Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 10 3 2010 10.5194/acpd-10-6797-2010 http://www.atmos-chem-phys-discuss.net/10/6797/2010/ http://www.atmos-chem-phys-discuss.net/10/6797/2010/acpd-10-6797-2010.html http://www.atmos-chem-phys-discuss.net/10/6797/2010/acpd-10-6797-2010.pdf 6797 6827 2010-03-11 Comparison of UV irradiances from Aura/Ozone Monitoring Instrument (OMI) with Brewer measurements at El Arenosillo (Spain) – Part 1: Analysis of parameter influence M. Antón V. E. Cachorro chiqui@goa.uva.es J. M. Vilaplana C. Toledano N. A. Krotkov A. Arola A. Serrano B. de la Morena Departamento de Física, Universidad de Extremadura, Badajoz, Spain Grupo de Óptica Atmosférica, Universidad de Valladolid GOA-UVA, Valladolid, Spain ESAt "El Arenosillo", INTA, Huelva, Spain GEST Center, University of Maryland, Baltimore County, Maryland, USA Finnish Meteorological Institute (FMI), Kuopio, Finland Laboratory of Atmosphere, NASA/Goddard Space Flight Center, Greenbelt, Maryland, USA The main objective of this study is to compare the erythemal UV irradiance (UVER) and spectral UV irradiances (at 305, 310 and 324 nm) from Ozone Monitoring Instrument (OMI) onboard NASA EOS/Aura polar sun-synchronous satellite (launched in July 2004, local equator crossing time 01:45 p.m.) with ground-based measurements from the Brewer spectroradiometer #150 located at El Arenosillo (South of Spain). The analyzed period comprises more than four years, from October 2004 to December 2008. The effects of several factors (clouds, aerosols, ozone and the solar elevation) on OMI-Brewer comparisons were analyzed. The proxies used for each factor were: OMI Lambertian Equivalent Reflectivity (LER) at 360 nm (clouds), the Aerosol Optical Depth (AOD) at 440 nm measured from the ground-based Cimel sun-photometer (<a href=http://aeronet.gsfc.nasa.gov target=_blank>http://aeronet.gsfc.nasa.gov</a>), OMI total column ozone, and solar elevation at OMI overpass time. <br><br> The comparison for all sky conditions reveals positive biases (OMI higher than Brewer) 12.3% for UVER, 14.2% for UV irradiance at 305 nm, 10.6% for 310 nm and 8.7% for 324 nm. The OMI-Brewer Root Mean Square Error (RMSE) is reduced when cloudy cases are removed from the analysis, (e.g., RMSE ~20% for all sky conditions and RMSE smaller than 10% for cloud-free conditions). However, the biases remain and even become more significant for the cloud-free cases with respect to all sky conditions. The mentioned overestimation is clearly documented as due to aerosol extinction influence. The differences OMI-Brewer typically decrease with increasing the Solar Zenith Angle (SZA). The seasonal dependence of the OMI-Brewer difference for cloud-free conditions is driven by aerosol climatology. <br><br> To account for the aerosol effect, a first evaluation in order to compare with previous TOMS results (Anton et al., 2007) was performed. This comparison shows that the OMI bias is between +14% and +19% for UVER and spectral UV irradiances for moderately-high aerosol load (AOD&gt;0.25). The OMI bias is decreased by a factor of 2 (the typical bias varies from +8% to +12%) under cloud-free and low aerosol load conditions (AOD&lt;0.1). More detailed analysis of absorbing aerosols influence on OMI bias at our station is presented in a companion paper (Cachorro et al., 2010). Antón, M., Cachorro, V. E., Vilaplana, J. M., Krotkov, N. A., Serrano, A., Toledano, C., de la Morena, B., and Herman, J. R.: Total ozone mapping spectrometer retrievals of noon erythemal-CIE ultraviolet irradiance compared with Brewer ground-based measurements at El Arenosillo (southwestern Spain), J. Geophys. Res., 112, D11206, doi:10.1029/2006JD007254, 2007. Antón, M., Serrano, A., Cancillo, M. L., Vilaplana, J. M., Cachorro, V. E., and Gröbner, J.: Correction of angular response error in Brewer UV irradiance measurements, J. Atmos. Ocean. Tech., 25, 2017–2018, doi:10.1175/2008JTECHA1040.1, 2008. Antón, M., López, M., Vilaplana, J. M., Kroon, M., McPeters, R., Bañón, M., and Serrano, A.: Validation of OMI-TOMS and OMI-DOAS total ozone column using five Brewer spectroradiometers at the Iberian Peninsula, J. Geophys. Res., 114, D14307, doi:10.1029/2009JD012003, 2009. Arola, A., Kazadzis, S., Krotkov, N., Bais, A., Gröbner, J., and Herman, J. R.: Assessment of TOMS~UV bias due to absorbing aerosols, J. Geophys. Res., 110, D23211, doi:10.1029/2005JD005913, 2005. Arola, A., Lindfors, A., Natunen, A., and Lehtinen, K. E. J.: A case study on biomass burning aerosols: effects on aerosol optical properties and surface radiation levels, Atmos. Chem. Phys., 7, 4257–4266, 2007. Arola, A., Kazadzis, S., Lindfors, A., et al.: A new approach to correct for absorbing aerosols in OMI~UV, Geophys. Res. Lett., 36, L22805, doi:10.1029/2009GL041137, 2009. Badarinath, K. V. S., Kharol, S. K., Kaskaoutis, D. G., and Kambezidis, H. D.: Influence of atmospheric aerosols on solar spectral irradiance in an urban area, J. Atmos. Sol.-Terr. Phy., 69, 589–599, 2007. Balis, D., Kroon, M., Koukouli, M. E., Brinksma, E. J., Labow, G., Veefkind, J. P., and McPeters, R. D: Validation of Ozone Monitoring Instrument total ozone column measurements using Brewer and Dobson spectrophotometer ground based observations, J. Geophys. Res., 112, D24S46, doi:10.1029/2007JD008796, 2007. Bhartia, P. K. and Wellemeyer, C. W.: TOMS-V8 total O₃ algorithm, in: OMI Algorithm Theoretical Basis Document, edited by: Bhartia, P. K., NASA Goddard Space Flight Cent., available at: http://eospso.gsfc.nasa.gov/eos_homepage/for_scientists/atbd/docs/OMI/ATBD-OMI02.pdf, last access: 8~March~2010, Greenbelt, Md., vol II, 15–32~pp., 2002. Bernard, W. F., Saxena, V. K., Wenny, B. N., and DeLuisi, J. J.: Daily surface UV exposure and its relationship to surface pollutant measurements, J. Air Waste Manage., 53, 237–245, 2003. Buchard, V., Brogniez, C., Auriol, F., Bonnel, B., Lenoble, J., Tanskanen, A., Bojkov, B., and Veefkind, P.: Comparison of OMI ozone and UV irradiance data with ground-based measurements at two French sites, Atmos. Chem. Phys., 8, 4517–4528, 2008. Cachorro, V. E., Vergaz, R., de Frutos, A. M., Vilaplana, J. M., Henriques, D., Laulainen, N., and Toledano, C.: Study of desert dust events over the southwestern Iberian Peninsula in year 2000: two case studies, Ann. Geophys., 24, 1493–1510, 2006. Cachorro, V. E., Toledano, C., Prats, N., Sorribas, M., Mogo, S., Berjón, A., Torres, B., Rodrigo, R., de Frutos, A. M., and de la Rosa, J.: The strongest desert dust intrusion mixed with smoke over the Iberian Peninsula registered with sun-photometry, J. Geophys. Res., 113, D14504, doi:10.1029/2007JD009582, 2008. Cachorro, V. E., Toledano, C., Antón, M., Berjon, A., Vilaplana, J. M., Arola, A., and Krotkov, N. A.: Comparison of UV irradiances from Aura/Ozone Monitoring Instrument (OMI) with Brewer measurements at El Arenosillo (Spain): II: Analysis of site aerosol influence, in preparation to submit to Atmos. Chem. Phys., 2010. \blackbox\bf Copernicus Cede, A., Luccini, E. , Nuñez, L., Piancetini, R. D., Blumthaler, M., and Herman, J. R.: TOMS-derived erythemal irradiance versus measurements at stations of Argentine UV Monitoring Network, J. Geophys. Res., 109, D08109, doi:10.1029/2004JD004519, 2004. Chubarova, N. Y., Yurova, A. Y., Krotkov, N., Herman, J. R., and Barthia, P. K.: Comparison between ground measurements of broadband ultraviolet irradiance (300 to 380 nm) and total ozone mapping spectrometer ultraviolet estimates at Moscow from 1979 to 2000, Opt. Eng., 41, 3070–3081, 2002. Chubarova, N. Y., Nezval, Y. E., Verdebout, J., Krotkov, N., and Herman, J.: Long-term UV irradiance changes over Moscow and comparison with UV estimates from TOMS and METEOSAT, in: Proc. Ultraviolet Ground- and Space-based Measurements, Models, and Effects~V, edited by: Bernhard, G., Slusser, J. R., Herman, J. R., and Gao, W., SPIE, San Diego, USA, 63–73~pp., 2005. Fioletov, V. E., Kimlin, M. G., Krotkov, N., McArthur, L. J., Kerr, J. B., Wardle, D. I., Herman, J. R., Meltzer, R., Mathews, T. W., and Kaurola, J.: UV index climatology over the United States and Canada from groundbased and satellite estimates, J. Geophys. Res., 109, D22308, doi:10.1029/2004JD004820, 2004. Gröbner, J., Vergaz, R., Cachorro, V., Henriques, D., Lamb, K., Redondas, A., Vilaplana, J., and Rembges, D.: Intercomparison of aerosol optical depth measurements in the UVB using Brewer spectrophotometers and a Li-Cor spectrophotometer, Geophys. Res. Lett., 28(9), 1691–1694, 2001. Gröbner, J. and Meleti, C.: Aerosol optical depth in the UVB and visible from Brewer spectrophotometer direct irradiance measurements: 1991 to 2002, J. Geophys. Res., 109(D9), D09202, doi:2003JD004409, 2004. Gröbner, J., Schreder, J., Kazadzis, S., Bais, A. F., Blumthaler, M., Görts, P., Tax, R., Koskela, T., Seckmeyer, G., Webb, A. R., and Rembges, D.: Traveling reference spectroradiometer for routine quality assurance of spectral solar ultraviolet irradiance measurements, Appl. Opt., 44, 5321–5331, 2005. Holben, B. N., Eck, T. F., Slutsker, I., Tanré, D., Buis, J. P., Setzer, A., Vermote, E. F., Reagan, J. A., Kaufman, I. Y., Nakajima, T., Lavenu, F., Jankowiak, I., and Smirnov, A.: ERONET – A federated instrument network and data archive for aerosol characterization, Remote Sens. Environ., 66, 1–16, 1998. Ialongo, I., Casale, G. R., and Siani, A. M.: Comparison of total ozone and erythemal UV data from OMI with ground-based measurements at Rome station, Atmos. Chem. Phys., 8, 3283–3289, 2008. Kalliskota, S., Kaurola, J., Taalas, P., Herman, J., Celarier, E., and Krotkov, N. : Comparison of daily UV doses estimated from Nimbus~7/TOMS measurements and ground-based spectroradiometer data, J. Geophys. Res., 105, 4273–4277, 2000. Kaskaoutis, D. G., Kambezidis, H. D., Jacovides, C. P., and Steven, M. D.: Modification of solar radiation components under different atmospheric conditions in the Greater Athens Area, Greece, J. Atmos. Sol.-Terr. Phy., 68, 1043–1052, 2006. Kazantzidis, A., Bais, A. F., Grobner, J., Herman, J. R., Kazadzis, S., Krotkov, N., Kyrö, E., den Outer, P. N., Garane, K., Görts, P., Lakkala, K., Meleti, C., Slaper, H., Tax, R. B., and Turunen, T.: Comparison of satellite-derived UV irradiances with ground-based measurements at four European stations, J. Geophys. Res., 111, D13207, doi:10.1029/2005JD006672, 2006. Kazadzis, S., Bais, A., Arola, A., Krotkov, N., Kouremeti, N., and Meleti, C.: Ozone Monitoring Instrument spectral UV irradiance products: comparison with ground based measurements at an urban environment, Atmos. Chem. Phys., 9, 585–594, 2009. Krotkov, N. A., Barthia, P. K., Herman, J. R., Fioletov, V., and Kerr, J.: Satellite estimation of spectral surface UV irradiance in the presence of tropospheric aerosols, J. Geophys. Res., 103, 8779–8793, 1998. Krotkov, N., Herman, J., Fioletov, V., Seftor, C., Larko, D., Vasilkov, A., and Labow, G.: Boundary layer absorbing aerosol correction of an expanded UV irradiance database from satellite Total Ozone Mapping Spectrometer, in Proceedings of the XX Quadrennial Ozone Symposium, Kos, Greece, 1159–1160,~pp., June~2004. Krotkov, N. A., Barthia, P. K., Herman, J. R., Slusser, J., Scott, G., Labow, G., Vasilkov, A. P., Eck, T. F., Dubovik, O., and Holben, B. N.: Aerosol ultraviolet absorption experiment (2000 to 2004), part~2: Absorption optical thickness, refractive index, and single scattering albedo, Opt. Eng., 44(4), 041005, doi:10.1117/12.638983, 2005. Levelt, P. F., Hilsenrath, E., Leppelmeier, G. W., Van den Oord, G. H. J., Bhartia, P. K., Tamminen, J., De Haan, J. F., and Veefkind, J. P. : The Ozone Monitoring Instrument, IEEE T. Geosci. Remote, 44(5), 1093–1101, 2006. McKenzie, R. L., Seckmeyer, G., Bais, A. F., Kerr, J. B., and Madronich, S.: Satellite retrievals of erythemal UV dose compared with groundbased measurements at northern and southern midlatitudes, J. Geophys. Res., 106, 24051–24062, 2001. McKinlay, A. F. and Diffey, B. L.: A reference spectrum for ultraviolet induced erythema in human skin, Commission Internationale d'Eclairage (CIE) Journal, 6, 21–27, 1987. Meloni, D., di Sarra, A., DeLuisi, J., Di Iorio, T., Fiocco, G., Junkermann, W., and Pace, G.: Tropospheric aerosols in the Mediterranean: 2 Radiative effects through model simulations and measurements, J. Geophys. Res., 108(D10), 4317, doi:10.1029/2002JD002807, 2003. Meloni, D., di Sarra, A., Herman, J. R., Monteleone, F., and Piacentino, S.: Comparison of ground-based and total ozone mapping spectrometer erythemal UV doses at the Island of Lampedusa in the period 1998–2003: Role of tropospheric aerosols, J. Geophys. Res., 110, D01202, doi:10.1029/2004JD005283, 2005. Sabburg, J., Rives, J. E., Meltzer, R. S., Taylor, T., Schmalzle, G., Zheng, S., Huang, N., Wilson, A., and Udelhofen, P. M.: Comparison of corrected daily integrated erythemal data from the U.S. E.PA/UGA network of Brewer spectroradiometer with model and TOMS-inferred data, J. Geophys. Res., 107(D23), 4676, doi:10.1029/2001JD001565, 2002. Schoeberl, M. R., Douglass, A. R., Hilsenrath, E., Bhartia, P. K., Beer, R., Waters, J. W., Gunson, M. R., Froidevaux, L., Gille, J. C., Barnett, J. J., Levelt, P. E., and DeCola, P.: Overview of the EOS Aura Mission, IEEE T. Geosci. Remote, 4, 1066–1074, 2006. Smirnov, A., Holben, B. N., Eck, T. F., Dubovik, O., and Slutsker, I.: Cloud screening and quality control algorithms for the AERONET database, Remote Sens. Environ., 73, 337–349, 2000. Tanskanen, A., Krotkov, N. A., Herman, J. R., and Arola, A.: Surface Ultraviolet Irradiance From OMI, IEEE T. Geosci. Remote, 44, 1267–1271, doi:10.1109/TGRS.2005.862203, 2006. Tanskanen, A., Lindfors, A., Maatta, A., Krotkov, N., Herman, J., Kaurola, J., Koskela, T.,Lakkala, K., Fioletov, V., Bernhard, J., McHenzie, R., Kondo, Y., O'Neill, M., Slaper, H., den Outer, P., Bais, A. F., and Tamminen, J.: Validation of daily erythemal doses from OMI with ground-based UV measurement data, J. Geophys. Res., 112, D24S44, doi:10.1029/2007JD008830, 2007. Toledano, C.: Climatología de los aerosoles mediante la caracterización de propiedades ópticas y masas de aire en la estación "El Arenosillo" de la red AERONET, PhD Dissertation, Universidad de Valladolid, Spain, 2005. Toledano, C., Cachorro, V. E., de Frutos, A. M., Sorribas, M., Prats, N., and de la Morena, B.: Inventory of African desert dust events over the southwestern Iberian Peninsula in 2000–2005 with an AERONET Cimel Sun photometer, J. Geophys. Res., 112, D21201, doi:10.1029/2006JD008307, 2007a. Toledano, C., Cachorro, V. E., Sorribas, M., Berjón, A., de la Morena, B. A., de Frutos, A. M., and Gouloub, P.: Aerosol optical depth and Ångström exponent climatology at "El Arenosillo" AERONET site (Huelva, Spain), Q. J. Roy. Meteorol. Soc., 133, 795–807, doi:10.1002/qj.54, 2007b. Torres, O. and Barthia, P. K.: Impact of tropospheric aerosol absorption on ozone retrieval from backscattered ultraviolet measurements, J. Geophys. Res., 104, 21569–21577, 1999. Torres, O., Tanskanen, A., Veihelmann, B., Ahn, C., Braak, R., Bhartia, P. K., Veefkind, P., and Levelt, P.: Aerosols and surface UV products from Ozone Monitoring Instrument observations: An overview, J. Geophys. Res., 112, D24S47, doi:10.1029/2007JD008809, 2007. Vilaplana, J. M.: Medida y análisis de ozono y de la radiación solar ultravioleta en El Arenosillo-INTA, Ph.D dissertation, Universidad de Valladolid, Spain, 2004. Weihs, P., Blumthaler, M., Rieder, H. E., Kreuter, A., Simic, S., Laube, W., Schmalwieser, A. W., Wagner, J. E., and Tanskanen, A.: Measurements of UV irradiance within the area of one satellite pixel, Atmos. Chem. Phys., 8, 5615–5626, 2008. World Meteorological Organization (WMO): Global ozone research and monitoring project, Tech. Rep 50, Sci. Assess of Ozone Depletion, Geneva, Switzerland, 2006.