Scenario: Binary Data from a Variety of Instruments (OWLeS Field Study)
CASE STUDY UNDER CONSTRUCTION
Tools at a Glance
Back to Scenarios
This case study describes an experiment that gathered data from
a range of atmospheric sensors, collected mostly in ASCII format.
Data files are converted to netCDF format using Unidata's Rosetta
data transformation tool, and data are made available using
Geode Systems' RAMADDA data server.
A team at the University of Wyoming led by PI Dr. Bart Geerts
particpated in the regional OWLeS
(Ontario Winter Lake-effect Systems) study conducted
December 2013 through January 2014. Additionally, the
University of Wyoming is home to the King Air Research
Aircraft (UWKA), which was used to collect data for the
OWLeS study; Project Manager Dr. Larry Oolman participated
in the data collection phase.
The OWLeS project, which involved nine universities and the
Center for Severe Weather Research (CSWR), had funding from
the National Science Foundation (NSF) and the National
Center for Atmospheric Research's Earth Observing Laboratory
(EOL). The OWLeS project was conducted to better understand
the factors that determine the severity of lake effect snow
events; Dr. Geerts' portion of the experiment specifically
investigated the role of long fetch winds under the
prevailing westerly wind belt.
Data collected as part of the OWLeS project are governed
by the OWLeS Data Policy.
OWLeS flight track from UWKA.
The Wyoming Cloud Lidar (WCL) and the Wyoming Cloud Radar
(WCR) instruments collect data in an instrument-specific binary format.
After a flight by the research aircraft, data are transferred
to computers at the University of Wyoming for processing
Tools Used for Data Processing and Analysis
The raw binary format data is processed by software written
at the Univeristy of Wyoming, converting it into a level 2
dataset. The data is also adjusted according to internal
conventions including atmospheric pressure corrections for
the WCL and ground mass corrections for the WCR. The final
format is netCDF, with a metadata READme file attached that
defines all variables contained in the netCDF file in
human-readable format. While most researchers prefer to use
this level 2 dataset, some also prefer to use the raw
dataset. In addition, the in-situ data collected via probes
on the research aircraft are also stored in netCDF format,
with a READme file attached.
Visualization of data collected by UWKA.
The processed WCL and WCR data are not compliant
with the Climate and Forecast (CF) conventions for metadata,
which do not currently define appropriate metadata for
radar and lidar moments data in radial (i.e. polar) coordinates.
(Note that efforts are underway to include the NCAR-developed CfRadial
format in the CF standard, which would solve this particular problem.)
The primary software used to analyze the data is the
Interactive Data Language (IDL). A Python-based tool set
called the Airborne
Weather Observations Toolkit (AWOT) for visualizing the
data is also under development at the University of Wyoming.
Data Storage Strategy and Tools Used
Collected data are stored within the
instrumentation until the end of a flight, then transferred to an internal data
server at the University of Wyoming for the project team to
jointly access. Data files are also mirrored in deep storage at NCAR.
Data Access Stragegy and Tools Used
Data from the OWLeS project are availble from a project page
at the NCAR Earth Observing Laboratory. Access to some items
in the Field Catalog require authorization from the university
that collected the data; other items are freely available, based
on the individual institutions' data access policies.
The DOI will point to a projects page, where there will
be a place for users to request a particular amount of data
files along with a specific file type. Three Digital Object
Identifiers (DOI) will be created to access the OWLeS
project data. Each DOI will correspond to either the WCL,
WCR, or the in situ data. This request is performed on a web
based interface, and will transfer selected files to a FTP
which will be emailed to the user.
Data Archiving Stragegy and Tools Used
The OWLeS team is currently archiving their data on
their own internal data servers at the University of Wyoming,
as well as mirroring their
data in deep storage at NCAR.