Atmospheric circulation and storm events in the Black Sea and Caspian Sea

Abstract

Extreme sea storms are dangerous and a potential source of damage. In this study, we examine storm events in the Black Sea and Caspian Sea, the atmosphere circulation patterns associated with the sea storm events, and their changes in the present and future (2046)(2047)(2048)(2049)(2050)(2051)(2052)(2053)(2054)(2055)(2056)(2057)(2058)(2059)(2060)(2061)(2062)(2063)(2064)(2065) climates. A calendar of storms for the present climate is derived from results of wave model SWAN (Simulating WAves Nearshore) experiments. On the basis of this calendar, a catalog of atmospheric sea level pressure (SLP) fields was prepared from the NCEP/NCAR reanalysis dataset for 1961-2000. The SLP fields were subjected to a pattern recognition algorithm which employed empirical orthogonal decomposition followed by cluster analysis. The NCEP/NCAR reanalysis data is used to evaluate the occurring circulation types (CTs) within the ECHAM5-MPI/OM Atmosphere and Ocean Global Circulation Model (AOGCM) for the period 1961-2000. Our analysis shows that the ECHAM5-MPI/OM model is capable of reproducing circulation patterns for the storm events. The occurrence of present and future ECHAM5-MPI/OM CTs is investigated. It is shown that storm CTs are expected to occur noticeably less frequently in the middle of the 21 st century.

Radar-derived convective storms' climatology for the Prut River basin: 2003–2017

“…In this case, high atmospheric pressure prevails to the west of the Black Sea region. The second SLP pattern shown by Surkova et al (2013) reveals an atmospheric trough spreading from the eastern Mediterranean towards the Black Sea, which is blocked to the north by a high-pressure field. Our correlation map linking the monthly number of convective systems in the Prut basin with the SLP (Fig.…”

“…13 and 14 supports the hypothesis that extratropical cyclones passing the Black Sea are the main large-scale dynamical drivers of convection in the Prut River basin. The patterns of atmospheric circulations which can lead to the presence of low SLP over the Black Sea are those identified by Surkova et al (2013) using clustering analysis. The first SLP pattern in the paper of Surkova et al (2013) shows an atmospheric trough extending from Scandinavia and the Baltic Sea to the Black Sea.…”

“…The patterns of atmospheric circulations which can lead to the presence of low SLP over the Black Sea are those identified by Surkova et al (2013) using clustering analysis. The first SLP pattern in the paper of Surkova et al (2013) shows an atmospheric trough extending from Scandinavia and the Baltic Sea to the Black Sea. In this case, high atmospheric pressure prevails to the west of the Black Sea region.…”

“…In Asia, Wang et al (2014) studied the statistical characteristics of convective initiation in the Beijing-Tianjin region, using radar data over the period 2008 showed that there are dense convective initiation activities around 200 m elevation, meaning that convective storms are more easily triggered over foothills; the highest convective initiation density was found in urban areas, while the second highest convective initiation density was found in the forest-type land cover areas. Radar-derived statistics of convective storms and their concomitant changes with thermodynamic variability in South-east Queensland, Australia, was performed by Peter et al (2015), concluding that convective storms are found to form and maintain along elevated topography, westerly regime storms occur less frequently and have shorter lifetimes, and westerly regime storms are primarily driven by large-scale forcing, whereas northerly and trade wind regime storms are more responsive to surface characteristics.…”

Wind waves in the Black Sea: results of a hindcast study

“…There are two prevailing types of large-scale sea level pressure (SLP) fields causing storms over the Black Sea (Surkova et al, 2013). These types are revealed by clustering analysis (k means) from the set of SLP fields only for storm days with SWH ≥ 4 m. One SLP pattern is characterized by a cyclone over the Black Sea or nearby.…”