, Peter Wadhams, Walker Smith, Jamie continued interaction with NPS faculty long after their de- Morison, and Miles McPhee. In their talks this afternoon parture from the Chair. The collegial relationships devel- you will hear of the similarities and differences between these oped at NPS have lead to joint partnerships on research two ice-covered oceans. projects and scholarly papers. I am also appreciative of the Naval Research Reviews help they gave me in providing lectures in the Polar Ocean- Table 3 ography course. Scientific Advances An important and integral part of the Arctic Chair team are the ONR Polar/High Latitude Program Managers who Circulation have provided guidance and financial support for the Chair. - improved knowledge of surface, intermediate, deep waters Leonard Johnson took over from Ron McGregor in the late - seasonal, interannual and decadal variability 1970s and he and Tom Curtin have since been the mainstays - role of continental shelves, convective cells, canyons of program support for the Chair, and Arctic marine science in general, for the past two decades. To them we owe a debt Ice Rheology of gratitude for steering numerous field programs from in- - improved models relating to ice deformation processes ception to successful completion. Tom Curtin, in the next talk, will highlight the purpose and scientific advances of Ice Concentration/Thickness some of these major programs. Today Mike Van Woert heads - temporal and spatial distribution up the ONR High Latitude program. He sends his regards to - long term trends our honored alumni. Unfortunately, he is unable to join us this afternoon as he is on a long awaited trip to Antarctica at Heat Flux this moment. - albedo, leads/polynyas, cloud cover, boundary layer We have chosen the theme of this anniversary session to look back upon the advances we have made in the past Geochemistry twenty years, and they are indeed impressive, and to suggest where we might focus our attention, resources and effort for - water mass, circulation tracers the next 5 to 10 years. Each of our Chairholders will ad- Acoustic Propagation dress the accomplishments and potential future direction for - underice scattering models the various disciplines they represent. It is our intention to - signal processing to reduce reverberation, improve target recog publish their talks as a collection of extended abstracts nition In order to kick off this theme I have prepared the two following tables which illustrate some of the technological Russian Data/Collaboration advances (Table 2) of the past 25 years and the scientific - access to Russian arctic advances (Table 3) that have resulted from this improved - historical data bases of many parameters technology. The lists are by no means complete but do serve to illustrate how far we have pushed the scope of our under- Climate Models standing of Arctic processes - dominant role of arctic region in global circulation, climate stud- As we look back over the past 20 years, I think we would all agree that indeed we have made substantial progress 1es in our understanding of the processes that drive the Arctic atmosphere ice-ocean environment. They have been years National/Naval Ice Center, ONR, the Naval Research Lab filled with challenging and exciting field programs, mostly and other commands. On the other hand, the operational conducted in the Alaskan-Canadian-Greenland sector of the forecasts they routinely produce and interpret were for the Arctic. We can look forward to increased mutual coopera- most part developed and continuously improved by the col- tion with our Russian colleagues and perhaps joint observa- lective efforts of many of you sitting in the audience this tional programs conducted in the Siberian Arctic. Much data afternoon. exchange has recently take place with Russian scientists and Because of the breadth and visibility that the Chair even more is anticipated. Instead of field programs con- brings to the study of polar marine science, I am pleased to ducted mainly in the spring and summer seasons, we can report that ONR will continue to support the Chair for the anticipate data collection efforts year ‘round as remote or foreseeable future. Announcements and advertisements in autonomous instruments will relay their data via satellite or EOS have gone out for next year’s Chair. So, if you are internet back to our labs. This may be the route that we will interested in spending a year at Monterey, starting next fall, take if we are to set up a continuous monitoring program to or perhaps sometime in the next few years, please contact observe the remarkable changes that have been taking place me. in the Arctic Ocean since the start of this decade. Now as we commence our program to celebrate the I think we can say that the goals of the Chair have Arctic Chair’s 20th anniversary, I salute our former been met. The Navy has developed a pool of officers who Chairholders and ONR program sponsors. I look forward to have a strong appreciation for the impact of the Arctic envi- welcoming many more of you to the Chair in the coming ronment on all aspects of naval operations. These officers years. occupy positions of technical and strategic importance at the One/1998 Historical Perspectives on the Arctic Program at the Office of Naval Research Thomas B. Curtin, Office of Naval Research, Arlington, VA “In the history of exploration of the North country, the ogy, geology, and environmental influences of the North United States Navy has played a most significant and excit- country on man and to that end is getting underway a pro- ing role. The names of Admiral Robert E. Perry, Admiral gram for the scientific information of Arctic conditions in Richard E Byrd, Commander Donald B. MacMillan, Com- the United States’ own Arctic territory, the northern slopes mander Richard Cruzen, Commander Lincoln Elllsworth and of Alaska. With this basis of information and the possibility of Dr. Elisha Kent Kane, a naval medical officer who led his of exchange of information from other sources, the Navy expedition in search of a lost Sir John Franklin expedition, should have a complete picture of the true north and there- immediately make one realize how great has been the role fore be able to use it to its fullest possible extent. that the United States Navy has played in searching the mys- “This last frontier of exploration presents an exciting teries of the North.” (Shelesnyak, M.C. and V. Stefansson, field not alone in terms of the old geographical exploration, 1947) but more in terms of the utilization of our finest and newest For more than fifty years, the Office of Naval Research techniques in geophysical and biological science applied to has continued the tradition of scientific inquiry by maintain- a large and vast area of relatively unknown territory. It is a ing an active, multi-disciplinary, Arctic basic research pro- true challenge to the research-minded youth of our country.” gram. The tenets of the program, set forth in 1947, remain (ibid., 1947) valid today: In addition to high quality investigations across a range “Specifically, however, the Office of Naval Research of scientific disciplines, key elements of the program, estab- is interested in precise information regarding the meteorol- lished at inception and maintained for over a half century, 6 Naval Research Reviews are international collaboration, bold field experiments, de- tified and its mechanisms elucidated. The Nordic Seas have velopment and use of innovative technology, and support of been determined to be carbonate vice silicate dominated graduate students. oceans, leading to a role in global carbon sequestration. Near Singular among federal research programs in any field, surface bacterial abundance at high latitude is far greater than the Arctic Program at the Office of Naval Research has been previously thought. The properties of permafrost are known managed by just seven people spanning over fifty years (Fig- and were used to great advantage in pipeline construction ure 1). The tradition of proactive, involved managers was Bathymetric, magnetic and gravity fields have been mapped established early as documented in one of the program’s first to useful, but not high, resolution. Understanding how much publications: there is yet to be understood is always sobering. However, The Office of Naval Research has many Arctic experts contrasting man’s knowledge of the Arctic marine environ- working on various phases of its Arctic research program. ment from a view in 1945 to one in 1998 gives an apprecia- Several of these men have contributed to this pamphlet. Sir tion of how much has been accomplished Hubert Wilkins has written a valuable introduction and Dr. Logistics has always been inextricable from science Vilhjalmur Stefansson has compiled a useful bibliography in the Arctic. Ice stations or camps have been central ways on Arctic literature. The main article of the pamphlet was of doing business since Nansen pioneered the method with written by Dr. M.C. Shelesnyak, Head of the Environmental the Fram. A relative ice station activity index for the pro- Physiology Branch, Office of Naval Research. gram is plotted at the bottom of Figure 2. During peak years, “Dr. Shelesnyak gathered material about the Arctic as logistics costs typically consumed 20-40% of the program United States Naval Observer with the Moving Forces, Ca- budget. The locations of ice stations since 1971 are shown nadian Army Winter Arctic Expedition, Operation Musk-Ox, in the inside front cover of this issue. From the mid sixties in 1945. The expedition traveled by motorized, tracked ve- to the late seventies, many expeditions in the western Arctic hicles 3100 miles across the Canadian Arctic prairies, Queen were staged from the Naval Arctic Research Laboratory Maude Gulf, Coronation Gulf and southward from (NARL) at Point Barrow, Alaska. Eastern Arctic stations Coppermine to Port Radium, across Great Bear Lake and were staged from Greenland or Norway. Since the Navy’s down through the bush country along the Alaskan-Canadian divestiture of NARL to the North Slope Borough in the late Highway to Edmonton. Dr. Shelesnyak’s first-hand knowl- seventies, there has been a slow but steady trend toward au- edge of the Arctic was further broadened by his experiences tonomous instrumentation. That trend is expected to accel- in traveling by dog sled from Coppermine N.W.T. to Cam- erate in the coming years with advances in microprocessors, bridge Bay, Victoria Island, having left the Moving Forces navigation and communication technology. Cunsidering the to rejoin them later.” (ibid., 1947) number and diversity of people involved, the variability and Measures of the fifty years of research supported by extremes of nature, the remote and Spartan accommodations the program are the associated cumulative scientific litera- on the ice, and the invariably tight budgets, it is a notable ture and the strategy and tactical procedures, both military tribute to the operations managers over the years that all have and commercial, influenced by that knowledge. A compre- returned safely to analyze their data. hensive bibliography has not been compiled. To do so would From a historical perspective, there have been three be a major task, and no doubt the result would be impres- stages of United States Naval interest in the Arctic. The first sive. A few of of the major insights achieved over the years stage was marked by exploration, driven by personalities like are highlighted in Figure 2. Atmospheric circulation pat- Figure 1 terns and pollutant (haze) pathways are now well established. Program managers of the Arctic Program since its inception The mechanical, electrical and chemical properties of sea at the Office of Naval Research. ice as well as its dynamics and thermodynamics over a hier- archy of scales are known well enough to enable predictive models with some skill. The statistics of sea ice extent, vari- 1947 - 1954 M.C. Shelesnyak ability, drift, and to some degree its thickness have been de- termined. Propagation of sound, both at low and high 1954 - 1970 M.E. Britton frequencies, including scattering and transformation into a rich class of plate waves some of which were discovered 1970 - 1975 R. McGregor initially in the Arctic, can now be modeled accurately. Am- bient noise mechanisms have been established. The Ekman 1975 - 1984 G.L. Johnson spiral, derived theoretically, was first observed in the Arc- tic, as was thermal microstructure. The ocean circulation, 1984 - 1994 T.B. Curtin including water mass residence times and mesoscale eddy distributions, is now generally known. Unique aspects of 1994 - 1996 M. Van Woert the internal wave spectrum have been documented. The high primary productivity in the marginal ice zone has been quan- 1998 - Dennis Conlon One/1998 Figure 2 A few of the major insights by discipline achieved over the years of the Arctic Program at the Office of Naval Research. Haze Origin, Composition MET Surface Pressure/Derived Wind Stress Fields Boundary Layer Model Polar Low Genesis Extent, Variability Drift Statistics Thickness Distribution Classes of Plate Waves Thermodynamic Model Dynamic Model Stress-Strain Fields Mechanical, Electrical, Chemical Properties Crack Propagation Ice Scattering Properties Propagation Models with Scattering Conn See eyeee seers Acoustic-Plate Wave Energy Partition Ambient Noise Mechanisms Phase Stability IASCECEAO USTICS Observed Ekman Spiral Circulation Beaufort Gyre Structure Mesesesie Saties Atlantic Layer Warming Internal Wave Spectrum nhSe rmal9 Microstructure Water Mass Resi, dence Times High Carbon Flux in Nordic Seas Composition of Scattering Layers MIZ Eddy Productivity Bacterial Abundance Permafrost Properties Bathymetric, Magnetic, Gravity Fields Ice Cover Paleo-Stability Tectonic Evolution of Western Arctic i i 1 i 1 4 1946 1955 1957-58 1966 1967 North Slope 1976 1986 ; DEW IGY SAT Development Arctic Buoy Program, Moorings, Arctic Chair (NPS) : , Line NAV ——_—Submarine Cruises —_ i NARL —_Decp Convection __ Perry, Byrd, Ellsworth and Kane. The second stage waschar- Ned Ostenso, Norbert Untersteiner and Willy Weeks con- acterized by more calculated investigations and classified tributed significantly to this article. operations, framed by the cold war and the advent of the nuclear submarine. The Office of Naval Research was es- REFERENCES tablished at the beginning of this second stage, and the Arc- tic program has existed only in this context until recently. Shelesnyak, M.C. and V. Stefansson, 1947. Across the Top The third stage began with the end of the cold war. The of the World, A Discussion of the Arctic. Office of investment strategy and method of operation for the current Naval Research, Navy Department, NAVEXOS P- Stage are evolving now. This evolution is in many ways un- 489, Washington, D.C., 71 p. precedented. Acknowledgments The collective principal investigators spanning fifty years are the essence of the ONR Arctic Program. The com- plete history of the Program lies in their accomplishments reflected both in the scientific literature and in numerous unrecorded, successful naval missions accomplished. Art Baggeroer, Andy Heiberg, Ken Hunkins, Leonard Johnson, Naval Research Reviews