arXiv subjects

Oleg S. Ugolnikov

Publications and source records attributed to Oleg S. Ugolnikov.

26 records · Page 2Linked to original sources

arXiv2015

Analysis of Twilight Background Polarization Directions across the Sky as a Tool for Multiple Scattering Separation

The direction angle of twilight sky background polarization in the celestial sphere points far from solar vertical is found to depend on the ratio of single and multiple scattering contributions. The polarization direction behavior during the twilight is related with general properties of background components and can be used to check the accuracy of their separation method. The basic assumptions of this method are confirmed by analysis made in this paper. This helps to hold the temperature and scattering medium study in the upper mesosphere, the least accessible layer of the Earth's atmosphere. The mesosphere temperature data obtained during the observations from 2011 till 2014 are also presented.

physics.ao-ph↗

arXiv2012

Summer Mesosphere Temperature Distribution from Wide-Angle Polarization Measurements of the Twilight Sky

The paper contains the results of wide-angle polarization camera (WAPC) measurements of the twilight sky background conducted in summer 2011 and 2012 at 55.2 degs.N, 37.5 degs.E, southwards from Moscow. The method of single scattering separation based on polarization data is suggested. The obtained components of scattering matrixes show the domination of Rayleigh scattering in the mesosphere for all observation days. It made possible to retrieve the altitude distribution of temperature in the mesosphere. The results are compared with the temperature data by TIMED/SABER and EOS Aura/MLS instruments for nearby dates and locations.

physics.ao-ph↗

arXiv2012

Trajectory Retrieval and Component Investigations of Southern Polar Stratosphere Based on High Resolution Spectroscopy of Totally Eclipsed Moon Surface

In this paper we present the high resolution spectral observations of the fragment of lunar surface during the total lunar eclipse of December 10, 2011. The observations were carried out with the fiber-fed echelle spectrograph at 1.2-m telescope in Kourovka Astronomical observatory (Ural mountains, central Russia). The observed radiation is transferred by tangent trajectory through the southern polar stratosphere before the reflection from the Moon and spectra contain a number of absorption bands of atmospheric gases (O2, O3, O4, NO2, H2O). High resolution analysis of three O2 bands and O4 absorption effects is used to trace the effective trajectory of solar emission through the stratosphere and to detect the contribution of scattered light. Bands of other gases allow us to measure their abundances along the trajectory.

astro-ph.EP↗

arXiv2011

Lunar Eclipse of June, 15, 2011: Three-color umbra surface photometry

The paper contains the result description of the photometric observations of the Moon surface during the total lunar eclipse of June, 15, 2011 conducted in southern Russia and Ukraine in three narrow spectral bands with effective wavelengths equal to 503, 677, and 867 nm. The photometric maps of umbra are built, the radial dependencies of relative brightness are compared with the theoretical ones for gaseous atmosphere. Dark anomalies of umbra are shown and related with the aerosol air pollution of the definite regions above the surface of Earth.

astro-ph.EP↗

arXiv2011

Undisturbed Mesosphere Optical Properties from Wide-Angle Frequent Twilight Sky Polarimetry

The paper describes the first results of all-sky polarization measurements of twilight background started in central Russia in the very beginning of summer 2011. Time-frequent data of sky intensity and polarization over the wide range of sky point zenith distances is used to separate the multiple scattering and to build the altitude dependency of scattering coefficient and polarization in the mesosphere (altitudes from 60 to 90 km) at different angles. Undisturbed structure of the mesosphere without the noticeable aerosol stratification during the observation days allows to estimate the atmosphere temperature at these altitudes.

astro-ph.EP↗

arXiv2009

Quadrantids 2008 and 2009: Detection of Dust in the Atmosphere by Polarization Twilight Sky Measurements

The paper contains the results of the polarization measurements of twilight sky background during the wintertime including the epoch of Quadrantids activity in January 2008 and 2009 in Crimea (Ukraine). Analysis of the twilight sky polarization behavior had shown the barely detectable depolarization effect at the scattering altitudes above 90 km right after the Quadrantids maximum. This effect can be related with the meteoric dust in the upper atmosphere of the Earth.

astro-ph.EP↗

arXiv2007

Altitude and Latitude Distribution of Atmospheric Aerosol and Water Vapor from the Narrow-Band Lunar Eclipse Photometry

The work contains the description of two narrow IR-bands observational data of total lunar eclipse of March, 3, 2007, one- and two-dimensional procedures of radiative transfer equation solution. The results of the procedure are the extinction values for atmospheric aerosol and water vapor at different altitudes in the troposphere along the Earth's terminator crossing North America, Arctic, Siberia and South-Eastern Asia. The altitude range and possible latitude and altitude resoltion of atmosphere remote sensing by the lunar eclipses observation are fixed. The results of water vapor retrieval are compared with data of space experiment, the scale of vertical water vapor distribution is found.

physics.ao-ph↗

arXiv2006

Detection of Leonids meteoric dust in the upper atmosphere by polarization measurements of the twilight sky

The method of detection of dust in the stratosphere and mesosphere by the twilight sky background observations is being considered. The polarization measurements are effective for detection of the meteoric dust scattering on the background consisting basically of troposphere multiple scattering. The method is based on the observed and explained polarization properties of the sky background during different stages of twilight. It is used to detect the mesosphere dust after the Leonids maximum in 2002 and to investigate its evolution. The polarization method takes into account the multiple scattering and sufficient contribution of moonlight scattering background and turns out to be more sensitive than existing analogs used in the present time.

astro-ph↗