An Investigation of the sun-as-a-Star Magnetic Field Through Spectropolarimetric Measurements     

M.L. Demidov  V.V. Zhigalov  V.S. Peshcherov  V.M. Grigoryev 《Solar physics》2002,209(2):217-232

We discuss some properties of the Sun-as-a-star magnetic field (SSMF) from measurements of the Stokes I and V profiles observed in several spectral lines simultaneously at the Sayan Observatory during 1999–2001. The data are analyzed both in terms of the Stokesmeter and magnetographic measuring techniques. Using, together with the SSMF observations, quasi-simultaneous measurements of V-profile distributions across the solar surface with an angular resolution of 100 arc sec we have shown that the SSMF signal is determined largely by the central area of the disk within 0.5 solar radius. We have explored the correlation and regression relations in different combinations of four Fraunhofer lines near the line Fei 525.021 nm and concluded that fine-structure elements with kilogauss strengths are main sources of the SSMF signal. We have obtained statistical estimates of asymmetry parameters and relative shifts of the Stokes V-profiles, which indicate the presence of dynamic processes in the magnetic elements. The relation between the Sayan and Stanford SSMF measurements is analyzed.  相似文献   

Suboxic and Anoxic Conditions of Deep Waters in the Gdansk Basin of the Baltic Sea     

Artamonova  K. V.  Demidov  A. N.  Zuev  O. A. 《Oceanology》2019,59(5):639-647

Oceanology - Long-term variability of the concentrations of oxygen and hydrogen sulfide in deep waters of the Gdansk Basin of the Baltic Sea for the last 25 years was considered. The dependence of...  相似文献   

Picophytoplankton Distribution at the Ob River Section and in the Western Part of the Kara Sea     

Belevich  T. A.  Ilyash  L. V.  Demidov  A. B.  Flint  M. V. 《Oceanology》2019,59(6):871-880

Oceanology - The spatial distribution of picophytoplankton abundance, biomass, chlorophyll a and the contribution of picoalgae to the total chlorophyll a was studied in the outer Ob River estuary...  相似文献   

Structure and transport of bottom waters through the chain fracture zone of the Mid-Atlantic Ridge     

A. N. Demidov  E. G. Morozov  R. Yu. Tarakanov 《Russian Meteorology and Hydrology》2011,36(8):542-548

During the 27th cruise of the research vessel Akademik Ioffe in 2009, the measurements in the area of the main saddle of the Chain fracture zone were carried out. They included the CTD-sounding and determination of current speeds by lowered acoustic Doppler current profiler (LADCP). As a result, the structure of waters was determined and the transport of bottom waters was estimated as 0.11–0.17 Sv that is significantly less than the previous estimates. The variability of bottom potential temperature values as compared with the measurements carried out in 1991–1994 is registered. At the station situated on the main saddle, the potential temperature increased by 0.1°C and at the station located behind the saddle, it decreased by 0.034°C.  相似文献   

Identification of marker horizon in bottom sediments of the Onega Periglacial Lake     

I. N. Demidov 《Doklady Earth Sciences》2006,407(1):213-216

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Variability of the Characteristics of the Antarctic Bottom Water in the Subtropical North Atlantic     

Krasheninnikova  S. B.  Demidov  A. N.  Ivanov  A. A. 《Oceanology》2021,61(2):151-158

Oceanology - In this study, we estimated the transport and potential temperature of the Antarctic Bottom Water (AABW) and its variability on intra-annual, interannual, and decadal scales based on...  相似文献   

Forecast of solar wind parameters according to STOP magnetograph observations     

Tlatov  A. G.  Pashchenko  M. P.  Ponyavin  D. I.  Svidskii  P. M.  Peshcherov  V. S.  Demidov  M. L. 《Geomagnetism and Aeronomy》2016,56(8):1095-1103

Geomagnetism and Aeronomy - The paper discusses the results of the forecast of solar wind parameters at a distance of 1 AU made according to observations made by the STOP telescope magnetograph...  相似文献   

Primary Production and Associated Environmental Conditions in the East Siberian Sea in Autumn     

Demidov  A. B.  Gagarin  V. I. 《Doklady Earth Sciences》2019,487(2):1006-1011

Doklady Earth Sciences - The spatial variability of primary production in the East Siberian Sea over a large-scale aquatic area was characterized for the first time by the data of cruise 69 of R/V...  相似文献   

Polarization characteristics of Jensch coelostat     

Mikhail L. Demidov 《Solar physics》1991,135(1):193-197

The polarization characteristics of the Jensch coelostat, used at the Sayan observatory, are presented. Results of calculations of the instrumental polarization (IP) are compared with the observations. It is shown that structural features of the Jensch coelostat lead to a very important dependence of the Stokes's parameters, that characterize the IP, on solar coordinates.  相似文献   

Quaternary palaeoenvironments and multi-storey valley fill architecture along the Mezen and Severnaya Dvina river valleys,Arkhangelsk region,NW Russia     

Maria A. Jensen  Igor N. Demidov  Eiliv Larsen  Astrid Lyså 《Quaternary Science Reviews》2009,28(23-24):2489-2506

The modern Severnaya Dvina and Mezen river systems in the Arkhangelsk region, NW Russia, are located within extensive palaeovalley systems. The palaeovalleys form depressions in bedrock and have controlled the drainage systems in the area at least since the Last Interglacial. Vertically stacked marine to fluvial sediments reflect deposition during fluctuating climate and sea levels.A compilation of lithostratigraphical data collected during the last decade has been coupled with bedrock topography and geomorphology from satellite images in order to describe the valley fill architecture for the two valley systems. Each system has been divided into a number of depositional units (storeys) separated by incision/non-deposition and used to investigate the timing of aggradational versus incisional phases. Time constraints for each phase are provided by optically stimulated luminescence (OSL) ages, and aggradation and incision are linked to independent records of climate and sea level change.The pattern of aggradation and erosion is regional and primarily driven by episodes of increasing and decreasing sediment supply. Aggradation is correlated to times of deglaciation with high sediment supply from the ice margin, release of sediment from ice-dammed lakes and low vegetation and degradation of permafrost on the flood plain. Incision is related to cold intervals with low sediment supply, delayed incision due to isostatic uplift and drainage of ice-dammed lakes. Relative sea level change controls the distribution of marine deposits, which show significant regional variations due to variable isostatic response across the region. Sea level change plays a limited role for fluvial aggradation/incision in the study area.  相似文献