Results from the Fourth WMO Filter Radiometer Comparison for aerosol optical depth measurements

Abstract. This study presents the results of the Fourth Filter Radiometer Comparison that was held in Davos, Switzerland, between 28 September and 16 October 2015. Thirty filter radiometers and spectroradiometers from 12 countries participated including reference instruments from global aerosol networks. The absolute differences of all instruments compared to the reference have been based on the World Meteorological Organization (WMO) criterion defined as follows: 95% of the measured data has to be within 0.005 ± 0.001∕m (where m is the air mass). At least 24 out of 29 instruments achieved this goal at both 500 and 865 nm, while 12 out of 17 and 13 out of 21 achieved this at 368 and 412 nm, respectively. While searching for sources of differences among different instruments, it was found that all individual differences linked to Rayleigh, NO2, ozone, water vapor calculations and related optical depths and air mass calculations were smaller than 0.01 in aerosol optical depth (AOD) at 500 and 865 nm. Different cloud-detecting algorithms used have been compared. Angstrom exponent calculations showed relatively large differences among different instruments, partly because of the high calculation uncertainty of this parameter in low AOD conditions. The overall low deviations of these AOD results and the high accuracy of reference aerosol network instruments demonstrated a promising framework to achieve homogeneity, compatibility and harmonization among the different spectral AOD networks in the near future.

[1]  J. Burrows,et al.  ATMOSPHERIC REMOTE-SENSING REFERENCE DATA FROM GOME — 2 . TEMPERATURE-DEPENDENT ABSORPTION CROSS SECTIONS OF O 3 IN THE 231 — 794 NM RANGE , 1998 .

[2]  B. Forgan,et al.  Aerosol Measurement in the Australian Outback: Intercomparison of Sun Photometers , 2003 .

[3]  K. Taylor.  Summarizing multiple aspects of model performance in a single diagram , 2001 .

[4]  The fictitious diurnal cycle of aerosol optical depth: A new approach for “in situ” calibration and correction of AOD data series , 2004 .

[5]  Soon-Chang Yoon,et al.  Global Surface-Based Sun Photometer Network for Long-Term Observations of Column Aerosol Optical Properties: Intercomparison of Aerosol Optical Depth , 2008 .

[6]  Qilong Min,et al.  The rotating shadowband spectroradiometer (RSS) at SGP , 1999 .

[7]  J. Slusser,et al.  Field comparison of network Sun photometers , 2003 .

[8]  The World Optical Depth Research and Calibration Center (WORCC) quality assurance and quality control of GAW-PFR AOD measurements , 2017 .

[9]  G. Shaw.  Error analysis of multi-wavelength sun photometry , 1976 .

[10]  Charles N. Long,et al.  An Automated Method of MFRSR Calibration for Aerosol Optical Depth Analysis with Application to an Asian Dust Outbreak over the United States , 2003 .

[11]  R. M. Mitchell,et al.  The Climatology of Australian Aerosol , 2017 .

[12]  T. Nakajima,et al.  Aerosol optical characteristics measured by sky radiometers during the ABC/EAREX2005 observation , 2006 .

[13]  J. Michalsky,et al.  Automated multifilter rotating shadow-band radiometer: an instrument for optical depth and radiation measurements. , 1994, Applied optics.

[14]  H. Neckel,et al.  The solar radiation between 3300 and 12500 Å , 1984 .

[15]  Alexander Smirnov,et al.  Cloud-Screening and Quality Control Algorithms for the AERONET Database , 2000 .

[16]  Teruyuki Nakajima,et al.  Application of the SKYRAD Improved Langley plot method for the in situ calibration of CIMEL Sun-sky photometers. , 2007, Applied optics.

[17]  B. Holben,et al.  The new sun-sky-lunar Cimel CE318-T multiband photometer-a comprehensive performance evaluation , 2015 .

[18]  Spectral ultraviolet radiation instrument and preliminary measurements in Mountainous terrain , 1993 .

[19]  L. Remer,et al.  The Collection 6 MODIS aerosol products over land and ocean , 2013 .

[20]  Thomas Carlund,et al.  Overview of Sun photometer measurements of aerosol properties in Scandinavia and Svalbard , 2012 .

[21]  Oleg Dubovik,et al.  Recent trends in aerosol optical properties derived from AERONET measurements , 2014 .

[22]  Donald A. McSparron,et al.  Spectral irradiance calibrations , 1987 .

[23]  T. Nakajima,et al.  Determination of the solar calibration constant for a sun-sky radiometer: proposal of an in-situ procedure. , 2004, Applied optics.

[24]  Brian Cairns,et al.  Automated cloud screening algorithm for MFRSR data , 2004 .

[25]  Brent N. Holben,et al.  Global and regional evaluation of over-land spectral aerosol optical depth retrievals from SeaWiFS , 2012 .

[26]  C. Wehrli,et al.  Calibrations of filter radiometers for determination of atmospheric optical depth , 2000 .

[27]  Petr Chylek,et al.  Aerosol radiative forcing and the accuracy of satellite aerosol optical depth retrieval , 2003 .

[28]  C. Long,et al.  SURFRAD—A National Surface Radiation Budget Network for Atmospheric Research , 2000 .

[29]  Karin Hinzer,et al.  Reconstruction of solar spectral resource using limited spectral sampling for concentrating photovoltaic systems , 2013, Other Conferences.

[30]  A. Smirnov,et al.  AERONET-a federated instrument network and data archive for aerosol Characterization , 1998 .

[31]  J. Gröbner,et al.  The World Optical Depth Research and Calibration Center (WORCC) quality assurance and quality control of GAW-PFR AOD measurements , 2017 .

[32]  Connor Flynn,et al.  Climatology of aerosol optical depth in north-central Oklahoma: 1992-2008 , 2010 .

[33]  Sang Woo Kim,et al.  Comparisons of aerosol optical depth and surface shortwave irradiance and their effect on the aerosol surface radiative forcing estimation , 2005 .

[34]  Alexander Smirnov,et al.  Comparison of aerosol optical depth from four solar radiometers during the fall 1997 ARM intensive observation period , 1999 .

[35]  Kathleen A. Crean,et al.  Multiangle imaging spectroradiometer (MISR) global aerosol optical depth validation based on 2 years of coincident Aerosol Robotic Network (AERONET) observations : Global aerosol system , 2005 .

[36]  C. Gueymard.  Parameterized transmittance model for direct beam and circumsolar spectral irradiance , 2001 .

[37]  Kurtis J. Thome,et al.  Determination of Precipitable Water from Solar Transmission. , 1992 .

[38]  Rosane Minghim,et al.  InteractiVenn: a web-based tool for the analysis of sets through Venn diagrams , 2015, BMC Bioinformatics.

[39]  Joseph Michalsky,et al.  An aerosol optical depth climatology for NOAA's national surface radiation budget network (SURFRAD) , 2008 .

[40]  M. P. Utrillas,et al.  Evaluation of the new ESR network software for the retrieval of direct sun products from CIMEL CE318 and PREDE POM01 sun-sky radiometers , 2012 .

[41]  B. Samset,et al.  Comparison of AOD, AAOD and column single scattering albedo from AERONET retrievals and in situ profiling measurements , 2017 .

[42]  J. Slusser,et al.  On Rayleigh Optical Depth Calculations , 1999 .

[43]  T. Eck,et al.  An emerging ground-based aerosol climatology: Aerosol optical depth from AERONET , 2001 .

[44]  C. Wehrli,et al.  Comparison of Sun photometer calibration by use of the Langley technique and the standard lamp. , 1995, Applied optics.

[45]  Glenn E. Shaw,et al.  Investigations of Atmospheric Extinction Using Direct Solar Radiation Measurements Made with a Multiple Wavelength Radiometer. , 1973 .

[46]  J. Deluisi,et al.  Features and effects of aerosol optical depth observed at Mauna Loa, Hawaii: 1982–1992 , 1994 .

[47]  U. Lohmann,et al.  Global indirect aerosol effects: a review , 2004 .

[48]  C. Wehrli,et al.  Remote Sensing of Aerosol Optical Depth in a global surface network , 2008 .

[49]  B. Holben,et al.  Use of sky brightness measurements from ground for remote sensing of particulate polydispersions. , 1996, Applied optics.

[50]  J. Gröbner,et al.  Ground-based aerosol optical depth trends at three high-altitude sites in Switzerland and southern Germany from 1995 to 2010 , 2012 .

[51]  A. Bucholtz,et al.  Rayleigh-scattering calculations for the terrestrial atmosphere. , 1995, Applied optics.

[52]  R. Charlson,et al.  Climate forcing and the physico-chemical life cycle of the atmospheric aerosol : Why do we need an integrated, interdisciplinary global research programme ? , 1996 .