Development and calibration of an automatic spectral albedometer to estimate near-surface snow SSA time series

Abstract. Spectral albedo of the snow surface in the visible/near-infrared range has been measured for 3 years by an automatic spectral radiometer installed at Dome C (75° S, 123° E) in Antarctica in order to retrieve the specific surface area (SSA) of superficial snow. This study focuses on the uncertainties of the SSA retrieval due to instrumental and data processing limitations. We find that when the solar zenith angle is high, the main source of uncertainties is the imperfect angular response of the light collectors. This imperfection introduces a small spurious wavelength-dependent trend in the albedo spectra which greatly affects the SSA retrieval. By modeling this effect, we show that for typical snow and illumination conditions encountered at Dome C, retrieving SSA with an accuracy better than 15 % (our target) requires the difference of response between 400 and 1100 nm to not exceed 2 %. Such a small difference can be achieved only by (i) a careful design of the collectors, (ii) an ad hoc correction of the spectra using the actual measured angular response of the collectors, and (iii) for solar zenith angles less than 75°. The 3-year time series of retrieved SSA features a 3-fold decrease every summer which is significantly larger than the estimated uncertainties. This highlights the high dynamics of near-surface SSA at Dome C.

[1]  J. H. Morrow,et al.  The impact of cosine collector geometry on aquatic spectroradiometer performance , 2000, OCEANS 2000 MTS/IEEE Conference and Exhibition. Conference Proceedings (Cat. No.00CH37158).

[2]  Thomas C. Grenfell,et al.  Representation Of A Nonspherical Ice Particle By A Collection Of Independent Spheres For Scattering And Absorption Of Radiation : 2 . Hexagonal Columns And Plates , 2003 .

[3]  Application of asymptotic radiative transfer theory for the retrievals of snow parameters using reflection and transmission observations , 2011 .

[4]  Stephen G. Warren,et al.  Effect of surface roughness on bidirectional reflectance of Antarctic snow , 1998 .

[5]  M. Fily,et al.  Modeling the effect of sastrugi on snow reflectance , 1998 .

[6]  A. Kokhanovsky,et al.  Intercomparison of retrieval algorithms for the specific surface area of snow from near-infrared satellite data in mountainous terrain, and comparison with the output of a semi-distributed snowpack model , 2013 .

[7]  T. Painter,et al.  MODIS-based Mosaic of Antarctica (MOA) data sets: Continent-wide surface morphology and snow grain size , 2007 .

[8]  M. Stibal,et al.  Biological processes on glacier and ice sheet surfaces , 2012 .

[9]  Andrew J. S. McGonigle,et al.  Comparison of Low Cost Miniature Spectrometers for Volcanic SO2 Emission Measurements , 2009, Sensors.

[10]  T. Painter,et al.  Reflectance quantities in optical remote sensing - definitions and case studies , 2006 .

[11]  V. Vitale,et al.  Continuous monitoring of spectral albedo of snowed surfaces in Ny-Ålesund , 2016, Rendiconti Lincei.

[12]  D. As,et al.  The Summer Surface Energy Balance of the High Antarctic Plateau , 2005 .

[13]  Laurent Arnaud,et al.  Determining snow specific surface area from near-infrared reflectance measurements: Numerical study of the influence of grain shape , 2009 .

[14]  A. Gardner,et al.  A review of snow and ice albedo and the development of a new physically based broadband albedo parameterization , 2010 .

[15]  S. Warren,et al.  Reflection of solar radiation by the Antarctic snow surface at ultraviolet, visible, and near‐infrared wavelengths , 1994 .

[16]  S. Warren,et al.  Spectral Bidirectional Reflectance of Antarctic Snow: Measurements and Parameterization , 2006 .

[17]  Martin Schneebeli,et al.  Measuring specific surface area of snow by near-infrared photography , 2006 .

[18]  Catherine Gautier,et al.  SBDART: A Research and Teaching Software Tool for Plane-Parallel Radiative Transfer in the Earth's Atmosphere. , 1998 .

[19]  Ping Yang,et al.  Snow optical properties for different particle shapes with application to snow grain size retrieval and MODIS/CERES radiance comparison over Antarctica , 2008 .

[20]  M. Frey,et al.  Snow optical properties at Dome C , Antarctica – implications for snow emissions and snow chemistry of reactive nitrogen , 2011 .

[21]  Teruo Aoki,et al.  Effects of snow physical parameters on spectral albedo and bidirectional reflectance of snow surface , 2000 .

[22]  S. Warren,et al.  Optical constants of ice from the ultraviolet to the microwave: A revised compilation , 2008 .

[23]  S. Warren,et al.  A Model for the Spectral Albedo of Snow. II: Snow Containing Atmospheric Aerosols , 1980 .

[24]  S. Morin,et al.  Summertime evolution of snow specific surface area close to the surface on the Antarctic Plateau , 2015 .

[25]  Laurent Arnaud,et al.  Influence of grain shape on light penetration in snow , 2013 .

[26]  Y. Reinert,et al.  Site testing for submillimetre astronomy at Dome C, Antarctica , 2011, 1110.4311.

[27]  R. Greve,et al.  Ice sheet mass loss caused by dust and black carbon accumulation , 2015 .

[28]  Timo Vihma,et al.  Measurements and modelling of snow particle size and shortwave infrared albedo over a melting Antarctic ice sheet , 2015 .

[29]  Thomas H. Painter,et al.  Contact spectroscopy for determination of stratigraphy of snow optical grain size , 2007, Journal of Glaciology.

[30]  S. Gerland,et al.  A modern concept for autonomous and continuous measurements of spectral albedo and transmittance of sea ice , 2009 .

[31]  R. Armstrong,et al.  The international classification for seasonal snow on the ground (UNESCO, IHP (International Hydrological Programme)–VII, Technical Documents in Hydrology, No 83; IACS (International Association of Cryospheric Sciences) contribution No 1) , 2009 .

[32]  A. Kylling,et al.  Tilt error in cryospheric surface radiation measurements at high latitudes: a model study , 2015 .

[33]  M. Dumont,et al.  Experimental determination of the absorption enhancement parameter of snow , 2014 .

[34]  Alexandre Roy,et al.  Brightness Temperature Simulations of the Canadian Seasonal Snowpack Driven by Measurements of the Snow Specific Surface Area , 2013, IEEE Transactions on Geoscience and Remote Sensing.

[35]  Alan H. Strahler,et al.  Commentary on Wang and Zender—MODIS snow albedo bias at high solar zenith angles relative to theory and to in situ observations in Greenland , 2011 .

[36]  A. Hall,et al.  What Controls the Strength of Snow-Albedo Feedback? , 2007 .

[37]  Thomas C. Grenfell,et al.  Representation of a nonspherical ice particle by a collection of independent spheres for scattering , 1999 .

[38]  Gert König-Langlo,et al.  Measurements of spectral snow albedo at Neumayer, Antarctica , 2006 .

[39]  Ghislain Picard,et al.  Measurement of the specific surface area of snow using infrared reflectance in an integrating sphere at 1310 and 1550 nm , 2009 .

[40]  E. Brun,et al.  Modeling the impact of snow drift on the decameter‐scale variability of snow properties on the Antarctic Plateau , 2014 .

[41]  Gunther Seckmeyer,et al.  New Entrance Optics for Solar Spectral UV Measurements , 1997 .

[42]  Eleonora P Zege,et al.  Scattering optics of snow. , 2004, Applied optics.

[43]  Roberto Salzano,et al.  Correlation between the specific surface area and the short wave infrared (SWIR) reflectance of snow , 2006 .

[44]  Stephen G. Warren,et al.  Optical Properties of Snow , 1982 .

[45]  D. Shindell,et al.  Anthropogenic and Natural Radiative Forcing , 2014 .

[46]  J. Dozier,et al.  A Hyperspectral Method for Remotely Sensing the Grain Size of Snow , 2000 .

[47]  L. Arnaud,et al.  Measurement of vertical profiles of snow specific surface area with a 1 cm resolution using infrared reflectance: instrument description and validation , 2011, Journal of Glaciology.

[48]  S. Warren,et al.  Visible and near-ultraviolet absorption spectrum of ice from transmission of solar radiation into snow. , 2006, Applied optics.

[49]  G. Picard,et al.  Vertical profile of the specific surface area and density of the snow at Dome C and on a transect to Dumont D'Urville, Antarctica – albedo calculations and comparison to remote sensing products , 2011 .

[50]  Wei Li,et al.  Retrieval of snow physical parameters by neural networks and optimal estimation: case study for ground-based spectral radiometer system. , 2015, Optics express.

[51]  A. Kokhanovsky,et al.  Influence of surface roughness on the reflective properties of snow , 2011 .

[52]  D. As,et al.  Assessing and Improving the Quality of Unattended Radiation Observations in Antarctica , 2004 .

[53]  Charles S. Zender,et al.  MODIS snow albedo bias at high solar zenith angles relative to theory and to in situ observations in Greenland , 2009 .

[54]  Laurent Arnaud,et al.  Inhibition of the positive snow-albedo feedback by precipitation in interior Antarctica , 2012 .

[55]  J. Ettema,et al.  Climate of the Greenland ice sheet using a high-resolution climate model – Part 2: Near-surface climate and energy balance , 2010 .

[56]  Laurent Arnaud,et al.  Snow spectral albedo at Summit, Greenland: measurements and numerical simulations based on physical and chemical properties of the snowpack , 2013 .

[57]  S. Warren,et al.  An explanation for the effect of clouds over snow on the top-of-atmosphere bidirectional reflectance , 2007 .

[58]  Ice.  The international classification for seasonal snow on the ground , 1990 .

[59]  Judith A. Curry,et al.  Sea Ice-Albedo Climate Feedback Mechanism , 1995 .

[60]  H. Iwabuchi,et al.  Effect of sastrugi on snow bidirectional reflectance and its application to MODIS data , 2011 .

[61]  Nigel P. Fox,et al.  Characterisation of the HDRF (as a proxy for BRDF) of snow surfaces at Dome C, Antarctica, for the inter-calibration and inter-comparison of satellite optical data , 2015 .

[62]  Yves Lejeune,et al.  Measurements and modeling of the vertical profile of specific surface area of an alpine snowpack , 2013 .

[63]  Y. Arnaud,et al.  High-accuracy measurements of snow Bidirectional Reflectance Distribution Function at visible and NIR wavelengths - comparison with modelling results , 2009 .

[64]  Julienne C. Stroeve,et al.  Evaluation of the MODIS (MOD10A1) daily snow albedo product over the Greenland ice sheet , 2006 .

[65]  Jean Jouzel,et al.  A detailed study of snow accumulation and stable isotope content in Dome C (Antarctica) , 1982 .

[66]  Thomas H. Painter,et al.  Retrieval of subpixel snow covered area, grain size, and albedo from MODIS , 2009 .

[67]  M. Mishchenko,et al.  Applicability of regular particle shapes in light scattering calculations for atmospheric ice particles. , 1996, Applied optics.

[68]  M. Frey,et al.  Snow optical properties at Dome C (Concordia), Antarctica; implications for snow emissions and snow chemistry of reactive nitrogen , 2011 .