A standardized methodology for the validation of short-term air quality forecast applications was developed in the framework of the Forum for Air quality Modeling (FAIRMODE) activities. The proposed approach, focusing on specific features to be checked when evaluating a forecasting application, investigates the model's capability to detect sudden changes in pollutant concentration levels, predict threshold exceedances and reproduce air quality indices. The proposed formulation relies on the definition of specific forecast modelling quality objectives and performance criteria, defining the minimum level of quality to be achieved by a forecasting application when it is used for policy purposes. The persistence model, which uses the most recent observed value as the predicted value, is used as a benchmark for the forecast evaluation. The validation protocol has been applied to several forecasting applications across Europe, using different modelling paradigms and covering a range of geographical contexts and spatial scales. The method is successful, with room for improvement, in highlighting shortcomings and strengths of forecasting applications. This provides a useful basis for using short-term air quality forecasts as a supporting tool for providing correct information to citizens and regulators.

Assessment of the concentrations of dust pollution resulting from both measurements at reference stations and those determined using mathematical modelling requires accurate identification of the sources of emission. Although the concentration of dust results from several complex transport processes, as well as chemical and microphysical transformations of aerosols, sources of emissions may have a significant impact on the local level of pollution. This pilot study aimed to use measurements of the concentrations of dust (with the specification of the PM10 and PM2.5 fractions) made over a heap/excavation and its surroundings using an airship equipped with equipment for testing the optical and microphysical properties of atmospheric aerosols, and a ground station located at the facility. On the basis of the measurements, the function of the source of emissions of dust was estimated. According to our study, the yearly emission of dust varies between 42,470 and 886,289 kg for PM10, and between 42,470 and 803,893 for PM2.5 (minimum and maximum values). A model of local air quality was also used, which allowed us to verify the parameterization of emissions of dust pollutants for the PM10 and PM2.5 fractions from heaps and excavations based on the modelling results.

A standardized methodology for the validation of short-term air quality forecast applications was developed in the framework of FAIRMODE activities. The proposed approach, focusing on specific features to be checked when evaluating a forecasting application, investigates the model capability to detect sudden changes of pollutants concentrations levels, to predict threshold exceedances and to reproduce air quality indices. The proposed formulation relies on the definition of specific forecast Modelling Quality Objective and Performance Criteria, defining the minimum level of quality to be achieved by a forecasting application when it is used for policy purposes. The persistence model, which uses the most recent observed value as predicted value, is used as benchmark for the forecast evaluation. The validation protocol has been applied to several forecasting applications across Europe, using different modelling paradigms and covering a range of geographical contexts and spatial scales. The method is successful, with room for improvement, in highlighting shortcomings and strengths of forecasting applications. This provides a useful basis for using short-term air quality forecast as a supporting tool for correct information to citizens and regulators.

The residential sector is one of the most important emissions sources affecting air quality in Poland. According to KOBiZE IEP-NRI, in 2018 this sector accounted for 63% and 82% of the national totals for PM10 and PM2.5.  We attempted to assess the impact of the national “Clean Air” Programme that focuses on the replacement of old solid-fuel furnaces and boilers. The proposed scenarios assumed that the heating devices were replaced in approx. 2 million single-family houses. A random selection of the building was applied:Scenario-1 - emission reduction for all administrative units in Poland.  Scenario-2 - emission reduction for administrative units were the annual average PM2.5 concentrations in 2019 exceeded the threshold of 20 µg/m3 The emission factors were changed to represent the fuel standards set for modern heating systems. The GEM-AQ air quality model was used as a computational tool (Kaminski et al. 2008).  We will present the scenario effectiveness based on different metrics. The implementation of emission reduction in the residential sector would significantly reduce health exposure due to PM10, PM2.5, and B(a)P dust. Due to the assumptions regarding the fuel mix of new installations, the background concentrations of nitrogen oxides and ozone would slightly increase, but this would not change the exposure.

Cities in Poland still suffer from poor air quality during winter. Most intense smog episodes, with very high PM10 and PM2.5 concentrations, occur during calm periods, with temperature inversions when the emission from residential sources with low injection height increases. Modelling results tend to underestimate those episodes, despite the good agreement with measured data during low and mid-concentration periods. While the variability of near-surface concentrations is well-known based on the fixed stations and the low-cost sensors measurements, the information on vertical distribution is limited.As measurements with drones tend to be problematic and weather balloons measure only meteorological parameters, new approaches are being developed. In Cracow (in the past one of the cities in Poland with the worst air pollution) measurement campaign with the use of sensors installed on sightseeing, hot air balloons have been carried out in 2019 to check the impact of meteorological conditions on the thickness of the atmospheric layer with poor air quality (Sekula et al., 2021). Helium tethered aerostat (Knap et al., 2021) with installed sensors is also used by the Polish Academy of Sciences as a measurement platform for vertical profiles in Warsaw (the capital city of Poland).These two platforms were used for a short-period measurement campaign in the winter of 2023. The main goal of the project was to assess differences between modelled and observed vertical profiles of temperature, relative humidity, PM10 and PM2.5 in Warsaw and Cracow cities. The national air quality forecast calculated with the GEM-AQ model was evaluated. In addition, the model's capability to reproduce temperature inversion will be examined.We will present and discuss the results of the measurement campaigns, and the comparison with the model results, in different meteorological and air quality conditions.