Tropical Storms Detection

This code was designed to detect and track tropical cyclones in global climate models (GCMs) using data that is typically archived by GCMs. The code is based on an algorithm developed by Frederic Vitart when he was a graduate student at GFDL. It has since been modified by Joe Sirutis, Ming Zhao, Kyle Olivo, and Keren Rosado. The code is meant to be used with atmospheric or coupled models with resolutions higher than 1 degree.

This software uses known physical features such as vorticity, vertical temperature, and moisture structure, to detect storms and categorize them by strength. TSTORMS is a single thread sequential program written in Fortran.

Global climate models are now achieving resolutions where tropical storms are seen in the resolved-scale flow. This is a recent development, and has allowed modelers to answer complex questions of great societal relevance such as: will the number of storms increase or decrease in a warming world? Will there be more or fewer destructive land-falling Atlantic hurricanes?

NOAA/GFDL is one of the world's leading centers of research in the study of tropical storms in a changing climate. In addition to the climate models developed by GFDL, other key tools are needed. TSTORMS allows us to:

• Find storms in the global temperature, water, and wind fields output by a model
• Track such a storm as it travels and evolves
• Count the gstorms that occur over a particular basin over a storm season

Getting Started

Environment Configuration

The following packages were used at GFDL to compile and run these tools. Newer versions of these packages will likely work, but remain untested.

• tcsh (6.14.00)
• Fortran compiler (gfortran 4.8.5 or Intel Compilers 11.1.073)
• NetCDF (4.2)
• NCO (4.0.3)
• Grace 2D plotting tool (5.1.22)
• Python (3.6) with Jinja2

Compilation Instructions

This package uses GNU Build System (autoconf, automake) to build and install the package files. Please refer to the INSTALL.md file for basic information on using the GNU Build system.

IB Tracks data

This package requires additional data files to run properly. These files are maintained on the GFDL ftp site at the following location:

ftp://ftp.gfdl.noaa.gov/perm/GFDL_pubrelease/TSTORMS/tstorm_ibtracs_data.tar.gz

During install time, the location of these files can be specified with the configure option --with-ibtracs=<path>. If this option is not given at configure time, the location can be specfied using either the environment variable IBTRACS_DIR, or specfiying the tropical_storms_wsfc -O <path> option. The -O option takes presedence over the IBTRACS_DIR environment variable. Both the -O option and the IBTRACS_DIR will override the default location set during configure.

Usage Instructions

To see the available options, just pass the -h flag to the main script.

NAME
   tropical_storms_wsfc

SYNOPSIS
   tropical_storms_wsfc [-W] -b <year> -e <year> -n <experiment> -i <input directory> -o <output directory>

DESCRIPTION
   Creates figures and statistics from atmospheric data.

OPTIONS
   -W    Enables the use of w850 input data instead of wsfc.
   -b    First year to start processing data.
   -e    Last year to stop processing data.
   -n    Experiment name.
   -O    Location of ibtracs data.
   -i    Location of post-processed input files.
   -o    Location for storing the analysis data and figures.
   -p    Generate plots only
   -w    Set wind threshold
   -V    Print version information
   -h    Print usage information

The input filenames are expected to be in this format: atmos.1981010100-1981123123.slp.nc.

The script and associated Fortran applications will generate trajectory information which you can then plot separately with the tool of your choosing.

Referenced Works

Knutson, Thomas R., Joseph J Sirutis, Stephen T Garner, Gabriel A Vecchi, and Isaac M Held, 2008: Simulated reduction in Atlantic hurricane frequency under twenty-first-century warming conditions. Nature Geoscience, 1, 359–364, DOI:10.1038/ngeo202

Vitart, F., D. Anderson, and T. N. Stockdale, 2003: Seasonal forecasting of tropical cyclone landfall over Mozambique. J. Climate, 16, 3932-3945, DOI:10.1175/1520-0442(2003)016<3932:SFOTCL>2.0.CO;2.

Vitart, F., J. L. Anderson, W. F. Stern, 1997: Simulation of Interannual Variability of Tropical Storm Frequency in an Ensemble of GCM Integrations. J. Climate, 10(4), 745-760, DOI:10.1175/1520-0442(1997)010%3C0745:SOIVOT%3E2.0.CO;2.

Vitart, F., T. N. Stockdale, 2001: Seasonal forecasting of tropical storms using coupled GCM integrations. MWR, 129, 2521-2537 DOI:10.1175/1520-0493(2001)129%3C2521:SFOTSU%3E2.0.CO;2.

Zhao, Ming, Isaac M Held, Shian-Jiann Lin, and Gabriel A Vecchi, December 2009: Simulations of global hurricane climatology, interannual variability, and response to global warming using a 50km resolution GCM. Journal of Climate, 22(24), DOI:10.1175/2009JCLI3049.1

Contacts

This software is provided under the GPLv2 license (please see the LICENSE.md file for more details). If you have questions about this package, you may contact GFDL's climate model info mailing list: gfdl.climate.model.info@noaa.gov