AGU, 2003 Greenland Iceland Shet- land Faroes image:AGU 2003 Cost ‐ efficient monitoring of the main Atlantis inflow to the Arctic Mediterranean B. Hansen, K.M.H Larsen, H. Hátún, S. Østerhus Atlantic inflow Arctic Mediterranean North Atlantic Atlantic 0.9 Sv 3.5 Sv 2.7 Sv Optimizing the North Atlantic observing system

AGU, 2003 image:AGU 2003 Iceland Faroes Monitoring section

The Monitoring section through the IF-inflow Salinity Velocity (cm/s) ADCPs

Weekly averaged Atlantic inflow between Iceland and Faroes

Problems with the existing monitoring system Extrapolating ADCPs to surface Interpolating between ADCPs Lack of T and S data Money and effort

Instrumentation

Future monitoring system One Deepwater ADCP Two trawl- resistant Bottom Temp- erature loggers Satellite altimetry

Temperature from up to 95 CTD cruises Atlantic water Average 4°C isotherm ± Standard deviation Satellite altimetry ADCP Bottom temperature How much of the variance in the lower boundary of Atlantic layer can be explained by measured variables 19% 21% 15% 15% 15% 3% 3% 3% explained by ADCP 17% 34% 42% 60% 48% 30% 25% 16% explained by Altimetry 50% explained by Bottom temp. Standard CTD station Monitoring heat- and salt-, but also volume transport requires monitoring temperature and salinity Arctic water

Temperature sensor Acoustic modem TEmperature Longterm Logging by BOttom Grounded Instrumentation Battery capacity > 10 years NACLIM

The research leading to these results has received funding from the European Union 7th Framework Programme (FP ), under grant agreement n NACLIM