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: 3.400 IF 3.400
  • IF 5-year value: 3.841 IF 5-year
    3.841
  • CiteScore value: 3.71 CiteScore
    3.71
  • SNIP value: 1.472 SNIP 1.472
  • IPP value: 3.57 IPP 3.57
  • SJR value: 1.770 SJR 1.770
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 70 Scimago H
    index 70
  • h5-index value: 49 h5-index 49
Discussion papers
https://doi.org/10.5194/amt-2019-321
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/amt-2019-321
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.

Submitted as: research article 14 Oct 2019

Submitted as: research article | 14 Oct 2019

Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Atmospheric Measurement Techniques (AMT).

Evaluation of satellite-based aerosol datasets and the CAMS reanalysis over ocean utilizing shipborne reference observations

Jonas Witthuhn, Anja Hünerbein, and Hartwig Deneke Jonas Witthuhn et al.
  • Leibniz Institute of Tropospheric Research, Leipzig, Germany

Abstract. Reliable reference measurements over ocean are essential for the evaluation and improvement of satellite- and model-based aerosol datasets. Within the framework of the Maritime Aerosol Network, shipborne reference datasets have been collected over the Atlantic ocean since 2004 with Microtops sun photometers. These were recently complemented by measurements with the multi-spectral shadowband radiometer GUVis-3511 during five cruises with the research vessel Polarstern. The AOD uncertainty estimate of both ship-borne instruments of ±0.02 can be confirmed, if the GUVis instrument is cross-calibrated to the Microtops instrument to account for differences in calibration, and an empirical correction to account for the broad shadowband and the effects of forward-scattering is introduced. Based on these two datasets, a comprehensive evaluation of aerosol products from the Moderate resolution Imaging Spectroradiometer (MODIS) flown on NASA's Earth Observing System satellites, the Spinning Enhanced Visible and Infra-Red Imager (SEVIRI) onboard the geostationary Meteosat satellite, and the Copernicus Atmosphere Monitoring Service reanalysis (CAMSRA) is presented. For this purpose, focus is given to the accuracy of the aerosol optical depth (AOD) at 630 nm in combination with the Angström exponent (AE), discussed in the context of the ambient aerosol type. In general, the evaluation of MODIS AOD from the official Level-2 aerosol products of C6.1 against the Microtops AOD product confirms that 76 % of datapoints fall into the expected error limits given by previous validation studies. The SEVIRI-based AOD product exhibits a 25 % larger scatter than the MODIS AOD products at the instrument's native spectral channels. Further, the comparison of CAMSRA and MODIS AOD versus the shipborne reference show similar performances of both datasets, with some differences arising from the assimilation and model assumptions. When considering aerosol conditions, an overestimation of AE is found for scenes dominated by desert dust for MODIS and SEVIRI products versus the shipborne reference dataset. This highlights the importance of considering aerosol type in evaluation studies for identifying problematic aspects.

Jonas Witthuhn et al.
Interactive discussion
Status: open (until 09 Dec 2019)
Status: open (until 09 Dec 2019)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement
Jonas Witthuhn et al.
Jonas Witthuhn et al.
Viewed  
Total article views: 188 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
146 39 3 188 1 1
  • HTML: 146
  • PDF: 39
  • XML: 3
  • Total: 188
  • BibTeX: 1
  • EndNote: 1
Views and downloads (calculated since 14 Oct 2019)
Cumulative views and downloads (calculated since 14 Oct 2019)
Viewed (geographical distribution)  
Total article views: 124 (including HTML, PDF, and XML) Thereof 124 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Cited  
Saved  
No saved metrics found.
Discussed  
No discussed metrics found.
Latest update: 14 Nov 2019
Publications Copernicus
Download
Short summary
Reliable reference measurements over ocean are essential for the evaluation and improvement of satellite- and model-based aerosol datasets. Here, a uniqe set of shipborne reference aerosol products obtained from Microtops sunphotometer and GUVis-3511 shadowband radiometer observations are compared to aerosol products from the MODIS and SEVIRI satellite sensors, and the CAMS reanalysis over the Atlantic ocean. The present evaluation highlights the importance of an aerosol-type based analysis.
Reliable reference measurements over ocean are essential for the evaluation and improvement of...
Citation