Draft
Draft
Draft
Breakout Group 2 Report
Don MacGorman and Bill Beasley Co-Chairs
Group Members
Beasley, Businger, Demetriades, Fuelberg, Jacobson, Jeffrey, Krider, MacGorman,
Onderlinde, Rudlosky, Trostel
Questions to be Addressed
1. What needs to be achieved (to improve Hurricane prediction models by use of
lightning data) in
Observational and Case Studies
Sensor Design and Development
Field Programs
over the next 3 to 5 years.
2. What are the scientific goals?
Quantify and understand electrical structure, electrification, lightning processes of
eyewall and rainbands, including how they relate to dynamics and microphysics and to
cyclongenesis and to intensification cycle (e.g., eyewall replacement)
Which lightning information can best be measured and provides the most useful
information for assimilation into models
Can lightning data map the location and evolution of hot towers, intense
convective cells in hurricane eyewall
Does lightning data provide indication of severe weather potential (high winds,
tornadoes, and hail) at and after landfall?
What does lightning data indicate about small scale structures/processes that
trigger upscale tendencies (storm cells to system intensification/dissipation)
Characterize mixed-phase microphysical parameters important to electrification
for maritime conditions
3. What are the metrics?
Obtain total lightning obs for eyewall and rainbands of 10 hurricane and 20
tropical cyclones, include measurements during intensification
Obtain lightning for early cyclogenesis (maybe use western Pacific)
Mine all existing data sets, e.g., TRMM, FG. safir and VLF data, to determine CG
fraction and relationships to eyewall replacement, and system intensification as depicted
by radar, sounders, etc --- complete in 24 months
Make microphysics measurements in mixed phase region of tropical storms in
conjunction with polarimetric radar measurements for 10 storms
2 month tropical field program Aug-Sept with total lightning, aircraft and balloonborne microphysics by 2013
Develop or obtain sensors needed for microphysics measurements (balloon borne
videosonde, charge particle measurement, liquid water, motes for spatially distributed E
and basic microphysics, obtain access to aircraft sensors)
Draft
Draft
Draft
4. What are the capability gaps that need to be filled?
5. What are the priorities? (Are current priorities the desired priorities?)
Discussion
1. Need total lightning (charge &/or E structure) for eyewall and rainbands of
hurricanes and TC and tropical storms
a. LANL VLF/VHF system
b. support other coastal VHF mapping networks (Houston, UAH, KSC,
Washington, DC)
c. French G. Safir
d. deployable VHF mapping network to place in path of landfalling
hurricanes/tropical storms: fill gaps and completely separate
e. mine available TRMM data for more hurricane/TS cases to build better
statistics
f. Need other locations – south Pacific, Yucatan, Caribbean islands
2. Need microphysical data in mixed phase region (#, size, habit [graupel, hail, ice
particle form, rain, drizzle], liquid water content, E, and charge in mixed phase
region, aerosol/CCN in inflow) of oceanic storms and tropical storms at minimum
and preferably in eyewall
3. Need to incorporate improved microphysical data in microphysics and electrical
parameterizations of models
4. Need to verify/improve electrification modules of models and to verify their
performance—necessary for confidence in assimilation techniques using more
than timing and location, also for forecast use of lightning data to diagnose
tropical cyclone intensification
5. Need to continue evaluating timing and location assimilation techniques and to
explore techniques for incorporating additional information besides timing and
location of convection in lightning data assimilation techniques (e.g., improved
latent heating profiles, cooling aloft, updraft mass flux through mixed phase
level)—includes assessment of various lightning-storm relationships and
techniques for assimilating this information---observational system dependent,
scale dependent
6. Need source strength distribution of VLF signals for analyses of detection
efficiency and cross validate satellite vs ground-based systems (including VLF
systems)
7. Stopgap:
a. analyze CG fraction in oceanic and tropical storms to assess need for total
lightning data
b. continue analyzing VLF data for tropical cyclone relationships,
particularly with eyewall replacement cycles and hurricane intensification
8. Field program for tropical storms and target of opportunity for TC and hurricanes
a. long enough that likely to get desired storm types
Draft
Draft
Draft
b.
c.
d.
e.
total lightning
radars: Edop, SMART-R, mobile X-band, SPOL, P3
in situ microphysics (combination of balloon, P3, A10-storm penetrating)
piggyback if possible on other field programs (e.g., 2010 monsoon
experiment?, 2011 experiments)
f. UAV/motes for microphysics, E
g. multiple locations to work with aircraft
h. include Caribbean &/or Pacific region
i.
Lightning in early cyclogenesis (easterly waves, western Pacific)
New instrumentation
in situ microphysics capability (balloon borne, motes, storm penetrating aircraft,
UAVs)
additional VHF mapping, particularly deployable and Gulf coast
Measurable goals