EGU21-10000
https://doi.org/10.5194/egusphere-egu21-10000
EGU General Assembly 2021
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Wave climate in the Black Sea: description and trend evaluation using new ECMWF-ERA5 reanalysis and wave-current interaction.

Salvatore Causio1, Piero Lionello2, Stefania Angela Ciliberti1, and Giovanni Coppini1
Salvatore Causio et al.
  • 1Fondazione Centro Euro-Mediterraneo sui Cambiamenti Climatici (CMCC), Lecce, Italy
  • 2University of Salento, Lecce, Italy

This study analyzes the evolution of the wave climate in the Black Sea basin in a 31-year long hindcast (1988-2018) performed with the third-generation wave model WaveWatchIII v5.16, forced by the ECMWF-ERA5 reanalysis winds at 30km of spatial resolution and 1-hour frequency. The wave model is implemented on a grid covering the whole Black Sea, with 3km grid step and is off-line coupled with a NEMO based hydrodynamical model. The wave spectrum is discretized using 24 directional sectors, and 30 frequencies, with 10% increment starting from 0.055Hz. The model is implemented to solve deep water processes, following the WAM Cycle4 model physics, with Ultimate Quickest propagation scheme and GSE alleviation, which is implemented in WWIII. Wind input and dissipation are based on Ardhuin et al. (2010), wave-wave interactions are based on Discrete Interaction Approximation. Currents and air-sea temperature difference are provided to the wave model to account for Doppler shift and atmospheric stability above the sea. Model validation and statistical analysis have been carried out to describe the wave climate of the Black sea, considering the following wave fields: significant wave height (Hs), mean wave period (Tm) and mean wave direction. Statistics as Mean, Maximum, 5th percentile and 95th statistics have been computed to produce monthly climatologies. The work considers also the evaluation of trends for Hs and Tm, and the evaluation of tendency in the occurrence frequency of mean and max fields for Hs and Tm.

There is no evidence about an overall trend in Hs and Tm, but tendencies can be highlighted in some months and seasons. The most evident trend occurs in Summer on the whole wave spectrum, with reduction of Hs and Tm in the Eastern basin, and increasing in the South-Western basins. Even the evaluation of occurrence frequencies suggests that Black Sea is subjected to a change in the wave regime.

How to cite: Causio, S., Lionello, P., Ciliberti, S. A., and Coppini, G.: Wave climate in the Black Sea: description and trend evaluation using new ECMWF-ERA5 reanalysis and wave-current interaction., EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10000, https://doi.org/10.5194/egusphere-egu21-10000, 2021.

Corresponding displays formerly uploaded have been withdrawn.