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Microphysical properties and high ice water content in continental and oceanic mesoscale convective systems and potential implications for commercial aircraft at flight altitude

Gayet, J.-F. and Shcherbakov, V. and Bugliaro, Luca and Protat, A. and Delanoë, J. and Pelon, J. and Garnier, A. (2014) Microphysical properties and high ice water content in continental and oceanic mesoscale convective systems and potential implications for commercial aircraft at flight altitude. Atmospheric Chemistry and Physics, 14 (2), pp. 899-912. Copernicus Publications. DOI: 10.5194/acp-14-899-2014 ISSN 1680-7316

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Official URL: http://www.atmos-chem-phys.net/14/899/2014/

Abstract

Two complementary case studies are conducted to analyse convective system properties in the region where strong cloud-top lidar backscatter anomalies are observed as reported by Platt et al. (2011). These anomalies were reported for the first time using in situ microphysical measurements in an isolated continental convective cloud over Germany during the CIRCLE2 experiment (Gayet et al., 2012). In this case, in situ observations quasi-collocated with CALIPSO (Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observation), CloudSat and Meteosat-9/SEVIRI observations confirm that regions of backscatter anomalies represent the most active and dense convective cloud parts with likely the strongest core updrafts and unusually high values of the particle concentration, extinction and ice water content (IWC), with the occurrence of small ice crystal sizes. Similar spaceborne observations of a maritime mesoscale cloud system (MCS) located off the Brazilian coast between 0° and 3° N latitude on 20 June 2008 are then analysed. Near cloud-top backscatter anomalies are evidenced in a region which corresponds to the coldest temperatures with maximum cloud top altitudes derived from collocated CALIPSO/IIR and Meteosat-9/SEVIRI infrared brightness temperatures. The interpretation of CALIOP (Cloud Aerosol Lidar with Orthogonal Polarization) data highlights significant differences in microphysical properties from those observed in the continental isolated convective cloud. Indeed, SEVIRI (Spinning Enhanced Visible and InfraRed Imager) retrievals in the visible spectrum confirm much smaller ice particles near the top of the isolated continental convective cloud, i.e. effective radius (Reff) ~ 15 µm as opposed to 22–27 µm in the whole MCS area. Cloud profiling observations at 94 GHz from CloudSat are then used to describe the properties of the most active cloud regions at and below cloud top. The cloud ice-water content and effective radius retrieved with the CloudSat 2B-IWC and DARDAR (raDAR/liDAR) inversion techniques, show that at usual cruise altitudes of commercial aircraft (FL 350 or ~ 10 700 m level), high IWC (i.e. up to 2 to 4 g m-3) could be identified according to specific IWC–Z (Z being the reflectivity factor) relationships. These values correspond to a maximum reflectivity factor of +18 dBZ (at 94 GHz). Near-top cloud properties also indicate signatures of microphysical characteristics according to the cloud-stage evolution as revealed by SEVIRI images to identify the development of new cells within the MCS cluster. It is argued that the availability of real-time information (on the kilometre-scale) about cloud top IR brightness temperature decreases with respect to the cloud environment would help identify MCS cloud areas with potentially high ice water content and small particle sizes against which onboard meteorological radars may not be able to provide timely warning.

Item URL in elib:https://elib.dlr.de/93082/
Document Type:Article
Additional Information:Im Paper werden Daten der CIRCLE-2 Messkampagne benutzt, die im Rahmen des PAZI-2 DLR-Projekts erfasst wurden.
Title:Microphysical properties and high ice water content in continental and oceanic mesoscale convective systems and potential implications for commercial aircraft at flight altitude
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Gayet, J.-F.Lab. de Mét. Physique, Univ. Blaise Pascal, Clermont-Ferrand, FUNSPECIFIED
Shcherbakov, V.Lab. de Mét. Physique, Univ. Blaise Pascal, Clermont-Ferrand, FUNSPECIFIED
Bugliaro, LucaDLR, IPAUNSPECIFIED
Protat, A.CAWCR, Melbourne, AUUNSPECIFIED
Delanoë, J.Lab. Atmosph., Uni. Pierre et Marie Curie, Guyancourt, FUNSPECIFIED
Pelon, J.Lab. de Mét. Physique, Univ. Blaise Pascal, Clermont-Ferrand, FUNSPECIFIED
Garnier, A.NASA Langley Research Center, USAUNSPECIFIED
Date:2014
Journal or Publication Title:Atmospheric Chemistry and Physics
Refereed publication:Yes
Open Access:Yes
Gold Open Access:Yes
In SCOPUS:Yes
In ISI Web of Science:Yes
Volume:14
DOI :10.5194/acp-14-899-2014
Page Range:pp. 899-912
Publisher:Copernicus Publications
ISSN:1680-7316
Status:Published
Keywords:convective mesoscale systems, microphysical properties, high ice water content, airtraffic threat
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Space
HGF - Program Themes:Earth Observation
DLR - Research area:Raumfahrt
DLR - Program:R EO - Erdbeobachtung
DLR - Research theme (Project):R - Vorhaben Atmosphären- und Klimaforschung
Location: Oberpfaffenhofen
Institutes and Institutions:Institute of Atmospheric Physics > Atmospheric Remote Sensing
Deposited By: Bugliaro Goggia, Dr.rer.nat. Luca
Deposited On:04 Dec 2014 11:15
Last Modified:02 May 2019 14:04

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