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On 27 June, a 1–2-m high wave struck the beaches of Odessa, the third largest Ukrainian city, and the neighbouring port-town Illichevsk (northwestern Black Sea). Throughout the day, prominent seiche oscillations were observed in several other ports of the Black Sea. Tsunamigenic synoptic conditions were found over the Black Sea, stretching from Romania in the west to the Crimean Peninsula in the east. Intense air pressure disturbances and convective thunderstorm clouds were associated with these conditions ; right at the time of the event, a 1.5-hPa air pressure jump was recorded at Odessa and a few hours earlier in Romania. We have utilized a barotropic ocean numerical model to test two hypotheses: (1) a tsunami-like wave was generated by an air pressure disturbance propagating directly over Odessa (‘‘Experiment 1’’) ; (2) a tsunami-like wave was generated by an air pressure disturbance propagating offshore, approximately 200 km to the south of Odessa, and along the shelf break (‘‘Experiment 2’’). Both experiments decisively confirm the meteorological origin of the tsunami- like waves on the coast of Odessa and imply that intensified long ocean waves in this region were generated via the Proudman resonance mechanism while propagating over the northwestern Black Sea shelf. The ‘‘Odessa tsunami’’ of 27 June 2014 was identified as a ‘‘beach meteotsunami’’, similar to events regularly observed on the beaches of Florida, USA, but different from the ‘‘harbour meteotsunamis’’, which occurred 1–3 days earlier in Ciutadella (Baleares, Spain), Mazara del Vallo (Sicily, Italy) and Vela Luka (Croatia) in the Mediterranean Sea, despite that they were associated with the same atmospheric system moving over the Mediterranean/Black Sea region on 23–27 June 2014.

A simulation of the Turkish Straits System (TSS) using a high-resolution, three-dimensional, unstructured mesh ocean circulation model with realistic atmospheric forcing for the 2008–2013 period is presented. The depth of the pycnocline between the upper and lower layers remains stationary after 6 years of integration, indicating that despite the limitations of the modelling system, the simulation maintains its realism. The solutions capture important responses to high-frequency atmospheric events such as the reversal of the upper layer flow in the Bosphorus due to southerly severe storms, i.e. blocking events, to the extent that such storms are present in the forcing dataset. The annual average circulations show two distinct patterns in the Sea of Marmara. When the wind stress maximum is localised in the central basin, the Bosphorus jet flows to the south and turns west after reaching the Bozburun Peninsula. In contrast, when the wind stress maximum increases and expands in the north–south direction, the jet deviates to the west before reaching the southern coast and forms a cyclonic gyre in the central basin. In certain years, the mean kinetic energy in the northern Sea of Marmara is found to be comparable to that of the Bosphorus inflow.

The Regional Ocean Modeling System ocean model is used to simulate the decadal evolution of the regional waters in offshore Iberia in response to atmospheric fields given by ECMWF ERA-40 (1961–2001) and ERA-Interim (1989–2008) reanalyses. The simulated sea surface temperature (SST) fields are verified against satellite AVHRR SST, and they are analysed to characterise the variability and trends of coastal upwelling in the region. Opposing trends in upwelling frequency are found at the northern limit, where upwelling has been decreasing in recent decades, and at its southern edge, where there is some evidence of increased upwelling. These results confirm previous observational studies and, more importantly, indicate that observed SST trends are not only due to changes in radiative or atmospheric heat fluxes alone but also due to changes in upwelling dynamics, suggesting that such a process may be relevant in climate change scenarios. Keywords: climate change, upwelling, ROMS, reanalyses (Published: 22 May 2013) Citation: Tellus A 2013, 65 , 19245, http://dx.doi.org/10.3402/tellusa.v65i0.19245