排序方式： 共有15条查询结果，搜索用时 31 毫秒
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Simulation of thermal and hydrological regimes of Siberian river watersheds under permafrost conditions from reanalysis data 总被引：1，自引：0，他引：1
Arzhanov M. M. Eliseev A. V. Demchenko P. F. Mokhov I. I. Khon V. Ch. 《Izvestiya Atmospheric and Oceanic Physics》2008,44(1):83-89
A one-dimensional dynamic model of heat and moisture transfer in the soil has been developed. The use of the ERA-40 reanalysis as input data makes it possible to compute characteristics of the soil thermal and hydrological regimes, including watershed runoff, from specified climatic characteristics of the atmosphere. Results are presented of numerical experiments on a comparison of the model estimates of the depths of seasonal thawing with observations at several Siberian stations. For the latter half of the 20th century, the depths of seasonal thawing are mapped and runoff from watersheds of the largest Siberian rivers is computed. The model reproduces observed runoff variations. For the Ob basin, the model-derived runoff estimates agree well with observational data if peat deposits in the upper 2-m layer are taken into account. 相似文献
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A. V. Khon 《Geography and Natural Resources》2013,34(4):401-406
On the basis of the regularities of channel flow dynamics and the propagation of the emptying wave, it is shown that the value of the mean flow velocity above the field of giant ripples necessary for the ridge movement cannot be attained under given hydraulic and geomorphological conditions. Presented are the erosional dissection mechanisms for the surface of fluvioglacial deposits which contribute to the subparallel occurrence of ephemeral streams. 相似文献
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Perspectives of Northern Sea Route and Northwest Passage in the twenty-first century 总被引：2，自引：0，他引：2
The ability of modern climate models to simulate ice season length in the Arctic, its recent changes and navigation season on Arctic marine routes along the Eurasian and the North American coastlines is evaluated using satellite ice cover observations for 1979–2007. Simulated mean sea ice season duration fits remarkably well to satellite observations and so do the simulated 20th century changes using historical forcing. This provides confidence to extend the analysis to projections for the twenty-first century. The navigation season for the Northern Sea Route (NSR) and Northwest Passage (NWP), alternative sea routes from the North Atlantic to Asia, will considerably increase during this century. The models predict prolongation of the season with a free passage from 3 to 6 months for the NSR and from 2 to 4 months for the NWP by the end of twenty-first century according to A1B scenario of the IPCC. This suggests that transit through the NSR from Western Europe to the Far East may be up to 15% more profitable in comparison to Suez Canal transit by the end of the twenty-first century. 相似文献
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Golitsyn G. S. Efimova L. K. Mokhov I. I. Rumyantsev V. A. Somova N. G. Khon V. Ch. 《Water Resources》2002,29(2):149-154
The characteristics of the Ladoga and Onega hydrological regimes were analyzed, and the features of the annual and long-term variations in their water balance components were determined. The statistically significant positive trends of the average annual precipitation and evaporation in the Ladoga water area and the water inflow for the period of 1932–1995 were determined. The relative effect of the Ladoga water balance components on the formation of its level was studied. Spectral analysis of the components of this balance revealed, in particular, characteristic periods of about four years in the last decades. Based on the analysis, including wavelet, of the longer series of long-term variations in the Ladoga water level, it was found that the spectral structure pronouncedly changed in the period from 1859 to 1995. 相似文献
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As global warming continues in the 21st century, one can expect a significant increase in the duration of the navigation period along the Northern Sea Route. In this study we found that, according to the representative concentration pathways 4.5 and 8.5 scenarios of the anthropogenic impact, the expected duration of the navigation period along the Northern Sea Route in the middle of the 21st century would be two to three months and three to six months by the end of the century. 相似文献
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The ability of present-day climate models to reproduce the mean annual regime of river runoff and its within-year distribution
is evaluated for major Eurasian basins, including the basins of the Volga and Amur and the major Siberian rivers: the Ob,
Yenisei, and Lena. Estimates are made for possible variations in seasonal runoff and characteristics of daily precipitation
(the amount, rate, and probability) in drainage areas for the late XXI century. The analysis involved the use of the results
of calculations by climatic general circulation models carried out under international Coupled Model Intercomparison Project. 相似文献