Best possible estimation of mass balance combining glaciological and geodetic methods
[Departement_IRSTEA]Eaux [TR1_IRSTEA]RIVAGE International audience Variance analysis of the long time series of mass balances recorded on Glacier de Sarennes(45807' N, 6807' E) France, since 1949 shows that the variability can be separated linearly in two spatial and temporal terms. Annual...
Published in: | Annals of Glaciology |
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Main Authors: | , |
Other Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2009
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Subjects: | |
Online Access: | https://hal.inrae.fr/hal-02591374 https://hal.inrae.fr/hal-02591374/document https://hal.inrae.fr/hal-02591374/file/div-class-title-best-possible-estimation-of-mass-balance-combining-glaciological-and-geodetic-methods-div.pdf https://doi.org/10.3189/172756409787769546 |
Summary: | [Departement_IRSTEA]Eaux [TR1_IRSTEA]RIVAGE International audience Variance analysis of the long time series of mass balances recorded on Glacier de Sarennes(45807' N, 6807' E) France, since 1949 shows that the variability can be separated linearly in two spatial and temporal terms. Annual balances deviate from their mean values over the period of record by an annual amount that is uniform over the glacier. Annual balances at each stake are therefore highly correlated, and sampling at a single site would be acceptable to record the annual deviation. A result of the linear character of the variance is the possibility of obtaining a systematic error-free estimate of the annual glacier-total budget by combining the mean annual balance obtained from photogrammetry and the annual deviation obtained from the variance analysis, rather than using the traditional area integration of balances at each stake. L'analyse de variance de la longue série de bilan de masse du glacier de Sarennes montre que la variabilité peut être séparée en 2 termes spatial et temporel. Les bilans annuels s'écartent donc de leur moyenne d'une valeur uniforme sur l'ensemble du glacier et sont fortement corrélés. Une conséquence de cette séparation linéaire de la variance est la possibilité d'obtenir une estimation sans biais du bilan d'ensemble en associant le bilan moyen obtenu par photogrammétrie et la déviation annuelle extraite par l'analyse de variance plutôt que d'utiliser une loi classique de pondération spatiale des bilans en chaque site. |
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