The most apparent problems—logistics and trafficability—caused by the Arctic ice, either in the marginal ice zone or in the permanent ice pack, are relatively well understood compared to the problems of Arctic warfare. Arctic warfare problems are largely concerned with submarine and aviation elements, since non-ice-strengthened surface combatants must steer clear of ice—infested waters if icebreaker support is not available—and even with icebreaker support they are still limited to the edges of the pack. (The Navy's old icebreakers were transferred to the Coast Guard years ago, and there have been no replacements.)
Assuming that antisubmarine warfare (ASW)—either with SSNs or with aviation units—is the major naval function to be performed in Arctic force projection, an ice cover leads to functional problems in hunting, killing, and search and rescue (SAR) that must be incorporated into integrated concept and exercise plans. Furthermore, the ice cover has important ramifications in developing tactical intelligence. Therefore, the technical knowledge of sea ice developed during the past two decades by government laboratories and their contractors, and by the Arctic off shore oil industry, must be transmuted into intelligence, planning, and operational concepts meaningful to high-level Navy policymakers.
Salt water, once frozen, forms an ice cover that attains an equilibrium thickness of three meters by the end of the freezing season, assuming there is no wind and ocean-current stress on the ice. Inmost areas, however, there are powerful stresses, and the ice—being elastic in large expanses—folds, crumples, and deforms into the underwater keel shapes, much deeper than three meters, well known to SSN navigators and sonarmen. This sea ice deformation varies widely from place to place. Figure 1 shows what this deformed under-ice surface looks like to an upward-looking sonar fathometer. There are several operational concerns that depend on this information.
Surfacing: Submarines need either open water or thin ice in order to surface. Foreknowledge of the probability of finding surface locations is valuable for operational, SAR, and intelligence purposes.
Hiding: Knowing the probability of finding keels could provide valuable intelligence and have an impact on plans development.
Passive or Active Sonar Tracking. The rougher the under-ice surface, the more the acoustic energy transmitted through the area will be attenuated, causing acoustically guided weapons to find targets. Knowledge of how this roughness varies geographically could impinge on both operations and intelligence-gathering, and should be considered in developing plans.
ASW from the Air: Figure 1 demonstrates how the ice cover limits the use of traditional airborne ASW techniques. The small region marked "thin ice" may have open-water areas suitable for standard sonobuoys; even a day before this record was taken, this region may have been all open water, as a result of stresses on the ice that ruptured it, forming a now mostly frozen "lead." However, this "thin ice" is the only area where standard sonobuoys could be emplaced. Looking again at Figure 1, an airborne drop into this area would have only a 20% chance of encountering ice of three meters or less.
The same arguments hold for airborne weapons deployment; the warhead would have to penetrate the ice into the water below. A knowledge, therefore, of the geographical distribution of ice deformation could be as important to ASW operations in the Arctic as standard navigation charts are to surface operations elsewhere.
SAR: Although search and rescue of aircraft downed in the Arctic Ocean is difficult, it has been successful at times. Chances are good that a disabled aircraft can land on the ice, rather than in the water. If the aircraft has an operable transmitter, and the crew members have adequate survival gear, they can be rescued by helicopter if one is within range; if not, a fixed-wing aircraft probably could land safely on the ice nearby. But it is not a straightforward proposition.
I was with the Office of Naval Research Arctic Program in the early 1960s. I was on watch when an R4D from the Naval Arctic Research Laboratory at Barrow, Alaska, went down on the ice in the dark of midwinter. Despite frantic calls from concerned Pentagon flag officers dimly aware of our Arctic flying operations, the Navy was ill-prepared to rescue the crew. Fortunately, the Air Force still had an active Arctic operation, based in Fairbanks, and had experienced pilots available who regularly made landings on the ice. The Air Force rescued the crew. One cannot help but wonder what the R4D crew's fate would be if the same disaster occurred today.
Sea ice vastly complicates SAR if an SSN needs assistance. Could she surface through the ice? If she could not break through the ice, but could come to rest against the ice's undersurface, could she bore a hole to the surface to let men escape, or to deploy an antenna? And once she does accomplish either of these things, what then? Careful planning in order to mount a cooperative effort between SSN and aviation units is probably necessary. Some areas will be far more complicated than others.
The more open water or thin ice in a given area, the greater the probability of finding a location for surfacing or ASW operations. See Figures 2 and 3. Figure 2 shows the percentage of the Arctic Ocean ice surface that is actually open water or thin ice; i.e., locations where a submarine may surface, or where airborne ASW can be most successfully conducted. Figure 3 is a chart of the probability of finding deep-draft keels (defined as greater than 30 meters deep). This chart indicates where it is safest to hide, and most difficult to conduct airborne ASW and gives locations of maximum acoustic attenuation. Information portrayed in charts similar to Figures 2 and 3 should play a substantial part in developing tactical strategies for combined airborne and SSN operations in the Arctic, which, in turn, should influence plans and exercises in this theater.
The charts in Figures 2 and 3, like old navigation charts, may well contain errors owing to the limited data used and the assumptions made in compiling data recorded at different times. However, such charts, even with errors, can be valuable guides for planning exercises and intelligence-gathering and, as new data become available, they can be corrected and updated.
Sea ice places Arctic operations in a special category. ASW tactics used by either aircraft or SSNs must be modified for the Arctic environment. These modifications are in addition to those needed for interpreting Arctic acoustic data. The Navy has already gathered much of the environmental data needed to modify ASW tactics and strategies. These data reside with the various Navy laboratories and need to be processed and presented in ways that benefit planners for both air and SSN ASW operations.
In recent years, the Arctic offshore oil industry has developed a large sea-ice data base that could be tapped, particularly regarding the crushing and fracturing strength of various types of sea ice and the remote sensing of sea ice from the air. An unprecedented joint Navy/oil industry remote-sensing operation conducted a few years ago yielded valuable data: an oil industry airborne laser profiler measured the ice surface while an SSN measured the under-ice surface along the same track. Correlations were made that permit predicting under-ice conditions from airborne laser data. More such cooperative ventures should be encouraged.
Planners need to recognize that the Arctic oceanic environment is substantially different from that of the open ocean, especially as far as employment of ASW tactics is concerned. As much sea ice data as possible need to be gathered, compiled, and put into a format that planners and operators can understand.