East Siberian Research Articles

Distinct vertical behavior of key Arctic copepods following the midnight sun period in the East Siberian continental margin region, Arctic Ocean

Diel vertical migration (DVM) of zooplankton plays a vital role in biological carbon pump and food web interactions. However, there is considerable debate about the DVM of zooplankton in response to environmental changes in the Arctic Ocean. We investigated DVM behavior in the key Arctic copepods Calanus glacialis, Calanus hyperboreus, and Metridia longa following the midnight sun period in the East Siberian continental margin region. The two Calanus species showed non-DVM behaviors, whereas M. longa showed a typical DVM pattern consistent with the solar radiation cycle. Additionally, these species showed different vertical distributions. Calanus glacialis was distributed at depths above 20 m in the warm fresh water, where the highest density gradient was observed. Calanus hyperboreus was distributed at depths between 30 and 55 m in the cold salty water, where a high contribution of micro phytoplankton and the subsurface chlorophyll maximum (SCM) layer were observed. M. longa was found across a broader range of temperature and salinity than both Calanus species, and it was distributed in the upper water column, where the SCM layer was observed at night and at depths between 100 and 135 m in the daytime. These results imply that M. longa can be well adapted to the changing Arctic Ocean environment, where sea ice loss and ocean warming are ongoing, whereas C. hyperboreus can be the most vulnerable to these changes. These findings provide important information for understanding variations in the vertical distributions of key copepod species in the rapidly changing Arctic marine environment.

Spatial and Temporal Variations of Arctic Sea Ice during 1992-2021

The variation of polar sea ice is an indicator of polar environmental change, which plays an important role in the study of regional and global climate change. The arctic is a region in transition to a warmer climate and one of the most visible signs of that change is in the declining sea ice cover. Sea ice in the arctic is one of the most rapidly changing components of the global climate system. The extent of area covered by arctic sea ice is an important indicator of changes in global climate because warmer air and water temperatures are reducing the amount of sea ice present. Sea ice extent plays an important role in reflecting sunlight back into space, regulating ocean and air temperatures, circulating ocean water, maintaining animal habitats. Similarly, sea ice concentration helps to determine the number of other important climate variables. In this paper, the sea ice data from different institutes were used to analyze the spatial and temporal variation of arctic sea ice concentration (SIC) and sea ice extent (SIE) over the 30-year period 1992-2021. During this period, the results shows that these two variables were increased in the arctic during 2021 due to the decrease of temperatures particularly near Chukchi, Kara, Beaufort, East Siberian and Greenland Seas.

Time-Domain Electromagnetics for Subsea Permafrost Mapping in the Arctic: The Synthetic Response Analyses and Uncertainty Estimates from Numerical Modelling Data

Subsea permafrost stability is the key to whether pre-performed methane sequestered in hydrate deposits escapes to the overlying strata. By making use of the 1D numerical modeling and field data, we analyze the capabilities of the time-domain (transient) electromagnetic method (TDEM) when being applied for subsea permafrost mapping, and study the effect of the background resistivity structure on the inversion models’ accuracy for a series of settings typical for the East Siberian Arctic Shelf—the broadest and shallowest shelf in the world ocean, which represents more than 70% of the subsea permafrost. The synthetic response analysis included the construction of a series of resistivity models corresponding to different settings (presence/absence of ice-bonded permafrost layer, different position of its top and bottom boundaries, different width and thickness of thawed bodies or taliks, variable seawater depth and its resistivity), and calculation of synthetic apparent resistivity responses used to assess their sensitivity to changes in the target parameters of the resistivity structure. This was followed by regularized inversion of synthetic responses and comparing resulting models with original (true) ones, which allowed us to understand the possible uncertainties in the geometry and resistivity of the reconstructed permafrost layer, depending on seawater depth and unfrozen layer thickness, as well as confirm the overall efficacy of TDEM technology for the subsea permafrost imaging. That is crucially important for understanding the current state of the subsea permafrost-hydrate system and possible future dynamics.

The bimodality of the East Siberian fast ice extent: mechanisms and changes

Abstract Using operational sea-ice maps, we provide first insight into the seasonal evolution of fast ice in the East Siberian Sea for the period between 1999 and 2021. The fast ice season tends to start later by 4.7 d per decade and to end earlier by 9.7 d per decade. As a result, there is a trend towards a shorter length of fast ice season by 2 weeks per decade. The analysis of air temperatures indicates that onset and end of the fast ice season are largely driven by thermodynamic processes. Two spatial modes (large, L-mode and small, S-mode) of East Siberian fast ice cover which have significant areal differences were distinguished. The occurrence of L- and S-modes was linked to the polarity of the Arctic Oscillation (AO) index. Negative AO phase leads to increased sea-ice convergence in the region, which in turn favours sea-ice grounding and promotes the development of large fast ice extent (L-mode). Lower deformation rates in the region during positive AO phase does not allow the formation of grounded features which results in small fast ice extent (S-mode). An analysis of sea-ice divergence confirms that L-mode seasons are characterised by higher on-shore convergence compared with S-mode seasons.

«Book Culture in the Digital Era»: the Results of the All-Russian (with International Participation) Scientific and Practical Conference. The Republic of Buryatia, November 24-25, 2022

The results of the All-Russian (with international participation) scientific and practical conference “Book Culture in the Digital Age”, organized by the Department of Library and Information Resources of the East Siberian State Institute of Culture within the framework of the implementation of the comprehensive scientific topic, are summarized. The reports presented at the plenary and sections sessions, panel discussion are characterized, and the recommendations formulated by the participants of the event are summarized.

Northern Buddhism in the culture of the East Siberian region of Russia (on the history of the Irkutsk Spiritual Mission of the Russian Orthodox Church).

The study of the cultural activity of the Spiritual missions of the Russian Orthodox Church in various regions of Russia is one of the urgent tasks in the context of the problematic field of the theory of regionalism, cultural studies and socio-philosophical knowledge. Russian settlements on the territory of the Yenisei River basin and the entry of ethnic groups and territories of Yakutia and Buryatia into the Russian Empire has become one of the most important stages of the integration of the ethnic groups of Siberia into a single statehood. The Irkutsk Spiritual Mission received a more perfect organization, institutionalized by increasing the number of missionary camps, which for successful Christian activities carried out among pagans allowed the formation of school educational institutions for the education and upbringing of a new Buryat generation of children in the doctrinal Orthodox canons, and Russian cultural traditions. In this regard, one of the key tasks of the missionaries was to establish a rational view of further life in new Christian-type formations, which was realized in socio-cultural activities: providing medical care to sick representatives of other ethnic groups, a friendly attitude to people of a different faith and a sincere desire to guide them on the path of righteousness, etc. It should be noted that the largest share of foreigners in this territory belonged to Buddhists, which was reflected in the influence of lamas on doctrinal issues, including economic ones. Since Buddhism in the Russian Empire belonged to the section of tolerant religions, direct (administrative) pressure on it was impossible. There remained funds of an exclusively spiritual nature, to which Orthodox missionary work was directed. Today in the Russian Federation, Buddhism, as well as Islam, Catholicism and Protestantism, as well as some other faiths belong to the category of traditional religions, which organizationally operate within the framework of the modern Russian Constitution.

Large-Scale Variation in Diversity of Biomass-Dominating Key Bryozoan Species in the Seas of the Eurasian Sector of the Arctic

An analysis of archival and literary materials, as well as recently collected data in coastal areas at 14 locations in the Eurasian seas showed that the diversity of biomass-dominating key bryozoan species is low, totaling 26 species, less than 1/15 of the total bryozoan fauna richness. Their number decreases eastward from 17 species with an average total biomass of >16 g/m2 in the Barents Sea to three species with an average biomass of about 3 g/m2 in the East Siberian Sea. In the Chukchi Sea, their number and average biomass increase to 10 species and ~12 g/m2, respectively. Average biomass strongly correlates with the number of species in each sea. Furthermore, variation in biomass is significantly correlated with the composition of bottom sediments and, in some locations, with depth. The marked decrease in the number of key species along the vector from Barents→Kara→Laptev→East Siberian Sea is due to a decline in the number of boreal and boreal–Arctic bryozoans of Atlantic origin. In contrast, the appearance of boreal and boreal–Arctic Pacific species is responsible for the increase in key species in the Chukchi Sea.

Lithological and Geochemical Indicators of Ice Gouging: Evidences from Holocene Sediments in the East Siberian Sea

Abstract —Cores of Holocene bottom sediment collected in the East Siberian Sea revealed layers with mixed textures and layers with breaks in sedimentation corresponding to the two sea levels defined as modern (upper) and Early Holocene (lower). The layers are characterized by distinctly chaotic variability in textural pattern (mottled appearance, multidirectional banding), colorimetric and geochemical parameters (sawtooth-like distribution curves). Such character of changes is associated with the physical action of dragging keels of ice/icebergs exerted on the seafloor and is referred to as ice gauging (scouring). Its analysis can be used for identification of ice scour-affected layers in other sediment cores collected in this region, and for the purpose of creating a representative database, predicting their occurrence and developing adequate measures to minimize the damaging impact from drifting sea ice and icebergs on the seafloor within the bounds of the Arctic shelf.

A Short Research Guide on Arctic Historical Bryozoan Collections and a Few Associated Biocoenosis at the Zoological Institute of the Russian Academy of Sciences

Russian bryozoans and other invertebrate biocenosis material collected in the Arctic Ocean over a period of more than 250 years, and the corresponding literature citing them, are deposited in the Zoological Institute of the Russian Academy of Sciences, Saint Petersburg, Russia. This paper provides a general description and historical quantitative information about the Historical Bryozoan Collection kept in this Russian institute. Access to species-level data is available via the data portal ( www.zin.ru ). The quantitative distribution of benthos, specifically bryozoans, in the Russian Arctic seas remained nearly unexplored until recent times. The first systematic quantitative studies were conducted by the Zoological Institute in the Laptev Sea, in its southeastern part, on the New Siberian Shoal in 1973; the Chaun Bay of the East Siberian Sea in 1986; and near Wrangel Island and Cape Schmidt of the Chukchi Sea in 1976.

Microbial life in 25-m-deep boreholes in ancient permafrost illuminated by metagenomics

This study describes the composition and potential metabolic adaptation of microbial communities in northeastern Siberia, a repository of the oldest permafrost in the Northern Hemisphere. Samples of contrasting depth (1.75 to 25.1 m below surface), age (from ~ 10 kyr to 1.1 Myr) and salinity (from low 0.1–0.2 ppt and brackish 0.3–1.3 ppt to saline 6.1 ppt) were collected from freshwater permafrost (FP) of borehole AL1_15 on the Alazeya River, and coastal brackish permafrost (BP) overlying marine permafrost (MP) of borehole CH1_17 on the East Siberian Sea coast. To avoid the limited view provided with culturing work, we used 16S rRNA gene sequencing to show that the biodiversity decreased dramatically with permafrost age. Nonmetric multidimensional scaling (NMDS) analysis placed the samples into three groups: FP and BP together (10–100 kyr old), MP (105–120 kyr old), and FP (> 900 kyr old). Younger FP/BP deposits were distinguished by the presence of Acidobacteriota, Bacteroidota, Chloroflexota_A, and Gemmatimonadota, older FP deposits had a higher proportion of Gammaproteobacteria, and older MP deposits had much more uncultured groups within Asgardarchaeota, Crenarchaeota, Chloroflexota, Patescibacteria, and unassigned archaea. The 60 recovered metagenome-assembled genomes and un-binned metagenomic assemblies suggested that despite the large taxonomic differences between samples, they all had a wide range of taxa capable of fermentation coupled to nitrate utilization, with the exception of sulfur reduction present only in old MP deposits.

Features of damage to the conductive structures of the nervous system in patients with vibration disease, burdened with diabetes mellitus and metabolic syndrome

Introduction. Of interest are the processes developing in vibration disease (VD) in combination with metabolic syndrome (MS) or diabetes mellitus (DM), combined forms of diseases worsen their course and prognosis.
 The study aims to assess the features of the state of central afferent conductive structures and peripheral nerves in patients with vibration disease, burdened with diabetes mellitus or metabolic syndrome.
 Materials and methods. The scientists have examined 155 workers with VD — group one with an established diagnosis of VD (86 people); group two — with VD combined with DM (30 people); group three — with VD burdened with MS (39 people). The authors have conducted the electroneuromyographic examination and registration of somatosensory evoked potentials, with stimulation of the median nerve in the wrist. Abduction points — Erb point, cervical spinal cord, from the scalp of the projection area of the precentral gyrus. The researchers have applied multivariate discriminant analysis from the STATISTICA — version 6 application software package of StatSoft Inc (USA).
 Results. With VD complicated by MS, changes were in the distal part of the motor axons, with VD burdened with DM, the amplitude of the motor component of the median and tibial nerves decreased, the speed of the pulse in the proximal part of the median nerve. Somatosensory evoked potentials in VD in combination with MS revealed an increase in latency of N13 and N20. The duration of N13-N18, N13-N20, latency N18, N20, N30 increased in the case of WB, burdened with DM.
 Limitations. The limitation of the study is the use of unrelated samples for statistical analysis. The study of the state of central and peripheral conductive structures in connected samples should be considered evidence-based: metabolic syndrome and further — diabetes mellitus.
 Conclusion. The patterns of peripheral nerve damage in VD associated with exposure to general and local vibration, burdened with DM or MS, were disorders of afferent axons of the upper and lower extremities, as well as changes in the distal parts of the motor component of the tibial and median nerves. The features of the peripheral nerve states in VD, burdened with DM, were the complex involvement of the motor component in the pathological process, characterized by changes in the amplitude, pulse transit time at the level of the terminal unmyelinated fibers of the median and tibial nerves and changes in the proximal part of the median nerve. In VD complicated by MS, pathological changes were characteristic of the distal part of the motor axons. The patterns of afferent conductive structures lesion in VD, burdened with DM or MS, consisted in a violation of the activity of neurons of the cervical spinal cord and the somatosensory cortex. The peculiarity of the state of the central afferent conducting structures in VD, burdened with DM, was the slowing down of the afferent excitation wave in the area of thalamic structures to the somatosensory zone of the cortex, a violation of the conduction from the trunk to the cortical projections of the somatosensory zone. In case of VD, complicated by MS — the time of the afferent excitation wave at the level of the cervical spine and the somatosensory cortex.
 Ethics. Conclusion of the MEC of the Federal State Budgetary Scientific Institution "East Siberian Institute of Medical and Environmental Research" No. 32 dated 09.10.2019.

Soils of the Krestovsky and Chetyryokhstolbovoy islands in the National Nature Reserve “Bear Islands” (East Siberian Sea)

This paper presents an investigation of previously unstudied soils of the Arctic islands (Krestovsky and Chetyryokhstolbovoy), which gained the status of a new protected area “Bear Islands” (70°37′–70°60′ N, 160°23′–162°33′ E). Their soils were formed mainly under permafrost conditions (approximately 1 m), with a seasonal thawing depth of 0.3–0.6 cm. The territory of Krestovsky Island is a combination of several landscapes characterized by various types of permafrost soils. Primitive gravelly soils (A–BC(C)) are exposed in mountainous areas. Permafrost tundra low-gley soils (OT–Bg–BCg(C)) are formed on the gentle long slopes under hummocky moss-herbaceous tundra. In natural depressions on cryogenic forms of surface, the soil cover represents a combination of permafrost arctotundra gleyic (O–B–Bg(BC)┴) and humus-gley soils (O–AH–AB–BG┴). Marsh soils (Ad–C(AC)–C′) occur along the low flooded gently sloping coasts of the island. All soils are acidic. Zonal types are characterized by gleying, which brings them closer to the soils of the mainland. The soil cover of Chetyryokhstolbovoy Island, with the most fully developed shrublichen-moss or forb-moss soils, is rather monotonous. Namely it is represented by arctotundra gleyic soils with a profile of the same type in terms of morphological features and physicochemical properties (О–Аd–АВ(g)–Вg(BCg)). The main features of this soil type include the thinness of the surface organogenic horizon, good decomposition of organic matter, high and medium content of humus in the soddy-humus horizon, the absence of surface gleying or its weak severity due to drying out in summer.

BITUMEN RESOURCES OF THE EAST SIBERIAN BASIN

The so‐called East Siberian “Basin” extends over an ancient continental block, the Siberian Platform, and is made up of a number of smaller‐scale basement arches and basins with a variable sedimentary cover of mostly Proterozoic and Palaeozoic ages. The basin hosts the oldest large‐scale petroleum systems known. Proterozoic (“Riphean”: 1650‐650 Ma) marine source rocks, which were deposited on the passive margins which surrounded much of the Platform, generated hydrocarbons as they were buried, folded and thermally matured during a series of mostly Late Proterozoic to Cambrian continental collisions, with the final collision taking place in the Early Cretaceous along the northeastern (Verkhoyan) margin. The hydrocarbons were transported by long‐distance migration to reservoirs in the sedimentary successions which drape basement uplifts, there forming giant oil and gas accumulations which were sealed by extensive Cambrian evaporites. Subsequent uplift and unroofing, especially in the north and east of the Platform where the seal is not present, led to degradation of the oil to leave giant accumulations of bitumen, defined here as petroleum with an API gravity of less than 10° which is immobile under reservoir conditions. A significantly younger petroleum system, which may still be active, is present in the Vilyui Basin in the NE of the Siberian Platform. This basin was initiated as a mid‐Devonian rift and has a later Palaeozoic and Mesozoic fill.Bitumen accumulations in the East Siberian Basin occur mainly in Precambrian, Cambrian and Permian reservoir rocks, and began to form from precursor oils during the Permian. Around twenty‐five named fields have been described, many of which comprise portions of more extensive belts of bitumen occurrence. Although geological mapping of natural resources in the East Siberian Basin has been carried out since the 19th century, the region remains under‐explored and none of the bitumen accumulations has yet been developed.An attempt is made in this paper to catalogue and map all recorded occurrences of bitumen throughout the East Siberian Basin. Regional geological studies have been conducted in order to understand the origin and habitat of each occurrence. So far as possible, data on the areal extent and stratigraphic thickness of each bitumen occurrence has been collated, together with data on bitumen saturations and quality. These data were used to calculate resource volumes for each accumulation from first principles. Thus the total bitumen resources within the East Siberian Basin have been calculated as 24,640 MM (million) tonnes. Disregarding accumulations regarded as either of insufficient resource‐density or too small to merit consideration, this figure has been reduced to 14,760 MM tonnes. Recoverable reserves, by analogy with comparable resources worldwide, are calculated as 6100 MM tonnes (approximately 33,900 MM brl)

Antireligious Work in the East Siberian Region in 1936 in the Survey of a Representative of The League of Militant Atheists

The article characterizes the antireligious work of Irkutsk, Cheremkhovsky and Ziminsky districts of the East Siberian Territory in the middle of the fourth decade of the XXth century based on the memos by M. P. Kuznetsov, a representative of the Central Council of the League of Militant Atheists (Union of the Militant Godless). On behalf of the Council and the Permanent Central Commission on Cults, he made a trip to a number of regions of Eastern Siberia, as a result of which he compiled several memos. Two of them are devoted to assessing the state of anti-religious work in Irkutsk, the administrative center of the East Siberian Region, as well as in Cheremkhovsky and Ziminsky districts. The documents are interesting due to both statistical data and analytical comments of the author. The research is based on the complex use of the fundamental principles of historical knowledge, as well as general and special scientific methods. We draw a conclusion that the subjectivism of the author of the memos is obvious and given the fact that he was a representative of the League of Militant Atheists, the data presented by him should be treated with caution. At the same time, the documents under consideration are an interesting source on the history of religions in Eastern Siberia. They supplement the available data on Irkutsk, Cheremkhovsky and Ziminsky districts of the East Siberian Region. Taking into account the availability of similar memos on a number of other administrative units of Eastern Siberia, it becomes possible to make a comparative analysis of the anti-religious activities of the authorities from the standpoint of an objective assessment of the available materials.

Celebrating the 300th Anniversary of the Joining of Siberia to Russia in Krasnoyarsk and Irkutsk: A Failed Act of Local Historical Politics

The article examines the celebration of the 300th anniversary of the annexation of Siberia to Russia in the key East Siberian cities – Krasnoyarsk and Irkutsk – from the standpoint of communication science, local historical memory and historical politics, as a symbolic action designed to impose on local communities a certain set of narratives associated with the concepts of “Siberia”, “Russia” and “accession” as significant factors of local life. The purpose of the study is to analyze the significance for the local urban communities of Krasnoyarsk and Irkutsk of the 300th anniversary of the annexation of Siberia to Russia as an essential act of local historical memory and an element of local historical politics. The methodological basis of this study is the tools of communication science: the celebration of the 300th anniversary of the annexation of Siberia to Russia is seen as a symbolic act of local historical politics, which was intended to impose on local communities a certain narrative (the key concepts of which are “Siberia” and “joining Russia”), and by the effectiveness of the implementation of which one can judge the self-perception of the urban East Siberian population. The study was carried out on the basis of archival materials (some of which are introduced into scientific circulation for the first time), materials of personal origin, local journalism and media materials. It is concluded that despite the active attempts of the regionalists and the local business elite to organize the celebration and communicative design of the anniversary as a symbolic act of local historical memory, the 300th anniversary of the annexation of Siberia as a significant narrative was shared by a very limited number of the population. The budgets of the event turned out to be sharply scarce, the dates were unclear until the last moment, and the preparations were chaotic. Contrary to the traditional interpretation of this event of 1881–1882, the 300th anniversary of Siberia as an attempt to form a local symbol was unsuccessful, which did not prevent interested subjects of socio-political communications (regionals, part of local elites and government officials) from presenting this event as significant for local life, doing this in fact according to the classical canons of historical politics.

ПЕДАГОГИЧЕСКИЕ ТЕХНОЛОГИИ В ПРЕОДОЛЕНИИ КЛИПОВОГО МЫШЛЕНИЯ СТУДЕНТОВ

The author’s experience of teaching students conceptual, critical thinking, building cause-and-effect relationships of the ethical and communicative phe-nomena under study, respect for the personality of the Other, need for self-development, etc. at the department of library and information resources of the FSBEI HE «East Siberian state institute of culture» is described. The attention is focused on the pros and cons of the students’ clip thinking.

Моделирование ветрового волнения в море Лаптевых, Восточно-Сибирском и Чукотском морях

The paper presents an analysis of wind wave parameters in the Laptev, East Siberian and Chukchi seas based on the results of numerical experiments with the WAVEWATCH III wave model for a period from 1979 to 2021. Wave modeling was carried out using an unstructured computational grid with a high resolution (up to 800 m) in the coastal zone. The NCEP/CFSR/CFSv2 reanalysis was used as wind forcing. The maps of the long-term mean values of the wave height, wave length and period were obtained. For the several points in the central part of each sea, the mean annual values of wave heights are calculated and the analysis of interannual variability is carried out. The maximum significant wave height was 5–6 m in the Laptev Sea, 6–7 m in the East Siberian Sea, and 7–7.5 m in the Chukchi Sea. The analysis of interannual variability showed that there is a positive trend in wave height for all seas under consideration. The largest increase in the annual mean wave height is observed in the East Siberian Sea (from 0.4 to 1.4 m in the ice-free period). Keywords: Laptev Sea, Chukchi Sea, East Siberian Sea, wave modeling, Arctic wind waves, WAVEWATCH III

Surface and Interior Dynamics of Arctic Seas Using Surface Quasi-Geostrophic Approach

This study assesses the capability of Surface Quasi-Geostrophy (SQG) to reconstruct the three-dimensional (3D) dynamics in four critical areas of the Arctic Ocean: the Nordic, Barents, East Siberian, and Beaufort Seas. We first reconstruct the upper ocean dynamics from TOPAZ4 reanalysis of sea surface height (SSH), surface buoyancy (SSB), and surface velocities (SSV) and validate the results with the geostrophic and total TOPAZ4 velocities. The reconstruction of upper ocean dynamics using SSH fields is in high agreement with the geostrophic velocities, with correlation coefficients greater than 0.8 for the upper 400 m. SSH reconstructions outperform surface buoyancy reconstructions, even in places near freshwater inputs from river discharges, melting sea ice, and glaciers. Surface buoyancy fails due to the uncorrelation of SSB and subsurface potential vorticity (PV). Reconstruction from surface currents correlates to the total TOPAZ4 velocities with correlation coefficients greater than 0.6 up to 200 m. In the second part, we apply the SQG approach validated with the reanalysis outputs to satellite-derived sea level anomalies and validate the results against in-situ measurements. Due to lower water column stratification, the SQG approach’s performance is better in fall and winter than in spring and summer. Our results demonstrate that using surface information from SSH or surface velocities, combined with information on the stratification of the water column, it is possible to effectively reconstruct the upper ocean dynamics in the Arctic and Subarctic Seas up to 400 m. Future remote sensing missions in the Arctic Ocean, such as SWOT, Seastar, WaCM, CIMR, and CRISTAL, will produce enhanced SSH and surface velocity observations, allowing SQG schemes to characterize upper ocean 3D mesoscale dynamics up to 400 m with higher resolutions and lower uncertainties.

Newly Acquired Data on the Geologic Structure and Hydrocarbon Potential in the Eastern Part of the East Siberian Sea Shelf

Abstract —We report results of an integrated interpretation of geophysical data (2D CDP seismic acquisition and gravity and magnetic survey) conducted by Gazpromneft Science and Technology Center in the North Wrangel lease block on the East Siberian Sea shelf. The newly obtained geophysical data have allowed us to update the geological model of the sedimentary cover within the North Wrangel lease block, to clarify the limits of the Drem-Khed Trough, to reconstruct the conditions under which sedimentary complexes formed, and to identify possible promising oil and gas accumulation zones. We were able to determine the position of the main stratigraphic unconformities, to propose several approaches to their interpretation, and to identify the clinoform architecture of the Aptian–Albian and Cenozoic complexes within the Drem-Khed Trough. The integrated review of geological and geophysical data has been helpful in refining the framework of the main structures adjoining the trough and predicting the extent of potential reservoirs and oil and gas source rocks throughout the sedimentary cover. The Upper Cretaceous and Cenozoic complexes are regarded as oil and gas exploration targets.

Decadal Prediction of the Summer Extreme Precipitation over Southern China

The decadal variability of the summer extreme precipitation over southern China (EPSC) is remarkable, especially for the significant decadal enhancement after the 1990s. The study documented that the summer sea surface temperature (SST) over the North Atlantic and spring sea ice concentration (SIC) over the East Siberian Sea can significantly affect the EPSC. The summer SST over the North Atlantic influences the low-pressure cyclone in the western Pacific by modulating the SST over the tropical Pacific, thus affecting EPSC. A decrease in the SIC of the East Siberian Sea induces a negative Arctic Oscillation, which induces the increased SST over northwest Pacific and the anomalous cyclone over there, in turn, affecting EPSC. Both predictors have a quasi-period of 10–14 years, which provides useful predictive signals for EPSC. The leading 7-year SST and the leading 5-year SIC are chosen to establish the prediction model based on the decadal increment method, which can well predict the EPSC, especially for the shift in the early 1990s. These results provide a clue to the limited predictability of decadal-scale extreme climate events.