| 1. |
- Koblet, Thomas, et al.
(författare)
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Reanalysis of multi-temporal aerial images of Storglaciären, Sweden (1959–99) – Part 1: Determination of length, area, and volume changes
- 2010
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Ingår i: The Cryosphere. - Göttingen : Copernicus. - 1994-0416 .- 1994-0424. ; 4, s. 333-343
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Tidskriftsartikel (refereegranskat)abstract
- Storglaciären, located in the Kebnekaise massif in northern Sweden, has a long history of glaciological research. Early photo documentations date back to the late 19th century. Measurements of front position variations and distributed mass balance have been carried out since 1910 and 1945/46, respectively. In addition to these in-situ measurements, aerial photographs have been taken at decadal intervals since the beginning of the mass balance monitoring program and were used to produce topographic glacier maps. Inaccuracies in the maps were a challenge to early attempts to derive glacier volume changes and resulted in major differences when compared to the direct glaciological mass balances. In this study, we reanalyzed dia-positives of the original aerial photographs of 1959, -69, -80, -90 and -99 based on consistent photogrammetric processing. From ther esulting digital elevation models and orthophotos, changes in length, area, and volume of Storglaciären were computed between the survey years, including an assessment of related errors. Between 1959 and 1999, Storglaciären lost an ice volume of 19×106 m3, which corresponds to a cumulative ice thickness loss of 5.69 m and a mean annual loss of 0.14 m. This ice loss resulted largely from a strong volume loss during the period 1959–80 and was partly compensated during the period 1980–99. As a consequence, the glacier shows a strong retreat in the 1960s, a slowing in the 1970s, and pseudo-stationary conditions in the 1980s and 1990s.
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| 2. |
- Przewoski, Barbara, et al.
(författare)
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Spin Exchange in Polarized Deuterium
- 2003
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Ingår i: Physical Review A: covering atomic, molecular, and optical physics and quantum information. - : American Physical Society. - 2469-9926 .- 2469-9934. ; 68:042705, s. 4-
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Tidskriftsartikel (refereegranskat)abstract
- We have measured the vector and tensor polarization of an atomic deuterium targte as a function of the target density. Th epolarized deuterium was produced in an atomic beam source and injected into a storage cell. For this experiment, the atomic beam sou
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| 3. |
- Zemp, Michael, et al.
(författare)
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Reanalysis of multi-temporal aerial images of Storglaciären, Sweden (1959-1999) – Part 2: Comparison of glaciological and volumetric mass balances
- 2010
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Ingår i: The Cryosphere. - Göttingen : Copernicus. - 1994-0424. ; 4, s. 345-357
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Tidskriftsartikel (refereegranskat)abstract
- Seasonal glaciological mass balances have been measured on Storglaciären without interruption since 1945/46. In addition, aerial surveys have been carried out on a decadal basis since the beginning of the observation program. Early studies had used the resulting aerial photographs to produce topographic glacier maps with which the in-situ observations could be verified. However, these maps as well as the derived volume changes are subject to errors which resulted in major differences between the derived volumetric and the glaciological mass balance. As a consequence,the original photographs were re-processed using uniform photogrammetric methods, which resulted in new volumetric mass balances for 1959–69, 1969–80, 1980–90, and 1990–99. We compared these new volumetric mass balances with mass balances obtained by standard glaciological methods including an uncertainty assessment considering all related previous studies. The absolute differences between volumetric and the glaciological mass balances are 0.8 m w.e. for theperiod of 1959–69 and 0.3 m w.e. or less for the other survey periods. These deviations are slightly reduced when considering corrections for systematic uncertainties due to differences in survey dates, reference areas, and internal ablation, whereas internal accumulation systematically increases the mismatch. However, the mean annual differences between glaciological and volumetric mass balance are less than the uncertainty of the in-situ stake reading and stochastic error bars of both data series overlap. Hence, no adjustment of the glaciological data series to the volumetric one is required.
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