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News in 2019
The 8th Workshop "Air Quality and modelling" will take place in Freiburg on 3th and 4th November 2020.
The bi-yearly workshop is intended to highlight current issues of air pollution management in a practice-oriented manner. Experts in the fields of air quality, planning and modelling from Germany and neighbouring countries will meet for talks and lively discussion. The workshop language is German.
If You are interested, please use the registration form or send us a e-mail .
Download registration form (in German) 
We would be pleased to welcome you in Freiburg!
Version 4.1 of the Handbook of Emission Factors for Road Transport (HBEFA) is available.
We are currently analyzing the new approaches and data and will integrate them in our products. As soon as the new version 8.0 of IMMISem/luft is available, our clients will be informed.
Available since August 2019:
VDI 3783 Part 15.1: Environmental meteorology - Simplified determination of the spatial distances for concentration and deposition of air pollutants - Emission of NOX, SO2 and NH3
An employee of IVU Umwelt contributed to the standard as a member of the respective working group.
The standard VDI 3783 Part 15 with its sub-parts describes simplified methods for determining spatial distances, based on a calculation of concentration and deposition values of air pollutants originating from emission sources with different release conditions. The concentration and deposition of the air pollutants NOX (nitrogen oxides), SO2 (sulphur dioxide), and NH3 (ammonia) are important in many investigations, e.g. in connection with the eutrophication and acidification of ecosystems. Starting from a certain distance away from the emission source outwards, the ground level concentration and the deposition of the air pollutants resulting from the emission source decrease constantly. There exists, therefore, a minimum spatial distance starting from which the concentration or the deposition drop below a given value.
This standard VDI 3783 Part 15.1 describes methods for determining minimum spatial distances for sources with a source elevation of up to 20 m above ground that release the air pollutants NOX, SO2, or NH3.
The standard has been developed and published by the ‘VDI/DIN-Commission on Air Pollution Prevention (KRdL) - Standards Committee'. VDI, the Association of German Engineers, is a financially independent and politically unaffiliated, non-profit organization of engineers as well as academics in other disciplines, especially in information science, the natural sciences and mathematics.
More information on VDI 3783 Part 15.1 (in German)
The Copernicus Atmosphere Monitoring Service (CAMS) provides data on atmospheric pollution as part of the European Copernicus programme. These are the results of seven chemical transport mod-els (CTM) and their ensemble. These models provide daily forecasts for the next 96 hours in hourly resolution for various pollutants such as ozone and PM10.
Since the late 1990s, the Federal Environment Agency (UBA) has been publishing maps of nationwide ozone forecasts for information purposes. These ozone forecasts are based on forecasts from the CAMS ensemble. Aim of the project described here was to analyse the extent to which the predictive quality of the CAMS ozone forecasts for Germany can be improved by postprocessing, particularly with regard to the detection of limit value exceedances. A corresponding study was carried out for the CAMS-PM10 forecasts:
For postprocessing, the CAMS forecasts are corrected in a first step at measurement locations using measured data. In a second step, the correction factors determined at the measurement locations are interpolated and applied to the model grid of the CAMS forecasts.
Three different correction methods (hybrid forecast, multiplicative correction, Kalman filter) were analysed using the CAMS forecast data for 2016 and two selected pollutant episodes from 2015 and 2017. The evaluation of both the CAMS forecast data and the corrected data was then carried out on the basis of statistical metrics and using the DELTA tool developed as part of the FAIRMODE initiative. It turned out that generally each of the three correction methods improves the CAMS forecasts. The Kalman filter often leads to the highest correlation coefficients. In addition, after correction with the Kalman filter, the forecast data best meet the quality criteria of the DELTA tool. However, the hybrid forecast often shows better behaviour when it comes to the detection of maximum values and limit value exceedances.
Based on the results of the evaluation, an online tool for correcting the CAMS forecasts operationally was developed.
The project was aiming at the development of first elements for a new strategy to assess air quality and exposure based on average values for areas or frequency distributions instead of point measurements. IVU Umwelt's report has been published by the German Federal Environment Agency (Umweltbundesamt, UBA):
In the project, NO2- and PM10-concentration fields were calculated for three cities in Germany in three spatial resolutions using the chemical transport model (CTM) REM-CALGRID (RCG). Within cities, there are huge variations of concentrations within one CTM grid cell of ca. 500 x 500 m² having a strong influence on exposure. Exemplary concentration distributions within selected CTM grid cells were calculated in high spatial resolution using a microscale model. The microscale modelling was performed with a coupling of the RANS-model MISKAM for flow modelling with the Lagrangian particle model LASAT for transport modelling. Average values and frequency distributions of concentrations were calculated for the scales of the CTM and the microscale modelling domains and comparatively analysed.
CTM modelling shows that cities do generate a signal in concentration fields with a spatial resolutions of 7 x 8 km². However, air quality is only coarsely represented. With increasing spatial resolution, the spatial distribution of concentrations is considerably differentiated and maximum concentrations in-crease. A high spatial resolution of around 1000 to 500 m is necessary for CTM modelling to capture the observed structure of urban background concentrations. With respect to exposure, this might lead to substantial increases of people affected by higher concentration levels.
Indicative relationships between CTM results and frequency distributions of small scale concentration values could be derived. Thus, first elements have been developed for a new strategy to assess air quality.
IVU Umwelt has contributed to the programme of the international conference HARMO 19 with the presentations:
The 19th International conference on Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes (HARMO 19) took place in Bruges, Belgium on 3 - 6 June 2019. The conference was aimed towards model developers, model users, environmental protection agencies and legislation experts. What distinguishes this conference from many others is its focus on common tools and methodologies. The series of international conferences on Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes is concerned with the improvement of 'modelling culture' both in Europe and at an international level.
The paper "Supporting the improvement of air quality management practices: The ‘FAIRMODE pilot' activity" presents first outcomes of the "FAIRMODE pilot" activity, aiming at improving the way in which air quality models are used in the frame of the European Air Quality Directive 2008/50/EG. In both "assessment" and "planning" of air quality, models can and should be used: To do so, the used modelling chain has to be fit-for-purpose and properly checked and verified. FAIRMODE has developed in the recent years a suite of methodologies and tools to check if emission inventories, modelling performance, source apportionment techniques and planning activities are fit-for-purpose. Within the "FAIRMODE pilot", these tools are used and tested by regional/local authorities, with the two-fold objective of improving management practices at regional/local scale, and providing valuable feedback to the FAIRMODE community. Results and lessons learnt from this activity are presented in this paper, as a showcase that can potentially benefit other authorities in charge of air quality assessment and planning.
