Airborne observations of the microphysical structure of two contrasting cirrus clouds

File Description SizeFormat 
O'Shea_et_al-2016-Journal_of_Geophysical_Research-_Atmospheres.pdfPublished version5.17 MBAdobe PDFDownload
AgNWs Final Consolidated Spiral.pdfPublished version5.7 MBAdobe PDFDownload
Title: Airborne observations of the microphysical structure of two contrasting cirrus clouds
Author(s): O'Shea, SJ
Choularton, TW
Lloyd, G
Crosier, J
Bower, KN
Gallagher, M
Abel, SJ
Cotton, RJ
Brown, PRA
Fugal, JP
Schlenczek, O
Borrmann, S
Pickering, JC
Item Type: Journal Article
Abstract: We present detailed airborne in situ measurements of cloud microphysics in two midlatitude cirrus clouds, collected as part of the Cirrus Coupled Cloud-Radiation Experiment. A new habit recognition algorithm for sorting cloud particle images using a neural network is introduced. Both flights observed clouds that were related to frontal systems, but one was actively developing while the other dissipated as it was sampled. The two clouds showed distinct differences in particle number, habit, and size. However, a number of common features were observed in the 2-D stereo data set, including a distinct bimodal size distribution within the higher-temperature regions of the clouds. This may result from a combination of local heterogeneous nucleation and large particles sedimenting from aloft. Both clouds had small ice crystals (<100 µm) present at all levels However, this small ice mode is not present in observations from a holographic probe. This raises the possibility that the small ice observed by optical array probes may at least be in part an instrument artifact due to the counting of out-of-focus large particles as small ice. The concentrations of ice crystals were a factor ~10 higher in the actively growing cloud with the stronger updrafts, with a mean concentration of 261 L−1 compared to 29 L−1 in the decaying case. Particles larger than 700 µm were largely absent from the decaying cirrus case. A comparison with ice-nucleating particle parameterizations suggests that for the developing case the ice concentrations at the lowest temperatures are best explained by homogenous nucleation.
Publication Date: 16-Nov-2016
Date of Acceptance: 16-Oct-2016
URI: http://hdl.handle.net/10044/1/56444
DOI: https://dx.doi.org/10.1002/2016JD025278
ISSN: 2169-8996
Publisher: American Geophysical Union (AGU)
Start Page: 13510
End Page: 13536
Journal / Book Title: Journal of Geophysical Research: Atmospheres
Volume: 121
Issue: 22
Replaces: http://hdl.handle.net/10044/1/48280
10044/1/48280
Copyright Statement: ©2016. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Sponsor/Funder: Natural Environment Research Council (NERC)
Funder's Grant Number: NE/K015133/1
Keywords: Science & Technology
Physical Sciences
Meteorology & Atmospheric Sciences
MESOSCALE ETA-MODEL
LAND-SURFACE
SENSITIVITY-ANALYSIS
SOIL HYDROLOGY
CLIMATE MODELS
PREDICTION
LAYER
PARAMETERIZATION
EVAPORATION
VALIDATION
Science & Technology
Physical Sciences
Meteorology & Atmospheric Sciences
MESOSCALE ETA-MODEL
LAND-SURFACE
SENSITIVITY-ANALYSIS
SOIL HYDROLOGY
CLIMATE MODELS
PREDICTION
LAYER
PARAMETERIZATION
EVAPORATION
VALIDATION
Publication Status: Published
Open Access location: http://onlinelibrary.wiley.com/doi/10.1002/2016JD025278/pdf
Appears in Collections:Space and Atmospheric Physics
Physics
Faculty of Natural Sciences



Items in Spiral are protected by copyright, with all rights reserved, unless otherwise indicated.

Creative Commons