Atlantic Water flow through the Barents and Kara Seas

The pathway and transformation of water from the Norwegian Sea across the Barents Sea and through the St. Anna Trough are documented from hydrographic and current measurements of the 1990s. The transport through an array of moorings in the north-eastern Barents Sea was between 0.6 Sv in summer and 2.6 Sv in winter towards the Kara Sea and between zero and 0.3 Sv towards the Barents Sea with a record mean net flow of 1.5 Sv. The westward flow originates in the Fram Strait branch of Atlantic Water at the Eurasian continental slope, while the eastward flow constitutes the Barents Sea branch, continuing from the western Barents Sea opening.About 75% of the eastward flow was colder than 0°C. The flow was strongly sheared, with the highest velocities close to the bottom. A deep layer with almost constant temperature of about −0.5°C throughout the year formed about 50% of the flow to the Kara Sea. This water was a mixture between warm saline Atlantic Water and cold, brine-enriched water generated through freezing and convection in polynyas west of Novaya Zemlya, and possibly also at the Central Bank. Its salinity is lower than that of the Atlantic Water at its entrance to the Barents Sea, because the ice formation occurs in a low salinity surface layer. The released brine increases the salinity and density of the surface layer sufficiently for it to convect, but not necessarily above the salinity of the Atlantic Water. The freshwater west of Novaya Zemlya primarily stems from continental runoff and at the Central Bank probably from ice melt. The amount of fresh water compares to about 22% of the terrestrial freshwater supply to the western Barents Sea. The deep layer continues to the Kara Sea without further change and enters the Nansen Basin at or below the core depth of the warm, saline Fram Strait branch. Because it is colder than 0°C it will not be addressed as Atlantic Water in the Arctic Ocean.In earlier decades, the Atlantic Water advected from Fram Strait was colder by almost 2 K as compared to the 1990s, while the dense Barents Sea water was colder by up to 1 K only in a thin layer at the bottom and the salinity varied significantly. However, also with the resulting higher densities, deep Eurasian Basin water properties were met only in the 1970s. The very low salinities of the Great Salinity Anomaly in 1980 were not discovered in the outflow data. We conclude that the thermal variability of inflowing Atlantic water is damped in the Barents Sea, while the salinity variation is strongly modified through the freshwater conditions and ice growth in the convective area off Novaya Zemlya.     

The variability of the East Asian summer monsoon and its relationship to ENSO in a partially coupled climate model

The variability of the East Asian summer monsoon (EASM) is studied using a partially coupled climate model (PCCM) in which the ocean component is driven by observed monthly mean wind stress anomalies added to the monthly mean wind stress climatology from a fully coupled control run. The thermodynamic coupling between the atmospheric and oceanic components is the same as in the fully coupled model and, in particular, sea surface temperature (SST) is a fully prognostic variable. The results show that the PCCM simulates the observed SST variability remarkably well in the tropical and North Pacific and Indian Oceans. Analysis of the rainfall-SST and rainfall-SST tendency correlation shows that the PCCM exhibits local air-sea coupling as in the fully coupled model and closer to what is seen in observations than is found in an atmospheric model driven by observed SST. An ensemble of experiments using the PCCM is analysed using a multivariate EOF analysis to identify the two major modes of variability of the EASM. The PCCM simulates the spatial pattern of the first two modes seen in the ERA40 reanalysis as well as part of the variability of the first principal component (correlation up to 0.5 for the model ensemble mean). Different from previous studies, the link between the first principal component and ENSO in the previous winter is found to be robust for the ensemble mean throughout the whole period of 1958–2001. Individual ensemble members nevertheless show the breakdown in the relationship before the 1980’s as seen in the observations.     

Latitudinal and temporal shifts in the radial growth-climate response of Siberian larch in the Polar Urals

This paper presents a dendroclimatic analysis of Siberian larch trees sampled along a latitudinal 260-km transect located in the Polar Urals,Russia. Three standardised chronologies were built over a length of 230–293 years using 79 individual tree-ring chronologies collected in the southern,middle and northern parts of the Polar Urals.Bootstrapped correlation functions showed that the annual growth of the larches was mainly influenced by the air temperatures in June and July. The relative role of the temperatures increased from south to north. Daily air temperature data analysis revealed that the duration of the growing season in the northern part of the Polar Urals is 24 days less than that in the southern part. At the present time, air temperatures exceeded threshold of 8~℃, 5 days earlier than it did in the beginning of the 20 th century In response to the increase in the duration of the growing season and the changing winter conditions in the Polar Urals over the last 130 years, radial growth–temperature relationships in larches have weakened;this effect was strongly pronounced in the southern part of the Polar Urals.     

Climate Change and Geochemistry May Explain the Finding of Marine Cyanobacteria in a Continental Saline Lake

正1 Introduction Alkaline Lake Khilganta located in a steppe zone of South Siberia(N 50°42'535,E 115°06'086)is unique among adjacent lakes because of a development of a thick(up to 3 cm)cyanobacterial mat dominated by     

An Anisotropic Cosmic-Ray Enhancement Event on 07-June-2015: A Possible Origin

A usual event, called anisotropic cosmic-ray enhancement (ACRE), was observed as a small increase (\({\leq}\,5\%\)) in the count rates of polar neutron monitors during 12?–?19 UT on 07 June 2015. The enhancement was highly anisotropic, as detected only by neutron monitors with asymptotic directions in the southwest quadrant in geocentric solar ecliptic (GSE) coordinates. The estimated rigidity of the corresponding particles is \({\leq}\,1\) GV. No associated detectable increase was found in the space-borne data from the Geostationary Operational Environmental Satellite (GOES), the Energetic and Relativistic Nuclei and Electron (ERNE) on board the Solar and Heliospheric Observatory (SOHO), or the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) instruments, whose sensitivity was not sufficient to detect the event. No solar energetic particles were present during that time interval. The heliospheric conditions were slightly disturbed, so that the interplanetary magnetic field strength gradually increased during the event, followed by an increase of the solar wind speed after the event. It is proposed that the event was related to a crossing of the boundary layer between two regions with different heliospheric parameters, with a strong gradient of low-rigidity (\({<}\,1\) GV) particles. It was apparently similar to another cosmic-ray enhancement (e.g., on 22 June 2015) that is thought to have been caused by the local anisotropy of Forbush decreases, with the difference that in our case, the interplanetary disturbance was not observed at Earth, but passed by southward for this event.     

Dynamical Properties of a Sample of Ellipticals

On the basis of Jeans equations we study some dynamical properties of a sample of E galaxies considered as oblate and prolate spheroids. Although the results emphasize the anisotropy as the dominant dynamical factor both for oblate and prolate configurations, the sample contains some oblate galaxies apparently isotropic consistent with full rotational support. Comparisons of the mass-to-luminosity ratios obtained from our models with ratios derived from recent evolutionary synthesis models do not seem to leave room for nonluminous matter within the ranges (of the order of one de Vaucouleurs' radius) of the kinematical observations. Such comparisons suggest that a flatter than the classical Salpeter IMF would lead to better agreement with the dynamical results obtained within the framework of our models.     

Actinic flux and photolysis frequency comparison computations using the model PHOTOGT

The accurate radiative transfer model GOMETRAN, initially designed to yield radiances at TOA in the wavelength range 240–790 nm, has been extended to allow for the computation of actinic fluxes down to 175 nm and for the calculation of photolysis frequencies in the atmosphere. The capability of the extended model PHOTOGT (PHOTOGOMETRAN) is demonstrated in a number of successful comparison studies both with recent experiments (ground-based, balloonborne, airborne) and model calculations of radiances, actinic fluxes and photolysis frequencies in the stratosphere and troposphere. In an atmospheric case study, the impact of new quantum yield data for the O₃ » O₂+O(¹ d) photodissociation channel on the photolytic production of O(¹ d) atoms in the lower atmosphere has been quantified.     

Martian Topography: Scaling, Craters, and High-Order Statistics

The high-order structure functions of Mars topography reveal three specific ranges of scales: (1) scaling range at small scales where the structure functions exhibit scaling behavior; (2) transition range where the structure functions continue to grow but do not reveal scaling; and (3) saturation range at large scales where the structure functions saturate. The scaling and saturation ranges are explored in detail in respect to scaling and intermittency. Analysis of the Mars Orbiter Laser Altimeter (MOLA) data and computer simulations suggest that there are two potential contributors to the small-scale scaling: (i) scale-invariant surface formation; and (ii) effects of discrete morphological forms such as craters. The crater effect also provides an explanation for the large-scale intermittency revealed using the normalized structure functions within the saturation range, which cannot be explained by the ‘scale-invariant’ concept. Overall, the obtained results suggest that the “crater” contribution to the structure function behavior often dominates over the effect of the scale-invariant surface formation.     

The improvement of greenhouse gas inventory as a tool for reduction emission uncertainties for operations with oil in the Russian Federation

The high quality inventory is an important step to greenhouse gas emission mitigation. The inventory quality is estimated by means of the uncertainty analysis. The level of uncertainty depends upon the reliability of activity data and the parameters used. An attempt has been made to improve the accuracy of the estimates through a shift from production-based method (IPCC Tier 1) (IPCC 2000) to enhanced combination of production-based and mass balance methods (IPCC Tier 2) (IPCC 2006) in the estimation of emissions from operations with oil that are key in the national greenhouse gas inventory of the Russian Federation. The IPCC Tier 2 (IPCC 2006) was adapted for the national conditions. The greenhouse gas emissions were calculated for 1990 to 2009 with the use of both methods. The quantitative uncertainty assessment of the calculations was performed, and the outcomes were compared. The comparison showed that the estimates made with the use of higher tier method resulted in higher accuracy and lower uncertainties (26 % respectively compared to previously derived 54 %).