Measurements of tropospheric NO<sub>2</sub> with an airborne multi-axis DOAS instrument
The AMAXDOAS instrument is an airborne multi-axis DOAS instrument covering the spectral range from 300 to 600 nm. During one flight of the SCIAVALUE campaign on 19 March 2003, the AMAXDOAS onboard the DLR Falcon detected tropospheric NO<sub>2</sub> over Europe under both cloudy...
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2005-01-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/5/337/2005/acp-5-337-2005.pdf |
| Summary: | The AMAXDOAS instrument is an airborne multi-axis DOAS instrument covering the spectral range from 300 to 600 nm. During one flight of the SCIAVALUE campaign on 19 March 2003, the AMAXDOAS onboard the DLR Falcon detected tropospheric NO<sub>2</sub> over Europe under both cloudy and cloud free conditions. By combining the measurements in nadir and zenith direction, and analysing the spectra in the UV and the visible spectral region, information was derived on where the bulk of the observed NO<sub>2</sub> was located. Vertical columns of up to 5.7x10<sup>16</sup> molec cm<sup>-2</sup> were observed close to Frankfurt, with a distribution peaking in the boundary layer and in good agreement with surface measurements. On several occasions, strong tropospheric NO<sub>2</sub> signals were also detected when flying above clouds. The ratio of zenith and nadir measurements indicates that the NO<sub>2</sub> observed was located within the cloud, and assuming the same profile as for the cloud free situation the NO<sub>2</sub> vertical column was estimated to be 5.0x10<sup>16</sup> molec cm<sup>-2</sup>. The results are relevant for the retrieval of tropospheric NO<sub>2</sub> columns from space-borne instruments in cloudy situations. |
|---|---|
| ISSN: | 1680-7316 1680-7324 |