Natalia Liora

Air-Quality Impact of Cruise and Passenger Ship Emissions in the Port of Thessaloniki

The impact of cruise and passenger ship emissions on air quality and human health risk in the greater Thessaloniki area has been studied for the present and future time. The study focuses on the pollutants regulated by the EU legislation. Simulations have been performed using the CALPUFF dispersion model for 2013, in order to estimate the pollutant surface concentrations due to passenger ship traffic. Additionally, projections for the year 2025 have been made, accounting also for emission mitigation measures including the use of LNG as ship fuel and the implementation of Cold ironing technology. Ship emissions have been estimated using the movement methodology of the EMEP/EEA. Population exposure maps have been prepared on the basis of the simulated surface concentrations, providing an overview of the affected areas and population. For both the present time and the future trend projection the NO2 is of major concern, with the hourly concentrations exceeding the air-quality limit. When the LNG scenario is adopted, future NO2 concentrations are expected to be reduced over the urban area by more than 40 %, while the exposure of the population will be significantly reduced.

Comparison of Ground-Based Tropospheric NO 2 Columns with OMI/Aura Products in the Greater Area of Thessaloniki by Means of an Air Quality Modeling Tool

Phaethon is a ground-based MAX-DOAS system, easily deployed at different locations to address specific air quality problems and support satellite validation studies. Three Phaethon systems have been deployed at different sites in the greater area of Thessaloniki, characterized by diverse local pollution levels representing urban, suburban and rural conditions, aiming at linking tropospheric trace-gas modeling with satellite products. Tropospheric NO2 columns derived at these sites located within an area of about 15 by 30 km, comparable to the size of OMI/Aura pixel, are compared with the satellite retrievals. The OMI/Aura products underestimate the NO2 in the city centre, representing the average pollution levels in the sub-satellite pixel area which, in the case of Thessaloniki, corresponds mostly to rural conditions. In order to minimize the collocation differences in spatial distribution between satellite and ground-based measurements, the former are adjusted by factors that are calculated by means of a high resolution air quality modeling tool, consisting of WRF meteorological model and CAMx air quality model. This approach shows significant improvement in the comparisons between ground-based and satellite-derived observations.

Vertical Separation of Desert Dust and Biomass Burning Aerosol Layers Over Thessaloniki Using the Synergy of Sunphotometer and Lidar Data

In this study we separate the layers of the dust aerosol component, arriving from the Saharan desert region, from the smoke layers, originating from fires in Ukraine during selected multi-layered measurement cases over the Balkans. We apply the Lidar-Radiometer Inversion Code (LIRIC) which is capable to derive the mass concentration profiles for the fine and coarse mode particles, using combined sunphotometer and lidar data. Lidar and CIMEL measurements, performed at the Laboratory of Atmospheric Physics of the Aristotle University of Thessaloniki, Greece (40.5N, 22.9E), were used for this purpose. The vertical separation of the layers is further examined against model simulation. Back trajectories from the Lagrangian model HYSPLIT are used in combination with MODIS satellite data for fires spots, in order to examine the origin of the aerosol layers. The daily evolution of the event is also analyzed using lidar and CIMEL measurements.

An Up-to-Date Assessment of the Air Quality in Greece with the Use of Modeling Tools

A modeling system that consists of the meteorological model WRF and the photochemical model CAMx has been applied in very high horizontal resolution (2 km) in order to assess the air quality in Greece. An updated, high resolution emission inventory was compiled for all the main anthropogenic pollutants (CO, NOx, SO2, NMVOCs, PM10, PM2.5) while emissions from natural sources (dust, sea salt and biogenic NMVOCs) were calculated using the Natural Emissions MOdel (NEMO). Toxic particulates, such as As, Cd, Pb, Ni and benzo-(a)-pyrene, were simulated as inert pollutants. Simulations were performed for one month of every season of the year 2012, namely for the months of January, April, July and October. The comparison of simulated pollutant levels and those measured at the stations of the National Monitoring Network of the Air Quality revealed a satisfactory performance of the photochemical model. Following the EU legislation for the protection of human health and vegetation, the exceedances of the air quality limits were calculated for every grid cell over Greece.

Study of the impact of natural sources on the air quality – Evaluation of a natural emissions model

A Natural Emissions MOdel (NEMO) driven by the meteorology of the Weather Research and Forecasting (WRF) model has been used in order to estimate particle emissions from windblown dust, sea salt and primary biological aerosol particles (PBAPs) as well as Biogenic Volatile Organic Compounds (BVOCs) emissions from vegetation. NEMO is applied on a 30km spatial resolution grid, which covers Europe for the year 2009. NEMO emissions results of dust, sea salt and BVOCs were incorporated in a photochemical modelling system consisted of the WRF model and the Comprehensive Air Quality model with extensions (CAMx). Anthropogenic emissions data have been taken by the Netherlands Organization (TNO). The modelling system is implemented for different emission scenarios, which concern the exclusion of natural sources in the simulations in order to study their impact on the European air quality. A model evaluation indicated a good model performance.