Mesosphere light scattering depolarization during the Perseids activity epoch by wide-angle polarization camera measurements

Planetary and Space Science

Maslov

Kozelov

et al. 2016

Self Cite

Wide-field polarization measurements of the twilight sky background during the several nights with bright and extended noctilucent clouds in central and northern Russia in 2014 and 2015 are used to build the phase dependence of degree of polarization of sunlight scattered by clouds particles in a wide range of scattering angles (from 40° to 130°). This range covers the linear polarization maximum near 90° and large-angle slope of the curve which are most sensitive to the particle size. The method of separation of scattering on clouds particles on the twilight background is presented. Results are compared with T-matrix simulations for different sizes and shapes of ice particles, the best-fit model radius of particles (0.06 μm) and maximum radius (about 0.1 μm) are estimated.

Section: Observationsmentioning

confidence: 99%

Noctilucent cloud polarimetry: Twilight measurements in a wide range of scattering angles

Planetary and Space Science

Maslov

Kozelov

et al. 2016

Self Cite

“…It points to a significant increase of the particle number. The event occurred straight after the maximum of Perseid meteor shower, when the number of dust particles in the upper mesosphere can grow (Ugolnikov and Maslov, 2014). Perseid is the strongest summer shower in the Northern Hemisphere.…”

Section: Discussionmentioning

confidence: 97%

Noctilucent cloud particle size determination based on multi-wavelength all-sky analysis

Planetary and Space Science

Galkin

Pilgaev

et al. 2017

Self Cite

The article deals with the analysis of color distribution in noctilucent clouds (NLC) in the sky based on multi-wavelength (RGB) CCD-photometry provided with the all-sky camera in Lovozero in the north of Russia (68.0°N, 35.1°E) during the bright expanded NLC performance in the night of August 12, 2016. Small changes in the NLC color across the sky are interpreted as the atmospheric absorption and extinction effects combined with the difference in the Mie scattering functions of NLC particles for the three color channels of the camera. The method described in this paper is used to find the effective monodisperse radius of particles about 55 nm. The result of these simple and cost-effective measurements is in good agreement with previous estimations of comparable accuracy. Non-spherical particles, Gaussian and lognormal distribution of the particle size are also considered.

“…The polarization study enables the multiple scattering background to be separated and the dust presence in the mesosphere to be detected. This was done for the Perseids activity epoch [Ugolnikov and Maslov, 2014].…”

Section: Introductionmentioning

confidence: 99%

Study of the mesosphere using wide-field twilight polarization measurements: Early results beyond the polar circle

Kozelov

2016

Cosmic Res

The paper describes the observations and first results of studying the mesosphere temperature and dust based on twilight wide-field polarization analysis using original all-sky camera started in 2015 in Apatity, northern Russia (67.6°N, 33.4°E). It is the first twilight polarization measurements session conducted in the polar region and the first measurements during the winter and early spring season. The general polarization properties of twilight sky and the separation procedure of single scattering are described. The Boltzmann temperature decrease above 70 km and lack of mesosphere dust that is typical for this season are the key results of the study.