[en] The near-infrared (NIR) part of the solar spectrum is of prime importance for solar physics and climatology, directly intervening in the Earth's radiation budget. Despite its major role, available solar spectral irradiance (SSI) NIR datasets, space-borne or ground-based, present discrepancies caused by instrumental or methodological reasons. We present new results obtained from the PYR-ILIOS SSI NIR ground-based campaign, which is a replication of the previous IRSPERAD campaign which took place in 2011 at the Izaña Atmospheric Observatory (IZO). We used the same instrument and primary calibration source of spectral irradiance. A new site was chosen for PYR-ILIOS: the Mauna Loa Observatory (MLO) in Hawaii (3397 m a.s.l.), approximately 1000 m higher than IZO. Relatively to IRSPERAD, the methodology of monitoring the traceability to the primary calibration source was improved. The results as well as a detailed error budget are presented. We demonstrate that the most recent results, from PYR-ILIOS and other space-borne and ground-based experiments, show an NIR SSI lower than the previous reference spectrum, ATLAS3, for wavelengths above 1.6 µm.
Arvesen, J. C., Griffin, R. N., and Pearson, D. J.: Determination of extraterrestrial solar spectral irradiance from a research aircraft, Appl. Opt., 8, 2215-2232, 1969.
Bennett, G. G.: The Calculation of Astronomical Refraction in Marine Navigation, J. Navigation, 35, 255-259, https://doi.org/10.1017/s0373463300022037, 1982.
Berk, A., Conforti, P., Kennett, R., Perkins, T., Hawes, F., and van den Bosch, J.: MODTRAN6: A major upgrade of the MODTRAN radiative transfer code, in: Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery XX, edited by: Velez-Reyes, M. and Kruse, F. A., SPIE, https://doi.org/10.1117/12.2050433, 2014.
Blanc, P., Espinar, B., Geuder, N., Gueymard, C., Meyer, R., Pitz-Paal, R., Reinhardt, B., Renné, D., Sengupta, M., Wald, L., and Wilbert, S.: Direct normal irradiance related definitions and applications: The circumsolar issue, Sol. Energy, 110, 561-577, https://doi.org/10.1016/j.solener.2014.10.001, 2014.
Bodhaine, B. A., Wood, N. B., Dutton, E. G., and Slusser, J. R.: On Rayleigh Optical Depth Calculations, J. Atmos. Ocean. Tech., 16, 1854-1861, https://doi.org/10.1175/1520-0426(1999)0162.0.co;2, 1999.
Bolsée, D.: Métrologie de la spectrophotométrie solaire absolue. Principes, mise en oeuvre et résultats. Instrument SOLSPEC à bord de la Station Spatiale Internationale, PhD thesis, Free University of Brussels, 2012.
Bolsée, D., Pereira, N., Decuyper, W., Gillotay, D., Yu, H., Sperfeld, P., Pape, S., Cuevas, E., Redondas, A., Hernandéz, Y., and Weber, M.: Accurate Determination of the TOA Solar Spectral NIR Irradiance Using a Primary Standard Source and the Bouguer-Langley Technique, Sol. Phys., 289, 2433-2457, https://doi.org/10.1007/s11207-014-0474-1, 2014.
Bolsée, D., Pereira, N., Cuevas, E., García, R., and Redondas, A.: Comments to the Article by Thuillier et al. "The Infrared Solar Spectrum Measured by the SOLSPEC Spectrometer Onboard the International Space Station" on the Interpretation of Groundbased Measurements at the Izaña Site, Sol. Phys., 291, 2473-2477, https://doi.org/10.1007/s11207-016-0914-1, 2016.
Burrows, J., Hölzle, E., Goede, A., Visser, H., and Fricke, W.: SCIAMACHY-scanning imaging absorption spectrometer for atmospheric chartography, Acta Astronaut., 35, 445-451, https://doi.org/10.1016/0094-5765(94)00278-T, 1995.
Collins, W. D., Lee-Taylor, J. M., Edwards, D. P., and Francis, G. L.: Effects of increased near-infrared absorption by water vapor on the climate system, J. Geophys. Res., 111, D18109, https://doi.org/10.1029/2005jd006796, 2006.
Elsey, J., Coleman, M. D., Gardiner, T., and Shine, K. P.: Can Measurements of the Near-Infrared Solar Spectral Irradiance be Reconciled? A New Ground-Based Assessment Between 4000 and 10 000 cm-1, Geophys. Res. Lett., 44, 10071-10080, https://doi.org/10.1002/2017gl073902, 2017.
Ermolli, I., Matthes, K., Dudok deWit, T., Krivova, N. A., Tourpali, K., Weber, M., Unruh, Y. C., Gray, L., Langematz, U., Pilewskie, P., Rozanov, E., Schmutz, W., Shapiro, A., Solanki, S. K., and Woods, T. N.: Recent variability of the solar spectral irradiance and its impact on climate modelling, Atmos. Chem. Phys., 13, 3945-3977, https://doi.org/10.5194/acp-13-3945-2013, 2013.
Friedrich, R., Fischer, J., and Strock, M.: Accurate calibration of filter radiometers against a cryogenic radiometer using a trap detector, Metrologia, 32, 509-513, 1995.
Gray, L. J., Beer, J., Geller, M., Haigh, J. D., Lockwood, M., Matthes, K., Cubasch, U., Fleitmann, D., Harrison, G., Hood, L., Luterbacher, J., Meehl, G. A., Shindell, D., van Geel, B., and White, W.: Solar influences on climate, Rev. Geophys., 48, RG4001, https://doi.org/10.1029/2009RG000282, 2010.
Gröbner, J. and Kerr, J. B.: Ground-based determination of the spectral ultraviolet extraterrestrial solar irradiance: Providing a link between space-based and ground-based solar UV measurements, J. Geophys. Res.-Atmos., 106, 7211-7217, https://doi.org/10.1029/2000JD900756, 2001.
Gröbner, J., Kröger, I., Egli, L., Hölsen, G., Riechelmann, S., and Sperfeld, P.: The high-resolution extraterrestrial solar spectrum (QASUMEFTS) determined from ground-based solar irradiance measurements, Atmos. Meas. Tech., 10, 3375-3383, https://doi.org/10.5194/amt-10-3375-2017, 2017.
Gueymard, C. A.: Parameterized transmittance model for direct beam and circumsolar spectral irradiance, Sol. Energy, 71, 325-346, https://doi.org/10.1016/s0038-092x(01)00054-8, 2001.
GUM: Evaluation of Measurement Data-Guide to the Expression of Uncertainty in Measurement, BIPM, Paris, 2008.
Harder, J., Lawrence, G., Rottman, G. J., and Woods, T. N.: The Spectral Irradiance Monitor (SIM) for the SORCE mission, in: Earth Observing Systems V., edited by: Barnes, W. L., Proc. SPIE, 4135, 204-214, 2000.
Harder, J., Lawrence, G. M., Fontenla, J. M., Rottman, G., and Woods, T. N.: The Spectral Irradiance Monitor: Scientific requirements, instrument design, and operation modes, Sol. Phys., 230, 141-167, 2005.
Harder, J. W., Fontenla, J. M., Pilewskie, P., Richard, E. C., and Woods, T. N.: Trends in solar spectral irradiance variability in the visible and infrared, Geophys. Res. Lett, 36, L07801, https://doi.org/10.1029/2008GL036797, 2009.
Harder, J. W., Thuillier, G., Richard, E. C., Brown, S. W., Lykke, K. R., Snow, M., McClintock, W. E., Fontenla, J. M., Woods, T. N., and Pilewskie, P.: The SORCE SIM solar spectrum: Comparison with recent observations, Sol. Phys., 263, 3-24, 2010.
Hilbig, T., Weber, M., Bramstedt, K., Noël, S., Burrows, J. P., Krijger, J. M., Snel, R., Meftah, M., Damé, L., Bekki, S., Bolsée, D., Pereira, N., and Sluse, D.: The New SCIAMACHY Reference Solar Spectral Irradiance and Its Validation, Sol. Phys., 293, 121, https://doi.org/10.1007/s11207-018-1339-9, 2018.
Kasten, F. and Young, A. T.: Revised optical air mass tables and approximation formula, Appl. Opt., 28, 4735, https://doi.org/10.1364/ao.28.004735, 1989.
Kiedron, P. W. and Michalsky, J. J.: Non-parametric and least squares Langley plot methods, Atmos. Meas. Tech., 9, 215-225, https://doi.org/10.5194/amt-9-215-2016, 2016.
Kindel, B. C., Qu, Z., and Goetz, A. F. H.: Direct solar spectral irradiance and transmittance measurements from 350 to 2500 nm, Appl. Opt., 40, 3483-3494, 2001.
Krystek, M. and Anton, M.: A weighted total least-squares algortihm fot fitting a straight line, Meas. Sci. Technol., 18, 3438-3442, 2007.
Lean, J.: Variations in the Suns radiative output, Rev. Geophys., 29, 505-535, https://doi.org/10.1029/91RG01895, 1991.
Mayer, B. and Kylling, A.: Technical note: The libRadtran software package for radiative transfer calculations-description and examples of use, Atmos. Chem. Phys., 5, 1855-1877, https://doi.org/10.5194/acp-5-1855-2005, 2005.
Meftah, M., Damé, L., Bolsée, D., Pereira, N., Sluse, D., Cessateur, G., Irbah, A., Sarkissian, A., Djafer, D., Hauchecorne, A., and Bekki, S.: A New Solar Spectrum from 656 to 3088 nm, Sol. Phys., 292, 101, https://doi.org/10.1007/s11207-017-1115-2, 2017.
Menang, K. P., Ptashnik, I. V., Coleman, M., Gardiner, T., and Shine, K.: A high-resolution near-infrared extraterrestrial solar spectrum derived from ground-based Fourier transform spectrometer measurements, J. Geophys. Res., 118, 1-13, 2013.
Noël, S., Bovensmann, H., Burrows, J. P., Frerick, J., Chance, K. V., Goede, A. P., and Muller, C.: SCIAMACHY instrument on ENVISAT-1, Sensors, Systems, and Next-Generation Satellites II., edited by: Fujisada, H., Proc. SPIE, 3498, 94-104, 1998.
Obaton, A. F., Ledenberg, J., Fischer, N., Guimier, S., and Dubard, J.: Two procedures for the estimation of the uncertainty of spectral irradiance measurement for UV source calibration, Metrologia, 44, 152-160, 2007.
Sapritsky, V. I., Khlevnoy, B. B., Khromchenko, V. B., Lisiansky, B. E., Mekhontsev, S. N., Melenevsky, U. A., Morozova, S. P., Prokhorov, A. V., Samoilov, L. N., Shapoval, V. I., Sudarev, K. A., and Zelener, M. F.: Precision blackbody sources for radiometric standards, Appl. Opt, 36, 5403-5408, 1997.
Schmid, B. and Wehrli, C.: Comparison of Sun photometer calibration by use of the Langley technique and the standard lamp, Appl. Opt., 34, 4500-4512, 1995.
Shaw, G. E.: Solar Spectral Irradiance: The Role of Earth-Based Measurements, in: The Solar Constant and the Earths Atmosphere, Proceedings of the Workshop held at Big Bear Solar Observatory, Big Bear City, CA, 19-21 May 1975, Big Bear Solar Observatory, edited by: Zirin, E. H. andWalter, J., 210-231 1975.
Shaw, G. E.: Error analysis of multi-wavelength sun photometry, Pure Appl. Geophys., 114, 1-14, https://doi.org/10.1007/BF00875487, 1976.
Shaw, G. E.: Solar spectral irradiance and atmospheric transmission at Mauna Loa Observatory, Appl. Opt., 21, 2006, https://doi.org/10.1364/ao.21.002006, 1982.
Sperfeld, P., Metzdorf, J., Galal Yousef, S., Stock, K. D., and Möller, W.: Improvement and extension of the black-body-based spectral irradiance scale, Metrologia, 35, 267-271, 1998.
Sperfeld, P., Galal Yousef, S., Metzdorf, J., N., B., and Möller, W.: The use of self-consistent calibrations to recover absorption bands in the black-body spectrum, Metrologia, 37, 373-376, 2000.
Taubert, D., Friedrich, R., Hartmann, J., and Hollandt, J.: Improved calibration of the spectral responsivity of Interference Filter Radiometers in the visible and near infrared spectral range at PTB, Metrologia, 40, S35-38, 2003.
Thuillier, G., Simon, P. C., Labs, D., Pastiels, R., and Neckel, H.: An instrument to measure the solar spectrum from 170 to 3200 nm on board Spacelab, Sol. Phys., 74, 531-537, 1981.
Thuillier, G., Hersé, M., Labs, D., Foujols, T., Peetermans, W., Gillotay, D., Simon, P. C., and Mandel, H.: The solar spectral irradiance from 200 to 2400 nm as measured by the SOLSPEC spectrometer from the ATLAS and EURECA missions, Sol. Phys., 214, 1-22, 2003.
Thuillier, G., Foujols, T., Bolsée, D., Gillotay, D., Hersé, M., Peetermans, W., Decuyper, W., Mandel, H., Sperfeld, P., Pape, S., Taubert, D. R., and Hartmann, J.: SOLAR/SOLSPEC: Scientific objectives, instrument performance and its absolute calibration using a blackbody as primary standard source, Sol. Phys., 257, 185-213, 2009.
Thuillier, G., Bolsée, D., Schmidtke, G., Foujols, T., Nikutowski, B., Shapiro, A. I., Brunner, R., Weber, M., Erhardt, C., Hersé, M., Gillotay, D., Peetermans, W., Decuyper, W., Pereira, N., Haberreiter, M., Mandel, H., and Schmutz, W.: The Solar Irradiance Spectrum at Solar 30 Activity Minimum Between Solar Cycles 23 and 24, Sol. Phys., 289, 1931-1958, https://doi.org/10.1007/s11207-013-0461-y, 2014.
Toledano, C., González, R., Fuertes, D., Cuevas, E., Eck, T. F., Kazadzis, S., Kouremeti, N., Gröbner, J., Goloub, P., Blarel, L., Román, R., Barreto, Á., Berjón, A., Holben, B. N., and Cachorro, V. E.: Assessment of Sun photometer Langley calibration at the high-elevation sites Mauna Loa and Izaña, Atmos. Chem. Phys., 18, 14555-14567, https://doi.org/10.5194/acp-18-14555-2018, 2018.
Weber, M.: Comment on the Article by Thuillier et al. "The Infrared Solar Spectrum Measured by the SOLSPEC Spectrometer onboard the International Space Station", Sol. Phys., 290, 1601-1605, https://doi.org/10.1007/s11207-015-0707-y, 2015.
Werner, L., Fischer, J., Johannsen, U., and Hartmann, J.: Accurate determination of the spectral responsivity of silicon trap detectors between 238 and 1015 nm, Metrologia, 37, 279-284, 2000.
Woolliams, E. R., Fox, N. P., Cox, M. G., Harris, P. M., and Harrison, N. J.: Final report on CCPR K1-A: Spectral irradiance from 250 nm to 2500 nm, Metrologia, 43, 02003, https://doi.org/10.1088/0026-1394/43/1A/02003, 2006.
