https://cdn.earthdata.nasa.gov/conduit/upload/5182/KeywordsCommunityGuide_Baseline_v1_SIGNED_FINAL.pdf 23.7 2026-04-15T10:53:30.610Z https://gcmd.earthdata.nasa.gov/KeywordViewer/scheme/projects/2e61366f-04e7-44c2-8d0f-ad44783eccdc ANSLOPE AnSlope seeks an answer to the question: What is the role of the AntarcticSlope Front and continental slope morphology in the exchanges of mass, heat,and freshwater between the shelf and oceanic regimes, in particular thoseleading to outflows of dense water into intermediate and deep layers of theadjacent deep basins and world ocean circulation?The importance to the global ocean circulation and climate of cold water massesoriginating in the Antarctic is now understood, but the processes by whichthese water masses enter the deep ocean circulation are not. We have developeda program called AnSlope to address this problem. Our primary goal is toidentify the principal physical processes that govern the transfer ofshelf-modified dense water into intermediate and deep layers of the adjacentdeep ocean. At the same time, we seek to understand the compensatory polewardflow of waters from the oceanic regime. We identify the upper continental slopeas the critical gateway for the exchange of shelf and deep ocean waters. Herethe topography, velocity and density fields associated with the nearlyubiquitous Antarctic Slope Front (ASF) must strongly influence the advectiveand turbulent transfer of water properties between the shelf and oceanicregimes.AnSlope has four specific objectives: [A] Determine the ASF mean structure andthe principal scales of variability (spatial from ~1 km to ~100 km, andtemporal from tidal to seasonal), and estimate the role of the Front oncross-slope exchanges and mixing of adjacent water masses; [B] Determine theinfluence of slope topography (canyons, proximity to a continental boundary,isobath divergence/convergence) on frontal location and outflow of dense ShelfWater; [C] Establish the role of frontal instabilities, benthic boundary layertransports, tides and other oscillatory processes on cross-slope advection andfluxes; and [D] Assess the effect of diapycnal mixing (shear-driven anddouble-diffusive), lateral mixing identified through intrusions, andnonlinearities in the equation of state (thermobaricity and cabbeling) on therate of descent and fate of outflowing, near-freezing Shelf Water.AnSlope addresses these objectives with an integrated observational andmodeling program structured as follows. A collaborative core program begins in2002, containing the components considered central to meeting AnSlopeobjectives, primarily through acquisition of a set of measurements focused overthe outer continental shelf and upper slope of the northwestern Ross Sea. Thiswill allow us to assess the regional AABW production rate, and to identify thecross-front exchange processes that must be taken into account when assessingprovision of dense water to the deep basins elsewhere around Antarctica. Thecore elements are: moorings; CTD/LADCP and CTD-based microstructure; tracers;and basic tidal modeling. 'Enhancement' proposals, to be submitted separately,request support for the modeling studies that are necessary to fully exploitthe measurements and develop the techniques for parameterizing cross-frontexchanges in regional and global models. Three cruises are proposed, beginningin Austral summer 2003, over a period of 12 to 14 months. Moorings would be inplace throughout this period. The Italian CLIMA program in the Ross Seaprovides a valuable international enhancement for the AnSlope observationalcomponent. The German BRIOS-2 coupled ice-ocean GCM program is complementary tothe US process-oriented modeling studies, and provides a test-bed forAnSlope-generated parameterizations of cross-front exchange.Additional information can be found at'http://www.ldeo.columbia.edu/res/div/ocp/projects/anslope.shtml'