Etesians are north to south direction winds in the lower atmosphere, blowing over the Aegean basin from early summer to early autumn. They are an important circulation component for the East Mediterranean (EMED) area, linked to the subsidence and ascent circulation over EMED and the extended Indian monsoon region, respectively. In this study we investigate the evolution of Etesian days and the associated wind speed (10 m) over the recent past (1979–2005) in simulations from Earth System Models (ESMs) available from the Coupled Model Intercomparison Project Phase 5. Results from this analysis are compared to the ERA‐Interim reanalysis. Moreover, we study the connection of the Etesians to the atmospheric circulation over EMED and the wider Indian monsoon area, in particular over the west Indian summer monsoon (wISM) and the Bay of Bengal (BoB). Our findings suggest that while the ESMs underestimate the wind speed of the Etesians, their frequency and summer cycle are in good agreement to reanalysis. ESMs can accurately represent the summer atmospheric circulation and depict the connection between EMED and Indian summer monsoon (ISM), capturing the link between them. Finally, we highlight here the capability and efficiency of ESMs in representing the climatology of Etesians and related atmospheric circulation.

One of people’s greatest concerns about air quality degradation is its impact on human health. This work is a case study that aims to investigate the air quality and the related impact on people’s health in a coastal city over the eastern Mediterranean. The analysis proceeded during a low-tourist density period, covering the days from 17 to 27 November 2022. Hourly ${\mathrm{PM}}_{2.5}$, ${\mathrm{NO}}_2$ and ${\mathrm{O}}_3$ concentration records from three, mobile, Air Quality Monitoring Systems (AQMS), established in an urban location, port and central area of Rhodes city, are analyzed. To investigate the impact of pollution levels on human health, the Air Quality Health Index (AQHI) is calculated. The daily and diurnal variation of pollutants’ concentration and AQHI among the different areas, as well as the relation among the ambient air pollutants and AQHI, are studied. Additionally, to investigate the impact of wind regime on the variation of pollution and AQHI levels, the hourly zonal and meridional wind-speed components, as well as the temperature at 2 m, the dew point temperature at 2 m, and the height of the boundary layer from ERA5 reanalysis, are retrieved for the region of the southeastern Mediterranean. Results show that the highest pollution level occurs in the city center of Rhodes, compared to the rest of the studied locations. In general, the findings do not show exceedances of the pollutants’ concentration according to the European Directive 2008/50/EC. Moreover, findings show that in some cases, the health risk is classified from Low to Moderate in terms of AQHI. The analysis indicates that the climate conditions affect the pollutants’ concentration due to dispersion, and likely, the atmospheric transport of pollutants. Finally, this work aims to improve the knowledge regarding the air quality of southeastern Greece, promoting the framework for the green and sustainable development of the South Aegean Sea.

The Mediterranean is recognized as one of the most sensitive regions regarding climate change. The northern sector winds are a dominant feature of summer low-tropospheric circulation over the Aegean basin in the eastern Mediterranean (EMed). This study is an updated assessment that uses state-of-the-art tools in order to investigate the projected changes in the meridional wind speed and Etesian regime during summer period (June-July-August) over the 21st century. The analysis is based on 17 Global Climate Models simulations (GCMs) available from Coupled Model Intercomparison Project Phase 6 (CMIP6) covering the historical period (from 1971 to 2014) and the future period (from 2015 to 2100) under two Shared Socioeconomic Pathways (SSPs), an intermediate-, and a very high-emission scenario (SSP2-4.5 and SSP5-8.5). Additionally, the results from GCMs analysis are compared to ERA5 reanalysis for the historical period from 1971 to 2000. Our findings suggest that the majority of GCMs reproduce the spatial pattern of Etesians but underestimate the meridional wind speed by about 0.5 to 1.0 m/s, as compared to ERA5. During the future period, the meridional wind speed is projected to be increased over the Aegean basin, mainly during the last period of 21st century. Findings show that the majority of GCM simulations (12 out of 17) show an increase in meridional wind speed of about 0.2 to 1.4 m/s for SSP5-8.5 and 0.2 to 0.6 m/s for SSP2-4.5, as compared to historical period from 1971 to 2000.

Emissions from port operation and shipping have a significant impact on climate risk, affecting the environment and human health in coastal regions (UNEP). The port of Heraklion, located on the island of Crete over the eastern Mediterranean, plays a key role in the sustainability of Southeast Europe. The impact on its operation affects the socio-economic life and development of the region because Heraklion is not just a tourist destination but also a significant trade and transportation center for the eastern Mediterranean. This study investigates the impact of port operation on the air quality of Heraklion between two representative periods. The first, which is considered as the high port activity season, was from 02 August 2018 to 08 August 2018, while the second period was between 11 May 2018 and 16 May 2018. For the air quality measurements, a low-cost sensor was used, while the recordings were initially compared and finally evaluated based on the available data of the monitoring station of the Ministry of Environment and Energy. To investigate the air quality differences between the two studied periods, the correlation analysis, the hourly evolution of pollutants, and the mean differences between high and low periods for gaseous pollutants and particulate matter are studied. Moreover, the effect of meteorology on air quality is investigated. The results indicate that the high season is characterized by significantly higher concentrations of pollutants compared to the other period. In both seasons studied, the air pollution level increases during hours of high port-activity, indicating the impact of port activity on air quality in Heraklion. The analysis shows that meteorology affects the air quality. In particular, strong wind speeds are associated with lower concentrations of gaseous pollutants other than ozone, which is affected by atmospheric circulation. Finally, the analysis emphasizes the importance of further investigation of the impact of port operations on coastal air quality in the context of sustainable development.

El Niño–Southern Oscillation (ENSO) and the Indian summer monsoon (ISM) are the dominant modes of climate variability affecting the tropical and subtropical regions. In this study, we investigate the impact of ENSO episodes, through the modulation of the ISM configuration, on the Eastern Mediterranean (EMed) summer atmospheric circulation over the whole 20th century using state of the art model simulations from the 5th phase of the Climate Model Intercomparison Project (CMIP5). Results are validated against the European Centre for Medium‐Range Weather Forecasts Re‐Analysis, ERA‐20C. Our findings indicate that the variability of ENSO has a significant impact on the low and middle tropospheric circulation of EMed. La Niña (El Niño) events are related to stronger (weaker) ISM activity, which leads to a deepening (weakening) of the Persian low that affects the EMed tropospheric circulation with stronger (weaker) northerly surface winds over the area. Further, La Niña (El Niño) events are related with stronger (weaker) 500 hPa subsidence over the EMed and an intensification (weakening) of the Subtropical Jet Stream between 35°N to 50°N. This work improves our understanding of the teleconnections between ENSO variability and the EMed summer tropospheric circulation via the modulation of the ISM activity and stresses the importance of ENSO on the EMed climate in summer.