Siberian Rivers Research Articles

Population genetic structure and phylogeography of sterlet (Acipenser ruthenus, Acipenseridae) in the Ob and Yenisei river basins

The sterlet (Acipenser ruthenus Linnaeus, 1758) is a relatively small sturgeon widely distributed in Eurasian rivers from the Danube to the Yenisei. During the twentieth century, all wild sterlet populations have declined due to anthropogenic factors including: overfishing, poaching, construction of dams, and pollution. Despite the necessity of characterization both wild and captive stocks, few studies of population genetics have been performed thus far. Here we studied the genetic diversity and geographic structure of sterlet populations across the eastern range – Ob-Irtysh and Yenisei basins – by sequencing a 628-bp fragment of mitochondrial DNA control region. We identified 98 new haplotypes, delineated 12 haplogroups and estimated the time of basal haplogroup divergence within the species as over 8 million years ago. Our data suggest that Ob-Irtysh and Yenisei populations are isolated from each other and much lower genetic diversity is present in the Yenisei population than in the Ob-Irtysh population. Our data imply that sterlet populations in Siberian rivers underwent bottleneck or fragmentation, followed by subsequent population expansion. The data obtained here are important for sterlet population monitoring and restocking management.

Isotopic Composition of Blood of Polar Bears (Ursus maritimus) of the Kara-Barents Sea Population.

The data on the content of carbon and nitrogen isotopes in the blood samples of polar bears obtained in the present study confirm that polar bears in the Taimyr region (and the Kara-Barents sea population in general) are partly dependent on the resources of terrestrial origin. However the "terrestrial carbon" evidently reaches bears' tissues indirectly, via marine food webs utilizing organic carbon brought into the polar basin by Siberian rivers.

Looking for a Way out: Trans-Siberian Transportation Projects at the Turn of the 20th Century

Referring to a large number of journalistic works of the turn of the 20th century that reflect the views of different business, political, and social groups, the author analyses the narrative strategies underlying the representation of both implemented and hypothetical Trans-Siberian transportation projects. The article aims to explicate the cultural attitudes and political goals of the authors of the transportation projects which formed their strategies of mental appropriation of territories. The author singles out and analyses three aspects related to the perception of Siberian space: imperial, regional, and transnational. According to the first aspect, Siberian space was regarded as an enormous geopolitical bridge meant to connect the centre of the country with remote Russian territories (the Far East) and Russia’s spheres of influence (Manchuria, Northeast China). This approach was implemented when the Great Siberian Railway was built and came to represent a horizontal distribution of power, connecting the imperial centre and the periphery. The regional idea of Siberia was a metaphor of its closedness: this was not induced by its nature but rather by artificial economic reasons. The Russian government favoured the export of Siberian butter but not that of grain. The Great Siberian Railway was thus regarded as a means of improving foreign trade. However, this route for Siberian grain was closed following the introduction of the Chelyabinsk railway tariff in 1896. Under such circumstances, Siberians had to resort to the idea of the 1860s–1870s of organising a transit trade route from Siberia to Europe. At the turn of the 20th century, there appeared two approaches to how this could be fulfilled: by joining the basins of Siberian and Central Russian rivers (Siberian River Routes) or establishing a connection between these rivers by means of the Kara Sea (Northern Sea Route). According to the third – transnational – aspect, all three routes were regarded as elements of global transit routes to be established. Following the 1904–1905 Russo-Japanese War, the Russian authorities considered it a national communication system which was not only of economic but also of military and strategic importance. On the eve of World War I, the idea of the Northern Sea Route as an international route was replaced by the idea of it as a “natural monopoly” of the Russian state.

Сравнительный анализ состава речной взвеси северотаежной и тундровой зон Западной Сибири

The study of suspended solids in the West Siberian rivers is of great importance from the point of view of biogeochemistry, since in the rivers there are the formation and transformation of abrasion products of banks and bottom, suspended and dissolved organic matter and solid river flow, which are carried out from the land to the Kara Sea and further to the North Arctic Ocean. Studies of river suspension are necessary to understand the processes of modern sedimentation, as well as for the ecological assessment of the water area state. Mechanisms of sedimentation are largely associated with the processes of physical and biological weathering, generation, transformation and transport of suspended matter from the catchment to floodplain landscapes. In this regard, the role of studying the connection of the qualitative composition of river suspended matter with landscape parameters (level of the catchment area swappiness, nature of the soil cover, composition of soil-forming rocks, presence (absence) of permafrost, etc. is high. For example, the river of the north-taiga subzone, the catchment area of which is heavily swamped, and the river of the tundra zone with a slightly swampy watershed are represented. The influence of flood waters on the concentration of some elements in rivers with contrasting watersheds is considered. The contribution of groundwater and the effect of soil solutions on the overall migration flow are estimated.

Permafrost Boundary Shift in Western Siberia May Not Modify Dissolved Nutrient Concentrations in Rivers

Identifying the landscape and climate factors that control nutrient export by rivers in high latitude regions is one of the main challenges for understanding the Arctic Ocean response to ongoing climate change. This is especially true for Western Siberian rivers, which are responsible for a significant part of freshwater and solutes delivery to the Arctic Ocean and are draining vast permafrost-affected areas most vulnerable to thaw. Forty-nine small- and medium-sized rivers (10–100,000 km2) were sampled along a 1700 km long N–S transect including both permafrost-affected and permafrost-free zones of the Western Siberian Lowland (WSL) in June and August 2015. The N, P, dissolved organic and inorganic carbon (DOC and DIC, respectively), particular organic carbon (POC), Si, Ca, K, Fe, and Mn were analyzed to assess the role of environmental parameters, such as temperature, runoff, latitude, permafrost, bogs, lake, and forest coverage on nutrient concentration. The size of the watershed had no influence on nutrient concentrations in the rivers. Bogs and lakes retained nutrients whereas forests supplied P, Si, K, Ca, DIC, and Mn to rivers. The river water temperature was negatively correlated with Si and positively correlated with Fe in permafrost-free rivers. In permafrost-bearing rivers, the decrease in T northward was coupled with significant increases in PO4, Ptot, NH4, pH, DIC, Si, Ca, and Mn. North of the permafrost boundary (61° N), there was no difference in nutrient concentrations among permafrost zones (isolated, sporadic, discontinuous, and continuous). The climate warming in Western Siberia may lead to a permafrost boundary shift northward. Using a substituting space for time scenario, this may decrease or maintain the current levels of N, P, Si, K, Ca, DIC, and DOC concentrations in rivers of continuous permafrost zones compared to the present state. As a result, the export flux of nutrients by the small- and medium-sized rivers of the Western Siberian subarctic to the Arctic Ocean coastal zone may remain constant, or even decrease.

DNA barcoding reveals invasion of two cryptic Sinanodonta mussel species (Bivalvia: Unionidae) into the largest Siberian river

This study provides the first record of the two distinct mitochondrial lineages of Sinanodonta mussels in the Yenisei River that forms the largest Siberian river basin. It is the first discovery of alien populations of these mussels in Russia. The two mussel lineages are living in sympatry in a river site heated by warm water discharge of the Krasnoyarsk thermal power plant. These lineages represent two cryptic species: Sinanodonta aff. woodiana lineage E and S. ovataBogatov and Starobogatov, 1996. The population of the first species from the Yenisei shares the invasive haplotype that is widely spread across Europe. The molecular evidence suggests that this lineage originated from the Yangtze River, China. The native distribution of the second species ranges across South Korea, Japan and small basins in the south of Primorsky Krai, Russian Far East. The possible vector of this invasion is the introduction of fish hosts or adult mussels by aquarists. Our results highlight that the populations of Sinanodonta species outside their native ranges may represent an overlooked but important threat for freshwater ecosystems in Russia that should be considered an unexpected nation-level ecological problem. Additionally, our discovery reveals the possibility of a successful joint invasion of different Sinanodonta species into a single river that may increase negative impacts of invaders on indigenous communities. Some implications of our findings for systematics of the unionid mussels are also discussed.

Heavy metal distribution in the surface layer of bottom sediments of the Kara Sea

This paper addresses the distribution of heavy metals (Co, Ni, Cu, Zn, Cd, Sn, Sb, Pb, and Bi) as well as Si, Al, Fe, and Mn in the surface (0–2 cm) layer of bottom sediments of the Kara Sea. The contents of these elements are determined in each of the previously distinguished facies-genetic types of terrigenous sediments: fluvial, glacial, estuarine, shallow water–marine, “background” marine, and relict sediments. It is shown that these types reflect the modern conditions of accumulation of river discharge material, which forms fans of two greatest Siberian rivers, Ob and Yenisei. The main stages are distinguished in heavy metal accumulation. The first stage is related to the avalanche sedimentation of terrigenous sediments in the estuary and characterized by the elevated contents of Co, Ni, Cu, Zn, Cd, Sb, and Bi. The second stage reflects the mechanical differentiation of sedimentary material by waves and bottom currents in a shallow-water sea part adjacent to the estuarine zone, with accumulation of Pb- and Sn-bearing “heavy” ore minerals. The deepwater background terrigenous–marine sediments accumulate mainly Ni, Zn, and Cd, as well as Mn. The relict sediments differ in the high contents of Si, Mn, and Sn.

On the geochemical heterogeneity of rivers draining into the straits and channels of the Canadian Arctic Archipelago

AbstractTen rivers across northern Canada and the Canadian Arctic Archipelago (CAA) were sampled during spring 2014 and summer 2015 to investigate their geochemical heterogeneity for comparison against larger North American (i.e., Mackenzie and Yukon Rivers) and Siberian rivers. In general, rivers draining the western and/or northern regions of the study area have higher solute concentrations and lower 87Sr/86Sr ratios compared to rivers draining the eastern and/or southern regions. The inorganic geochemical signatures largely reflect the bedrock geology, which is predominately carbonate in the western and/or northern regions and silicate in the eastern and/or southern regions. Riverine δ18O values primarily correlate with latitude, with only a few exceptions. Measurements of total alkalinity (TA) were combined with a regional analysis of bedrock geology and extrapolated to produce a range for the mean characteristic TA of rivers draining into the straits and channels of the CAA (628–819 µeq kg−1). Combining this estimate with contributions from the Mackenzie River yields a revised North American river runoff TA of 935–1182 µeq kg−1, which is much lower than that of the Mackenzie River (1540 µeq kg−1). This lower concentration suggests that TA may not be used to distinguish between North American and Siberian river contributions in regions such as Davis Strait.

On the taxonomic composition of the graylings (Thymallidae) from the Ob and Yenisei River Basins

The article offers a general view of the graylings (Thymallidae) from the largest Siberian river basins, namely those of the Ob and Yenisei, including the Khantayskoye and Baikal Lakes. It provides data on some of the most important morphological features. It is shown that it is erroneous to consider the graylings only within the subspecies Thymallus arcticus arcticus. The reservoirs of the Altai-Sayan highlands, which drain to the north into the inland waters of Mongolia, should also be considered, as one of the two major centres of speciation and morphogenesis for graylings.

Temporal and spatial variations of rock weathering and CO2 consumption in the Baltic Sea catchment

This study provides the first estimate of silicate and carbonate weathering rates and derived CO2 consumption rates for the Baltic Sea catchment using river chemistry data of 78 rivers draining into the Baltic Sea. The silicate weathering rates (denoted as total dissolved solids) of individual river basin range from 0.014Tg/year to 4.55Tg/year and the carbonate weathering rates range from 0.079Tg/year to 6.49Tg/year. The total CO2 consumption across the Baltic catchment is approximately 3.9TgC/year and is almost equally shared by silicates and carbonates. Uncertainty associated with the weathering estimate is around 32%, which is mainly caused by incomplete pollution correction for a few major rivers in the south. The calculations for the boreal river basins have higher certainties because of less human impacts. The CO2 consumption rate of individual river basin vary between 0.53 and 5.66gC/m2/year with an average of 2.97gC/m2/year, in which carbonates consume CO2, 1.4gC/m2/year and silicates take 1.5gC/m2/year. This is in the same range as has been reported for the Mackenzie River and Siberian river basins, but at the lower range of tropical rivers, suggesting the Baltic Sea catchment holds solid weathering signals for high-latitude systems, especially in the pristine boreal silicate-dominated areas. The amount of CO2 consumed by weathering in the Baltic Sea catchment accounts for approximately 3–30% of the net ecosystem carbon exchange (10–100gC/m2/year), implying that weathering contributes as a significant sink of atmospheric CO2. Although many studies have shown the positive relation between temperature and weathering rates in various river catchments, multiple regression analysis using the 40-year continuous records of river chemistry in the boreal area of the Baltic Sea catchment reveals a strong correlation between weathering flux and precipitation, but no statistically significant correlation between weathering and temperature. This suggests not only that temperature is not necessarily to be primary controlling factor for weathering rates, but also besides precipitation, other factors, like increased soil organic matter contents and water path changes may have high impact on weathering rates. The 40-year data analysis also shows generally increasing weathering fluxes by 10–20% in the pristine boreal area over the past decades. This indicates that increased CO2 consumption by weathering and the resulting elevated dissolved inorganic carbon delivery to the ocean act as a negative feedback for ocean acidification, such as the Arctic Ocean that has become more acidic due to high terrestrial organic carbon delivery together with increased river water input.

Future changes in peak river flows across northern Eurasia as inferred from an ensemble of regional climate projections under the IPCC RCP8.5 scenario

Climate change simulation based on 30-member ensemble of Voeikov Main Geophysical Observatory RCM (resolution 25 km) for northern Eurasia is used to drive hydrological model CaMa-Flood. Using this modeling framework, we evaluate the uncertainties in the future projection of the peak river discharge and flood hazard by 2050–2059 relative to 1990–1999 under IPCC RCP8.5 scenario. Large ensemble size, along with reasonably high modeling resolution, allows one to efficiently sample natural climate variability and increase our ability to predict future changes in the hydrological extremes. It has been shown that the annual maximum river discharge can almost double by the mid-XXI century in the outlets of major Siberian rivers. In the western regions, there is a weak signal in the river discharge and flood hazard, hardly discernible above climate variability. Annual maximum flood area is projected to increase across Siberia mostly by 2–5% relative to the baseline period. A contribution of natural climate variability at different temporal scales to the uncertainty of ensemble prediction is discussed. The analysis shows that there expected considerable changes in the extreme river discharge probability at locations of the key hydropower facilities. This suggests that the extensive impact studies are required to develop recommendations for maintaining regional energy security.

Probing the aluminum complexation by Siberian riverine organic matter using solid-state DNP-NMR

In a Siberian river, the concentrations of chemical species vary with the hydrological regime. Dissolved Organic Matter (DOM) and aluminum ions show a parallel trend in the course of the hydrological year. However, the speciation of aluminum in this natural environment remains an open question. We propose here a combination of spectroscopic techniques to investigate the proximity between the aluminum atoms and DOM. First, one-dimensional (1D) solid-state Nuclear Magnetic Resonance (NMR), Electron Paramagnetic Resonance (EPR) and 1D and 2D solution NMR spectra were acquired, providing a clear overview of the DOM composition. Second, the sensitivity enhancement yielded by Dynamic Nuclear Polarization enabled the NMR detection of proximities between the 27Al and 13C nuclei. Hence, we show that 8.3±1.3% of the carboxylate groups observed by NMR are connected to the Al3+ ions in the DOM sample. We here demonstrate for the first time how advanced solid-state NMR methods can provide key information about the localization of aluminum in such complex natural materials.

The fate of terrigenous dissolved organic carbon on the Eurasian shelves and export to the North Atlantic

AbstractDissolved lignin phenols, chromophoric dissolved organic matter (CDOM) absorption, and fluorescence were analyzed along cross‐slope mooring locations in the Barents, Laptev, and East Siberian Seas to gain a better understanding of terrigenous dissolved organic carbon (tDOC) dynamics in Arctic shelf seas and the Arctic Ocean. A gradient of river water and tDOC was observed along the continental shelf eastward into the East Siberian Sea. Correlations of carbon‐normalized yields of lignin‐derived phenols supplied by Siberian rivers with river water fractions and known water residence times yielded in situ decay constants of 0.18–0.58 yr−1. Calculations showed ∼50% of annual tDOC discharged by Siberian rivers was mineralized in estuaries and on Eurasian shelves per year indicating extensive removal of tDOC. Bioassay experiments and in situ decay constants indicated a reactivity continuum for tDOC. CDOM parameters and acid/aldehyde ratios of vanillyl (V) and syringyl (S) lignin phenols showed biomineralization was the dominant mechanism for the removal of tDOC. Characteristic ratios of p‐hydroxy (P), S, and V phenols (P/V, S/V) also identified shelf regions in the Kara Sea and regions along the Western Laptev Sea shelf where formation of Low Salinity Halocline Waters (LSHW) and Lower Halocline Water (LHW) occurred. The efficient removal of tDOC demonstrates the importance of Eurasian margins as sinks of tDOC derived from the large Siberian Rivers and confirms tDOC mineralization has a major impact on nutrients budgets, air‐sea CO2 exchange, and acidification in the Siberian Shelf Seas.

Lithological and geochemical typification of surface bottom sediments in the Kara Sea

The Kara Sea is part of the Western Arctic shelf of Eurasia. The deposition of sediments in this shallow sea is largely determined by solid runoff from two great Siberian rivers (the Yenisei and Ob) and the glacial periods when the sea area repeatedly (during the Quaternary) dried up and was covered by continental glaciers. The rise of the World Ocean due to Holocene warming resulted in a significant expansion of the sea area to the south and complete degradation of the ice sheet. In this article, new data on the geochemical composition of the surface (0- to 2-cm) layer of sea-bottom sediments are considered, which reflects the spatial distribution of marine sediments during the maximum sea level. Cluster analysis of the variance for 24 chemical elements reveals sediment chemotypes, and critical analysis of their relationship with lithotypes is performed. The presented data have been collected on cruises of the R/V Akademik Boris Petrov in 2000, 2001, and 2003 and the R/V Akademik Mstislav Keldysh in 2015.

Distribution and Grazing of Dominant Zooplankton Species in the Ob Estuary: Influence of the Runoff Regime

Major interactions between terrestrial and marine environments in the Kara Sea occur within the estuaries of the largest Siberian rivers, the Ob and Yenisei. Mesozooplankton community plays an important role in the transformation of allochthonous organic matter. All published data on zooplankton activity in the Ob Estuary have been obtained for the period of decreased river discharge. The aim of our study was to assess zooplankton distribution and grazing under various hydrological regimes (high-low river discharge and varying wind direction) in order to better understand the mechanisms governing this process. The study was carried out along a quasi-latitudinal transect in the Ob Estuary at the beginning of August (high discharge) and end of September 2010 (decreased discharge) and end of August 2014 (high discharge and onshore winds). Zooplankton grazing was assessed with the gut fluorescent approach. Under high river discharge, zooplankton biomass was low (mean 98 mg wet weight m−3), peaks of species abundance were spatially separated, and grazing did not exceed 2% of phytoplankton biomass. Weakening river discharge at the end of September led to the formation of hydrographic fronts, and zooplankton biomass was an order of magnitude higher (mean value 947 mg wet weight m−3) with dense local aggregations with biomass reaching 3600 mg wet weight m−3. These aggregations formed a pelagic “biofilter” grazing up to 26% of phytoplankton biomass per day. The peaks of abundance of the majority of species coincided at the pronounced hydrographic front forming dense local aggregations with biomass reaching 3600 mg wet weight m−3. These aggregations formed a pelagic biofilter utilizing daily up to 26% of phytoplankton biomass.

Analysis of Siberian river runoffs in the 21st century

We discuss the results from the analysis of the hydrological input data for a model of Siberian river runoff for the 21st century. The INM, CRNM, GFDL, MIROC5, and HadGEM model calculations according to the RCP 8.5 scenario of the IPCC CMIP5 Project were used for the analysis. The calculations show a positive centennial trend for all the models. These data were used for the calculations of Siberian river discharge to the Arctic Ocean. The river runoff calculations in accordance with the data also indicate a positive trend, though with a different runoff magnitude.

Expected change of hydrologic cycle in Northern Eurasia due to disappearance of multiyear sea ice in the Arctic Ocean

The effects are considered that global warming and rapid sea ice decline in the Arctic (up to the formation of ice-free conditions in the Arctic Ocean in summer) made on the hydrological regime of Northern Eurasia. Ensemble computations of climate are provided and changes in the atmospheric water cycle and in water balance in large catchment areas after the loss of multiyear sea ice in the Arctic are estimated. Considerable changes in the hydrological regime are demonstrated on the example of the large catchments of the Siberian rivers; the changes are especially manifested in the period of intense snow melting, i.e., in spring and in early summer. It is revealed that the increase in the frequency of spring floods is expected in the river catchments adjoining the Arctic Ocean. It is demonstrated that the Arctic Ocean ice reduction does not exert as significant influence on variations in the water cycle in Northern Eurasia as the global warming does.

Sources, Distributions, and Dynamics of Dissolved Organic Matter in the Canada and Makarov Basins

A comprehensive survey of dissolved organic carbon (DOC) and chromophoric dissolved organic matter (CDOM) was conducted in the Canada and Makarov Basins and adjacent seas during 2010-2012 to investigate the dynamics of dissolved organic matter (DOM) in the Arctic Ocean. Sources and distributions of DOM in polar surface waters were very heterogeneous and closely linked to hydrological conditions. Canada Basin surface waters had relatively low DOC concentrations (69±6 µmol L-1), CDOM absorption (a325: 0.32±0.07 m-1) and CDOM-derived lignin phenols (3±0.4 nmol L-1) and high spectral slope values (S275-295: 31.7±2.3 µm-1), indicating minor terrigenous inputs and evidence of photochemical alteration in the Beaufort Gyre. By contrast, surface waters of the Makarov Basin had elevated DOC (108±9 µmol L-1) and lignin phenol concentrations (15±3 nmol L-1), high a325 values (1.36±0.18 m-1) and low S275-295 values (22.8±0.8 µm-1), indicating pronounced Siberian river inputs associated with the Transpolar Drift and minor photochemical alteration. Observations near the Mendeleev Plain suggested limited interactions of the Transpolar Drift with Canada Basin waters, a scenario favoring export of Arctic DOM to the North Atlantic. The influence of sea-ice melt on DOM was region-dependent, resulting in an increase (Beaufort Sea), a decrease (Bering-Chukchi Seas), and negligible change (deep basins) in surface DOC concentrations and a325 values. Halocline structures differed between basins, and the Canada Basin upper halocline and Makarov Basin halocline were comparable in their average DOC (65-70 µmol L-1) and lignin phenol concentrations (3-4 nmol L-1) and S275-295 values (22.9-23.7 µm-1). Deep-water DOC concentrations decreased by 6-8 µmol L-1 with increasing depth, water mass age, nutrient concentrations, and apparent oxygen utilization. Maximal estimates of DOC degradation rates (0.036-0.039 µmol L-1 yr-1) in the deep Arctic were lower than those in other ocean basins, possibly due to low water temperatures. DOC concentrations in bottom waters (>2500 m; 46±2 µmol L-1) of the Canada and Makarov Basins were slightly lower than those reported for deep waters of the Eurasian Basin and Nordic Seas. Elevated a325 values (by 10-20%) were observed near the seafloor, indicating biological activity in Arctic basin sediments.

Polycyclic aromatic hydrocarbons in a small eastern siberian river: sources, delivery pathways, and behavior

The sources of polycyclic aromatic hydrocarbons (PAHs) and sources of water that deliver PAHs to an investigated river were apportioned using an end-member mixing approach. The identification of sources and tracers was based on bounding the samples by end-member sources on the mixing diagram using coordinates of source tracer concentrations. The sums of PAHs with the same molecular weight were used as PAH source tracers, and the dissolved organic carbon to base cations ratio was used as a tracer for water sources. The source contributions were evaluated by solving systems of linear equations. Most of the water samples were bound by a triangle formed by wood combustion, oil-fired boilers, and aluminum smelters in the mixing space defined by the concentrations of the principal mass 178 and 228 PAHs. There were notable seasonal variations in the PAH source contributions at each sampling site due to different contributions of groundwater, surface flow, and interflow to stream water. The differences in the PAH source contributions among sites were due to both different proportions of the flow components and different positions of the sites relative to the emission sources. Most of the bottom sediment samples were bound by a triangle formed by the same sources, but in the mixing space defined by the principal mass 252 and 276 PAHs. There were no spatial or temporal differences in the PAH source proportions among the samples because the PAH composition of the bottom sediments at each location represents the time- and space-weighted average of all the sediment loads from upstream.

Recent interdecadal changes in the interannual variability of precipitation and atmospheric circulation over northern Eurasia

This study investigated the interannual variability and trends in precipitation and atmospheric circulation patterns over northern Eurasia using long-term Precipitation REConstruction over Land and atmospheric Japanese 55-year Reanalysis data (JRA-55) from 1958 to 2012. Special emphasis was placed on the recent increase in summer (June, July and August) precipitation around the Lena river basin in eastern Siberia. We found interdecadal modulation in the relationships between interannual variability in summer precipitation and atmospheric circulation patterns among the three major Siberian river basins (Lena, Yenisei, and Ob). The interannual variations in summer precipitation over the Ob and Lena river basins were negatively correlated from the mid-1970s to the mid-1990s. However, after the mid-1990s, this negative correlation became insignificant. In contrast, a significant positive correlation was apparent between the Yenisei and Lena river basins. We also found that there has been a significant increasing (positive) trend in geopotential height in the low-level troposphere since the mid-1980s over Mongolia and European Russia, resulting in an increasing trend of westerly moisture flux into the Yenisei and Lena river basins. Summer precipitation in both basins was continuously high from 2005 to 2008 under a trough that broadly extended from the Yenisei and Lena river basins, which has been a typical pattern of interannual variation since the mid-1990s. This trough increased the meridional pressure gradient between Mongolia and eastern Siberia in combination with the trend pattern. This further enhanced the eastward moisture flux towards the Lena river basin and its convergence over the basin, resulting in high summer precipitation from 2005 to 2008.