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Original languageEnglish
Number of pages8
Pages (from-to)1-8
JournalAtmospheric Environment
Journal publication date1 Apr 2017
Volume154
Early online date17 Jan 2017
DOIs
Publication statusPublished - 1 Apr 2017

Abstract

We present results of the vertical distribution variation of volcanic aerosol layers in the upper troposphere and lower stratosphere. The data were taken with our multiwavelength aerosol Raman lidar at Gwangju (35.10 N, 126.53 E), Korea. The volcanic ash particles and gases were released around 12 June 2011 during the eruption of the Nabro volcano (13.37 N, 41.7 E) in Eritrea, east Africa. Forward trajectory computations show that the volcanic aerosols were advected from North Africa to East Asia. The first measurement of the aerosol layer over Korea was on 19 June 2011. The aerosol layers appeared between 15 km and 17 km height asl (above sea level). The maximum value of the aerosol layer of the particle backscatter coefficient (1.5 ± 0.3 Mm1 sr1) and the linear particle depolarization ratio at 532 nm (2.2%) were observed at 16.4 km height asl. We continuously probed the upper troposphere and lower stratosphere for this volcanic aerosol layer during the following 6 months, until December 2011. The volcanic aerosol layer showed a single-peak of the particle backscatter coefficient and a comparably narrow vertical thickness at our observation site at the beginning of our observation period (i.e. comparably soon after the initial eruption period). After that initial period the vertical distribution of the plume changed. Multiple peaks and a comparably broad geometrical thickness developed with progressing observation time. The vertical thickness of the volcanic aerosol layer expanded up to 10 km by 3 August 2011. The linear particle depolarization ratios were larger in the lower part of the aerosol layer than the upper part of the aerosol layer. We observed a strong variation of the AOD (aerosol optical depth) in the first two months of our lidar observations. After these two months the AOD gradually
decreased with time from September to December 20111 and the maximum particle backscatter coefficients consistently decreased. The corresponding e-folding decay time of the layer AOD was 117 days.

Notes

Young Min Noh, Dong Ho Shin, and Detlef Müller, ‘ Variation of the vertical distribution of Nabro volcano aerosol layers in the stratosphere observed by LIDAR’, Atmospheric Environment, Vol. 154, pp 1-8, first published online on 17 January 2017, is available online via doi: http://dx.doi.org/10.1016/j.atmosenv.2017.01.033 © 2017 The Authors. Published by Elsevier Ltd. This is an open access article distributed under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

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