Articles | Volume 19, issue 11
https://doi.org/10.5194/gmd-19-4797-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/gmd-19-4797-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Model description paper
| 
04 Jun 2026
Model description paper |
| 04 Jun 2026
| 04 Jun 2026
Ammonia bidirectional flux model tailored for satellite retrieval parameter inversions
Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario, Canada
Mark W. Shephard
Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario, Canada
Shailesh K. Kharol
Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario, Canada
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CrIS NH3 satellite observations are assimilated into the LOTOS-EUROS model using two different methods. In the first method the data are used to fit spatially varying NH3 emission time factors. In the second method a local ensemble transform Kalman filter is used. Compared to in situ observations, combining both methods led to the most significant improvements in the modeled concentrations and deposition, illustrating the usefulness of CrIS NH3 to improve the spatiotemporal distribution of NH3.
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Short summary
Bidirectional flux models give a unified model for emission and dry deposition, but few studies have been conducted in which satellite observations are used to refine the parameters in these models. A new bidirectional flux model for ammonia was developed that was designed specifically for use with satellite observations. Ammonia satellite observations were used to refine bidirectional flux model parameters, which improved the agreement of the model with ammonia surface observations.
Bidirectional flux models give a unified model for emission and dry deposition, but few studies...
