Kolyma River Research Articles

IMPACT OF FLOODS IN THE KOLYMA RIVER DELTA ON NAVIGATION CONDITIONS IN THE EAST SIBERIAN SEA

The problem of improving the quality of medium- and long-term forecasting of changes in the ice situation on the Northern Sea Route, and in particular in the East Siberian Sea, where one of the methods for choosing waterways is the passage of vessels in the areas of flaw polynya, is considered. The hypothesis that in the summer months such changes can be significantly affected by the terms of floods onset in the Kolyma River Delta is tested. The data of the GLORYS12v1 global reanalysis supported by the Copernicus Marine Service are used as factual material on the ice cover and levels of the East Siberian Sea in the months from May to October of 1993-2019. The reanalysis is based on mathematical models of the NEMO family, verified using altimetry data from satellite measurements. Using the developed methodology for the selected periods of the year, the dates of sharp changes in the level and ice cover on the pre-estuary seaside of the Kolyma River are estimated. Using statistical methods, the validity of the stated hypothesis for a number of the East Siberian Sea areas, along which the shipping lanes of the Northern Sea Route pass, is confirmed. It has been established that the greatest influence of the floods terms on the ice situation and navigation conditions in such areas takes place in July. It has been shown that early floods in the Kolyma delta generally lead to an improvement in the ice situation, and late floods lead to its complication. The identified relationships are recommended for use in forecasting changes in ice conditions. The assumption that with further climate warming and a shift in the flood terms to earlier dates, it is possible that the ice conditions will become more complicated due to the freezing of the formed polynya, is made.

Seasonal and spatial variations in riverine DOC exports in permafrost-dominated Arctic river basins

• Seasonality of riverine DOC exports is strongly associated with hydrological regimes. • The extent and degradation of permafrost regulate riverine DOC mobilization. • Water temperature is an important factor influencing riverine DOC exports. Climate warming is accelerating the release of voluminous organic carbon from thawing permafrost into the Arctic Ocean via riverine transport. However, the seasonal variations in riverine dissolved organic carbon ( DOC ) exports in Arctic river basins with different areal extents of permafrost and how changes in water temperature ( T w ) impact seasonal DOC exports are not fully understood. In this study, the concentrations, ages and seasonality of riverine DOC in the estuaries of six major Arctic rivers (Ob, Yenisei, Lena, Kolyma, Yukon and Mackenzie) were analysed using Arctic Great Rivers Observatory (ArcticGRO) datasets from 2003 to 2019. The results showed that DOC concentrations generally increased with the increases in the streamflow, but always dropped to the minimum with the oldest Δ 14 C-DOC ages (as old as 1650 years BP) in the freezing period (November–April), when the streamflow originates predominantly from groundwater. During the flood pulse period (May or June), a rapid increase in riverine DOC concentration with younger organic carbon (Δ 14 C values from −61 to 152‰) was observed, likely associated with snowmelt-dominated runoff regimes (lower δ 18 O-H 2 O of approximately −20.4 ± 1.6‰). During the ice-free period (June–September), DOC concentrations decreased due to the enhanced dilution of streamflow from precipitation. In the Lena and Kolyma River basins with large areal extents of continuous permafrost, over 70% of DOC flux exported during the ice-free period originated from DOC sources from ∼410 years and ∼230 years BP to the present, respectively; this suggests that greater permafrost extents restrict the release of older DOC into rivers. However, riverine DOC exports likely respond positively to changes in T w during the ice-free period. In addition, such a positive response is likely to be enhanced in basins with larger percentages of sporadic permafrost, thicker active layers, more precipitation and less soil organic carbon. Ultimately, under a warming climate, riverine DOC exports are expected to rise with increasing river water temperatures.

Heavy mineral assemblages of the De Long Trough and southern Lomonosov Ridge glacigenic deposits: implications for the East Siberian Ice Sheet extent

Abstract. The Arctic's glacial history has classically been interpreted from marine records in terms of the fluctuations of the Eurasian and North American ice sheets. However, the extent and timing of the East Siberian Ice Sheet (ESIS) have remained uncertain. A recently discovered glacially scoured cross-shelf trough extending to the edge of the continental shelf north of the De Long Islands has provided additional evidence that glacial ice existed on parts of the East Siberian Sea (ESS) during previous glacial periods MIS 6 and 4. This study concentrates on defining the heavy mineral signature of glacigenic deposits from the East Siberian continental margin which were collected during the 2014 SWERUS-C3 expedition. The cores studied are 20-GC1 from the East Siberian shelf, 23-GC1 and 24-GC1 from the De Long Trough (DLT), and 29-GC1 from the southern Lomonosov Ridge (LR). Heavy mineral assemblages were used to identify prominent parent rocks in hinterland and other sediment source areas. The parent rock areas include major eastern Siberian geological provinces such as the Omolon massif, the Chukotka fold belt, the Verkhoyansk fold belt, and possibly the Okhotsk–Chukotka volcanic belt. The primary riverine sources for the ESS sediments are the Indigirka and Kolyma rivers, the material of which was glacially eroded and re-deposited in the DLT. The higher abundances of amphiboles in the heavy mineral assemblages may indicate ESS paleovalley of the Indigirka River as a major pathway of sediments, while the Kolyma River paleovalley pathway relates to a higher share of pyroxenes and epidote. The mineralogical signature in the DLT diamicts, consisting predominantly of amphiboles and pyroxenes with a minor content of garnet and epidote, shows clear delivery from the eastern part of the ESIS. Although the physical properties of the DLT glacial diamict closely resemble a pervasive diamict unit recovered from the southern LR, their source material is slightly different. The assemblages with elevated amphibole and garnet content, along with higher titanite and ilmenite content of the southern LR ice-rafted diamict, emphasise the Verkhoyansk fold belt as a possible primary source. The presence of glacial sediments and the recovered glacial–tectonic features on the East Siberian continental shelf and slope, along with the results from this heavy mineral analysis, imply that glacial ice not only grew out of the East Siberian shelf but also from the De Long Islands, and that there was also ice rafting related sediment transportation to the southern LR from westerly sources, such as the Laptev Sea.

Fluorescent signatures of autochthonous dissolved organic matter production in Siberian shelf seas

The East Siberian Sea is an area of high biogeochemical activity caused by multiple factors, such as an influence of river runoff, Atlantic, and Pacific waters, formation and melting of sea ice, and internal circulation. Extensive amounts of carbon are accumulated in sub-sea permafrost within the Arctic shelf in East Siberia. Thawing permafrost and resulting microbial decomposition of frozen carbon pool is a potential feedback process affected global climate dynamics. Several studies of dissolved organic carbon (DOC) distribution in the East Siberian Sea have demonstrated untypical for other Arctic shelf seas pronounced non-conservative DOC behavior. Using seawater samples from the 69th cruise of R/V Akademik Mstislav Keldysh conducted in the Laptev and East Siberian seas in September 2017, this study examines the distribution of fluorescent dissolved organic matter (FDOM) along the shelf-crossing transects including the areas affected by the Khatanga, Lena, Indigirka, and Kolyma river runoff. The set of 137 excitation-emission matrices (EEMs), analyzed with Parallel Factor analysis (PARAFAC), was described by a 4-component model demonstrating Tucker’s congruence coefficient above the 0.95 threshold. Spectral characteristics of the resulting components allowed identifying them as well-known humic-like A and C, protein-like B/T, and marine humic-like M fluorophores. Component C1 (A fluorophore) showed a good correlation with salinity for different river plume influenced regions. As well as chromophoric DOM (CDOM) absorption, it can be used as marker of input of terrestrial DOM to the Arctic Ocean. A distinctive feature of the East Siberian Sea shelf waters in comparison with the Laptev Sea is the higher content of the C2 and C4 components, exhibiting protein-like and marine humic-like fluorescence. Component C3 (C fluorophore) which is usually identified as terrestrial-derived material, was found to be produced locally on the East Siberian Sea shelf and in the continental slope region of the Khatanga transect. Destruction of dead algae cells, production of marine biota and dissolved organic matter (DOM) reworking are considered as possible autochthonous FDOM sources in the Siberian shelf seas.

Sediment sources and transport pathways on shelves of the Chukchi and East Siberian Seas: Evidence from the heavy minerals and garnet geochemistry

Study of sediment sources and transport pathways in the Chukchi and East Siberian Seas is vital for understanding the interaction of fluvial, ocean, and sea-ice dynamics. In this study, 42 samples were analyzed for heavy minerals and 23 were analyzed for garnet geochemistry. These analyses suggest that the surface sediment is mainly sourced from the surrounding rivers. There are distinctive performances between the heavy minerals and garnet geochemistry of sediments in the Chukchi Sea and the East Siberian Sea. The content of hypersthene increased significantly on the outer shelf of the Chukchi Sea. The garnet was derived from volcanic rocks of the Okhotsk-Chukotka volcanic province and transported from the Gulf of Anadyr by the Pacific inflow. Coastal erosion materials dominated in the inner shelf of the Chukchi Sea. A significant amount of river input occurred in the western, middle, and eastern parts of the East Siberian Sea. The inputs from the Indigirka River and Kolyma River tend to be distributed eastward. The garnet geochemistry shows that there was a mixed sedimentary zone located south of Wrangel Island. The sediments in the outer shelf of the East Siberian Sea show a stable mixed sedimentary environment.

Overview of the fish fauna of the Chaunskaya basin – the area of the natural reserve "Chaunskaya Guba" and the port of Pevek (East Siberian Arctic)

The fishes of the Chaunskaya Bay and its Basin have been little studied. Part of the coast of this vast Arctic estuary (about 9 thousand km2) is included in the state nature reserve “Chaunskaya Guba”; at the entrance to the bay there is the seaport of Pevek, a transit hub of the Northern Sea Route. The area has been identified as one of the priorities for the protection of biodiversity in the seas of the Russian Arctic. Solving the problem of biota conservation begins with an inventory of the fauna. The paper presents the results of summarizing data on the species composition of marine, anadromous and freshwater fishes in the Chaunskaya Bay and its basin. The updated list includes 36 species of 28 genera, 16 families and 10 orders. In marine waters there are 31 species (18 marine, 13 anadromous and semi-anadromous fish), in rivers and lakes there are 5 freshwater (and 13 anadromous and semi-anadromous) species. The Muksun Coregonus muksun (Pallas, 1814) and the pike Esox lucius Linnaeus, 1758, which were absent in the fauna lists, are added. The lamprey Lethenteron kessleri (Anikin, 1905), the Pacific herring Clupea pallasii Valenciennes, 1847, and the Arctic charr Salvelinus alpinus (Linnaeus, 1758), which were previously recorded, are not confirmed by reliable findings. The marine fish community of the Chaunskaya Bay is an impoverished shelf fauna of the East Siberian Sea and includes species adapted to desalination. The freshwater ichthyofauna of the basin differs from the fauna of the neighboring Kolyma River region in the loss of a number of freshwater species, which are believed to have been extinct because of the Holocene cooling. A significant part of the fish complex consists of elements of the North Pacific fauna that spread to the East Siberian Sea in the postglacial period.

Eskimo Problem in the Light of New Data

Purpose. The problem of the origin of the Eskimos has received considerable attention, at the same time also providing insights about human presence in far Northeast Siberia and America. I review earlier studies and discuss some of the more exciting recent results emerging from ancient DNA data sets. I also highlight important features of genetic and archeological data and discuss key questions and future research directions. Results. The Paleo-Eskimos and Neo-Eskimos ancestors along the Q-NWT01 Y-DNA line lived in the Kolyma River basin at the turn of the Late Pleistocene and Early Holocene. The migration of the East Asian ancestors of the Paleo-Eskimos was associated with the representatives of the Neolithic cultures of Northeast Asia, which brought the ancestral haplotype for mtDNA haplogroup D2a to Alaska. The emergence of the Neo-Eskimo cultures took place in the Bering strait area on the basis of the local Paleo-Eskimo tradition and under the influence of the cultural traditions of Southwestern Alaska and Chukotka. The Ust'-Belaya culture of Chukotka could act as a genetic source for the development of the Neo-Eskimo cultures.Conclusion. Analysis of ancient DNA from human remains over the past decade has had a transformative effect on the study of the origin of the Eskimos. Data sets of ancient DNA have revealed an increasingly complex picture of human demographic history in North-East of Asia and America and development of Paleo-Eskimo and Neo-Eskimo traditions, suggesting multiple waves of migration over the Bering Strait and episodes of admixture of different groups of population, including Ancient Paleosiberian, East Asian, Paleo-Indian, Paleo-Eskimos, Neo-Eskimos and others.

Seasonal variability in particulate organic carbon degradation in the Kolyma River, Siberia

Major Arctic rivers are undergoing changes due to climate warming with higher discharge and increased amounts of solutes and organic carbon (OC) draining into rivers and coastal seas. Permafrost thaw mobilizes previously frozen OC to the fluvial network where it can be degraded into greenhouse gases and emitted to the atmosphere. Degradation of OC during downstream transport, especially of the particulate OC (POC), is however poorly characterized. Here, we quantified POC degradation in the Kolyma River, the largest river system underlain with continuous permafrost, during 9–15 d whole-water incubations (containing POC and dissolved OC—DOC) during two seasons: spring freshet (early June) and late summer (end of July). Furthermore, we examined interactions between dissolved and particulate phases using parallel incubations of filtered water (only DOC). We measured OC concentrations and carbon isotopes (δ13C, Δ14C) to define carbon losses and to characterize OC composition, respectively. We found that both POC composition and biodegradability differs greatly between seasons. During summer, POC was predominantly autochthonous (47%–95%) and degraded rapidly (∼33% loss) whereas freshet POC was largely of allochthonous origin (77%–96%) and less degradable. Gains in POC concentrations (up to 31%) were observed in freshet waters that could be attributed to flocculation and adsorption of DOC to particles. The demonstrated DOC flocculation and adsorption to POC indicates that the fate and dynamics of the substantially-sized DOC pool may shift from degradation to settling, depending on season and POC concentrations—the latter potentially acting to attenuate greenhouse gas emissions from fluvial systems. We finally note that DOC incubations without POC present may yield degradation estimates that do not reflect degradation in the in situ river conditions, and that interaction between dissolved and particulate phases may be important to consider when determining fluvial carbon dynamics and feedbacks under a changing climate.

New Holocene formal subdivision – application for the Russian Arctic

The subject of the study is a new formal subdivision of Holocene epoch applied to the northern regions of the Russian permafrost. The following criteria are considered: criteria for the modern allocation of three calendar periods of the Holocene; comparison with the Blitt-Sernander scheme; comparison with the three-term division of the Holocene for the Russian Arctic, proposed by Yu.K.Vasilchuk. In 2008, the International Commission on Stratigraphy (IUGS) established the boundary between the Holocene and the Neo-Pleistocene at the turn of about 11,700 calibrated years ago (cal. l. n.). In 2018, in addition to the well-known Blitt-Sernander division, the Holocene was divided by IUGS into three tiers: Greenland (from 11,700 to 8,200 cal. years ago), North Grippian (from 8200 to 4200 cal. years ago) and Meghalayan (beginning 4200 cal. years ago). The features of the development of polygonal vein arrays during three Holocene periods were established and the average January air temperatures for four key regions of the Russian cryolithozone were reconstructed - the north of the European part of Russia, the north of Western Siberia, the lower reaches of the Kolyma River and the east of Chukotka. It is shown that, taking into account the new division of the Holocene, the Greenland and North Grippian periods of the Holocene (between 11.7 and 4.2 thousand years ago) are the stage of the most active development of peat bogs and the simultaneous formation of re–vein ice in them. The Meghalayan Holocene period was characterized by a marked decrease in the development of peatlands, but syngenetic growth of re-vein ice continued within the emerging floodplains and laids, especially within the torn-off areas. The reconstructed average January air temperatures for four key regions of the Russian cryolithozone showed that the Greenland and North Grippian periods of the Holocene were characterized by slightly higher values (on average 1-2 °C higher) than the Meghalayan, with the exception of eastern Chukotka, for which an increase in the average January air temperature during the Meghalayan period was noted.

Mining Industry of the Republic of Sakha (Yakutia) and Problems of Environmental and Social Security of Indigenous Peoples

The Republic of Sakha (Yakutia; RS(Y)) is located in the northeast of Siberia (Russia) in the basins of the Lena, Yana, and Indigirka rivers, in the lower reaches of the Kolyma River. Yakutia is an industrial–agrarian republic with a developed mining, fuel, and energy industry. Indigenous peoples live mainly in the Arctic regions, where the large-scale development of mineral resources is planned, and South Yakutia, where the mining industry is well developed. The aim of this study is the development of methodological approaches to assessing the impact of the mining industry on the natural environment and the social sphere in the places of residence and traditional economic activities of the indigenous peoples of the North. We used the results of research work (R&D), materials of expeditionary work, and regulatory documents of the Republic of Sakha (Yakutia) and the Russian Federation (RF). The state of the environment (ES) was assessed on the basis of the analysis of indicators for three areas: (a) anthropogenic load, (b) environmental and social consequences, and (c) resistance of natural complexes to technogenic impacts. In total, 22 indicators were used for the 3 areas, for example, population density, person/km2; the volume of extraction of rock mass, million m3; and emissions, t/year. To bring dissimilar indicators into comparable ones, we used a methodological approach with the use of the social risk index (SRI). In Arctic regions (mainly agricultural), the ES is in a favorable and relatively favorable state: SRI 0.61–0.70; in the central regions (mainly agricultural), it is satisfactory and relatively satisfactory: SRI 0.71–1.0; in the southern and western regions with a developed mining industry, it is relatively tense and tense: SRI 1.01–3.0. An extremely tense state of environmental conditions has developed in the city of Yakutsk: SRI ≥ 3. Generally, the deterioration of the environmental situation and vital activity of the indigenous peoples in investigated Arctic region correlated with the impact of the mining industry.

The landforms associated with industrial placer gold mining in Siberia

Industrial placer gold mining creates specific montane relief shapes. The character of these landforms is influenced by the mining technology used, the management of the site and mining area, the organization of the work and the subsequent measures after the termination of mining. Available classifications of known landforms can also be partially applied to shapes created during placer gold mining. Field research was conducted on gold-bearing fields in the upper courses of the Indigirka and Kolyma rivers. Drawn and photographic documentation of sample landforms was obtained, and their dimensions were ascertained, or their genesis was observed. The landforms found often differ in character and size from shapes known from other raw material mining and industrial gold panning sites. The mining landforms created during the industrial panning of gold in Siberia are documented by drawings according to the facts found during the field research. The text presents their basic differences from the hitherto known landforms.

Impact of Floods in the Kolyma River Delta on Navigation Conditions in the East Siberian Sea

Problem of improving the quality of medium- and long-term forecasting of changes in ice conditions in the Northern Sea Route, and in particular in the east Siberian sea, where one of the methods of selecting waterways is the passage of ships in areas of ice-covered polynya. The hypothesis is verified that during the summer months, such changes may be significantly influenced by the timing of the onset of high water in the Kolyma River delta. Data from the global reanalysis GLORYS12v1 supported by the European Copernicus Marine Service were used as factual material on the ice cover and levels of the East Siberian Sea in the months of May to October 1993-2019. The analysis is based on mathematical models of the NEMO family verified by satellite altimetry data. Using the developed methodology, the dates of abrupt changes in level and sea ice extent on the Kolyma River estuarine seashore have been estimated for selected periods of the year. The study uses statistical methods to confirm the validity of the stated hypothesis for a number of areas of the East Siberian Sea, through which the shipping routes of the Northern Sea Route pass. It has been established that the greatest influence of flood timing on ice conditions and navigation conditions in such areas takes place in July. It is shown that early floods in the Kolyma delta generally lead to improvement of ice conditions, while late floods lead to complication of ice conditions. The identified relationships are recommended for use in forecasting changes in ice conditions. It has been suggested that with further climate warming and shifting of flood dates to earlier dates, the complication of ice conditions due to freezing of the formed polynya is not excluded.

Yup’ik Loanword Etymologies for the Yukaghir Languages and Dialects

In this paper, up to twenty-eight new Yukaghir etymologies are described as Eskimo borrowings into the Yukaghir languages and dialects of far northeastern Siberia, with phonological and semantic considerations for each suggestion. These findings provide new insights into the historical phonology of these ancient borrowings as well as fairly clear etymologies for a number of isolated Yukaghir words. The chronology of the borrowings is also considered, and various factors reveal two different competing hypotheses: the Yukaghir correspondences have either resulted from chronologically different borrowing layers through the ages, or the correspondences actually represent the remnants of an ancient genetic language affiliation between the two, a hypothesis supported by the very divergent phonological shapes and semantics of the correspondences. It is argued that the Eskimo correspondences are invariably of the Yup’ik variety (instead of the Inuit variety), and that Yup’ik language(s) were spoken in much earlier times around the Kolyma River, where Yukaghir is still spoken, and in particular close to the Tundra Yukaghirs. The semantic categorization of the borrowings places most of them as elementary phenomena, actions, and perceptions, and if not actually describing an actual genetic language relationship, this at least suggests very intense linguistic contacts between Yup’ik and Yukaghir under bi- or multi-lingual conditions, such as through tribal marriages and where code-switching was the norm for generations.

Reconstruction of the Indigenous Sources of Gold of the Glu-Kharinsky Placer (Kolyma River Basin, Magadan Region, Russia)

A comparative analysis of typomorphic features of gold placers and indigenous sources of gold was carried out for the Glukharinsky ore-placer node (the Nadezhda deposit and Glukharinskoye, Tyomnoye, and Tyi-Jurye ore occurrences). A correlation between fineness of placer native gold and composition of relic minerals preserved inside gold particles was obtained for the first time. This made it possible to establish mineral parageneses of native gold from potential indigenous sources. The study of placer gold fineness in combination with com-position of mineral inclusions allowed us to identify seven types of gold paragenesis: petzite-hessite with a fineness of 855‰, pyrite-polybasite-galena (a fineness of 670‰), bismuth telluride (900‰), cosalite-vikingite (790‰), galena (870‰), glaucodot (950‰), and hydrohematite (840‰). It was also shown that the placer contains the material from ore occurrences of different formation: gold-quartz-porphyry occurrences in granitoids (Au-Te-Bi type) and gold-silver occurrences. The method developed by us allows one to estimate the percentage of each ore source in placer formation.

Intraspecific structure of the Coregonus lavaretus complex in water bodies of Siberia: a case of postglacial allopatric origin of Yukagirian whitefish

The results of morphological and genetic analyses of forms/species of the Coregonus lavaretus pidschian (Gmelin, 1789) complex from the Indigirka and Kolyma river basins are presented in the context of there being recent postglacial speciation events. It has been found that the studied whitefishes belong to the sparsely rakered and low lateral-line forms and have previously been described as Coregonus lavaretus pidschian n. jucagiricus Drjagin (Berg), 1932. Based on these characters, this whitefish does not differ from most Arctic whitefish populations (in particular from Coregonus lavaretus glacialis Kirillov, 1972). Analysis of variability of the ND1 gene (mtDNA) showed that whitefishes from the Indigirka and Kolyma basins belong to a distant phylogenetic lineage, which is significantly different from all previously studied whitefish lineages from the Ob, Yenisei, Lena, Anadyr, and Amur river basins. Analysis of variability of the ITS1 fragment (nDNA) showed that all studied forms/species (from Ob River to Amur River basins), including C. l. pidschian n. jucagiricus, have a tandem arrangement of two identical nucleotide fragments and very similar nucleotide composition of the ITS1 region. Based on contemporary data, this phylogenetic lineage of the C. pidschian complex could be considered a young postglacial allopatric species.

Systemization of Indicators for Assessing the Impact of Power Engineering Facilities on the Environment of the Arctic Zone in Yakutia

The development of mineral resources in the Arctic zone of Yakutia is followed by a progressively increasing impact on the environment. Under these conditions, it is necessary to develop such directions for reducing the negative consequences of industrial development that could support the entire ecosystem of the North in a balanced state in strict accordance with the laws of structure, processes and changes in the landscape structure. This can provide a complex geoecological approach that involves a systematic study of the relationships between both natural and man-made objects. In general, this approach is based on the study of the impact processes of athropogenic activities on the environment, changes in the environment and consequences that affect natural and social conditions. Under conditions of extremely low resistance of natural landscapes to any impacts, it is necessary to assess and search for directions reducing the consequences of industrial development. In this regard, a schematic model of indicators systematization of environmental and socio-economic consequences of the functioning of energy supply facilities is developed on the example of the Yana, Indigirka and Kolyma river basins in accordance with the laws of structure, processes and changes in the landscape structure.

Effect of Permafrost Thawing on Discharge of the Kolyma River, Northeastern Siberia

With permafrost warming, the observed discharge of the Kolyma River in northeastern Siberia decreased between 1930s and 2000; however, the underlying mechanism is not well understood. To understand the hydrological changes in the Kolyma River, it is important to analyze the long-term hydrometeorological features, along with the changes in the active layer thickness. A coupled hydrological and biogeochemical model was used to analyze the hydrological changes due to permafrost warming during 1979–2012, and the simulated results were validated with satellite-based products and in situ observational records. The increase in the active layer thickness by permafrost warming suppressed the summer discharge contrary to the increased summer precipitation. This suggests that the increased terrestrial water storage anomaly (TWSA) contributed to increased evapotranspiration, which likely reduced soil water stress to plants. As soil freeze–thaw processes in permafrost areas serve as factors of climate memory, we identified a two-year lag between precipitation and evapotranspiration via TWSA. The present results will expand our understanding of future Arctic changes and can be applied to Arctic adaptation measures.

The effect of estuarine system on the meiofauna and nematodes in the East Siberian Sea

Arctic meiofauna and nematodes were examined at 12 stations in the East Siberian Sea, covering a depth range of 13–59 m and an estuarine-shelf system from the Indigirka and Kolyma rivers to the adjacent shelf. Our data reveal the low diversity of the meiofauna at the East Siberian Sea shelf. The meiobenthos abundance was influenced by river run-off and the sea bottom landscape. The samples comprised a total of 28 families and 72 genera, and the number of genera per station ranged from 15 to 32. The Comesomatidae was the dominant family with genus Sabatieria. Among all factors, depth, water temperature and the total organic carbon appeared to be important variables explaining spatial variations in meiofauna and nematodes abundance. Depth and river run-off were defining in controlling the density of nematodes in the study area.

Holocene ice wedges of the Kolyma Lowland and January paleotemperature reconstructions based on oxygen isotope records

AbstractIce wedges in the Holocene deposits of alases and floodplains have been studied in the Kolyma Lowland region. Most ice wedges have been found within alases dated to between 11 and 4.2 cal kyr BP, corresponding to the Greenlandian and Northgrippian stages of the Holocene. This study confirms that the greatest intensity of ice wedge growth occurred during ~10.5–6 cal kyr BP. A decrease in their growth was mainly caused by alas draining and reduced sedimentation. In the last 4–4.5 cal kyr BP (defined as the Meghalayan stage of the Holocene), ice wedges continued to grow in old alases, sometimes as a younger generation, as well as within young alases and floodplains of the Kolyma River and its tributaries. Mean January air temperatures were quite stable during the Holocene and varied usually approximately between −33 and −41°C, with a slight cooling during the Meghalayan stage. Minor variations in mean January air temperature may indicate a stability of winter climate of northern Yakutia, probably as a result of the stable influence of the Siberian anticyclone.

Phylogenetic Relationships in Vendace and Least Cisco, and Their Distribution Areas in Western Eurasia

I conducted a population-genetic study of the Eurasian cisco complex in an area extending from the Baltic Sea to the East-Siberian Sea using 30 enzyme loci. The results indicate that the least cisco (Coregonus sardinella) populations from most rivers of the Kara, Laptev and East-Siberian sea basins are genetically fairly homogeneous, and that the cluster they form is different from the one for the vendace (C. albula) populations from the waterbodies of the Baltic and White seas (Nei's genetic distance (DN) = 0.076). The least cisco and vendace originated from two major phylogenetic lineages of the species occurring as the purest form in the above regions. As a result of the evolution and complex interactions among local populations within the two phylogenetic lineages of cisco at the various stages of Middle and Late Quaternary glaciations, most extant modern populations are hybrid in origin. For example, the Barents Sea populations and the easternmost population from the East-Siberian Sea basin (Kolyma River) emerged as a result of hybridization during the last colonization wave by the least cisco (East Siberian) along the Arctic coast upon cisco's interaction with local ciscoes in the west and east. The White and Kovzhskoye lake populations from the Caspian Sea basin, which form a joint cluster with them, are the hybrids of the local vendace and the descendants of the first wave of least cisco's (West Siberian) expansion to Europe. In this paper, I also discuss the most probable scenarios of cisco's colonization of the study area using paleolimnological reconstructions.