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: 3.248 IF 3.248
  • IF 5-year value: 3.650 IF 5-year 3.650
  • CiteScore value: 3.37 CiteScore 3.37
  • SNIP value: 1.253 SNIP 1.253
  • SJR value: 1.869 SJR 1.869
  • IPP value: 3.29 IPP 3.29
  • h5-index value: 47 h5-index 47
  • Scimago H index value: 60 Scimago H index 60
Volume 9, issue 9 | Copyright
Atmos. Meas. Tech., 9, 4569-4585, 2016
https://doi.org/10.5194/amt-9-4569-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 16 Sep 2016

Research article | 16 Sep 2016

Comparison of the aerosol optical properties and size distribution retrieved by sun photometer with in situ measurements at midlatitude

Aurélien Chauvigné1, Karine Sellegri1, Maxime Hervo1,2, Nadège Montoux1, Patrick Freville1, and Philippe Goloub3 Aurélien Chauvigné et al.
  • 1Laboratoire de Météorologie Physique, OPGC, CNRS, Université Blaise Pascal, BP 10448, 63000 Clermont-Ferrand, France
  • 2Federal Office of Meteorology and Climatology MeteoSwiss, Payerne, Switzerland
  • 3Laboratoire d'Optique Atmosphérique, Université des Sciences et Techniques de Lille, Villeneuve d'Ascq, France

Abstract. Aerosols influence the Earth radiative budget through scattering and absorption of solar radiation. Several methods are used to investigate aerosol properties and thus quantify their direct and indirect impacts on climate. At the Puy de Dôme station, continuous high-altitude near-surface in situ measurements and low-altitude ground-based remote sensing atmospheric column measurements give the opportunity to compare the aerosol extinction measured with both methods over a 1-year period. To our knowledge, it is the first time that such a comparison is realised with continuous measurements of a high-altitude site during a long-term period. This comparison addresses to which extent near-surface in situ measurements are representative of the whole atmospheric column, the aerosol mixing layer (ML) or the free troposphere (FT). In particular, the impact of multi-aerosol layers events detected using lidar backscatter profiles is analysed. A good correlation between in situ aerosol extinction coefficient and aerosol optical depth (AOD) measured by the Aerosol Robotic Network (AERONET) sun photometer is observed with a correlation coefficient around 0.80, indicating that the in situ measurements station is representative of the overall atmospheric column. After filtering for multilayer cases and correcting for each layer optical contribution (ML and FT), the atmospheric structure seems to be the main factor influencing the comparison between the two measurement techniques. When the site lies in the ML, the in situ extinction represents 45% of the sun photometer ML extinction while when the site lies within the FT, the in situ extinction is more than 2 times higher than the FT sun photometer extinction. Moreover, the assumption of a decreasing linear vertical aerosol profile in the whole atmosphere has been tested, significantly improving the instrumental agreement. Remote sensing retrievals of the aerosol particle size distributions (PSDs) from the sun photometer observations are then compared to the near-surface in situ measurements, at dry and at ambient relative humidities. When in situ measurements are considered at dry state, the in situ fine mode diameters are 44% higher than the sun-photometer-retrieved diameters and in situ volume concentrations are 20% lower than those of the sun-photometer-retrieved fine mode concentration. Using a parameterised hygroscopic growth factor applied to aerosol diameters, the difference between in situ and retrieved diameters grows larger. Coarse mode in situ diameters and concentrations show a good correlation with retrieved PSDs from remote sensing.

Publications Copernicus
Download
Citation
Share