.png)
.png)
.png)
Email this article 
Reconstruction of the temperature in the active layer of the glacier on the Western plateau of Elbrus for 1930–2008
https://doi.org/10.31857/S2076673420040054
Abstract
The reconstruction of changes in the temperature of the base of the active layer (at a depth of 10 m) of the glacier on the Western plateau of Elbrus for the period 1930–2008 was performed. The temperature dynamics at this depth generally corresponds to the average annual changes in the air temperature at the height of the plateau (5100 m), since seasonal temperature fluctuations take place in the active layer. The initial data for the mathematical model are: 1) the temperature measurements in a borehole with a depth of 181.8 m, drilled on the plateau (2009); 2) vertical profile of the density of the firn/ice thickness; 3) vertical profile of the advection rate (ice speed), recently obtained from the analysis of the ice core (2015). Temperature changes are reconstructed by solving an incorrect inverse problem for the 1D heat equation with coefficients depending on the depth. The following conditions are added to the heat conduction equation: 1) the initial one that is calculated stationary temperature profile related to the beginning of the reconstruction period; 2) the boundary condition at the glacier bed – calculated permanent geothermal heat flux; 3) the condition of redefinition, i.e. distribution of the temperature measured in the borehole at the end of the reconstruction period. Solving the inverse problem, we obtain a previously unknown boundary condition on the surface which is the temperature of the active layer base as a function of time. The depth is reckoned from the base of the active layer. The method used for solving the inverse problem is the Tikhonov regularization, implemented numerically as an iterative procedure. The boundary condition on the surface (the restored function of the temperature changes) was found as a finite sum of harmonics with indeterminate coefficients. To improve the accuracy of the reconstruction, we used harmonic frequencies obtained from another indirect climate indicator – the tree-ring chronology for the Central Caucasus. Wavelet analysis was used to extract characteristic frequencies from the dendrochronological data. Our reconstruction determined the temperature changes within range from –17.7 to –15.3 °C for the investigated period. The reconstruction data were compared with independent polynomial smoothed temperature series from the studied region: with ENCEP/ENCAR reanalysis (significant correlation coefficient 0.76), as well as with temperature measurements at the Terskol (0.53) and Teberda weather stations. The reconstruction clearly reflects the main climate trends of the twentieth century: a warmer period in the 1940s, a colder period in the 1960s and 1980s, and extreme warming around 2000.
About the Authors
S. A. TyuflinRussian Federation
Moscow
O. V. Nagornov
Russian Federation
Moscow
G. A. Chernyakov
Russian Federation
Moscow
V. N. Mikhalenko
Russian Federation
Moscow
P. A. Toropov
Russian Federation
Moscow
S. S. Kutuzov
Russian Federation
Moscow
References
1. Dolgova E.A., Solomina O.N. First quantitative reconstruction of air temperature for the warm period in the Caucasus based on dendrochronological data. Doklady Akademii Nauk. Proc. of the Academy of Sciences. 2010, 431 (2): 252–256. [In Russian].
2. Solomina O.N., Kalugin I.A., Aleksandrin M.Y., Bushueva I.S., Darin A.V., Dolgova E.A., Jomelli V., Ivanov M.N., Matskovsky V.V., Ovchinnikov D.V., Pavlolva I.O., Razumovsky L.V., Chepurnaya A.A. Coring of Karakel’ Lake sediments (Teberda River valley) and prospects for reconstruction of glaciation and Holo cene climate history in the Caucasus. Led i Sneg. Ice and Snow. 2013, 2 (122): 102–111. doi: 10.15356/2076-6734-2013-2-102-111. [In Russian].
3. Zagorodnov V., Nagornov O., Scambos T.A., Muto A., Mosley-Thompson E., Pettit E.C., Tyuflin S. Borehole temperatures reveal details of 20th century warming at Bruce Plateau, Antarctic Peninsula. The Cryosphere. 2012, 6 (3): 675–686. doi: 10.5194/tc-6-675-2012.
4. Yang J.-W., Han Y., Orsi A.J., Kim S.-J., Han H., Ryu Y., Jang Y., Moon J., Choi T., Hur S.D., Ahn J. Sur face temperature in twentieth century at the Styx Glacier, northern Victoria Land, Antarctica, from borehole thermometry. Geophys. Research Letters. 2018, 45 (18): 9834–9842. doi: 10.1029/2018GL078770.
5. Suman A., Dyer F., White D. Late Holocene temperature variability in Tasmania inferred from borehole temperature data. Climate of the Past. 2017, 13 (6): 559–572. doi: 10.5194/cp-13-559-2017.
6. Huang S., Pollack H.N., Shen P.-Y. Temperature trends over the past five centuries reconstructed from borehole temperatures. Nature. 2000, 403 (6771): 756–758. doi: 10.1038/35001556.
7. Beltrami H., Bourlon E. Ground warming patterns in the Northern Hemisphere during the last five centuries. Earth and Planetary Science Letters. 2004, 227 (3–4): 169–177. doi: 10.1016/j.epsl.2004.09.014.
8. Huang S. Merging information from different resources for new insights into climate change in the past and future. Geophys. Research Letters. 2004, 31 (13). doi: 10.1029/2004GL019781.
9. Demezhko D.Yu., Solomina O.N. Ground surface temperature variations on Kunashir Island in the last 400 years inferred from borehole temperature data and tree-ring records. Doklady Akademii Nauk. Proc. of the Academy of Sciences. 2009, 426 (2): 240–243. doi: 10.1134/S1028334X09040266. [In Russian].
10. Tikhonov A.N., Arsenin V.Ya. Metody resheniya nekorrektnykh zadach. The methods of solution of ill-posed problems. Moscow: Nauka, 1986: 288 p. [In Russian].
11. MacAyeal D.R., Firestone J., Waddington E. Paleothermometry by control methods. Journ. of Glaciol ogy. 1991, 37 (127): 326–338. https://doi/: 10.3189/S0022143000005761.
12. Mosegaard K. Resolution analysis of general inverse problems through inverse Monte Carlo sampling. In verse Problems. 1998, 14 (3): 405–426. https://doi/10.1088/0266-5611/14/3/004.
13. Konovalov Yu.V., Nagornov O.V., Zagorodnov V.S., Thompson L.G. Reconstruction of the glacier surface temperature based on the bore hole temperature measurements. Matematicheskoe modelirovanie. Mathemat ical modelling. 2001, 13 (11): 48–68. [In Russian].
14. Mikhalenko V.N., Kutuzov S.S., Nagornov O.V., Tyuflin S.A, Lavrentiev I.I., Marchenko S.A., Okopny V.I. Stratigraphic structure and thermal regime of the in filtration layer at the Elbrus west plate. Ekstremal'nyye prirodnyye yavleniya i katastrofy. Extreme natural phenomena and disasters. 2011, 2: 180–188. [In Russian].
15. Mikhalenko V., Sokratov S., Kutuzov S., Ginot P., Legrand M., Preunkert S., Lavrentiev I., Kozachek A., Ekaykin A., Faïn X., Lim S., Schotterer U., Lipenkov V., Toropov P. Investigation of a deep ice core from the Elbrus western plateau, the Caucasus, Russia. The Cryosphere. 2015, 9: 2253–2270. doi: 10.5194/tc-9-2253-2015.
16. Dolgova E. June–September temperature reconstruction in the Northern Caucasus based on blue inten sity data. Dendrochronologia. 2016, 39: 17–23. doi: 10.1016/j.dendro.2016.03.002.
17. Nagornov O.V., Tyuflin S.A, Konovalov Y.V., Kostin A.B. Obratnyye zadachi paleotermometrii. Inverse problems of paleothermometry. Moscow: MEPhI, 2008: 173 p. [In Russian].
18. Masurenkov Yu.P. Density of the thermal flow and depth of the magma source under the Elbrus volcano. Byul. vulkanol. stantsiy. Bull. volcanic stations. 1971, (47): 79–82. [In Russian].
19. Likhodeev D.V., Mikhalenko V.N. Temperature estimation for the most upper part of magmatic chamber of the Elbrus volcano. Geofizicheskiye issledovaniya. Geo phys. Research. 2012, 13 (4): 70–75. [In Russian].
20. Тoropov P.A., Мikhalenko V.N., Kutuzov S.S., Morozova P.A., Shestakova A.A. Temperature and radiation regime of glaciers on slopes of the Мount Elbrus in the ablation period over last 65 years. Led i Sneg. Ice and Snow. 2016, 56 (1): 5–19. doi: 10.15356/2076-6734-2016-1-5-19. [In Russian].
21. Sherwood S.C., Meyer C.L., Allen R.J., Titchner H.A. Robust tropospheric warming revealed by iteratively ho mogenized radiosonde data. Journ. of Climate. 2008, 21 (20): 5336–5350. doi: 10.1175/2008JCLI2320.1.
22. Pepin N., Bradley R.S., Diaz H.F., Baraer M., Caceres E.B., Forsythe N., Fowler H., Greenwood G., Hashmi M.Z., Liu X.D., Miller J.R., Ning L., Ohmura A., Palazzi E., Rangwala I., Schöner W., Severskiy I., Shahgedanova M., Wang M.B., Williamson S.N., Yang D.Q. Elevation-dependent warming in mountain regions of the world. Nature Climate Change. 2015, 5 (5): 424–430. doi: 10.1038/nclimate2563.
23. Toropov P.A., Aleshina M.A., Grachev A.M. Largescale climatic factors driving glacier recession in the Greater Caucasus, 20th–21st century. Intern. Journ. of Climatology. 2019, 39 (12): 4703–4720. doi: 10.1002/joc.6101.
Supplementary files
For citation: Tyuflin S.A., Nagornov O.V., Chernyakov G.A., Mikhalenko V.N., Toropov P.A., Kutuzov S.S. Reconstruction of the temperature in the active layer of the glacier on the Western plateau of Elbrus for 1930–2008 Ice and Snow. 2020;60(4):485-497. https://doi.org/10.31857/S2076673420040054
Refbacks
- There are currently no refbacks.
ISSN 2076-6734 (Print)
ISSN 2412-3765 (Online)