Polarization Analysis and Probable Origin of Bright Noctilucent Clouds with Large Particles in June 2018

TL;DR

This study investigates the brightness and particle size of noctilucent clouds observed in Russia in June 2018, linking their properties to meteorological factors and a nearby meteorite impact.

Contribution

It introduces polarization measurement techniques to estimate ice particle sizes in NLCs and correlates these with satellite data and a meteorite impact.

Findings

Bright NLCs observed after meteorite impact

Effective ice particle size estimated from polarization data

Correlation between NLC brightness and atmospheric conditions

Abstract

A sequence of very bright noctilucent clouds (NLC) was observed in central Russia during the last decade of June, 2018. It followed the meteorite impact 300 km southwards from Moscow in the morning of June 21. Polarization measurements of NLC in a wide range of scattering angles allowed finding the effective size of ice particles forming the clouds. These estimations together with satellite data on gravity waves, temperature, and water vapor mixing ratio during these days help to understand the basic causes of the observed NLC brightness and particle size anomaly.