Journal ArticleDOI
The 2D-S (Stereo) Probe: Design and Preliminary Tests of a New Airborne, High-Speed, High-Resolution Particle Imaging Probe
TLDR
In this paper, the design, laboratory calibrations, and flight tests of a new optical imaging instrument, the twodimensional stereo (2D-S) probe, are presented.Abstract:
The design, laboratory calibrations, and flight tests of a new optical imaging instrument, the twodimensional stereo (2D-S) probe, are presented. Two orthogonal laser beams cross in the middle of the sample volume. Custom, high-speed, 128-photodiode linear arrays and electronics produce shadowgraph images with true 10-m pixel resolution at aircraft speeds up to 250 m s 1 . An overlap region is defined by the two laser beams, improving the sample volume boundaries and sizing of small (100 m) particles, compared to conventional optical array probes. The stereo views of particles in the overlap region can also improve determination of three-dimensional properties of some particles. Data collected by three research aircraft are examined and discussed. The 2D-S sees fine details of ice crystals and small water drops coexisting in mixed-phase cloud. Measurements in warm cumuli collected by the NCAR C-130 during the Rain in Cumulus over the Ocean (RICO) project provide a test bed to compare the 2D-S with 2D cloud (2D-C) and 260X probes. The 2D-S sees thousands of cloud drops 150 m when the 2D-C and 260X probes see few or none. The data suggest that particle images and size distributions ranging from 25 to 150 m and collected at airspeeds 100 m s 1 by the 2D-C and 260X probes are probably (erroneously) generated from out-of-focus particles. Development of the 2D-S is in its infancy, and much work needs to be done to quantify its performance and generate software to analyze data.read more
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Journal ArticleDOI
Rain in Shallow Cumulus Over the Ocean: The RICO Campaign
Robert M. Rauber,Bjorn Stevens,Bjorn Stevens,Harry T. Ochs,Charles A. Knight,Bruce A. Albrecht,Alan M. Blyth,Christopher W. Fairall,Jørgen Jensen,Sonia Lasher-Trapp,Olga L. Mayol-Bracero,Gabor Vali,James R. Anderson,Bruce Baker,Alan R. Bandy,E. Burnet,Jean-Louis Brenguier,W. A. Brewer,P. R. A. Brown,Patrick Y. Chuang,William R. Cotton,Larry Di Girolamo,Bart Geerts,H. Gerber,Sabine Göke,L. Gomes,Brian G. Heikes,James G. Hudson,Pavlos Kollias,R. P. Lawson,Steven K. Krueger,Donald H. Lenschow,Louise Nuijens,Daniel O'Sullivan,Robert A. Rilling,D. C. Rogers,A. P. Siebesma,Eric Snodgrass,Jeffrey L. Stith,Donald C. Thornton,S. Tucker,Cynthia H. Twohy,Paquita Zuidema +42 more
TL;DR: Rain in Cumulus over the Ocean (RICO) field campaign as mentioned in this paper emphasized measurements of processes related to the formation of rain in shallow cumuli, and how rain subsequently modifies the structure and ensemble statistics of trade wind clouds.
Journal ArticleDOI
Airborne observations of the Eyjafjalla volcano ash cloud over Europe during air space closure in April and May 2010
Ulrich Schumann,Bernadett Weinzierl,Oliver Reitebuch,Hans Schlager,Andreas Minikin,Caroline Forster,Robert Baumann,Thomas Sailer,Kaspar Graf,H. Mannstein,Christiane Voigt,Stephan Rahm,R. Simmet,Monika Scheibe,Michael Lichtenstern,Paul Stock,H. Rüba,Dominik Schäuble,Arnold Tafferner,Marc Rautenhaus,T. Gerz,Helmut Ziereis,M. Krautstrunk,Christian Mallaun,Jean-François Gayet,K. Lieke,Konrad Kandler,Martin Ebert,Stephan Weinbruch,Andreas Stohl,Josef Gasteiger,Silke Groß,Volker Freudenthaler,Matthias Wiegner,Albert Ansmann,Matthias Tesche,Haraldur Ólafsson,K. Sturm +37 more
TL;DR: In this article, the authors performed in-situ measurements of volcanic ash plumes over Europe between Southern Germany and Iceland with the Falcon aircraft during the eruption period of the Eyjafjalla volcano between 19 April and 18 May 2010.
Journal ArticleDOI
Indirect and semi-direct aerosol campaign: The impact of Arctic aerosols on clouds
Greg M. McFarquhar,Steven J. Ghan,Johannes Verlinde,Alexei Korolev,J. Walter Strapp,Beat Schmid,Jason Tomlinson,Mengistu Wolde,Sarah D. Brooks,Daniel J. Cziczo,Manvendra K. Dubey,Jiwen Fan,Connor Flynn,Ismail Gultepe,John M. Hubbe,Mary K. Gilles,Alexander Laskin,Paul Lawson,W. Richard Leaitch,P. S. K. Liu,Xiaohong Liu,Dan Lubin,Claudio Mazzoleni,Claudio Mazzoleni,Ann Marie MacDonald,Ryan C. Moffet,Hugh Morrison,Mikhail Ovchinnikov,Matthew D. Shupe,David D. Turner,Shaocheng Xie,Alla Zelenyuk,Kenny Bae,Matt Freer,Andrew Glen +34 more
TL;DR: A comprehensive dataset of microphysical and radiative properties of aerosols and clouds in the boundary layer in the vicinity of Barrow, Alaska, was collected in April 2008 during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) as discussed by the authors.
Journal ArticleDOI
A review of the light scattering properties of cirrus
TL;DR: In this paper, the light scattering properties of naturally occurring ice crystals that are found in cirrus are discussed and the need for particular microphysical and space-based measurements is stressed in order to further constrain ice crystal light scattering models.
Journal ArticleDOI
In Situ Observations of the Microphysical Properties of Wave, Cirrus, and Anvil Clouds. Part II: Cirrus Clouds
B. Baker,R. Paul Lawson +1 more
TL;DR: A Learjet research aircraft was used to collect microphysical data, including cloud particle imager (CPI) measurements of ice particle size and shape, in 22 midlatitude cirrus clouds as mentioned in this paper.
References
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Journal ArticleDOI
An overview of microphysical properties of Arctic clouds observed in May and July 1998 during FIRE ACE
TL;DR: In the first International Satellite Cloud Climatology Project (ISCCP) Regional Experiment Arctic Cloud Experiment (FIRE ACE) as mentioned in this paper, the authors collected microphysical data from the NCAR C-130 research aircraft during the first ISCCP regional experiment Arctic cloud experiment and showed that the adiabatic clouds provided a test of the performance of liquid water content (LWC) probes but only in low LWC conditions.
Journal ArticleDOI
The Optical Array: An Alternative to Scattering or Extinction for Airborne Particle Size Determination
TL;DR: In this article, an electro-optical technique for the measurement of the size distributions of cloud and precipitation particles is described, which utilizes a linear array of photodetectors as a size measuring grid in a typical shadowgraph-type imaging system.
Journal ArticleDOI
The cloud, aerosol and precipitation spectrometer: a new instrument for cloud investigations
TL;DR: In this paper, a new airborne particle spectrometer was developed with the same measurement capabilities of the Forward Scattering Spectrometer Probes (FSSP) models 100 and 300, two-dimensional optical imaging probe (2D-OAP), the Multiangle Aerosol Spectrometers Probe (MASP) and hot-wire liquid water probe, but with a single integrated system.
Book ChapterDOI
Techniques for probing cloud microstructure
TL;DR: In this paper, the performance of specific instruments using optical scattering to size cloud droplets, optical imaging to provide size and structural information on precipitation elements, and polarization to differentiate liquid from ice is analyzed.
Journal ArticleDOI
In Situ Observations of the Microphysical Properties of Wave, Cirrus, and Anvil Clouds. Part II: Cirrus Clouds
B. Baker,R. Paul Lawson +1 more
TL;DR: A Learjet research aircraft was used to collect microphysical data, including cloud particle imager (CPI) measurements of ice particle size and shape, in 22 midlatitude cirrus clouds as mentioned in this paper.