Notice: The MC3E Cloud Microphysics data were updated on October 14,2014 and update of any downloaded files is recommended. More information can be found here.
Introduction
The University of North Dakota (UND) Cessna Citation aircraft, an in-situ platform for the MC3E campaign, carried a suite of instruments for measurements of cloud microphysics, state of the atmosphere parameters, aerosols, three-dimensional winds and turbulence. The Citation flew 15 data missions, which totaled 42.6 flight hours. The data are stored as a separate file for each flight, with a primary (*.mc3e) file containing both direct and derived parameters. The Data Quality Infomation lists the operational status of the instruments and provides update infomation. . Raw data files for each cloud instrument are also archived to allow investigators who wish to use their own processing software. Particle size spectra for the imaging probes were processed by NCAR and are archived and distributed as a separate dataset (Particle probes).
Campaign
The Midlatitude Continental Convective Clouds Experiment (MC3E) took place in central Oklahoma during the April-June 2011 period. The experiment was a collaborative effort between the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility and the National Aeronautics and Space Administration's (NASA) Global Precipitation Measurement (GPM) mission Ground Validation (GV) program. The field campaign leveraged the unprecedented observing infrastructure currently available in the central United States, combined with an extensive sounding array, remote sensing and in situ aircraft observations, NASA GPM ground validation remote sensors, and new ARM instrumentation purchased with American Recovery and Reinvestment Act funding. The overarching goal was to provide the most complete characterization of convective cloud systems, precipitation, and the environment that has ever been obtained, providing constraints for model cumulus parameterizations and space-based rainfall retrieval algorithms over land that had never before been available.
Further details on GPM MC3E are available at http://gpm.nsstc.nasa.gov/mc3e/. Information on MC3E ARM is available at http://campaign.arm.gov/mc3e/.
Platform Description
The UND Cessna Citation II Research Aircraft used for the MC3E experiment is owned and operated by the University of North Dakota. The Citation II is a twin-engine fanjet with an operating ceiling of 43,000 feet (13.1 km). The turbofan engines provide sufficient power to cruise at speeds of up to 340 knots (175 m s-1) or climb at 3300 feet per minute (16.8 m s- 1). These high performance capabilities are accompanied by relatively low fuel consumption at all altitudes, giving the Citation an on-station time of 3-5 hours, depending on mission type. Long wings allow it to be operated out of relatively short airstrips and to be flown at the slower speeds (140 kts/72 m s-1) necessary for many types of measurements. The Citation is certified for flight into known icing conditions. Further details on the UND Cessna Citation II are available at http://cumulus.atmos.und.edu/.
This dataset contains some of the following instrument measurements.
temperature/pitot instrument:
corrected air temperature, potential temperature, indicated air speed, true air speed, pressure altitude,
static pressure
EG&G Probe:
dewpoint temperature
Laser Hygrometer:
mixing ratio, dew point temperature, frost point temperature
Applanix POS System:
aircraft roll angle, pitch angle, heading angle, Z-direction (vertical) acceleration, latitude, longitude,
altitude, speed
King Probe:
liquid water content
PMS 2D-C Probe:
number concentration of droplets, mean droplet diameter, mean droplet volume diameter,
effective droplet radius
Rosemount Icing Detector:
current sensor (MSO) frequency
UHSAS:
total concentration
Cloud Droplet Probe, CPI Probe, HVPS:
number concentration of droplets, liquid water content, droplet diameter, >droplet volume diameter,
effective droplet radius
The complete list of measurements and associated instruments is available in the header block of the QC processed data files.
Investigators
Michael Poellot
University of North Dakota
4149 University Avenue
Stop 9006
Grand Forks, ND 58202-9006
Andrew Heymsfield
NCAR
P.O. Box 3000
Boulder, CO, 80307-3000
File Naming Convention
QC processed files and browse files are of the form:
yyyy_mm_dd_hh_mi_ss.conc.cdp.1Hz
yyyy_mm_dd_hh_mi_ss.mc3e
CPI_dataCPyyyymmdd_hhmiss_##.png
where
conc = concentration
cdp = Cloud Droplet Probe
Hz = Hertz
mc3e = Midlatitude Continental Convective Clouds Experiment
CPI = Cloud Particle Imager
CP = Cloud Physics
## = flight number
yyyy = year
mm = month
dd = day
hh = hour
mi = minute
ss = seconds
png = Portable Network Graphics
Raw files are of the form:
yyyymmdd_hhmiss_mmddhhmi.roi
yyyy_mm_dd_hh_mi_ss.sea
CMDLOGyyyymmddhhmiss.HVPS
NAVyyyymmddhhmiss.HVPS
baseyyyymmddhhmiss.HVPS
UHSAS_yyyymmddhhmiss.log
UHSAS_yyyymmddhhmiss.ini
UHSAS_yyyymmddhhmiss.txt
UHSAS_yyyymmddhhmissPBP.txt
yyyymmdd_hhmiss_Spec2ds.log
yyyymmdd_hhmiss_spec2d.ini
where
roi = report object instance
sea = Science Engineering Associates
CMDLOG = command log
HVPS = High Volume Precipitation Spectrometer
NAV = navigation
UHSAS = Ultra-High Sensitivity Aerosol Spectrometer
PBP = particle-by-particle
Spec= SPEC, Inc.
2ds = 2D-S (Stereo) Optical Array Cloud Particle Imaging Probe
yyyy = year
mm = month
dd = day
hh = hour
mm = minute
ss = seconds
ini = configuration file
txt = ASCII data file
Data Format
The GPM Ground Validation UND Citation Cloud Microphysics MC3E dataset consists of QC processed (.conc.cdp.1Hz and .mc3e) files and browse (.png) files. Processed data files are in the UND-NASA-AMES format. The dataset also contains the raw (.roi, .sea, .HVPS, .log, .ini and .txt) files. The Science Engineering and Associates (SEA) model M300 data system manual contains file format information for the .sea files. In order to process the raw .sea data files, the M300 instrument tag numbers need to be used. The SPEC Inc. CPI manual contains file format information for the .roi files. File format information for the .HVPS, spec2d.ini and Spec2ds.log files is available in the SPEC Inc. HVPS3 manual. The CPI and HVSP manuals can be downloaded at http://www.specinc.com/downloads. The DMT PADS and UHSAS manuals contain file format information for the UHSAS .log, .ini, .PBP.txt and .txt files.
Citation
Our data sets are provided through the NASA Earth Science Data and Information System (ESDIS) Project and the Global Hydrology Resource Center (GHRC) Distributed Active Archive Center (DAAC). GHRC DAAC is one of NASA's Earth Observing System Data and Information System (EOSDIS) data centers that are part of the ESDIS project. ESDIS data are not copyrighted; however, in the event that you publish our data or results derived by using our data, we request that you include an acknowledgment within the text of the article and a citation on your reference list. Examples for general acknowledgments, data set citation in a reference listing, and crediting online web images and information can be found at: http://ghrc.nsstc.nasa.gov/uso/citation.html
References
Delene, D. J., Airborne Data Processing and Analysis Software Package, Earth Science Informatics, 4(1), 29-44, 2011, URL: http://dx.doi.org/10.1007/s12145-010-0061-4, DOI: 10.1007/s12145-010-0061-4.
Contact Information
To order these data or for further information, please contact:
Global Hydrology Resource Center
User Services
320 Sparkman Drive
Huntsville, AL 35805
Phone: 256-961-7932
E-mail: support-ghrc@earthdata.nasa.gov
Web: http://ghrc.nsstc.nasa.gov/
