NO<sub>2</sub> observations over the western Pacific and Indian Ocean by MAX-DOAS on <i>Kaiyo</i>, a Japanese research vessel
Nitrogen dioxide (NO<sub>2</sub>) profile retrievals were performed by ship-borne Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) using a compact/low-power spectrometer on the Japanese research vessel <i>Kaiyo</i> during two ocean cruises around Japan and J...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2012-10-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | http://www.atmos-meas-tech.net/5/2351/2012/amt-5-2351-2012.pdf |
| _version_ | 1818318892296044544 |
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| author | Y. Kanaya F. Syamsudin H. Irie H. Takashima |
| author_facet | Y. Kanaya F. Syamsudin H. Irie H. Takashima |
| author_sort | Y. Kanaya |
| collection | DOAJ |
| description | Nitrogen dioxide (NO<sub>2</sub>) profile retrievals were performed by ship-borne Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) using a compact/low-power spectrometer on the Japanese research vessel <i>Kaiyo</i> during two ocean cruises around Japan and Japan–Bali (Indonesia)–Indian Ocean. DOAS analysis using a 425–450 nm fitting window revealed a clear land–ocean contrast in NO<sub>2</sub> differential slant column densities (DSCDs) but poor fitting results and negative values, especially at low elevation angles at low latitudes (<~20° N). The poor fitting resulted in sparse NO<sub>2</sub> volume mixing ratio (VMR) data for the 0–1 km layer after applying our vertical profile retrieval method. In contrast, NO<sub>2</sub> VMRs retrieved using fitting results from 460–490 nm are positive even at low latitudes, while they are reasonably similar to those obtained from 425–450 nm at mid-latitudes. Because NO<sub>2</sub> DSCD for 425–450 nm shows a negative correlation with water vapor (H<sub>2</sub>O) DSCD, the poor fitting appears to be due primarily to interference by H<sub>2</sub>O. We analyzed a 338–370 nm fitting window, which is free from H<sub>2</sub>O, and found good agreement between NO<sub>2</sub> VMRs retrieved from 460–490 nm and 338–370 nm, even at low latitudes, at NO<sub>2</sub> VMRs higher than ~0.2 ppbv. The results indicate that the background value of NO<sub>2</sub> VMR over the western Pacific and Indian Ocean during the cruises was less than ~0.2 ppbv, with occasional enhancement to levels of ~0.2–0.4 ppbv. |
| first_indexed | 2024-12-13T10:00:26Z |
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| institution | Directory Open Access Journal |
| issn | 1867-1381 1867-8548 |
| language | English |
| last_indexed | 2024-12-13T10:00:26Z |
| publishDate | 2012-10-01 |
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| record_format | Article |
| series | Atmospheric Measurement Techniques |
| spelling | doaj.art-c4107c86919140a99f64a78bbdfec3822022-12-21T23:51:41ZengCopernicus PublicationsAtmospheric Measurement Techniques1867-13811867-85482012-10-015102351236010.5194/amt-5-2351-2012NO<sub>2</sub> observations over the western Pacific and Indian Ocean by MAX-DOAS on <i>Kaiyo</i>, a Japanese research vesselY. KanayaF. SyamsudinH. IrieH. TakashimaNitrogen dioxide (NO<sub>2</sub>) profile retrievals were performed by ship-borne Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) using a compact/low-power spectrometer on the Japanese research vessel <i>Kaiyo</i> during two ocean cruises around Japan and Japan–Bali (Indonesia)–Indian Ocean. DOAS analysis using a 425–450 nm fitting window revealed a clear land–ocean contrast in NO<sub>2</sub> differential slant column densities (DSCDs) but poor fitting results and negative values, especially at low elevation angles at low latitudes (<~20° N). The poor fitting resulted in sparse NO<sub>2</sub> volume mixing ratio (VMR) data for the 0–1 km layer after applying our vertical profile retrieval method. In contrast, NO<sub>2</sub> VMRs retrieved using fitting results from 460–490 nm are positive even at low latitudes, while they are reasonably similar to those obtained from 425–450 nm at mid-latitudes. Because NO<sub>2</sub> DSCD for 425–450 nm shows a negative correlation with water vapor (H<sub>2</sub>O) DSCD, the poor fitting appears to be due primarily to interference by H<sub>2</sub>O. We analyzed a 338–370 nm fitting window, which is free from H<sub>2</sub>O, and found good agreement between NO<sub>2</sub> VMRs retrieved from 460–490 nm and 338–370 nm, even at low latitudes, at NO<sub>2</sub> VMRs higher than ~0.2 ppbv. The results indicate that the background value of NO<sub>2</sub> VMR over the western Pacific and Indian Ocean during the cruises was less than ~0.2 ppbv, with occasional enhancement to levels of ~0.2–0.4 ppbv.http://www.atmos-meas-tech.net/5/2351/2012/amt-5-2351-2012.pdf |
| spellingShingle | Y. Kanaya F. Syamsudin H. Irie H. Takashima NO<sub>2</sub> observations over the western Pacific and Indian Ocean by MAX-DOAS on <i>Kaiyo</i>, a Japanese research vessel Atmospheric Measurement Techniques |
| title | NO<sub>2</sub> observations over the western Pacific and Indian Ocean by MAX-DOAS on <i>Kaiyo</i>, a Japanese research vessel |
| title_full | NO<sub>2</sub> observations over the western Pacific and Indian Ocean by MAX-DOAS on <i>Kaiyo</i>, a Japanese research vessel |
| title_fullStr | NO<sub>2</sub> observations over the western Pacific and Indian Ocean by MAX-DOAS on <i>Kaiyo</i>, a Japanese research vessel |
| title_full_unstemmed | NO<sub>2</sub> observations over the western Pacific and Indian Ocean by MAX-DOAS on <i>Kaiyo</i>, a Japanese research vessel |
| title_short | NO<sub>2</sub> observations over the western Pacific and Indian Ocean by MAX-DOAS on <i>Kaiyo</i>, a Japanese research vessel |
| title_sort | no sub 2 sub observations over the western pacific and indian ocean by max doas on i kaiyo i a japanese research vessel |
| url | http://www.atmos-meas-tech.net/5/2351/2012/amt-5-2351-2012.pdf |
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