A NNUAL AND SEASONAL VARIABILITY OF WIND WAVE PARAMETERS ON THE B LACK S EA F.N. Gippius, V.S. Arkhipkin and G.V. Surkova Lomonosov Moscow State University 11.G

Aims & Tasks The aim is an assessment of wind waves parameters and their multiannual variability on the Black Sea Science of the Future Tasks: Preparation of a digital terrain model of the Black Sea’s bottom and coasts Preparation of a meteorological dataset Simulation of wind waves on the Black Sea Evaluation of seasonal average and extreme parameters Evaluation of multiannual trends Analysis and interpretation of results 2

DATA & METHODS

DTM of bottom and coasts Science of the Future Basis – nautical chart of the Black Sea, M=1:2,5 Mio| Golden Software MapViewer was used to digitize the map | Result – a 129 ×242 cells matrix with 5 km spatial resolution 4

Meteorological data & Wave model NCEP/NCAR Reanalysis Time span from 1948 Spatial resolution – 1,875° × 1,9046° Temporal resolution – 6 hours Meteorological data interpolated on numerical grid SWAN wave model 3G wind-wave model Bottom friction, nonlinear wave-wave interaction, diffraction and breaking considered Science of the Future5

MODEL VALIDATION

AVISO satellite altimetry Science of the Future Late 2009 – nowaday 5-day averaged multimission SWH values 1° × 1° spatial resolution 7

SWAN vs AVISO Science of the Future8

RESULTS

Average wave parameters Science of the Future SWH P L 10

Seasonal SWH maxima Science of the Future WinterSpring Summer Autumn 11

Typical storm cases Science of the Future12

Total storm duration Science of the Future13

Extreme wave parameters Maximal wave height possible once in 100 years (m) Science of the Future14

Interannual storminess variability Annual total duration of storms (h) Science of the Future15 r ≈ -0.35

Interannual storminess variability Annual total duration of storms (h) Science of the Future16 r ≈ -0.25

Seasonal storminess variability Science of the Future17

Conclusion 1.Wave parameters of the Black Sea were simulated continuously from 1948 to Seasonal extreme wind parameters and their spatial distribution were assessed. 3.Trends of interannual duration and quantity of storms derived. Practically no alterations of storm activity observed over the entire hindcast period. 4.Increases and recessions of storminess on the Black Sea correlate with the NAO index Further reading: Arkhipkin, V. S., Gippius, F. N., Koltermann, K. P., and Surkova, G. V.: Wind waves on the Black Sea: results of a hindcast study, Nat. Hazards Earth Syst. Sci. Discuss., 2, , doi: /nhessd , Science of the Future18