Annual Regime and Seasonal Change of Cyclone Parameters in the Black Sea-Mediterranean Region in 1951–2017

Intense Cyclones in the Black Sea Region: Change, Variability, Predictability and Manifestations in the Storm Activity

“…Thus, the results obtained confirmed that the indicated climatic processes can be responsible for the interannual variability of the frequency of deep cyclones in the Black Sea region. Earlier, we showed in [42] that correlation coefficients of the winter-spring parameters of the total number of cyclones in the Black Sea region exceeded 0.6 with NAO indices, while they reached 0.49 with Southern Oscillation indices at time lags of 4-6 months, and the joint influence of NAO and ENSO significantly exceeded 50% of the interannual variability of cyclones in the studied region. That is why a similar correlation is expected with deep cyclones identified by quantiles.…”

“…Summer anomalies of extreme cyclones were negligible (Figure 5h). This clearly anomalous period approximately from the mid-1960s to the mid-1970s, with a notable maximum in the number of cyclones, was found both in depth and intensity of the total number of cyclones over the Black Sea region on shorter time series in earlier papers [23,42,70], as well as in the frequency of wave heights [15] and water temperature (on the surface and 100 m horizon) [71]. This and other periods of intensification of deep cyclones are consistent with the periods of increasing and decreasing storm activity in the Black Sea region identified in the papers [15,[72][73][74][75][76].…”

“…Earlier, the authors of this paper showed in [42] that most energy of variability of the total number of cyclones in the Black Sea region in 1948-2006 was concentrated at low frequencies (more than 30 years), and after removing the periodicities of more than 20 years, spectral peaks were observed at periods of about 2 and 4 years. Previously, the range of tasks did not include either analysis of the periodicities of the numbers of deep cyclones, which is of greatest practical interest, or their seasonal contribution to the annual spectra.…”

“…This study was carried out as a part of ongoing research of regional climatic-environmental anomalies in the Black Sea region. Earlier papers were devoted to the number of cyclones in the region [23,42,70] or individual cases of intense cyclones [40], but not to their climatology. The focus of this study was on the long-term variability of the frequency of deep cyclones, which have an important socioeconomic impact.…”

“…First, let us consider and compare the mean values and the spread of values (standard deviation σ) of the frequency of the identified series of deep cyclones by seasons and months. As for the total number of cyclones in the region, an increase was expected in winter and a decrease in summer [42].…”