1. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy Peter G. Black 1, Jon Moskaitis 2, James Doyle 2, Chris Velden 3 and Scott Braun 4 (With special thanks to Michael Black, NOAA/AOML/HRD for sonde processing) 1 Naval Research Laboratory and SAIC, Inc., Monterey, CA 2 Naval Research Laboratory, Monterey, CA 3 U. Wisconsin/ Cooperative Institute for Meteorological Satellite Studies, Madison, WI 4 NASA Goddard Space Flight Center, Greenbelt, MD Analyses of hurricane outflow layer structure using dropsonde observations deployed from a NASA Global Hawk AUV during HS3

2. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy Understand the coupling between the inflow and outflow branches of the secondary circulation (and the relationship of this coupling to intensity changes): o Upper-level outflow changes lead to increased convection and intensification.  Active Outflow  Interaction of environment with TC o Upper-level outflow changes result from increased convection/ low level forcing  Passive Outflow  Interaction of TC with environment o Dependencies on boundary layer characteristics o Secondary eyewall cycles Key Science Issue

3. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy Upper-Level Outflow Background schematic courtesy of NASA Low-Level Inflow Secondary Circulation: IN, UP & OUT Radar SFMR CPL HIRAD HIWRAP GPS Dropsonde GPS Sonde Upper-Level Outflow Strategy: 1) Global Hawks to observe the outflow layer and environment 2) WC-130Js to observe the inflow layer structure and intensity

4. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy 15 10 5 0 radius (nm) Height (km) Outflow 300 600 100 Air Force WC-130J: SFMR: Surface winds/ intensity Radar: Precipitation structure AVAPS Dropsondes: Inflow layer vertical structure SFMR Radar Global Hawk: AV-1 remote sensors  HIRAD  HIWRAP  HAMSR? AV-6 Remote Sensors  CPL  S-HIS  AVAPS Dropsondes Outflow layer vertical structure Strategy: i) Global Hawks to observe the outflow layer and environment ii) WC-130J to observe inflow layer and inner-core intensity Observational Strategy

5. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy Lifecycle Hypothesis Schematic of Outflow Channel Morphology from 7 case studies: -WPAC: Roke and Songda -ATL: Earl and Irene -GOM: Charlie, Katrina, and Opal Led to hypothesis relating TC outflow morphology changes to TC intensity changes: HYPOTHESIS: There is a characteristic evolution of the outflow as the storm interacts with the environment that corresponds to changes in intensity and structure. Phase I- TC developmentPhase II- RI I. II. III. Phase III- Mature & decay

6. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy Leslie (7 Sept, 2012): Divergent outflow jets resulting from environmental interaction force inner-core convection? ACTIVE OUTFLOW OR Nadine (14-15 Sept, 2012): Outflow forced by Supercell Convection? PASSIVE OUTFLOW 6

7. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy NASA HS3 Observations of Leslie and Nadine Nadine: 11 Sep – 04 Oct 2012NASA HS3 Global Hawk Flight Tracks Nadine was the 5 th longest-lived Atlantic hurricane on record. Nadine intensity varied from a 35 knot tropical storm to 80 knot hurricane. NASA HS3 Global Hawk deployed over 300 dropsondes during 5 flights in Nadine and 30 dropsondes in Leslie. 30 Drops 70 Drops 76 Drops 58 Drops 34 Drops 75 Drops 35 kts 65 kts 70 kts 50 kts 55 kts 65 kts 80 kts

8. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy Global Hawk Dropsonde Failure Rate- Nadine, 2012 No. reporting = 283

9. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy Cross Section 6 sondes X Leslie Center HS3 Observations of Leslie’s Outflow (150 mb) 20 40 60 80 Vmax (kt) Leslie CAT1 46 578 Sept 9 CIMSS SATCON

10. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy 7 Sep 2012 1041-1111Z HS3 Observations of Leslie’s Outflow Black, Red, Blue and Pink lines: Global Hawk observed wind speed and temperature profiles along jet maximum from dropsondes Green line: COAMPS-TC model wind speed profile Red line: Satellite wind speed vertical average Solid black: Tropopause Dashed: Cirrus top / jet max Dotted:Cirrus cloud base Yellow shading:Cloud Physics Lidar (CPL) domain

11. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy South North HS3 dropsondes reveal unprecedented detail in depiction of outflow jet Sharp shear zone just above the sloping tropopause (~14 km) and below outflow jet Top of outflow jet coincident with top of cirrus deck from CPL Detailed cirrus fine structure suggestive of multiple turbulent mixing mechanisms Total Wind Speed Isotachs every 2.5 m/s Tropopause Cloud Physics LIDAR (CPL): Outflow layer cloud image

12. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy 5 10 15 20 25 30 CIMSS shear: 0-20 kt SHIPS/CIRA shear: 0-50 kt SHIPS/CIRA SST: 20-30 C RSS MW-OI SST: 20-30 C Nadine GH AV-6 Flight

13. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy Outflow jet in Nadine, 14-15 Sept, sampled by multiple dropsondes (triangles- left) and Atmospheric Motion Vectors (AMVs- right). Outflow originates with active supercell west of center 13

14. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy Outflow forced by SUPERCELL Convection: PASSIVE OUTFLOW? OR: Supercell forced by divergent outflow as a result of environmental interaction: ACTIVE OUTFLOW

15. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy o Double jet max below tropopause (dashed line) o Main jet max decreases in height, becomes stronger and thinner with increasing radial distance. o Structures repeatable in 6 sondes along jet max.  Double wind max and constant wind layers are not observable with satellite AMVs over layer average (green dashed line) and may reflect physical processes not presently understood. 15

16. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy Green is CIMSS mean upper wind at sonde location.

17. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy Dramatic Upper-Level Outflow Change during Hurricane Sandy o Jet streak associated with upper-level trough (thick blue arrow) approaches Sandy, creating expanded outflow structure (white arrows) toward the north and east. o Intensity decreases slightly, but the size of the storm increases dramatically. o Strong anticyclonic outflow displaced east of the center (pink dot): supports asymmetric deep convection.  Strong outflow displaced west and north, intensifying and expanding (jet max of 100–140 kt), with dramatic change forced by intensifying ridge northeast of Sandy (blue arrows).  Sandy intensifies, further expands and accelerates just prior to landfall. 10/27/06z: Sandy intensity = 60 kt 10/29/12z: Sandy intensity = 80 kt

18. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy Resulting Hurricane Sandy Landfall Impact Landfall of larger, more intense storm 12- hours earlier than expected. Devastating storm surge superimposed on high tide rather than weaker storm surge superimposed on low tide 12-hours later. Driven by Active Outfow?

19. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy Recommendations and Future Plans Focus 2013-14 flight plans on more detailed dropsonde observation of outflow jet vertical structure (see following final slide). Obtain observation of magnitude and phasing of low-level mass inflow with respect upper mass outflow and jet structure evolution, i.e. secondary circulation development. Extend Global Hawk outflow layer studies to WPAC monsoon depression TCs and interaction with WPAC TUTT cells. Key Results Fine scale outflow layer features and vertical outflow jet structures were recently observed in Hurricanes Leslie and Nadine (2012) by dropsondes deployed from high-altitude Global Hawk AUV They provide a new and more accurate representation of TC outflow layers that complement time evolution provided by AMV’s only. 19

20. NASA Ames Research Center, Moffett Field, CA HS3 Science & Deployment Preparation Meeting, 7-9 May, 2013 A New TC Observing Strategy Outflow Jet Fan patternOutflow Jet Racetrack pattern