Hurricane outflow structures observed during HS3 2012-13 from AV-6 dropsondes and CIMSS ...
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29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA
Hurricane outflow structures observed during HS3 2012-13 from AV-6 dropsondes and
CIMSS Atmospheric Motion Vectors
Peter G. Black1, James D. Doyle2, Jon Moskaitis2, Scott Braun3 and Chris Velden4
1SAIC, Inc./ Naval Research Laboratory, Monterey, CA2Naval Research Laboratory, Monterey, CA
3NASA Goddard Spaceflight Center, Greenbelt, MD4Cooperative Institute for Meteorological Satellite Studies, University of Wisconsin,
Madison, WI
29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA
ObjectiveEstablish the pattern of outflow layer jet features with which hurricane structure and intensity change may be associated.
Utilize in-situ, new-generation atmospheric profiling dropsondes (AVAPS minisonde, HDSS/XDD-2014) and state-of-the-art remote sensors flown on Global Hawk UAVs and reconditioned WB-57 aircraft, in concert with satellite-derived Atmospheric Motion Vectors (AMVs), to directly observe hurricane outflow layer features.
Approach
29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA
HYPOTHESIS
I. TC development- Single Equatorward-directed JetII. Intensification and RI: Dual Equatorward and Poleward JetsIII. Mature & decay: Primarily, single Poleward-directed Jet
TC Life Cycle, including Rapid Intensification (RI),is associated with environmentally-forced
outflow jet evolution:
29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA
Leslie, 2012
Storm Intensity
Nadine, 2012
29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA
Leslie
Leslie Outflow Jet
29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA
LeslieCloud Physics Lidar
29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA
Nadine
Nadine
Nadine Outflow Jet
29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA
29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA
200 mb
925 mb
• Single environmental, poleward-directed outflow jet develops during GH legs 3-hr after center passage.• Thick outflow jet typical
of inner-core develops with multiple constant-wind shear layers• Intense convective
development south of P.R., 100 km east of surface, after GH sampling- from WC-130J, NWS 88D Radar.
Pre-Gabrielle (30 kt), 2013
04/ 1930Z – 05/ 1017Z4 Sept 18Z, 14L
5 Sept 06Z, 02L
5 Sept 00Z, 20L
0240-0435Z,2240-0035L
29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA
Convective DevelopmentACHA vs SJU Radar
Pre-Gabrielle 2013
05/0000Z
05/0000Z 05/0600Z
05/0600Z
05/0330Z
05/0330Z
05/0600Z 05/0900Z 05/1200Z 05/1500Z
04/2130Z
04/2130Z
04/1730L
29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA
5 Sept 00Z, 4/20L
AMV DiurnalOutflow Pattern
4 Sept 18Z, 14L
Pre- Gabrielle2013
5 Sept 06Z, 02L
4 Sept 21Z, 17L
5 Sept 03Z, 4/23L 5 Sept 09Z, 05L
5 Sept 12Z, 08L 5 Sept 15Z, 11L 5 Sept 18Z, 14L
29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA
Key Features from Major Hurricanes TCs have a clear diurnal cycle in IR Brightness Temperature (TB) The TC diurnal cycle has the form of a pulse with coldest TB originating near
the inner core at midnight, propagating outward to the 600 km radius by evening (1800-2100 LST)
Upper outflow jets appear to exhibit a strong diurnal pulse.
TC Diurnal Cycle(2001-2010: 31 Major Hurricanes)
Courtesy: Jason Dunion
29 April – 1 May, 2014HS3 Science Team Meeting Moffet t Field, CA
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Outflow Layer Analysis
Achievements and Key Findings
Three TC outflow layers sampled 2012-13: Leslie, Nadine, Pre-Gabrielle.
Outflow layer jets appear to precede intense inner core convection
— Thin peripheral outflow jets are forced by environmental features: Leslie
Subtropical jets Upper cold lows Tropical Upper Tropospheric Troughs (TUTTs)
— Thick inner-core outflow jets associated with convective bursts: Nadine and Pre-Gabriel
Here-to-for unknown outflow jet fine-structure may lead to instabilities which enhance outflow layer mixing not yet adequately modelled.
Outflow jets appear to have diurnal modulation.