December 18, 2008 Meeting Summary
Vijay Tallapragada presented some slides on the status of the HWRF T&E.
Two more storms were run for H044 (gravity wave drag experiments) from
the 2008 Atlantic hurricane season - Cristobal and Fay. Overall, there
was no significant impact on track or intensity using H044 for these
storms. The H045 (sea spray) runs are still a work in progress, as is
Qingfu's work on the new initialization. The impact of initial and
boundary conditions on the HWRF was tested using the ECM (GFS) data
provided by DaNa Carlis for August 16, 2008. The only storm available
for that time in the Atlantic was Fay. So far, a positive impact was
seen with more investigation to follow.
Vijay also led a discussion of the GSI in HWRF. Some inconsistencies
were discovered in H047 runs using the new GFS/GSI Q1FY09. Some
questions raised included: Why does inputting HWRF guess fields into the
CRTM yield AMSU-A channel 6 brightness temperatures which are closer to
observed values than what we see using GFS guess fields? Is this CRTM
sensitivity due to different vertical structures in the HWRF and GFS?
Should we be using the global angle-dependent bias correction values in
the HWRF? Should prepbufr files, which are currently not used in
operations or H047 be used when the storm is near land? The overall
consensus was to keep the current configuration in place and address the
questions mentioned above at a later date when more time to run test
cases was available. It was suggested that Mingjing run the system she's
using for her experiments involving assimilating airborne Doppler radar
data in parallel with the HWRF for the 2009 hurricane season.
Hyun-Sook Kim presented some slides on the diagnosis of HWRF atmospheric
flux with and without a bug fix for the land surface temperature. With
the bug fix, there is more inner structure and higher, more realistic
flux values over land compared to without the bug fix.
All additions/revisions of HWRF code for the 2009 implementation should
be ready around January 15, 2009. This includes the land bug fix,
gravity wave drag, new GFS/GSI, and restart option. The new
initialization is almost ready and the sea spray code has more tests to