Florida Bay Rainfall
- Principal Investigator:
- Frank Marks
- Other Scientists:
- Paul Willis (CIMAS)
- Dean Churchill (UM/RSMAS)
- Peter Dodge
Objective
This research attempts to provide fields of rainfall accumulation over Florida Bay and the Everglades using the National Weather Service WSR-88D radars in South Florida (Melbourne, Miami, Tampa, and eventually Key West) in support of the Florida Bay Program.
Rationale
We are evaluating an number of methods to produce the rainfall accumulations, together with techniques to fine tune the radar reflectivity/rainfall algorithms, and assess the accuracy of the radar rainfall estimates.
Method
HRD has developed a probability matching method (PMM) to derive the relationship between observed radar reflectivities (Ze) and concurrently measured rainfall rates from drop size distributions (DSD) from an aircraft disdrometer (Marks et al 1993). This method constrains the Ze-R function so that the probability density functions of the radar data and the drop size distribution(or gage) dat
a match. The method allows actual radar data to be compared to simultaneous rainfall data, even at large ranges.
Accomplishments
Through one month of effort in FY 95 HRD has collected 18 h of NOAA P-3 aircraft drop size distributions (DSD) over three days (26, 28, and 29 September) in range of two South Florida WSR-88D radars.
DATE Start of aircraft mission Middle of aircraft mission
1700 UTC 2100 UTC
28 September 
29 September 
[Table-enhanced version of this information]
HRD has also established a high temporal resolution rain gage and disdrometer site in the Everglades at the US National Park Service Research Center with the help of NOAA/AOML Ocean Acoustics Division (OAD).
The efforts over the next year will focus on five activities:
- Produce daily and monthly accumulated precipitation atlases for Florida Bay and adjacent areas on a demonstration basis. Update the atlases based on improvements of the Z-R relationship using the PMM methodology. Produce higher r
esolution products for special cases and projects, i.e. heavy precipitation events, onset of wet season, etc. Make these data available via the Internet to other federal, state and local groups performing research in Florida Bay.
- Collect a sample of NOAA WP-3D DSD in range of the South Florida WSR-88D radars and apply these data within a PMM methodology to refine the rainfall algorithm as a function of range and rainfall type.
- Instrument a van using an aircraft PMS optical hydrometeor spectrometer (borrowed from NOAA AOC) and PC-based data system and make transects of DSDs across the Everglades during precipitation events as input to the PMM methodology.
- Collaborate with OAD to analyze disdrometer measured DSD and high resolution gage data at an Everglades site.
- Use available rain gage data to assess the accuracy of the WSR-88D surface rainfall estimates. High time resolution (1-5 min) gage data will be used in the PMM methodology if available from OAD, or other source.
References
- Marks, F.D., D. Atlas, and P.T. Willis, 1993: Probability-matched reflectivity-rainfall relations for a hurricane from aircraft observations. J. Appl. Meteor., 32, 1134-1141.
Return to HRD homepage
marks@aoml.noaa.gov
Updated Dec. 21, 1995
