Monitoring the marine environment

Transcription

1 Monitoring the marine environment D. Velaoras & E. Krasakopoulou Hellenic Center for Marine Research (HCMR) Seasera Mediterranean Workshop September 2012 Ifremer Toulon

2 POSEIDON multi parametric monitoring stations (buoys) Yellow colored positions show multi-depth stations

3 Cretan Sea buoy In-situ temperature May 2007 to January 2009

4 Cretan Sea buoy Salinity May 2007 to January 2009

5 East Ionian Sea (Pylos) buoy salinity January 2008 to January 2011

6 Cretan Sea intermediate layer (400m) : Temperature and Salinity increase (~0.2 o C and 0.06 psu) between October 2007 and October 2008 South-East Ionian Sea (Pylos) intermediate layer (250m): Temperature and Salinity increase (~0.7 o C and 0.2 psu) between October 2008 and October 2010 _ In general, interannual changes in intermediate/deep water masses in the EMed signify changes in circulation as well as in oceanic biogeochemical processes and carbon sequestration. Consequently, it is extremely important to monitor physical and biogeochemical parameters in their formation sites, namely the Cretan Sea and the Rhodes Gyre area.

7 CIESM / HYDROCHANGES deep water monitoring mooring Θ at 850m depth (Fall 2007 Fall 2010)

8 ARGO float profiles June 2010 March 2012 Data from ARGO profilers is a cost-effective way to monitor water mass characteristics.

9 In this transect example, LSW and CIW/LIW masses are observed in the Cretan Sea in March 2011.

10 Monitoring deep basin nutrients in the North Aegean Sea Evolution of DO and nutrients at the deep layer (>400m) in Lemnos basin (North Aegean) during the stagnation period following the deep water formation event of 1993 (last EMT peak production year) All quantities in mole 9.0x x10 10 DO 8.6x x x x x x10 7 PO 4 5x x10 9 4x10 7 SiO 4 2.0x x x x x x x x x10 8 NO years after major deep water formation

11 while during deep-water formation episodes nutrient content decreases in the deep layers and nutrient enriched masses move towards the euphotic zone enhancing biological production (example: 1987 deep layer characteristics in Lemnos basin) Nutrient content Winter 1987 x10 7 mol Summer 1987 x10 7 mol Difference x10 7 mol PO SiO NO Using similar data at the other basins which behaved in a similar way, we get a total of 18.2 x 10 7 mol PO 4 upwelled, ten times more than the spring Dardanelles outflow

12 Sediment trap moorings as well as CTD casts, investigate atmospheric deposition, particle and biogeochemical fluxes, including contaminants, nutrient dynamics and productivity

13 Total mass flux

14 Increased particle fluxes after 2008 may be linked to upwelling due to the reversal of the Ionian circulation which at this time has changed to anticyclonic (BiOs theory) C org (left) and N tot (bottom) fluxes

15 Future perspectives for the next 3 years: Reducing the POSEIDON monitoring stations to 3 (Athos, Cretan Sea, Pylos) with enhanced capabilities. Buoys will be equipped with additional sensors (air and surface CO 2, surface ph, as well as T, S and Oxygen sensors at various depths) Installing sediment traps at various depths at the POSEIDON sites. Characterization of sinking particles could provide valuable information on the C and N sources and budgets and on the biogeochemical processes Introducing 2 Gliders to fill knowledge gaps in the Aegean and Ionian Seas Installing upgraded deep moorings in each of the Cretan Straits capable of monitoring temperature, salinity and current, to successfully diagnose deep water outflow from the Cretan Sea to the EMed

16 Future perspectives for the next 3 years: Taking part in major multidisciplinary EU and national projects in the Greek Seas and the EMed: PERSEUS The Aegean Sea Experiment (AEGEX), closely aligned with the data provided by the POSEIDON Observing System, will investigate atmospheric deposition, particle and biogeochemical fluxes including contaminants, nutrient dynamics and productivity in the Aegean Sea and interpret them in relation to circulation dynamics, dense water formation on shallow banks and cascading, as well as inter-basin transport. MedEx Studying the impact on the ecosystems in the vicinity of the Straits connecting the Mediterranean Sea with the adjacent Basins. Five cruises were performed in the period from early December to mid-may in an area most affected by BSW as well as in adjacent areas free from this water mass.

17 Future perspectives for the next 3 years: MedEcos Studying the decadal scale Variability of the Mediterranean Ecosystem (re-evaluation of field observations, hydrodynamic and ecosystem modelling, high resolution analysis of sedimentary records) AegeanMarTec - Technological and oceanographic cooperation Network for the Study of mechanisms fertilizing the North-East Aegean Sea. The project investigates the two major physical mechanisms of fertilization of the Aegean Sea, i.e. the inflow of mesotrophic waters from the Black Sea in the North Aegean, and the wind-generated coastal upwelling taking part in the Eastern Aegean every summer and their consequent effect on the carbon uptake by the ocean.

18 Thank you for your attention!