Impact of 3D cloud structures on the atmospheric trace gas products from UV–Vis sounders – Part 3: Bias estimate using synthetic and observational data
<p>Three-dimensional (3D) cloud structures may impact atmospheric trace gas products from ultraviolet–visible (UV–Vis) sounders. We used synthetic and observational data to identify and quantify possible cloud-related bias in NO<span class="inline-formula"><sub>2</sub...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2022-06-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | https://amt.copernicus.org/articles/15/3481/2022/amt-15-3481-2022.pdf |
| _version_ | 1828335331424862208 |
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| author | A. Kylling C. Emde H. Yu M. van Roozendael K. Stebel B. Veihelmann B. Mayer |
| author_facet | A. Kylling C. Emde H. Yu M. van Roozendael K. Stebel B. Veihelmann B. Mayer |
| author_sort | A. Kylling |
| collection | DOAJ |
| description | <p>Three-dimensional (3D) cloud structures may impact atmospheric trace gas products from ultraviolet–visible (UV–Vis) sounders. We used synthetic and observational data to identify and quantify possible cloud-related
bias in NO<span class="inline-formula"><sub>2</sub></span> tropospheric vertical column density (TVCD). The synthetic data were based on high-resolution large eddy simulations which were input to a 3D radiative transfer model. The simulated visible spectra for low-earth-orbiting and geostationary geometries were analysed with standard retrieval methods and cloud correction schemes that are employed in operational NO<span class="inline-formula"><sub>2</sub></span> satellite products. For the observational data, the NO<span class="inline-formula"><sub>2</sub></span> products from the TROPOspheric Monitoring Instrument (TROPOMI) were used, while the Visible Infrared Imaging Radiometer Suite (VIIRS) provided high-spatial-resolution cloud and radiance data. NO<span class="inline-formula"><sub>2</sub></span> profile shape, cloud shadow fraction, cloud top height, cloud optical depth, and solar zenith and viewing angles were identified as the metrics being the most important in identifying 3D cloud
impacts on NO<span class="inline-formula"><sub>2</sub></span> TVCD retrievals.
For a solar zenith angle less than about 40<span class="inline-formula"><sup>∘</sup></span> the synthetic
data show that the NO<span class="inline-formula"><sub>2</sub></span> TVCD bias is typically below 10 %, while
for larger solar zenith angles the NO<span class="inline-formula"><sub>2</sub></span> TVCD is low-biased by tens of percent. The horizontal variability of NO<span class="inline-formula"><sub>2</sub></span> and differences in TROPOMI and VIIRS overpass times make it challenging to identify a similar bias in the observational data. However, for optically thick clouds above 3000 m, a low bias appears to be present in the observational data.</p> |
| first_indexed | 2024-04-13T21:44:57Z |
| format | Article |
| id | doaj.art-e984083fc2af477e8f7d6e851cf6d5f6 |
| institution | Directory Open Access Journal |
| issn | 1867-1381 1867-8548 |
| language | English |
| last_indexed | 2024-04-13T21:44:57Z |
| publishDate | 2022-06-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Measurement Techniques |
| spelling | doaj.art-e984083fc2af477e8f7d6e851cf6d5f62022-12-22T02:28:38ZengCopernicus PublicationsAtmospheric Measurement Techniques1867-13811867-85482022-06-01153481349510.5194/amt-15-3481-2022Impact of 3D cloud structures on the atmospheric trace gas products from UV–Vis sounders – Part 3: Bias estimate using synthetic and observational dataA. Kylling0C. Emde1H. Yu2M. van Roozendael3K. Stebel4B. Veihelmann5B. Mayer6NILU – Norwegian Institute for Air Research, Kjeller, NorwayLudwig Maximilian University, Meteorological Institute, Munich, GermanyBelgian Institute for Space Aeronomy, Brussels, BelgiumBelgian Institute for Space Aeronomy, Brussels, BelgiumNILU – Norwegian Institute for Air Research, Kjeller, NorwayESA-ESTEC, Noordwijk, the NetherlandsLudwig Maximilian University, Meteorological Institute, Munich, Germany<p>Three-dimensional (3D) cloud structures may impact atmospheric trace gas products from ultraviolet–visible (UV–Vis) sounders. We used synthetic and observational data to identify and quantify possible cloud-related bias in NO<span class="inline-formula"><sub>2</sub></span> tropospheric vertical column density (TVCD). The synthetic data were based on high-resolution large eddy simulations which were input to a 3D radiative transfer model. The simulated visible spectra for low-earth-orbiting and geostationary geometries were analysed with standard retrieval methods and cloud correction schemes that are employed in operational NO<span class="inline-formula"><sub>2</sub></span> satellite products. For the observational data, the NO<span class="inline-formula"><sub>2</sub></span> products from the TROPOspheric Monitoring Instrument (TROPOMI) were used, while the Visible Infrared Imaging Radiometer Suite (VIIRS) provided high-spatial-resolution cloud and radiance data. NO<span class="inline-formula"><sub>2</sub></span> profile shape, cloud shadow fraction, cloud top height, cloud optical depth, and solar zenith and viewing angles were identified as the metrics being the most important in identifying 3D cloud impacts on NO<span class="inline-formula"><sub>2</sub></span> TVCD retrievals. For a solar zenith angle less than about 40<span class="inline-formula"><sup>∘</sup></span> the synthetic data show that the NO<span class="inline-formula"><sub>2</sub></span> TVCD bias is typically below 10 %, while for larger solar zenith angles the NO<span class="inline-formula"><sub>2</sub></span> TVCD is low-biased by tens of percent. The horizontal variability of NO<span class="inline-formula"><sub>2</sub></span> and differences in TROPOMI and VIIRS overpass times make it challenging to identify a similar bias in the observational data. However, for optically thick clouds above 3000 m, a low bias appears to be present in the observational data.</p>https://amt.copernicus.org/articles/15/3481/2022/amt-15-3481-2022.pdf |
| spellingShingle | A. Kylling C. Emde H. Yu M. van Roozendael K. Stebel B. Veihelmann B. Mayer Impact of 3D cloud structures on the atmospheric trace gas products from UV–Vis sounders – Part 3: Bias estimate using synthetic and observational data Atmospheric Measurement Techniques |
| title | Impact of 3D cloud structures on the atmospheric trace gas products from UV–Vis sounders – Part 3: Bias estimate using synthetic and observational data |
| title_full | Impact of 3D cloud structures on the atmospheric trace gas products from UV–Vis sounders – Part 3: Bias estimate using synthetic and observational data |
| title_fullStr | Impact of 3D cloud structures on the atmospheric trace gas products from UV–Vis sounders – Part 3: Bias estimate using synthetic and observational data |
| title_full_unstemmed | Impact of 3D cloud structures on the atmospheric trace gas products from UV–Vis sounders – Part 3: Bias estimate using synthetic and observational data |
| title_short | Impact of 3D cloud structures on the atmospheric trace gas products from UV–Vis sounders – Part 3: Bias estimate using synthetic and observational data |
| title_sort | impact of 3d cloud structures on the atmospheric trace gas products from uv vis sounders part 3 bias estimate using synthetic and observational data |
| url | https://amt.copernicus.org/articles/15/3481/2022/amt-15-3481-2022.pdf |
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