Scenario: Data Generated by Computer Models
Tools at a Glance
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This case study describes research investigating the sensitivity
of global climate models to increases in model resolution. The comparison
involves output from several models, stored in formats including
GRIB and netCDF (with and without the Climate and Forecast (CF) metadata
conventions). Output files are converted between formats using
NCEP's Unified Post Processor or the NCAR Command Language.
Researchers at North Carolina State University (NCSU) led by PI Dr. Gary Lackmann
investigated the possible changes in the North Atlantic Storm Track
associated with climate change, specifically with taking into account
enhanced condensational latent heating which accompanies warming.
The team combined century-scale global climate modeling results with
high-resolution synoptic dynamics to study possible changes to the
expected storm track.
The research was supported by a National Science Foundation grant
awarded in 2010, before Foundation-wide data management policies
were implemented. Interested readers can peruse
“The Importance of Resolving Mesoscale Latent Heating in the North Atlantic Storm Track”,
which captures some of the results of the project.
Output from the Global Forecast System (GFS) model final
analysis (FNL), retrieved from the NCAR Research Data
Archive (RDA) in GRIB format, was used to establish initial
and boundary conditions for a Weather Research and
Forecasting (WRF) model simulation of a tropical cyclone
that began December 30th, 2001. Similarly, a range of
projections from the Coupled Model Intercomparison Project
phase 3 (CMIP3) and phase 5 (CMIP5), in CF-compliant netCDF
files, were used to initialize the WRF model for simulations
of ten winter seasons in the North Atlantic.
In all cases, output from the WRF model took the form of
Tools Used for Data Processing and Analysis
Staggered-grid output files from the WRF model runs were
processed using the NCEP Unified Post Processor software,
Interpolates the forecasts from the model's native vertical
coordinate to NWS standard output levels;
Destaggers the forecasts from the staggered native grid to
a regular non-staggered grid;
Computes diagnostic output quantities;
Outputs the results in NWS and WMO standard GRIB format.
The resulting GRIB and GEMPAK format files were then analyzed
using Matlab and other software tools. In some cases, the NCAR
Command Language was used to extract subsets of the data for
Data Storage Strategy and Tools Used
The WRF model output was initially stored directly on large-capacity
(3-5 terabyte) external hard drives connected to the NCSU
Data Access Strategy and Tools Used
Initially, data sharing was accomplished manually, with the
research team using NCAR Command Language (NCL) programs
to select subsets of the WRF model output, which were then
made accessible to selected individuals via FTP.
Rather than sharing the entire raw WRF model output,
the team provided the initial and boundary condition
files, the WRF model namelist, along with the WRF model
instructions, which allowed others to replicate the WRF model
Working with Unidata, Dr. Lackmann is also making the
initial boundary layer conditions, the model, and model
instructions available via a RAMADDA server running at
NCSU. Portions of the dataset and results are also on the
NCSU RAMADDA server.
Researchers who have data needs beyond what is publicly
available on the RAMADDA server should contact Dr. Lackmann.
Data Archiving Strategy and Tools Used
Dr. Lackmann's current plans call for keeping the project files
at NCSU, available to the scientific community via the NSCU RAMADDA