Rainband and Intensity Change Experiment “RAINEX”

1. Rainband and Intensity Change Experiment “RAINEX” An Observational and Modeling Study of Hurricane Rainbands and Intensity Changes (Collaboration between NSF & NOAA, NSF ~$ 3+M) NSF PIs: Shuyi S. Chen and Robert A. Houze, Jr. dropsondes model Doppler radar

2. Approach: • Use a/c Doppler radar to observe both eyewall and rainband internal vorticity structures simultaneously • Use intensive dropsondes for thermodynamic environment of mesoscale rainbands and eyewall to support both analysis and modeling Seek match between model and aircraft- observed structures at an instant of time, in both eyewall and rainband • Use model to determine how the vorticity features evolve and storm intensity changes

3. RAINEX Meeting Objectives • Foundation for project operations plan, to be written after meeting • Critical operations issues: • Flight track plan, incorporating both Doppler & dropsondes • Communications links, including radar data • Science operations center, for near real time synthesis of a/c data, model output, & other info • Contingency plans, if weather doesn’t cooperate • Other • Data management & archive • Timeline leading up to hurricane season • Meeting report—due next week!!

5. Four characteristic tropical cyclone rainband/eyewall structures

6. RAINEX A/C Plan Suggested tracks of GIV,C130

7. 3 a/cmission NRL-black Piggy-white Kermit-blue GIV/C130-red 100 km

8. 2 a/cmission Piggy-white Kermit-blue GIV/C130-red 100 km

9. 2 a/cmission NRL-black Kermit-blue GIV/C130-red 100 km

11. Simplified RAINEX Data Flow C130/GIV Kermit NRL/P3 Piggy air ground RSMAS ATD HRD NHC JOSS

13. P3 Airborne Mission Scientists Lee (NRL) Smull (NOAA or NRL) Jorgensen* (NOAA or NRL) Chen (NOAA or NRL) Rogers (NOAA) M. Black (NOAA) Gamache (NOAA) Dodge (NOAA) Zipser* (NOAA) *volunteer

15. Some Issues identified yesterday Dropsondes from high altitude Environment Eyewall Principal rainband Protocol for requesting dropsondes RAINEX-HRD-NHC-EMC-CARCAH Communications & coordination— 43 needs to be lead P3 Need to transmit LF every 10 to 15 mins, content? People who will do this development Operations Dropsonde chute on NRL P3 (pressurization)

16. RAINEX A/C Plan Suggested tracks of GIV,C130

18. Specific Questions Regarding Dropsonde Flight Tracks • RAINEX critically needs PV budget information Þ need dropsondes launched from the GIV and/or C130 flying at 30,000 feet. Best if in eyewall region and principal band region. To what extent can this be done? • Can RAINEX desired tracks be done within the constraints of NOAA operational surveillance flights and HRD research flights? • Can GIV dropsonde flight tracks be reprogrammed while a/c are in the air? • What is the exact protocol for RAINEX to request special dropsonde flight patterns?

22. 2004 2005 Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Field phase Planning Meeting in Miami Practice Missions Funding Approval Final setup & testing of Science Operations Center Initial information gathering trip to HRD and RSMAS Initial setup of Science Operations Center RAINEX TIMELINE

24. Science Objectives • Use a/c to examine the dynamic and thermodynamic structuresof hurricane outer rainband regions where the positive potential vorticity associated with deep convective cores are located • Use model to investigate the interactionsof the rainbands and primary hurricane vortex circulation and their role in hurricane intensity change.

25. Working hypothesis, based on recent research: In the convective rainband region outside of the hurricane inner core, convectively induced potential vorticity may be “axisymmetrized” by high wave number Rossby waves.

26. Specific questions • How do PV maxima associated with rainbands organize (axisymmetrize) into the primary eyewall? • How do PV maxima associated with rainbands outside the primary eyewall interact with the eyewall? • How do PV maxima associated with rainbands outside the primary eyewall axisymmetrize into a secondary eyewall • How do the secondary and primary eyewall interact with each other