1. Meteotsunamis in the Mediterranean Sea: rare but destructive extreme sea level events occurring under specific synoptic conditions Ivica Vilibić, Jadranka Šepić Institute of Oceanography and Fisheries, Split, Croatia, vilibic@izor.hr  About meteotsunamis  Mediterranean events  Connection to the synoptics  Some conclusions and perspectives

2. About meteotsunamis Sea Level Workshop, Palma, June 2015  Highly resonant phenomenon, very rare occurrence at destructive levels Šepić et al., Sci. Rep., 2015

3. About meteotsunamis Sea Level Workshop, Palma, June 2015  Driven by travelling air pressure disturbances (occasionaly winds) Vilibić et al., JGR, 2004 Vilibić et al., PAGEOPH, 2008

4. Mediterranean events Sea Level Workshop, Palma, June 2015 milghuba šćiga marrobbio rissaga  Recorded at different Mediterranean locations and basins

5. Sea Level Workshop, Palma, June 2015 Mediterranean events  Some events: Vela Luka, Croatia, 21 June 1978  6-m waves at the top of the bay

6. Sea Level Workshop, Palma, June 2015  Some events: Vela Luka, Croatia, 21 June 1978  6-m waves at the top of the bay Mediterranean events Vučetić et al., Phys. Chem. Earth, 2009

7. Sea Level Workshop, Palma, June 2015  Some events: Ciutadella, Spain, 15 June 2006  5-m waves at the top of the bay, strong currents Tens of sunk and damaged yachts, loss of ~30 MEuro. Mediterranean events Monserrat et al., NHESS, 2006

8. Sea Level Workshop, Palma, June 2015  Normally occurring locally at destructive levels, encompassing a few tens of kilometres at most  bays of Mali Lošinj and Ist (distanced by 50 km) were not hit by a meteotsunami at the same time 21 June 1978 Vela Luka (~6 m) 5 October 1984 Ist (~4 m) 27 June 2003 Stari Grad (~3.5 m) Mali Ston (currents) 22 August 2007 Ist (~4 m) 15 August 2008 Mali Lošinj (~3 m) 25 June 2014 Vela Luka (~3 m) Stari Grad (~1 m) Vrboska (~1.5 m) Rijeka dubrovačka (~2.5 m, currents) Mediterranean events

9. Sea Level Workshop, Palma, June 2015 Mediterranean events  Small changes in disturbance speed may end up in several times different wave heights  extremely sensitive to resonant conditions Šepić et al., JGR, 2015

10. Sea Level Workshop, Palma, June 2015  However, exceptional events may occur over thousand of kilometres  Fresh example of 22-27 June 2014 (Šepić et al., 2015)  A series of destructive meteotsunamis hit the Mediterranean and Black Seas, following a peculiar atmospheric setting at synoptic scale Mediterranean events Šepić et al., Sci. Rep., 2015

11. Sea Level Workshop, Palma, June 2015  27 June 2014: 2-m wave injured 12 people in Odessa  Due to Ukrainian situation, extraordinary explanations flooded the media Mediterranean events

12. Sea Level Workshop, Palma, June 2015  The event was connected to a propagating upper troposphere "storm", giving rise to a numerous air pressure disturbances ("boiling atmosphere") Connection to synoptics Šepić et al., Sci. Rep., 2015

13. Sea Level Workshop, Palma, June 2015  A half of moderate and strong meteotsunami events observed on the Balearic Islands are followed by similar events in the Adriatic Sea within 1-2 days Connection to synoptics Šepić et al., Phys. Chem. Earth, 2009

14. Sea Level Workshop, Palma, June 2015 Connection to synoptics Šepić et al., JGR, 2012  That was already recognized in research of the Balearic and Adriatic meteotsunamis  quite useful for creation of a warning system  however, only qualitative forecasts may be issued  Below: Average SLP, T at 850 hPa and winds at 500 hPa reanalysis fields for 16 events at Rovinj (Adriatic)

15. Sea Level Workshop, Palma, June 2015 Connection to synoptics  Confirmed by numerical modelling (atmosphere)  Below: air pressure and winds during the 2007 ist meteotsunami as reproduced by the WRF mesoscale model 22 August 2007, 15:12 UTC Šepić et al., JGR, 2009

16. Sea Level Workshop, Palma, June 2015 Connection to synoptics  In general, high-frequency sea level oscillations in the Mediterranean (not only meteotsunamis) may be attributed to synoptic patterns  Details may be found on the poster by Šepić et al. Šepić et al., Prog. Ocean., 2015, under review

17. Sea Level Workshop, Palma, June 2015 Some conclusions and perspectives  Ocean physics during meteotsunamis well understood and reproduced by ocean models  Atmosphere physics a less well understood, but quite hard to reproduce by numerical models  a need for better knowledge on gravity wave generation and propagation in the atmosphere  Connection to a propagating synoptic patterns exists  useful for warning systems  also useful for assessing long-term and future meteotsunami potential from climate models  Efficient meteotsunami warning systems are still far from operational, but a concept of such a system is developable  based on an assessment of synoptic conditions, real-time high- frequency air pressure measurements and remote sensing data (satellites, HF radars)