Improving PM2.5 modelling results through development of the new hourly temporal emission profile – a case study of Poland

High concentrations of atmospheric aerosols with aerodynamic diameter below 2.5 mm (PM2.5) are frequently observed in several Central European countries during the heating season (October – March). Poland belongs to a group of EU countries with the highest concentrations of PM2.5, according to the European Environmental Agency. Large exposure to atmospheric pollutants leads to significant number of premature deaths attributable to adverse air quality in Poland.

Coal combustion for residential heating is one of the main sources of PM2.5 in Poland. The quality of this fuel is often unknown, and this increases the uncertainty of national emission inventories and makes the modelling of PM2.5 concentrations challenging. Second, daily temporal emission profile (i.e. hours of the day when emission is released to the atmosphere) in residential heating sector is also rather uncertain. In this work, we developed a daily temporal emission profile using available measurements of PM2.5 and PM10 concentrations from the 2017-2018 heating season. The profile was compared with the existing profile proposed within the INERIS project. New profile has longer peak of afternoon and night time emission, if compared to INERIS, and the morning peak is significantly lower. It means that more emission is released to the atmosphere during unfavorable meteorological conditions such as calm winds and temperature inversions, which are frequently observed during the afternoon and night.

We have run two simulations using the EMEP4PL model with new and old (INERIS) emission profile. The simulations covered three heating seasons of 2015-2016, 2017-2018 and 2018-2019. Application of the new emission profile results in increased model – measurements correlation and reduced model bias.