Atlantic water extent on the Faroe Current monitoring section

This is the third in a series of reports documenting efforts to optimize the future monitoring system for the Faroe Current and optimize algorithms that allow high-quality extension of transport time series back to the start of satellite altimetry in 1993. Together, these reports serve to update the algorithms presented in Hansen et al. (2015). The first of these three reports (Hansen et al., 2019a) addressed the velocity field on the monitoring section and concluded that this field could be adequately simulated from satellite altimetry, once the altimetry data had been calibrated by in situ observations. The second report (Hansen et al., 2019b) addressed the hydrographic fields with the main focus on a preliminary analysis of the results from an experiment with two PIES (Pressure Inverted Echo Sounders) deployed on the section 2017-2019. From the analyses in this second report, it was concluded that PIES ought to be an integral part of the future monitoring system. The present report builds further on that and presents a complete design for the future monitoring system. The main topic discussed here is, however, how best to combine satellite and in situ data in order to simulate the Atlantic water extent and its variations throughout the satellite altimetry period, which is a prerequisite for generating time series of volume, heat, and salt transport of the Atlantic water in the Faroe Current as far back in time as possible at the present stage.