Пространственное распределение снежного покрова и поле температур в верхнем слое политермического ледника

The thermal regime of the upper layers of any glacier largely determines the thermal structure of its entire thickness. Its formation is influenced by both, external and internal factors and the most important one among them is the snow cover. Playing the role of a heat insulator in winter and preventing the ablation of ice in summer, the snow cover mainly determines the winter storage of cold in the ice, and the temperature at the bottom of the active layer. In 2011–2015, the close relationship between the thickness of snow and temperatures in the upper horizons of ice had been found in the course of researches carried out on the glacier East Grønfjord (Svalbard). Comparison of snow measurement survey data, obtained for different years of the period under investigation, did show that, in every year, the maximum snow accumulation took place within the left branch of the glacier, while the snow thickness within the right branch was comparable to that on the glacier tongue. Thus, observed differences in the snow accumulation cause differences in the temperature structure of the upper layers of the ice. Inter-annual variations of the snow cover thickness indicate that conditions of freezing remain stable overthe greater part of the glacier. Only in the upper reaches of the glacier left branch the great snow accumulation creates conditions unfavorable for freezing. This part of the glacier is more inert to changes in climate, and due to that a wide area of warm ice still remains at the bottom of the glacier.Представлены данные термометрии скважин на политермическом леднике Восточный Грёнфьорд в конце периода аккумуляции 2013/14 г. Запас холода во льду ледника тесно связан с толщиной снежного покрова. Для ледника характерна устойчивая асимметрия снегонакопления между ветвями, вызывающая неоднородности температурного поля активного слоя. Ледник термически неоднороден: правая ветвь и язык ледника стабильно выхолаживаются, а левая ветвь за счёт большего снегонакопления промерзает медленнее и в её основании ещё сохраняется тёплый лёд

Оценка поверхностной абляции и баланса массы ледника Восточный Грёнфьорд (Западный Шпицберген)

Due to climatic changes in Spitsbergen the glaciation of the Nordenskjold Land (West Spitsbergen) has significantly degraded over the past 100 years. Changes in glaciers are undoubtedly associated with intensive melting caused by a rise of summer air temperatures. Based on the results of field measurements of ablation on the East Grenford glacier, data on the ice reduction were obtained since 2004. Analysis of the results showed that magnitude of the surface ablation is in a good agreement with the values calculated by the Krenke–Hodakov formula, in which the argument is the average summer air temperature. The parabolic dependence of the Krenke-Hodakov formula with the exponent of 3.25 presented the best approximation to the field measurements for all high-altitude zones of the glacier with a correlation coefficient of 0.96. The calculated values of ablation of ice and snow were used to estimate the mass balance of the East Grenford glacier since 2004. The calculations were based on the following: measured values of jump in temperature at the boundary of the glacier, averaged values of the air temperature gradient, and averaged data on snow storage on the glacier. Data on the mass balance of the glacier is indicative of its shortening during the last decade, despite the interannual variations. In 2016, the glacier mass balance reached the lowest value equal to −1990 mm, the calculated value was equal to −1960 mm. Analysis of the data demonstrated that the average summer air temperature is the major factor affecting the glacier mass balance. These results may be useful for estimating  melting and mass balance of a number of mountain glaciers of the Nordenskjold Land. Многолетние наблюдения на леднике Восточный Грёнфьорд показали значительное сокращение его площади и снижение поверхности ледника. Расчёт абляции проводился по четырём высотным зонам с учётом реальных значений температурного градиента и температурного скачка на краю ледника. Результаты, полученные на этом леднике, позволяют оценить летнюю абляции и баланс массы горных ледников на западе Земли Норденшельда

Spatial distribution of snow cover and temperature in the upper layer of a polythermal glacier

The thermal regime of the upper layers of any glacier largely determines the thermal structure of its entire thickness. Its formation is influenced by both, external and internal factors and the most important one among them is the snow cover. Playing the role of a heat insulator in winter and preventing the ablation of ice in summer, the snow cover mainly determines the winter storage of cold in the ice, and the temperature at the bottom of the active layer. In 2011–2015, the close relationship between the thickness of snow and temperatures in the upper horizons of ice had been found in the course of researches carried out on the glacier East Grønfjord (Svalbard). Comparison of snow measurement survey data, obtained for different years of the period under investigation, did show that, in every year, the maximum snow accumulation took place within the left branch of the glacier, while the snow thickness within the right branch was comparable to that on the glacier tongue. Thus, observed differences in the snow accumulation cause differences in the temperature structure of the upper layers of the ice. Inter-annual variations of the snow cover thickness indicate that conditions of freezing remain stable overthe greater part of the glacier. Only in the upper reaches of the glacier left branch the great snow accumulation creates conditions unfavorable for freezing. This part of the glacier is more inert to changes in climate, and due to that a wide area of warm ice still remains at the bottom of the glacier

Estimation of the surface ablation and mass balance of Eustre Grønfjordbreen (Spitsbergen)

Due to climatic changes in Spitsbergen the glaciation of the Nordenskjold Land (West Spitsbergen) has significantly degraded over the past 100 years. Changes in glaciers are undoubtedly associated with intensive melting caused by a rise of summer air temperatures. Based on the results of field measurements of ablation on the East Grenford glacier, data on the ice reduction were obtained since 2004. Analysis of the results showed that magnitude of the surface ablation is in a good agreement with the values calculated by the Krenke–Hodakov formula, in which the argument is the average summer air temperature. The parabolic dependence of the Krenke-Hodakov formula with the exponent of 3.25 presented the best approximation to the field measurements for all high-altitude zones of the glacier with a correlation coefficient of 0.96. The calculated values of ablation of ice and snow were used to estimate the mass balance of the East Grenford glacier since 2004. The calculations were based on the following: measured values of jump in temperature at the boundary of the glacier, averaged values of the air temperature gradient, and averaged data on snow storage on the glacier. Data on the mass balance of the glacier is indicative of its shortening during the last decade, despite the interannual variations. In 2016, the glacier mass balance reached the lowest value equal to −1990 mm, the calculated value was equal to −1960 mm. Analysis of the data demonstrated that the average summer air temperature is the major factor affecting the glacier mass balance. These results may be useful for estimating  melting and mass balance of a number of mountain glaciers of the Nordenskjold Land