| Autor: |
Seyler, André, Meier, Andreas C., Wittrock, Folkard, Kattner, Lisa, Mathieu-Üffing, Barbara, Peters, Enno, Richter, Andreas, Ruhtz, Thomas, Schönhardt, Anja, Schmolke, Stefan, Burrows, John P. |
| Jazyk: |
angličtina |
| Rok vydání: |
2018 |
| ISSN: |
1867-8548 |
| Popis: |
This study describes a novel application of an onion peeling like approach to MAX-DOAS measurements of shipping emissions aiming at investigating the strong horizontal inhomogeneities in NO2 over a shipping lane. To monitor ship emissions on the main shipping route towards the port of Hamburg, a two-channel (UV and visible) MAX-DOAS instrument was deployed on the island Neuwerk in the German Bight, 6–7 km south of the main shipping lane. Utilizing the fact that the effective light path length in the atmosphere depends systematically on wavelength, simultaneous measurements and DOAS retrievals in the UV and visible spectral range are used to probe air masses at different horizontal distances to the instrument to estimate two-dimensional pollutant distributions. Two case-studies have been selected to demonstrate the ability to derive the approximate plume positions in the observed area. A situation with northerly wind shows high NO2 concentrations close to the measurement site and low values in the north of the shipping lane. The opposite situation with southerly wind, unfavorable for the on-site in situ instrumentation, demonstrates the ability to detect enhanced NO2 concentrations several kilometers away from the instrument. To validate the approach, a comparison to air-borne imaging DOAS measurements during the NOSE campaign in July 2013 is performed, showing good agreement between the approximate plume position derived from the onion peeling MAX-DOAS and the air-borne measurements. Combining synergistically information about the plume width from the air-borne measurements and about the vertical plume extent from MAX-DOAS, yields NO2 concentrations in the plume from both measurements which agree very well. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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