1 Establishing the Origin of Particulate Matter in Eastern Germany …
7
1.4 Conclusion
The model performance during PM episodes has been improved through the use of
improved emissions and improved timing in combination with updated deposition
numbers over snow. Additional investigation is needed to further close the gap with
observations during cold stable episodes with PM exceedances.
The source apportionment shows an increased contribution from neighbouring
countries (and even further away) during high PM concentrations. The main sector contributing during the analysed events is residential combustion (not shown
here). Currently, the results from the model are being compared to a measurement
based source attribution (PMF) and a more detailed evaluation of episodes is being
performed.
Questions and Answers
QUESTIONER: W. Lefebre
QUESTION: Do you have a clue of the uncertainty of the source contribution (especially on the regions)?
ANSWER: We do not have any numbers on the uncertainty. The comparison of the
model results with PMF results are aimed at getting more insight into the uncertainty
of the contributions from different source sectors. Unfortunately PMF does not give
you any information on the geographical origin. However there are also trajectory
based analyses that will be used to check the confidence in the contributions from
different regions.
QUESTIONER: Anthony Dore
QUESTION: You mentioned that sea salt concentrations were overestimated in the
boundary conditions. Sea salt emissions are highly sensitive to wind speed. Was the
overestimate caused by emissions being too high during extreme wind events?
ANSWER: The high sea-salt concentrations in the boundary conditions originate
from a model version of the global -IFS model known to produce too high sea salt
concentrations. This was indeed most prominent during extreme wind events, since
the sea salt emissions are proportional to the wind speed
3 . This problem is believed
to be solved for newer versions of the model.
Acknowledgements The work presented here was funded through the Umweltbundesamt (UBA)
Project number: FKZ 3716 51 203 0.
References
1. A.M.M. Manders, P.J.H. Builtjes, L. Curier, H.A.C. Denier van der Gon, C. Hendriks, S.
Jonkers, R. Kranenburg, J.J.P. Kuenen, A.J. Segers, R.M.A. Timmermans, A.J.H. Visschedijk,
R.J. Wichink Kruit, W.A.J. van Pul, F.J. Sauter, E. van der Swaluw, D.P.J. Swart, J. Douros, H.
Eskes, E. van Meijgaard, B. van Ulft, P. van Velthoven, S. Banzhaf, A.C. Mues, R. Stern, G. Fu,
S. Lu, A. Heemink, N. van Velzen, M. Schaap, Curriculum vitae of the LOTOS–EUROS (v2.0)
chemistry transport model. Geosci. Model Dev. 10, 4145–4173 (2017). https://doi.org/10.5194/
gmd-10-4145-2017
7
1.4 Conclusion
The model performance during PM episodes has been improved through the use of
improved emissions and improved timing in combination with updated deposition
numbers over snow. Additional investigation is needed to further close the gap with
observations during cold stable episodes with PM exceedances.
The source apportionment shows an increased contribution from neighbouring
countries (and even further away) during high PM concentrations. The main sector contributing during the analysed events is residential combustion (not shown
here). Currently, the results from the model are being compared to a measurement
based source attribution (PMF) and a more detailed evaluation of episodes is being
performed.
Questions and Answers
QUESTIONER: W. Lefebre
QUESTION: Do you have a clue of the uncertainty of the source contribution (especially on the regions)?
ANSWER: We do not have any numbers on the uncertainty. The comparison of the
model results with PMF results are aimed at getting more insight into the uncertainty
of the contributions from different source sectors. Unfortunately PMF does not give
you any information on the geographical origin. However there are also trajectory
based analyses that will be used to check the confidence in the contributions from
different regions.
QUESTIONER: Anthony Dore
QUESTION: You mentioned that sea salt concentrations were overestimated in the
boundary conditions. Sea salt emissions are highly sensitive to wind speed. Was the
overestimate caused by emissions being too high during extreme wind events?
ANSWER: The high sea-salt concentrations in the boundary conditions originate
from a model version of the global -IFS model known to produce too high sea salt
concentrations. This was indeed most prominent during extreme wind events, since
the sea salt emissions are proportional to the wind speed
3 . This problem is believed
to be solved for newer versions of the model.
Acknowledgements The work presented here was funded through the Umweltbundesamt (UBA)
Project number: FKZ 3716 51 203 0.
References
1. A.M.M. Manders, P.J.H. Builtjes, L. Curier, H.A.C. Denier van der Gon, C. Hendriks, S.
Jonkers, R. Kranenburg, J.J.P. Kuenen, A.J. Segers, R.M.A. Timmermans, A.J.H. Visschedijk,
R.J. Wichink Kruit, W.A.J. van Pul, F.J. Sauter, E. van der Swaluw, D.P.J. Swart, J. Douros, H.
Eskes, E. van Meijgaard, B. van Ulft, P. van Velthoven, S. Banzhaf, A.C. Mues, R. Stern, G. Fu,
S. Lu, A. Heemink, N. van Velzen, M. Schaap, Curriculum vitae of the LOTOS–EUROS (v2.0)
chemistry transport model. Geosci. Model Dev. 10, 4145–4173 (2017). https://doi.org/10.5194/
gmd-10-4145-2017