Codes Employed
The software packages used in the HWRF Sensitivity to Cumulus Parameteizations Test included:
•WRF https://svn-wrf-model.cgd.ucar.edu/tags/hwrf-baseline-20120216-2300 wth few additions to include cumulus schemes
This is a developmental version used for pre-implenetation testing in Feb 2012. The official HWRF3.4a realeasewas done in Sugust 2012.
•WPS https://svn-wrf-wps.cgd.ucar.edu/tags/hwrf-baseline-20120216-2300
•UPP https://svn-dtc-unifiedpostproc.cgd.ucar.edu/tags/hwrf-baseline-20120216-2300
•Vortex relocation and initialization, prep_hybrid, miscellaneous
libraries and tools - hwrf-utilities https://svn-dtc-hwrf-utilities.cgd.ucar.edu/tags/hwrf-baseline-20120216-2300
•Princeton Ocean Model (POM) https://svn-dtc-pomtc.cgd.ucar.edu/tags/hwrf-baseline-20120216-2300
•NCEP Coupler ://svn-dtc-ncep-coupler.cgd.ucar.edu/tags/hwrf-baseline-20120216-2300
•GFDL Vortex Tracker https://svn-dtc-gfdl-vortextracker.cgd.ucar.edu/tags/hwrf-baseline-20120216-2300
•National Hurricane Center Verification System
https://svn-dtc-nhcvx.cgd.ucar.edu/trunk revision 32
HWRF Model: Control Configuration (HPHY)
Configured using a developmental version used in pre-implementation testing in February 2012
by EMC.
HPHY Configuration:
|
Scheme |
Namelist Option |
| Cumulus |
SAS (no shallow convection) |
84 |
| Microphysics |
Tropical Ferrier |
85 |
| Radiation SW/LW |
GFDL/GFDL |
98/98 |
| Land Surface Model |
GFDL slab model |
88 |
| PBL |
GFS |
3 |
Other cumulus configurations
The cumulus option was swapped keeping other options same as control (HPHY).
HNSA - HWRF configuration using the New SAS cumulus scheme implemented by YSU
HKF1 - HWRF configuration using the Kain Fritsch scheme
HTDK - HWRF configuration using the Tiedtke scheme
Domain Configuration
The HWRF domain was configured in a similar way as the NCEP/EMC operational system. The atmospheric model employed a parent and two movable nested grid.
The parent grid covered a 80x80 deg area with approximately 27 km horizontal grid spacing.
There were a total of 216 x 432 grid points in the parent grid.
The d02 domain covered a 11 x 10 deg area with approximately 9 km grid spacing.
There were a total of 88 x 170 grid points in the nest.
The d03 domain covered a 6 x 5.5 deg area with approximately 3 km grid spacing.
There were a total of 154 x 272 grid points in the nest.
The location of the parent and nests as well as the pole of the projection, varied from run to run and were dictated by the location of the storm at the time of initialization.
HWRF was run coupled to the POM ocean model for Atlantic storms and in atmosphere-only mode for East Pacific storms.
The POM domain for the Atlantic storms depended on the location of the storm at the initialization time and on the 72-h NHC forecast for the storm location.
Those parameters defined whether the East Atlantic or United domain of the POM was used.
The image shows the atmospheric parent and nest domains (yellow) and the United POM domain (pink).
Click for larger image.
Cases
Cases for Atlantic (2011 season):
|
Storm ID |
Begin |
End |
| Harvey |
08L |
081900 |
082206 |
| Irene |
09L |
082100 |
082818 |
| Katia |
12L |
082906 |
091012 |
| Maria |
14L |
090618 |
091612 |
| Ophelia |
16L |
092100 |
100306 |
| Rina |
18L |
102318 |
102812 |
Cases for East Pacific (2011 season):
|
Storm ID |
Begin |
End |
| Dora |
04E |
071812 |
072418 |
| Eugene |
05E |
073112 |
080606 |
| Fernanda |
06E |
081600 |
082000 |
Verification
The characteristics of the forecast storm (location, intensity, structure) were compared against the Best Track using the National Hurricane Center (NHC) Verification System (NHCVx). The HPHY, HNSA, HKF1 and HTDK ATCF files were produced by the DTC as part of this test. The NHCVx was run separately for each case, at 6-hourly forecast lead times, out to 120 h, in order to generate a distribution of errors. Verification was performed for any geographical location for which Best Track was available, including over land. No verification was performed when the observed storm was classified as a low or wave.
An R-statistical language script was run on an homogenous sample of the above datasets to aggregate the errors and to create summary metrics including the mean of track error, intensity error, absolute intensity error, and radii of 34, 50, and 64 kt wind in all four quadrants. All metrics are accompanied of 95% confidence intervals to describe the uncertainty in the results due to sampling limitations.
For the purposes of comparing the HPHY and the other cumlus parameterizations forecasts, pairwise differences (HPHY-other cumulus scheme) of track error, and absolute intensity error, and absolute wind radii error were computed and aggregated with a R-statistical language script. Ninety-five percent confidence intervals on the median were computed to determine if there is a statistically significant difference between the two configurations.
