Solar activity and cosmic ray variations as a factor of intensity of cyclonic processes at midlatitudes     

S. V. Veretenenko  V. A. Dergachev  P. B. Dmitriyev 《Geomagnetism and Aeronomy》2007,47(3):375-382

Long-period variations in the cyclonic activity at middle and subpolar latitudes of the North Atlantic are studied on the basis of the data from the MSLP archive of the surface pressure (Climatic Research Unit, UK) for 1874–1995. It has been found that in the cold half year (the period of the most intense formation and development of extra-tropical cyclones) in the studied region, oscillations of the surface pressure with periods close to the main periods of solar activity (～80 and ～11 years) are observed. The obtained results make it possible to assume that solar activity and related variations in the galactic cosmic rays are one of the factors influencing the intensity of cyclonic processes at midlatitudes on the time scales of ～10 to ～100 years.  相似文献   

Defect distribution and dissolution morphologies on low-index surfaces of α-quartz     

Svetlana V. Yanina  Kevin M. Rosso 《Geochimica et cosmochimica acta》2006,70(5):1113-1127

The dissolution of prismatic and rhombohedral quartz surfaces by KOH/H₂O solutions was investigated by atomic force microscopy. Rates of dissolution of different classes of surface features (e.g., steps, voids, and dislocation etch pits) were measured. The prismatic surface etched almost two orders of magnitude faster than the rhombohedral surface, mostly due to the difference in the number and the rate of dissolution of extended defects, such as dislocations. Because of the presence of imperfect twin boundaries, defect densities on the prismatic surface were estimated at 50-100 μm⁻², whereas the rhombohedral surface possessed only ∼0.5-1.0 μm⁻², mostly in the form of crystal voids. Crystal voids etched almost one order of magnitude faster on the prismatic surface than on the rhombohedral surface due to differences in the number and the density of steps formed by voids on the different surfaces. In the absence of extended defects, both surfaces underwent step-wise dissolution at similar rates. Average rates of step retreat were comparable on both surfaces (∼3-5 nm/h on the prismatic surface and ∼5-10 nm/h on the rhombohedral surface). Prolonged dissolution left the prismatic surface reshaped to a hill-and-valley morphology, whereas the rhombohedral surface dissolved to form coalescing arrays of oval-shaped etch pits.  相似文献   

The topology and polarization of sub-beams associated with the 'drifting' subpulse emission of pulsar B0943 + 10 – III. Analysis of Pushchino 103/40-MHz observations     

Joanna M. Rankin  †  Svetlana A. Suleymanova  Avinash A. Deshpande ‡ 《Monthly notices of the Royal Astronomical Society》2003,340(4):1076-1086

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Effect of solar and galactic cosmic rays on the duration of macrosynoptic processes     

I. V. Artamonova  S. V. Veretenenko 《Geomagnetism and Aeronomy》2013,53(1):5-9

The effect of solar and galactic cosmic ray variations on the duration of elementary synoptic processes (ESPs) in the Atlantic-European sector of the Northern Hemisphere has been studied. It has been found that solar cosmic ray (SCR) bursts result in an increase in the duration of ESPs, which belong to the western and meridional forms of atmospheric circulation. Forbush decreases in galactic cosmic rays (GCRs) are accompanied by an increase in the duration of ESPs, which belong to the meridional atmospheric circulation form, and in a decrease in the duration of ESPs, which are related to the western and eastern circulation forms. It has been assumed that the observed variations in the ESP duration are caused by the effect of short-period cosmic ray variations on the intensity of cyclonic processes at middle and high latitudes, namely, the regeneration of cyclones near the southeastern coast of Greenland after SCR bursts and the development of blocking anticyclones over the northeastern Atlantic, Europe, and Scandinavia during GCR Forbush decreases.  相似文献   

Thermodynamic Evaluation of Mineral Balance in Water Thickness of the Soda Lake Doroninskoe(Eastern Transbaikalia,Russia)     

Svetlana V. BORZENKO  Leonid V. ZAMANA  Daria S. SUVOROVA 《《地质学报》英文版》2014,88(Z1):123-124

正In recent years,lakes,including salted,attract the attention of researchers,also when reconstructing last climate changes using the bottom sediments(Solotchina et al.,2008,et al.).In this case the different geochemical  相似文献   

Multi-Waveband Emission Maps of Blazars     

Alan Marscher  Svetlana G. Jorstad  Valeri M. Larionov  Margo F. Aller  Anne Lähteenmäki 《Journal of Astrophysics and Astronomy》2011,32(1-2):233-237

We are leading a comprehensive multi-waveband monitoring program of 34 γ-ray bright blazars designed to locate the emission regions of blazars from radio to γ-ray frequencies. The ‘maps’ are anchored by sequences of images in both total and polarized intensity obtained with the VLBA at an angular resolution of ～0.1 milliarcseconds. The time-variable linear polarization at radio to optical wavelengths and radio to γ-ray light curves allow us to specify the locations of flares relative to bright stationary features seen in the images and to infer the geometry of the magnetic field in different regions of the jet. Our data reveal that some flares occur simultaneously at different wavebands and others are only seen at some of the frequencies. The flares are often triggered by a superluminal knot passing through the stationary ‘core’ on the VLBA images. Other flares occur upstream or even parsecs downstream of the core.  相似文献   

Vibration diagnostics of weak base embankments     

Evgenij Ashpiz  Vladimir Kapustin  Svetlana Klepikov  Maxim Shirobokov 《寒旱区科学》2013,5(5):0530-0533

In this paper the theoretical background was analyzed for vibration diagnostics method and experience in its application for weak base embankments. General schemes of survey and recommendations on hard...  相似文献   

The diurnal variation of polar mesospheric cloud frequency near 55°N observed by SHIMMER     

Michael H. Stevens  Christoph R. Englert  Mark Hervig  Svetlana V. Petelina  Werner Singer  Kim Nielsen 《Journal of Atmospheric and Solar》2009,71(3-4):401-407

We present the first measurement of polar mesospheric cloud (PMC) occurrence frequency over the diurnal cycle from a satellite. The observations are made during the 2007 northern hemisphere PMC season by the Spatial Heterodyne IMager for MEsospheric Radicals (SHIMMER), which views the limb near 309 nm typically between 34 and 98 km. The PMC diurnal variation is derived between 50 and 58°N, where local times at the tangent point precess by ～30 min/day allowing for observations between 0330 and 2130 local time during the PMC season. We find that the occurrence frequencies exhibit a strong semidiurnal behavior with peaks near 0600 and 1800 local time and a minimum between 0900 and 1600 during which they are on average an order of magnitude less. The semidiurnal dependence is strongly correlated with concurrent ground-based measurements of meridional winds and temperatures measured at the same latitude. Our results for PMC frequency over the diurnal cycle can be used to help reconcile observations from other satellites that only permit cloud measurements at discrete local times.  相似文献   

Solar activity and cosmic rays: Influence on cloudiness and processes in the lower atmosphere (in memory and on the 75th anniversary of M.I. Pudovkin)     

O. M. Raspopov  S. V. Veretenenko 《Geomagnetism and Aeronomy》2009,49(2):137-145

The works by M.I. Pudovkin and his group devoted to studies of the influence of cosmic ray fluxes modulated by solar activity variability on the processes in the lower atmosphere and climatic parameters are briefly analyzed. The issues to be addressed for the solution of the problem are identified.  相似文献   

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

Vladimir A. Alexeev  Igor Esau  Igor V. Polyakov  Sarah J. Byam  Svetlana Sorokina 《Climatic change》2012,111(2):215-239

Spatiotemporal 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 compared 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 data 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.  相似文献