Variation Trend and Characteristics of Anthropogenic CO Column Content in the Atmosphere over Beijing and Moscow          下载免费PDF全文

WANG Pu-Cai  Georgy S.GOLITSYN  WANG Geng-Chen  Evgeny I.GRECHKO  Vadim S.RAKITIN  Ekaterina V.FOKEEVA  Anatoly V.DZHOLA 《大气和海洋科学快报》2014,(3):243-247

The anthropogenic CO column content in the atmosphere is derived from measurements with infrared grating spectrometers in Beijing, China, and Moscow, Russia, during 1992-2012. Some specific variation char- acteristics and long-term variation trends of the CO col- umn content in the atmosphere in these regions are dis- cussed. An evident variation trend of anthropogenic CO in the atmosphere for the Beijing region is not observed during 1992-2012, while for the Moscow region, it de- creases yearly by about 1.4% for the same period. High CO concentrations appear quite frequently in Beijing, but much less frequently in Moscow, except during the natu- ral fire events in summer 2010. From back trajectory analysis, the high CO concentration observed in Beijing can be attributed to the intensive CO emission sources in its surrounding areas.  相似文献   

The Last Permafrost Maximum (LPM) map of the Northern Hemisphere: permafrost extent and mean annual air temperatures, 25–17 ka BP     

Jef Vandenberghe  Hugh M. French  Aldar Gorbunov  Sergei Marchenko  Andrey A. Velichko  Huijun Jin  Zhijiu Cui  Tingjun Zhang  Xudong Wan 《Boreas: An International Journal of Quaternary Research》2014,43(3):652-666

This paper accompanies a map that shows the extent of permafrost in the Northern Hemisphere between 25 and 17 thousand years ago. The map is based upon existing archival data, common throughout the Northern Hemisphere, that include ice‐wedge pseudomorphs, sand wedges and large cryoturbations. Where possible, a distinction is made between areas with continuous permafrost and areas where permafrost is either spatially discontinuous or sporadic. The associated mean annual palaeo‐temperatures that are inferred on the basis of present‐day analogues increase understanding of the possible changes in permafrost extent that might accompany current global warming trends. Areas with relict permafrost and areas that were formerly exposed due to lower sea level (submarine permafrost) are also mapped. Mapping is mostly limited to lowland regions (areas approximately <1000 m a.s.l.). Striking features that appear from the map are (i) the narrow permafrost zone in North America, which contrasts with the broader LPM permafrost zone in Eurasia (that may be related to different snow thickness or vegetation cover), (ii) the zonal extent of former LPM permafrost (that may reflect sea‐ice distribution), which contrasts with the present‐day pattern of permafrost extent (especially in Eurasia) and (iii) the relatively narrow zones of LPM discontinuous permafrost (that may indicate strong temperature gradients).  相似文献   

An asymptotic method of modeling radio occultations     

M. E. Gorbunov 《Journal of Atmospheric and Solar》2003,65(16-18):1361-1367

A short-wave asymptotic method of modeling radio signals registered during radio occultation experiments is discussed. The method uses the theory of Fourier integral operators. Use of this method allows for a faster simulation of radio occultation data as compared to the method of multiple phase screens. The method was tested using global fields from analyses of the European Centre for Medium-Range Weather Forecast. The comparison of the asymptotic solution with the multiple phase screen method shows their good agreement. The limits of the applicability of the new method are discussed.  相似文献   

Secular bar formation in galaxies with a significant amount of dark matter     

Octavio Valenzuela  Anatoly Klypin 《Monthly notices of the Royal Astronomical Society》2003,345(2):406-422

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Tectonics of Venus: A review     

Nikishin  Anatoly M. 《Earth, Moon, and Planets》1990,(1):101-125

The article presents a new tectonic scheme of Venus and gives the following interpretation of the planet's main structural units: (1) plains — areas of flood volcanism over stretched crust; (2) dome-like uplifts — areas of uplifting and volcanic activity above the mantle hot-spots; (3) coronae —former dome-like uplifts, partially subsided and diffused by gravity; (4) ridge belts — fold zones; (5) tesserae — fragments of ductile compression and shortening of crust; (6) supercoronae — coronae formed in the course of further evolution and relaxation of Beta-type uplifts. Ishtar Terra is considered to be a fragment of an ancient tessera paleocontinent, on the edge of which the Lakshmi supercorona is superimposed. Aphrodite Terra is considered as a belt of mantle hot-spot structures (dome-like uplifts, coronae, supercoronae, volcanoes, rifts).Three types of planetary belts have been distinguished on Venus: uplifted 'weakened' belts with an abundance of mantle hot-spot structures; a northern fan of ridge belts; and belts of low basalt plains. The center of the planetary system of uplifted weakened belts is situated in Atla Regio.The present tectonic structure of Venus is inferred to have formed during two stages of evolution characterized by different tectonic regimes. Stage I is a regime of soft ductile plates (formation of tessera uplifts and volcanic plains). Stage II is a formation of 'weakened' uplifted planetary belts, various tectonic regimes of mantle hot-spots, and plains-forming volcanism.'Geology and Tectonics of Venus', special issue edited by Alexander T. Basilevsky (USSR Acad. of Sci. Moscow), James W. Head (Brown University, Providence), Gordon H. Pettengill (MIT, Cambridge, Massachusetts) and R. S. Saunders (J.P.L., Pasadena).  相似文献   

Joint use of TEM and MRS methods in a complex geological setting     

Anatoly Legchenko  Michael Ezersky  Christian Camerlynck  Abdallah Al-Zoubi  Konstantinos Chalikakis 《Comptes Rendus Geoscience》2009,341(10-11):908-917

Transient Electromagnetic (TEM), known also as Time Domain Electromagnetic (TDEM) and Magnetic Resonance Sounding (MRS) methods were applied jointly to investigate variations in lithology and groundwater salinity in the Nahal Hever South area (Dead Sea coast of Israel). The subsurface in this area is highly heterogeneous and composed of intercalated sand and clay layers over a salt formation, which is partly karstified. Groundwater is very saline, with a chloride concentration of 100–225 g/l. TEM is known as an efficient tool for investigating electrically conductive targets like saline water, but it is sensitive to both the salinity of groundwater and the porosity of rocks. MRS, however, is sensitive primarily to groundwater volume, but it also allows delineating of lithological variations in water-saturated formations. MRS is much less sensitive to variations in groundwater salinity in comparison with TEM. We show that MRS enables us to resolve the fundamental uncertainty in TEM interpretation caused by the equivalence between groundwater resistivity and lithology. Combining TEM and MRS, we found that the sandy Dead Sea aquifer filled with Dead Sea brine is characterized by a bulk resistivity of ρ_x > 0.4 Ωm, whereas zones with silt and clay in the subsurface are characterized by a bulk resistivity of ρ_x < 0.4 Ωm. These observations are confirmed by calibration of the TEM method performed near 18 boreholes.  相似文献   

Geochemical investigation and characterisation of Neogene sediments from Valjevo-Mionica Basin (Serbia)     

Aleksandra Šajnović  Ksenija Stojanović  Branimir Jovančićević  Anatoly Golovko 《Environmental Geology》2009,56(8):1629-1641

Sediments from the Valjevo-Mionica Basin of Neogene age were investigated in this study using different geochemical methods. The results of the inorganic part analyses suggest that during genesis of the sediments, the contents of Na₂O, B and As changed the most, which indicates that genesis of the investigated sediments was followed by climate changes and volcanic activity. The quantity of other macro- and microelements did not vary significantly. Investigations of the organic substance showed that it is native organic matter, which has been preserved to a significant extent, formed predominantly of algal precursor organisms, which provided good quality, deposited under reducing conditions and that it is at a low maturity level. As it has been established that genesis of the investigated sediments was mostly affected by an arid climate with more intensive salinity, the aim of this study, was also to identify the processes which were the most affected by the change in salinity, as well as biomarkers which are the most sensitive to this change. The results led to the conclusion that the salinity increase in the depositional environment had a primary effect on the preservation of the organic substance and the formation of the mineral searlesite. In addition, it was noticed that besides the Sq/nC₂₆ ratio, the parameters nC₁₇/nC₂₇, CPI and Ph/nC₁₈, are also significantly sensitive to salinity change in a depositional environment in case of immature organic substance deposited under reducing conditions.  相似文献   

The distribution function of dark matter in massive haloes     

Rados&#;aw Wojtak  Ewa L. &#;okas  Gary A. Mamon  Stefan Gottlöber  Anatoly Klypin  Yehuda Hoffman 《Monthly notices of the Royal Astronomical Society》2008,388(2):815-828

We study the distribution function (DF) of dark matter particles in haloes of mass range  10¹⁴–10¹⁵ M_⊙  . In the numerical part of this work we measure the DF for a sample of relaxed haloes formed in the simulation of a standard Λ cold dark matter (ΛCDM) model. The DF is expressed as a function of energy E and the absolute value of the angular momentum L , a form suitable for comparison with theoretical models. By proper scaling we obtain the results that do not depend on the virial mass of the haloes. We demonstrate that the DF can be separated into energy and angular momentum components and propose a phenomenological model of the DF in the form     . This formulation involves three parameters describing the anisotropy profile in terms of its asymptotic values (β₀ and  β_∞  ) and the scale of transition between them ( L ₀). The energy part   f _E ( E )  is obtained via inversion of the integral for spatial density. We provide a straightforward numerical scheme for this procedure as well as a simple analytical approximation for a typical halo formed in the simulation. The DF model is extensively compared with the simulations: using the model parameters obtained from fitting the anisotropy profile, we recover the DF from the simulation as well as the profiles of the dispersion and kurtosis of radial and tangential velocities. Finally, we show that our DF model reproduces the power-law behaviour of phase-space density   Q =ρ( r )/σ³( r )  .  相似文献   

Analysis of the optics of the 2.5-m telescope of the Sternberg Astronomical Institute     

S. A. Potanin  I. A. Gorbunov  A. V. Dodin  A. D. Savvin  B. S. Safonov  N. I. Shatsky 《Astronomy Reports》2017,61(8):715-725

The results of alignment and acceptance tests of the optics system of the 2.5-m telescope installed at the Caucausus Mountain Observatory of the Sternberg Astronomical Institute in 2013–2015 are reported. The optical elements of the Ritchey–Chrétien system of the telescope were manufactured by REOSC (France). Measurements of aberrations were carried out using a specially manufactured Shack–Hartmann wavefront sensor. Adjustment of the load-distribution mechanisms of the primary mirror and automatic correction for bending of the structure have made it possible to achieve the target image quality at all operational positions of the telescope, corresponding to 80% of the energy being concentrated in a circle 0.3″ in diameter. Factory interferograms of the mirrors and methods for measuring their abberation using stellar images are presented.  相似文献   

The problem of past megatsunami reconstructions on the southern Kurils     

N. G. Razzhigaeva  L. A. Ganzey  T. A. Grebennikova  A. A. Kharlamov  Kh. A. Arslanov  V. M. Kaistrenko  A. O. Gorbunov  A. Yu. Petrov 《Russian Journal of Pacific Geology》2017,11(1):34-45

Tsunamis are reconstructed on the basis of distribution of tsunamigenic sediments in coastal lowland sections. Reflections of anomalous tsunamis are recorded in detail in the lacustrine–boggy sections of the Lesser Kuril Ridge, while only fragments of these sediments have been found on the islands of the Greater Kuril Ridge. The distribution and composition of the sediments left by recent large-scale tsunamis (locally documented 1994 and 1894 Shikotan tsunamis and transoceanic 2011 Tohoku tsunami) are analyzed for the purpose of understanding deposition features during large and megatsunamis. Interregional correlation of the events during the last ~2.5 kyr is carried out with estimation of their scales. It is established that large events took place in the 17th and 18th centuries and approximately at 1.0, 1.4–1.6, 1.7–1.8, and 2.0–2.1 ka ago. New data on large tsunami chronology since the Middle Holocene are presented. A unique natural peatland section with abundant tsunamigenic sand layers is studied on the Pacific side of Zelenyi Island (Rudnya Bay), where deposition continued through the entire Holocene. The largest tsunamis which happened on the South Kuril Islands during the last ~7.5 kyr and can be classed as megatsunamis are revealed.  相似文献