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

Citation

Picard, G and Libois, Q and Arnaud, L and Verin, G and Dumont, M, Development and calibration of an automatic spectral albedometer to estimate near-surface snow SSA time series, The Cryosphere, 10, (3) pp. 1297-1316. ISSN 1994-0416 (2016) [Non Refereed Article]


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DOI: doi:10.5194/tc-10-1297-2016

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.

Item Details

Item Type:Non Refereed Article
Keywords:near-surface snow, Antarctica, automatic spectral albedometer, specific surface area
Research Division:Earth Sciences
Research Group:Physical Geography and Environmental Geoscience
Research Field:Glaciology
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Environmental Sciences
Author:Picard, G (Dr Ghislain Picard)
ID Code:118151
Year Published:2016
Web of Science® Times Cited:7
Deposited By:CRC-Antarctic Climate & Ecosystems
Deposited On:2017-07-05
Last Modified:2017-07-05
Downloads:0

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