The Fram Strait acoustic tomography system

Abstract

The deep and wide Fram Strait between Greenland and Spitzbergen is the main influx and efflux gate to the Arctic Basin. Although major resources are invested in measurements of current and temperature here (http://asof.npoar.no), the flux estimates still have significant deficiencies and errors. Our objective is to build, test, validate and use an innovated integrated observing and modeling system, including acoustic tomography, for improved monitoring of volume, heat and freshwater transports in the Fram Strait. As part of the DAMOCLES-IP, (=Developing Arctic Modeling and Observing Capabilities for Long-term Environmental Studies - Integrated Project) a first step acoustic tomography system is to be installed in the Fram Strait between East Greenland and West Spitzbergen in August 2008. The first step tomography system consists of one acoustic source near the Svalbard shelf and one receiver array in the middle of the Fram Strait. An extended acoustic system serving both tomography and glider navigation is planned implemented in 2009 within the recently funded project "Acoustic technology for observing the interior of the Arctic Ocean" (ACOBAR). We will present the specification of the tomography systems; our experimental plans, and plans for data analysis, including data assimilation.