Journal cover Journal topic
Atmospheric Measurement Techniques An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 3.668 IF 3.668
  • IF 5-year value: 3.707 IF 5-year
  • CiteScore value: 6.3 CiteScore
  • SNIP value: 1.383 SNIP 1.383
  • IPP value: 3.75 IPP 3.75
  • SJR value: 1.525 SJR 1.525
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 77 Scimago H
    index 77
  • h5-index value: 49 h5-index 49
Volume 5, issue 10
Atmos. Meas. Tech., 5, 2351–2360, 2012
© Author(s) 2012. This work is distributed under
the Creative Commons Attribution 3.0 License.
Atmos. Meas. Tech., 5, 2351–2360, 2012
© Author(s) 2012. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 05 Oct 2012

Research article | 05 Oct 2012

NO2 observations over the western Pacific and Indian Ocean by MAX-DOAS on Kaiyo, a Japanese research vessel

H. Takashima1,2, H. Irie3, Y. Kanaya1, and F. Syamsudin4 H. Takashima et al.
  • 1Japan Agency for Marine-Earth Science and Technology (JAMSTEC)/Research Institute for Global Change (RIGC), Japan
  • 2Department of Earth System Science, Faculty of Science, Fukuoka University, Japan
  • 3Center for Environmental Remote Sensing, Chiba University, Japan
  • 4Agency for the Assessment and Application of Technology (BPPT), Indonesia

Abstract. Nitrogen dioxide (NO2) 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 Kaiyo 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 NO2 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 NO2 volume mixing ratio (VMR) data for the 0–1 km layer after applying our vertical profile retrieval method. In contrast, NO2 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 NO2 DSCD for 425–450 nm shows a negative correlation with water vapor (H2O) DSCD, the poor fitting appears to be due primarily to interference by H2O. We analyzed a 338–370 nm fitting window, which is free from H2O, and found good agreement between NO2 VMRs retrieved from 460–490 nm and 338–370 nm, even at low latitudes, at NO2 VMRs higher than ~0.2 ppbv. The results indicate that the background value of NO2 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.

Publications Copernicus