PRESENTATIONS at ABFM/LAP Workshop
May 12-15, 2003
Jim Dye
Results from Nov 2002 workshop and Progress on Action Items
http://box.mmm.ucar.edu/abfm/webpage/Reports/Nov02MtgSummaryFinal.htm
Emag Scatter Plot Results For All Anvil Cases
Anvil Summary Plots
Unfiltered,
filter for WSR74C atten. and radar cone voids,
filter for lightning within +/- 20 km and - 5 min of A/C location/time
filter for atten. and lightning
http://box.mmm.ucar.edu/abfm/webpage/Archive/Scatter_Plots/old_Scatter_Plots_030513/summary_60_kV_per_m/view_summary_plots.html
Filter of Lightning Using 4 LDAR sources (compared to 1 LDAR source)
http://box.mmm.ucar.edu/abfm/webpage/Archive/Scatter_Plots/old_Scatter_Plots_030513/Four_LDAR_Sources/summary/view_summary_plots.html
CONCLUSIONS:
- Not much difference using 4 LDAR sources vs 1 LDAR source for lightning filtering.
- Weak increase of Avg dBZ for increasing Emag
- Floor of Avg dBZ values couple of dB lower for -10 dBZ cutoff
- Floor of Avg dBZ using -10 dBZ cutoff is below 5 dBZ
- Need 0 dBZ as limit for violations if use -10 dBZ cutoff
- Bulk of NEXRAD values higher than WSR74C due to NEXRAD thresholding
BOTTOM LINE:
- 11x11 or 21x21 Col Avg dBZ with cutoff of -10 dBZ with Violation Limit of 0 dBZ
- or cutoff of 0 dBZ with Violation Limit of 5 dBZ
- provide a basis for a rule using either WSR74C or NEXRAD
- (but effective cutoff for NEXRAD over KSC is ~ -5 dBZ.)
http://box.mmm.ucar.edu/abfm/webpage/june2001/CAPPI_NEXRAD/hc/010628/hc_2000_2005_010628.gif
NON-ANVIL CASES:
http://box.mmm.ucar.edu/abfm/webpage/Archive/Scatter_Plots/old_Scatter_Plots_030513/summary/view_summary_plots.html
*NOTE:
• There is similar behavior in terms of providing a lower limit of Col. Avg dBZ below which there are no violators.
• But the gross behavior of Avg dBZ vs. Emag is different than anvil cases.
• There is not a gradual increase of Avg dBZ with increasing Emag for Emag >5 kV/m.
• This probably reflects the difference in the charge separation mechanism
for convective storms with anvils from stratiform type convection.
Microphysics Overview, Scatter Plots And Influence On E Decay Times
Microphysics Influence on Electrical Decay Time
Examine penetrations of June 13, 2000 case from anvil edge to core for across and along anvil
http://box.mmm.ucar.edu/abfm/webpage/Reports/AreaSizeDistributions/AreaSizeDistributions.htm
*NOTE: The large changes in particle surface area and E Decay Time
Examine Max Particle Surface Area Distributions for Different Cases
[At bottom of page on previous link.]
Examine composite scatter plots of Number Concentration in different size ranges vs. calculated E Time Scales
http://box.mmm.ucar.edu/abfm/webpage/Edecay_Plots/000000/
http://box.mmm.ucar.edu/abfm/webpage/Edecay_Plots/000000/conc_ets_ALL_inanvil_Anvil_cases_fit.gif
*NOTE:
• High degree of correlation of N200-1000 vs ETmScl
• N>1000 also high correlation with ETmScl
• No correlation of HVPS >3000 vs ETmScl
IMPLICATION:
REFLECTIVITY IS UNLIKELY TO BE A DIRECT MEASURE OF ELECTRICAL DECAY TIME IN ANVILS
Examine correspondance and consistency of various portions of the particle size range for all Anvil cases.
http://box.mmm.ucar.edu/abfm/webpage/Edecay_Plots/000000/var_conc_ALL_inanvil_Anvil_cases_fit.gif
*NOTE:
• FSSP has bi-modal correspondance with N200-1000
• High correlation of N>1000 with N200-1000
• No correlation of N>3000 with N200-1000
CONCLUSION:
As commented at both previous workshops for ABFM cases there is a lot of
consistency in the particle size distributions from anvil to anvil on different days.