1. A new Deep Water formed in the NW Mediterranean in 2005 J. Font (1), J. Salat (1), M. Emelianov (1), P. Puig (1), A. Palanques (1), A. Julià (1), J.L. López-Jurado (2), C. González-Pola (3) and J. Flos (4) (1) Institut de Ciències del Mar CSIC, Barcelona, Spain (2) Instituto Español de Oceanografia, Palma de Mallorca, Spain (3) Instituto Español de Oceanografia, Gijón, Spain (4) Universitat de Barcelona, Barcelona, Spain (contact: jfont@icm.csic.es)

2. NW Mediterranean, a well known site for dense water formation (1) Westen Mediterranean Deep Water (WMDW) Open sea convection Where: offshore the Gulf of Lions: MEDOC area (42º N, 5º E) How: 1. Salty LIW is brought to near surface due to winter convection 2. Mixing with surface “old” AW + intense cooling and evaporation (Mistral wind) = WMDW violent sinking during strong Mistral episodes. LIW upwelling is maintained to compensate sinking. 3. New WMDW spreads in the deep ocean Schott and Leaman, JPO, 1991

3. NW Mediterranean, a well known site for dense water formation (2) Western Intermediate Waters (WIW) Open sea convection Where: near the northern continental slope How: 1. Surface relatively less salty water, “recent” AW brought by the Northern current + intense cooling and evaporation = WIW sinking above the LIW layer (up to 400 m). 2. New WIW spreads along the slope advected to the south by the Northern current.

4. NW Mediterranean, a well known site for dense water formation (3) Other dense watersCascading Where: over the shelf How: 1. Surface lower salinty (river influenced) water + intense cooling and evaporation (Mistral wind) = dense water sinking to the bottom of the shelf to reach the slope. 2. Cascading over the slope and canyons down to match its density. Typically WIW layer. Exceptionally deeper if winter is very cold, windy or dry

5. NW Mediterranean Water masses LIW WIW LIW WMDW

6. Exceptional 2004-2005 winter Precipitation on the W Mediterranean catchment area during winter 2004-2005 was very scarce. Minimum absolute values ever recorded in many of the meteorological stations. From 25 January to 10 March, 2005, air temperatures were lower, especially daily maxima, than the climatological average, and northerlies were strong and persistent Maximum NCEP heat flux since 1948 (72% above average) Fevrier 2005: Sur 16 jours de tramontane, le vent a atteint ou dépassé pendant quatre jours les 100 km/h. Le 28 Février un record du maximum le plus bas a été battu à PERPIGNAN: 1.5°C (précédent record: 3.8°C en 1934) Janvier 2005: Sur dix-huit jours de tramontane, le vent a atteint ou dépassé pendant trois jours 100 km/h. From climatological summaries of MétéoFrance for the Mediterranean coast

7. Sequence of Chl_a daily images January - March 2005: Dense water formation area (identified by low Chl_a) very persistent and extense

8. CIESM Hydro-Changes CSIC mooring 41º 28’ N / 3º 40.4’ E 1845-m depth T, S, and current (October 2003 - July 2005) EuroStrataform CSIC moorings Cap de Creus C. 200, 500 and 750-m depth T, S, Turb. and current (September 2004 - April 2005) Moorings in NW Mediterranean

9. Intense events in early 2005, followed by a new warmer, saltier steady state CIESM Hydro-Changes site Records at 1830 m Very intense current when the most dense water arrives

10. EuroStrataform winter 2003-2004 Monitoring of 7 submarine canyon heads at 300-m depth Shelf water cascading, preferably towards the W sector Palanques, A., Durrieu de Madron, X., Puig, P., Fabrés, J., Guillén, J., Calafat, A., Heussner, S., Canals, M., Boninn, J. (2005). Suspended sediment fluxes and transport processes in the Gulf of Lions submarine canyons. The role of storms and dense water cascading. Marine Geology, submitted. - 1.5 ºC

11. EuroStrataform winter 2004-2005 Focused study in the Cap de Creus canyon head Intense (earlier and longer) shelf water cascading - 3 ºC + 70 cm/s

12. CIESM Hydro-Changes + EuroStrataform sites Current direction

13. Catalan coast monitoring in winter 2005: shelf stations WMDW

14. Open sea: “EFLUBIO-3” cruise B/O “Cornide de Saavedra” 15 March - 6 April 2005 15-22 March 24 March-06 April Underway surface salinity Potential density at 25 m

16. MEDOC area

17. MEDOC + other open sea areas

18. Cross-slope section near Barcelona: no front, LIW ascent

19. Detailed general S diagram: WMDW O N C

20. θS of mooring time series

21. CONCLUSIONS The anomalously dry, windy and relatively cold 2004 – 2005 winter produced an intense deep convection covering a long period and larger area: The smaller fresh water inputs and limited supply of recent AW, plus strong winds, produced a widespread cascading over the shelves recorded in the coastal monitoring Type C WMDW formation recorded at the mooring while falling downslope to deeper areas of the W Mediterranean and at the Barcelona slope cross-section A large amount of LIW is brought to near surface over the area typically occupied by the relatively recent AW recorded by surface underway analysis during the cruise: especially from the MEDOC area to Barcelona and at the Barcelona slope cross-section Type N WMDW formation where WIW is typically produced recorded at many cruise stations: MEDOC area, North and East of Balearic Islands (+ saltier LIW? + more LIW from Sicily channel?) Type O WMDW formation in open seas recorded at many cruise stations: MEDOC area, North and East of Balearic Islands

22. Summer 2005, open sea TUNIBAL St. 321 Latitude: 40 40.15 N Longitude: 03 23.30 E 15 July 2005 A new deep water structure is present in the NW Med Are we sensing the effects of the Eastern Mediterranean Transient? And for sure the dramatic effects of an anomalously dry and windy winter