The structure of Atlantic Water at Eurasian continental slope in summer 2007

Intensive field campaigns during the IPY (2007-2009) allowed unprecedented coverage of Eurasian continental slope by CTD measurements. These data allowed detailed mapping of the warm Atlantic water on its way from Fram Strait to the East Siberian Sea. Fourteen cross-slope sections, carried out by Russian, US and German scientists in August-September 2007 were used to determine position and properties of the warm Atlantic water core. Temperature and salinity data were examined against traditional concept of warm intermediate layer in the Arctic Ocean and in the view of recently introduced new ideas (e.g. seasonal oscillations in AW layer far from Fram Strait). Joined analysis of CTD data with long-term mooring observations demonstrated complex nature of warming-cooling pulses, which enter Arctic Ocean through Fram Strait and effect thermal conditions in Eurasian sector of the Arctic Ocean

Arctic Ocean variability derived from historical observations

This study has been motivated by reports of extraordinary change in the Arctic Ocean observed in recent decades. Most of these observations are based on synoptic measurements, while evaluation of anomalies requires an understanding of the underlying long-term variability. Historical climatologies give reference means, and while these datasets are a reliable source of the mean Atlantic Layer temperature, they significantly underestimate variability. Using historical data, we calculated statistical parameters for selected Arctic Ocean regions. They demonstrate a high level of Atlantic Layer temperature variability in the Nansen Basin and sea-surface salinity fluctuations on the Siberian shelf and the Amundsen Basin. These estimates suggest strong limitations on our ability to define amplitudes of anomalies by comparing recent synoptic measurements with climatologies, especially for regions characterized by strong variability

An observation-based assessment of the influences of air temperature and snow depth on soil temperature in Russia

This study assessed trends in the variability of soil temperature (T-SOIL) using spatially averaged observation records from Russian meteorological land stations. The contributions of surface air temperature (SAT) and snow depth (SND) to T-SOIL variation were quantitatively evaluated. Composite time series of these data revealed positive trends during the period of 1921-2011, with accelerated increases since the 1970s. The T-SOIL warming rate over the entire period was faster than the SAT warming rate in both permafrost and non-permafrost regions, suggesting that SND contributes to T-SOIL warming. Statistical analysis revealed that the highest correlation between SND and T-SOIL was in eastern Siberia, which is underlain by permafrost. SND in this region accounted for 50% or more of the observed variation in T-SOIL. T-SOIL in the non-permafrost region of western Siberia was significantly correlated with changes in SAT. Thus, the main factors associated with T-SOIL variation differed between permafrost and non-permafrost regions. This finding underscores the importance of including SND data when assessing historical and future variations and trends of permafrost in the Northern Hemisphere

Predictive analysis of rotor machines fluid-film bearings operability

The present paper considers a multi-criteria analysis algorithm of turbo generator fluid-film bearing operability and its connection with rotor machine monitoring system data. It is substantiated that implementation of predictive analysis of load capacity, locus curves and dynamic displacements allows prognosis of useful life of a fluid-film bearings and improvement of reliability of a rotor machine

Thermohaline structure and variability in the eastern Nansen Basin as seen from historical data

Newly available historical Russian data are used to quantify year-to-year variations in the structure and properties of the halocline and Atlantic Water layers in the eastern Nansen Basin. The data come from a series of aerial surveys of the central Arctic Ocean done during winter between 1973 and 1979, and repeated Polygon surveys of the shelf, slope, and basin north of Severnaya Zemlya in the 1980s, and thus allow a perspective on shelf-basin exchange. A water-mass census shows substantial survey-to-survey variability in several water-mass categories, with volumetric fluctuations of ∼17% in the Upper Polar Deep Water category, ∼14% in Atlantic Water, and ∼39% for cold surface waters with T \u3c −1.5°C. Mean water-mass production rates in the polygon area are found to be 0.6–1.2 Sv for Upper Polar Deep Water, and an effective loss rate of 0.75–1.5 Sv is found for Atlantic Waters. On average Atlantic Water loses 16% of its initial heat content within the 350 km-long survey area, possibly enhanced by double-diffusive processes. Mean upward heat fluxes above the Atlantic Water are estimated to be between 4 and 6 W/m2, based on heat budget considerations. Upward heat fluxes of this magnitude would have a major effect on sea ice, which is regularly observed to be thinner in this area of the Nansen Basin. Shallow-water profiles taken close to Severnaya Zemlya show cold and salty waters denser than offshore waters at similar depths, and evidence of convection is seen in many profiles taken over the continental shelf and slope, reflecting deep convective events extending in some cases below the deepest observed depth of 1000 m

Vertical structure of recent arctic warming from observed data and reanalysis products

The final publication is available at Springer via http://dx.doi.org/10.1007/s10584-011-0192-8Spatiotemporal patterns of recent (1979–2008) air temperature trends are evaluated using three reanalysis datasets and radiosonde data. Our analysis demonstrates large discrepancies between the reanalysis datasets, possibly due to differences in the data assimilation procedures as well as sparseness and inhomogeneity of high-latitude observations. We test the robustness of Arctic tropospheric warming based on the ERA-40 dataset. ERA-40 Arctic atmosphere temperatures tend to be closer to the observed ones in terms of root mean square error compare to other reanalysis products used in the article. However, changes in the ERA-40 data assimilation procedure produce unphysical jumps in atmospheric temperatures, which may be the likely reason for the elevated tropospheric warming trend in 1979-2002. NCEP/NCAR Reanalysis show that the near-surface upward temperature trend over the same period is greater than the tropospheric trend, which is consistent with direct radiosonde observations and inconsistent with ERA-40 results. A change of sign in the winter temperature trend from negative to positive in the late 1980s is documented in the upper troposphere/lower stratosphere with a maximum over the Canadian Arctic, based on radiosonde data. This change from cooling to warming tendency is associated with weakening of the stratospheric polar vortex and shift of its center toward the Siberian coast and possibly can be explained by the changes in the dynamics of the Arctic Oscillation. This temporal pattern is consistent with multi-decadal variations of key Arctic climate parameters like, for example, surface air temperature and oceanic freshwater content. Elucidating the mechanisms behind these changes will be critical to understanding the complex nature of high-latitude variability and its impact on global climate change.acceptedVersio

Tachyon Stabilization in the AdS/CFT Correspondence

We consider duality between type 0B string theory on $AdS_5\times S^5$ and the planar CFT on $N$ electric D3-branes coincident with $N$ magnetic D3-branes. It has been argued that this theory is stable up to a critical value of the `t Hooft coupling but is unstable beyond that point. We suggest that from the gauge theory point of view the development of instability is associated with singularity in the dimension of the operator corresponding to the tachyon field via the AdS/CFT map. Such singularities are common in large $N$ theories because summation over planar graphs typically has a finite radius of convergence. Hence we expect transitions between stability and instability for string theories in AdS backgrounds that are dual to certain large $N$ gauge theories: if there are tachyons for large AdS radius then they may be stabilized by reducing the radius below a critical value of order the string scale.Comment: 10 pages, harvmac; v2: 1 minor clarification, 1 reference adde

Toward a warmer Arctic Ocean: Spreading of the early 21st century Atlantic Water warm anomaly along the Eurasian Basin margins

We document through the analysis of 2002–2005 observational data the recent Atlantic Water (AW) warming along the Siberian continental margin due to several AW warm impulses that penetrated into the Arctic Ocean through Fram Strait in 1999–2000. The AW temperature record from our long-term monitoring site in the northern Laptev Sea shows several events of rapid AW temperature increase totaling 0.8°C in February–August 2004. We hypothesize the along-margin spreading of this warmer anomaly has disrupted the downstream thermal equilibrium of the late 1990s to earlier 2000s. The anomaly mean velocity of 2.4–2.5 ± 0.2 cm/s was obtained on the basis of travel time required between the northern Laptev Sea and two anomaly fronts delineated over the Eurasian flank of the Lomonosov Ridge by comparing the 2005 snapshot along-margin data with the AW pre-1990 mean. The magnitude of delineated anomalies exceeds the level of pre-1990 mean along-margin cooling and rises above the level of noise attributed to shifting of the AW jet across the basin margins. The anomaly mean velocity estimation is confirmed by comparing mooring-derived AW temperature time series from 2002 to 2005 with the downstream along-margin AW temperature distribution from 2005. Our mooring current meter data corroborate these estimations

Algorithms for determining the circumstances relevant for the case in the software for informational-technological support of judicial decisions

Objective to create a computer program of information technology support for making motivated court decisions to obtain constructive criticism of the grounds of and objections to claim presented in the software forms in order to improve it. Methods general dialecticalmaterialistic method in translating the law enforcement process into the language of information technology analysis and synthesis of the law enforcement process formal legal method for translating the requirements of the law and legal science to law enforcement into the program to be used by the judge and case participants objectoriented approach to modeling objectoriented programming methodology relational approach to database design. Results a part of the computer program is created for making motivated court decisions on cases of claim proceedings under the rules of civil proceedings solving the tasks of Article 148 of the Civil Procedural Code of the Russian Federation. Scientific novelty for the frst time a part of a computer program is presented which obliges the judge to take into account all the arguments of the parties regarding the circumstances to be established in the case to draw conclusions on them and in parallel with the conclusions and arguments of the judge for each choice to make a reasoned decision. It seems that the workload of the courts can be eliminated by the software for making and motivating court decisions which will signifcantly reduce the time for its production. The program has no analogues among the software solutions of legal disputes aimed at determining the circumstances relevant to the case. Practical significance the presented part of the program shows how a judge and case participants determine the legally signifcant circumstances of the lawsuit which are subject to proving and justifcation. The generated list of circumstances forces by the program logic to make a reasoned conclusion about the proofs and legal relevance of each circumstance. The interim fndings determine the solution for the claim