SNOW THICKNESS ON AUSTRE GRØNFJORDBREEN, SVALBARD, FROM RADAR MEASUREMENTS AND STANDARD SNOW SURVEYS

• Published in: Ice and Snow
• Main Authors: I. Lavrentiev I., S. Kutuzov S., A. Glazovsky F., Yu. Macheret Ya., N. Osokin I., A. Sosnovsky V., R. Chernov А., G. Cherniakov A., И. Лаврентьев И., С. Кутузов С., А. Глазовский Ф., Ю. Мачерет Я., Н. Осокин И., А. Сосновский В., Р. Чернов А., Г. Черняков А.
• Other Authors: Fundamental scientific studies within the project «Assessments of the current state and current changes in the internal hydrothermal regime of glaciers, with the identification of data on reference glaciers», Reg. No. 01201352474 (0148-2014-0006), Project 3.1 «Adaptation Modes of Glaciers in the Polar Regions of the Earth to Climate Change» of the P-15 Program of the RAS Presidium», project of RAS «Investigation of changeability of snow cover and estimation of its influence on stability of permafrost based on modeling and radio-echo sounding» and RSF grant № 14-37-00038, I.Yu. Solovyanova and AARII colleagues for snow measurements data and to Russian Scientific Center on the Spitsbergen Archipelago for the supplied set of radar equipment pulseEKKO PRO, Фундаментальные научные исследования по проекту «Оценки современного состояния и текущих изменений внутреннего гидротермического режима ледников, с выделением данных по эталонным ледникам», Рег. № 01201352474 (0148-2014-0006), по проекту 3.1 «Режимы адаптации ледников полярных областей Земли к изменениям климата» программы П-15 Президиума РАН», поддержана проектом РАН «Исследование изменчивости арктического снежного покрова и оценка его влияния на устойчивость многолетней мерзлоты на основе моделирования и радиозондирования» и грантом РНФ № 14-37-00038
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: IGRAS 2018
• Subjects: Арктика; ледник; радиолокация; снегомерные измерения; снежный покров; Шпицберген; Svalbard; Austre Grønfjordbreen; Annals of Glaciology; Arctic; glacier; Polar Research; The Cryosphere
• Online Access: https://ice-snow.igras.ru/jour/article/view/432; https://doi.org/10.15356/2076-6734-2018-1-5-20

Summary Comparison of two methods of measurements of snow cover thickness on the glacier Austre Grønfjordbreen, Svalbard was performed in the spring of 2014. These methods were the radar (500 MHz) observations and standard snow surveys. Measurements were conducted in 77 different points on the surface of the glacier. A good correlation (R2 = 0.98) was revealed. In comparison with the data of snow surveys, the radar measurements show a similar but more detailed pattern of the distribution of the snow cover depth. The discrepancy between the depths of snow cover on maps plotted from data of both methods did not exceed 30 cm in most parts of the glacier. The standard error of interpolation of the radar data onto the entire glacier surface amounts, on average, to 18 cm. This corresponds to the error of radar measurements of 18.8% when an average snow depth is about 160 cm and 9.4% at its maximum thickness of 320 cm. The distance between the measurement points at which the spatial covariance of the snow depth disappears falls between 236 and 283 m along the glacier, and between 117 and 165 m across its position. We compared the results of radar measurements of the pulse-delay time of reflections from the base of the snow cover with the data of manual probe measurements at 10 points and direct measurements of snow depth and average density in 12 snow pits. The average speed of radio waves propagation in the snow was determined as Vcr = 23.4±0.2 cm ns−1. This magnitude and the Looyenga and Kovacs formulas allowed estimating the average density of snow cover ρL = 353.1±13.1 kg m−3 and ρK = 337.4±12.9 kg m−3. The difference from average density measured in 12 pits ρav.meas = 387.4±12.9 kg m−3 amounts to −10.8% and −14.8%. In 2014, according to snow and radar measurements, altitudinal gradient of snow accumulation on the glacier Austre Grønfjordbreen was equal to 0.21 m/100 m, which is smaller than the average values (0.35 m/100 m). According to the results of snow measurements of 2011–2014, the average thickness of the ...