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

Journal metrics

  • IF value: 3.089 IF 3.089
  • IF 5-year<br/> value: 3.700 IF 5-year
    3.700
  • CiteScore<br/> value: 3.59 CiteScore
    3.59
  • SNIP value: 1.273 SNIP 1.273
  • SJR value: 2.026 SJR 2.026
  • IPP value: 3.082 IPP 3.082
  • h5-index value: 45 h5-index 45
https://doi.org/10.5194/amt-2017-365
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 4.0 License.
Research article
02 Nov 2017
Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Atmospheric Measurement Techniques (AMT).
CALIPSO Lidar Calibration at 532 nm: Version 4 Nighttime Algorithm
Jayanta Kar1,2, Mark A. Vaughan2, Kam-Pui Lee1,2, Jason L. Tackett1,2, Melody A. Avery2, Anne Garnier1, Brian J. Getzewich1,2, William H. Hunt1,2,†, Damien Josset1,2,a, Zhaoyan Liu2, Patricia L. Lucker1,2, Brian Magill1,2, Ali H. Omar2, Jacques Pelon3, Raymond R. Rogers2,b, Travis D. Toth2, Charles R. Trepte2, Jean-Paul Vernier1,2, David M. Winker2, and Stuart A. Young1 1Science Systems and Applications Inc., Hampton, VA, USA
2NASA Langley Research Center, Hampton, VA, USA
3LATMOS, Université de Versailles Saint Quentin, CNRS, Verrières le Buisson, France
anow at: U.S. Naval Research Laboratory, Stennis Space Center, MS, 39529, USA
bnow at: Lord Fairfax Community College, Middletown, Va, USA
deceased
Abstract. Data products from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on board Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) were recently updated following the implementation of new (version 4.1) calibration algorithms for all of the level 1 attenuated backscatter measurements. In this work we present the motivation for and the implementation of the version 4.1 nighttime 532 nm parallel channel calibration. The nighttime 532 nm calibration is the most fundamental calibration of CALIOP data, since all of CALIOP’s other radiometric calibration procedures – i.e., the 532 nm daytime calibration and the 1064 nm calibrations during both nighttime and daytime – depend either directly or indirectly on the 532 nm nighttime calibration. The accuracy of the 532 nm nighttime calibration is significantly improved by raising the molecular normalization altitude from 30–34 km to 36–39 km to substantially reduce stratospheric aerosol contamination. Due to the greatly reduced molecular number density and consequently reduced signal-to-noise ratio at the higher altitudes used to avoid aerosols, the signal is averaged over a larger number of samples. The new calibration procedure is shown to eliminate biases introduced in earlier versions and consequently leads to an improved representation of stratospheric aerosols. Validation results using airborne lidar measurements are also presented. Biases relative to collocated measurements acquired by the Langley Research Center (LaRC) airborne High Spectral Resolution Lidar (HSRL) are reduced from 3.6 % ± 2.2 % in the version 3 data set to 1.6 % ± 2.4 % in the version 4.1 release.

Citation: Kar, J., Vaughan, M. A., Lee, K.-P., Tackett, J. L., Avery, M. A., Garnier, A., Getzewich, B. J., Hunt, W. H., Josset, D., Liu, Z., Lucker, P. L., Magill, B., Omar, A. H., Pelon, J., Rogers, R. R., Toth, T. D., Trepte, C. R., Vernier, J.-P., Winker, D. M., and Young, S. A.: CALIPSO Lidar Calibration at 532 nm: Version 4 Nighttime Algorithm, Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2017-365, in review, 2017.
Jayanta Kar et al.
Jayanta Kar et al.
Jayanta Kar et al.

Viewed

Total article views: 169 (including HTML, PDF, and XML)

HTML PDF XML Total BibTeX EndNote
122 44 3 169 1 3

Views and downloads (calculated since 02 Nov 2017)

Cumulative views and downloads (calculated since 02 Nov 2017)

Viewed (geographical distribution)

Total article views: 169 (including HTML, PDF, and XML)

Thereof 169 with geography defined and 0 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 24 Nov 2017
Publications Copernicus
Download
Short summary
We present the motivation for and the implementation of the version 4.1 nighttime 532 nm parallel channel calibration of the CALIOP lidar. The accuracy of calibration is significantly improved by raising the molecular normalization altitude from 30–34 km to 36–39 km to substantially reduce stratospheric aerosol contamination. The new calibration procedure eliminates biases in earlier versions and leads to an improved representation of stratospheric aerosols.
We present the motivation for and the implementation of the version 4.1 nighttime 532 nm...
Share