Please use this identifier to cite or link to this item:
Title: Ice-nucleating particle versus ice crystal number concentrationin altocumulus and cirrus layers embedded in Saharan dust:a closure study
Authors: Ansmann, Albert 
Mamouri, Rodanthi-Elisavet 
Bühl, Johannes 
Seifert, Patric 
Engelmann, Ronny 
Hofer, Julian 
Nisantzi, Argyro 
Atkinson, James D. 
Kanji, Zamin A. 
Sierau, Berko 
Vrekoussis, Mihalis 
Sciare, Jean 
Major Field of Science: Natural Sciences
Field Category: Physical Sciences
Keywords: Cirrus;Cloud microphysics;Concentration (composition);Cumulus;Dust;Ice cover;Ice crystal;Nucleation
Issue Date: 13-Dec-2019
Source: Atmospheric Chemistry and Physics, 2019, vol. 19, no. 23, pp. 15087-15115
Volume: 19
Issue: 23
Start page: 15087
End page: 15115
Project: ERATOSTHENES: Excellence Research Centre for Earth Surveillance and Space-Based Monitoring of the Environment 
Journal: Atmospheric Chemistry and Physics 
Abstract: For the first time, a closure study of the relationship between the ice-nucleating particle concentration (INP; INPC) and ice crystal number concentration (ICNC) in altocumulus and cirrus layers, solely based on groundbased active remote sensing, is presented. Such aerosol- cloud closure experiments are required (a) to better understand aerosol-cloud interaction in the case of mixed-phase clouds, (b) to explore to what extent heterogeneous ice nucleation can contribute to cirrus formation, which is usually controlled by homogeneous freezing, and (c) to check the usefulness of available INPC parameterization schemes, applied to lidar profiles of aerosol optical and microphysical properties up to the tropopause level. The INPC-ICNC closure studies were conducted in Cyprus (Limassol and Nicosia) during a 6-week field campaign in March-April 2015 and during the 17-month CyCARE (Cyprus Clouds Aerosol and Rain Experiment) campaign. The focus was on altocumulus and cirrus layers which developed in pronounced Saharan dust layers at heights from 5 to 11 km. As a highlight, a long-lasting cirrus event was studied which was linked to the development of a very strong dust-infused baroclinic storm (DIBS) over Algeria. The DIBS was associated with strong convective cloud development and lifted large amounts of Saharan dust into the upper troposphere, where the dust influenced the evolution of an unusually large anvil cirrus shield and the subsequent transformation into an cirrus uncinus cloud system extending from the eastern Mediterranean to central Asia, and thus over more than 3500 km. Cloud top temperatures of the three discussed closure study cases ranged from - 20 to -57 °C. The INPC was estimated from polarization/Raman lidar observations in combination with published INPC parameterization schemes, whereas the ICNC was retrieved from combined Doppler lidar, aerosol lidar, and cloud radar observations of the terminal velocity of falling ice crystals, radar reflectivity, and lidar backscatter in combination with the modeling of backscattering at the 532 and 8.5 mm wavelengths. A good-to-acceptable agreement between INPC (observed before and after the occurrence of the cloud layer under investigation) and ICNC values was found in the discussed three proof-of-concept closure experiments. In these case studies, INPC and ICNC values matched within an order of magnitude (i.e., within the uncertainty ranges of the INPC and ICNC estimates), and they ranged from 0.1 to 10 L-1 in the altocumulus layers and 1 to 50 L-1 in the cirrus layers observed between 8 and 11 km height. The successful closure experiments corroborate the important role of heterogeneous ice nucleation in atmospheric ice formation processes when mineral dust is present. The observed longlasting cirrus event could be fully explained by the presence of dust, i.e., without the need for homogeneous ice nucleation processes.
ISSN: 1680-7324
DOI: 10.5194/acp-19-15087-2019
Rights: © 2019 Author(s).
Type: Article
Affiliation : Leibniz Institute for Tropospheric Research 
Cyprus University of Technology 
Ethical Power 
Cyprus Institute 
University of Bremen 
Appears in Collections:Publications under the auspices of the EXCELSIOR H2020 Teaming Project/ERATOSTHENES Centre of Excellence

Files in This Item:
File Description SizeFormat
Mamouri.pdfFulltext25.32 MBAdobe PDFView/Open
CORE Recommender
Show full item record

Citations 20

checked on Apr 14, 2021


Last Week
Last month
checked on Apr 14, 2021

Page view(s)

Last Week
Last month
checked on Apr 19, 2021


checked on Apr 19, 2021

Google ScholarTM



This item is licensed under a Creative Commons License Creative Commons