AUVs Under Ice: A Four-Decade Retrospective on Strategy and Risk Through the Autosub Looking Glass

Abstract

Abstract Autonomous underwater vehicles (AUVs) have been used in the polar regions for decades. The technical challenges are well understood, and since the mid 1990s, missions of several hundred kilometers under sea ice have been possible. However, there remains a large gap between the endurance achieved in practice and the 1000+ km needed for large-scale sea ice studies; multiple, parallel sections under West Antarctic ice shelves; or sections under the Filchner-Ronne Ice Shelf. This retrospective examines how the U.K. Autosub program's requirements for under ice observations were determined and how those requirements helped build a strategy for a decade of technical progression and scientific achievement. At times progress was faltering, vehicle reliability was inadequate and the approach to risk management was reactive rather than proactive. New analytical tools, some controversial, were developed to assess and manage risk and to drive improvements. While new satellite techniques arguably reduced the need for deployments under sea ice, they remain the only effective solution to fill data-gaps in bathymetry and ocean/ice interactions under ice shelves. The challenge for international collaboration is to accelerate the development of robust and reliable vehicles. The first task remains to survey the basic geometry of the key Antarctic ice shelf cavities. Taking a decadal view, AUV capability should expand to be capable of yearlong deployments under critical ice shelves.