A data fusion method to improve winter PM10 concentration predictions in Budapest based on the CAMS air quality models
<div> <p><span>Winter air pollution in Budapest is a major environmental issue, caused by an interaction of residential heating, urban traffic and large-scale transport.&#160;I</span><span>ncreasing public and political&#160;demand&#160;are</span><span>&#160;present to achieve&#160;</span><span>more accurate air quality predictions to support both real-time public health measures and long-term mitigation policies.&#160;&#160;</span><span>A</span><span>tmospheric chemistry and transport models of the Copernicus Atmospheric Monitoring Service (CAMS) provide&#160;</span><span>near-real-time&#160;</span><span>air quality forecasts for Europe</span><span>. The validation of these model predictions for Budapest showed that although large-scale processes are well captured,&#160;the complex interaction of large-scale plumes with significant and highly variable local residential emissions leads to the underestimation of winter PM10 concentrations. Furthermore, CAMS models are not expected to fully predict the non-representative concentrations at specific urban monitoring locations, which, on the other hand, serve as the legal basis of all public policies and measures. Therefore, obtaining a relationship between monitoring site observations and CAMS model predictions is of primary importance.</span>&#160;</p> </div><div> <p><span>In this study, we used observed PM10 concentration data from 12 air quality monitoring sites within Budapest, as well as 24-hour predictions from 7 of the 9 CAMS models to </span><span>produce an optimal linear combination of models that best matched, in terms of RMSE, the observed time series. A zero-degree term to correct the model bias was also applied. The applied data fusion method was cross-validated on urban monitoring sites not used in fitting the model, and&#160;found to improve PM10 forecast validation statistics compared to the pointwise model median (CAMS ensemble) as well as each of the 7 single models. The presented fusion of CAMS models can therefore provide an improved prediction of PM10 concentrations at urban monitoring sites in Budapest.&#160;</span>&#160;</p> </div>