Tropical Cyclone Structure 2008 I Tropical Cyclone Formation

Tropical Cyclone Structure - 2008 I: Tropical Cyclone Formation II: Tropical Cyclone Intensification III: Tropical Cyclone Structure Change Acknowledgments: Office of Naval Research, Marine Meteorology National Science Foundation, Large-Scale Dynamics USAF, 13 th AF

Key science questions to be addressed in a program aimed at increased understanding and predictability of tropical cyclone characteristics during formation, intensification, and recurvature over the western North Pacific • Highlights – Incorporates multiple space and time scales • Large scale controls – Global and basin-wide spatial scales – Medium-range and synoptic temporal scales • Mesoscale organization pathways – During formation – During intensification – Primary hypotheses with respect to: • Large-scale role in pre-conditioning • Mesoscale organizational pathways leading to construction of a potential vorticity monolith – Role of low-level convergence associated with deep convective cells – Stratiform regions of mesoscale convective systems • Relative roles of environmental and vortex structures in determining the evolution of the outer wind structure – In tandem with the THORPEX Pacific Asian Regional Campaign (TPARC)

Tropical cyclone formation, structure and structure change: Challenges to Maritime Operations • Variety of conditions from which a tropical cyclone may form over the western North Pacific Pre-TY Tokage monsoon depression TY Tokage 0000 UTC 14 October 2004 Warning graphics from the Joint Typhoon Warning Center for TY Tokage. The shaded region defines the danger area to be avoided. This area is based on the uncertainty associated with track and outer wind structure over the ensuing five days. TY Tokage: 0000 UTC 14 October 2004 Note: The danger area nearly covers the entire East China Sea for a period of at least 5 days. The change in track forecast from TY Tokage: 1200 UTC 15 October 2004 straight to recurvature, which may be due to the influence of the outer wind structure

What are the relative roles of the primary mesoscale mechanisms (bottom -up and top-down) in determining the location, timing, and rate of tropical cyclone formation in the monsoon trough environment of the tropical western North Pacific? http: //www. nrlmry. navy. mil/sat_products. html 10 o Pre-Fitow (10 W 2007) disturbance http: //www. nrlmry. navy. mil/sat_products. html 19 o Pre-Man-Yi (04 W 2007) disturbance Objective: Increased predictability associated with the location, timing, and rate of tropical cyclone formation over the western North Pacific

clo Co nes La mb Tr rge ina op a ti ic nd on al Cy Sm type cl all on es Sy n Lar optic ge Tro Type pic : al C y Synoptic Forcing What are the relative roles of environmentally-induced and vortexgenerated mechanisms versus cyclogenesis-determined initial conditions in determining the outer wind structural evolution of western North Pacific tropical cyclones? s e on e: ycl p ty l C e al pica c os Tro s Me all Sm Mesoscale Forcing Objective: Increased understanding and predictability of factors that impact the evolution of the outer-wind structure of an intensifying tropical cyclone over the western North Pacific.

Satellite – Aircraft Comparisons NOAA 43 1430 -1520 Z 10, 000’ TMI 85 H 9 -22 -05 1443 Z NW North Hurricane Rita Graphic supplied by J. Hawkins

VALIDATION OF SATELLITE ALGORITHMS WESTERN NORTH PACIFIC TROPICAL CYCLONE STRUCTURE AND STRUCTURE CHANGE INCLUDING INTENSITY CHANGE AF C-130 STEPPED FREQUENCY MICROWAVE RADIOMETER (SFMR) AND DROPWINDSONDES AT ALL STAGES FROM FORMATION TO EXTRATROPICAL TRANSITION IN COOPERATION WITH T-PARC DOPPLER WIND LIDAR ON NRL P-3 VERTICAL PROFILES OF WIND VECTORS TO THE SURFACE (CROSS-CALIBRATION WITH C-130 SFMR) IN CLOUD-FREE SCENES – FIRST TIME IN TROPICAL CYCLONE COHERENT WIND STRUCTURES IN BOUNDARY LAYER OVER OCEAN IN TROPICAL CYCLONES (Emmitt and Foster)

Observing Platforms (1 August – 30 September) • NRL P-3/ NCAR ELDORA/ DWL lidar/ GPS Dropwindsondes • 50/50 funding split between NSF and ONR • Operation from Andersen AFB, Guam, Kadena AFB, Okinawa, Atsugi NAF, Misawa NAF Japan • Total of 150 research hours • 450 dropwindsondes (30 sondes per mission) • USAF Reserve 53 rd Weather Squadron (Hurricane Hunter) WC-130 J • Funding from ONR and USAF • Operation from Andersen AFB, Guam, Kadena AFB, Okinawa, Yokota AFB, Japan • Dropwindsondes • Stepped Frequency Microwave Radiometer • AXBTs, Drifting Buoys • Other Components • DOTSTAR • Driftsondes – Launch from Hawaii – 20 balloons with dropwindsonde gondolas – 40 dropwindsondes per gondola • Satellite: MTSAT rapid scan, Polar orbiting platforms

Pre- TY 10 W (Fitow) Disturbance Combined missions during tropical cyclone formation Use of Eldora to measure characteristics associated with deep convection Use of WC-130 to measure the environmental characteristics

Pre-Pabuk Tropical Wave PGUM Lawnmower Pattern

Tropical Storm WC-130 J Survey: BUTTERFLY 1944 UTC 10 July 2007 TMI 85 Gh. Z H Targeting Option Track PA~300 -700 mb, IAS~280 -240 kt (280 kt transit) Leg radii~110 nm 9. 5 hr duration 1. 5 hr creep/day GPS Dropsonde: PGUM Butterfly Pattern Man Yi 7 sondes per leg +3 = 24 total (eyewall multisonde ~5 per leg = +15; 39 total) AXBTs: 7 AXBTs per leg +2 diagonals x 4 = 29 total

Summary • • Much recent national and international attention on TCs Four Major Weather Forecast Problems in the Pacific Lack of understanding of storm scale processes is the biggest knowledge gap (basic research common to all four) Proposing: – First major WESTPAC field experiment since TCM 93 – First detailed observations of TC outer winds, genesis & life-cycle (in situ aircraft, radar, dropsondes, lidar, remote sensing) – First measurements. to validate new and advanced satellite obs. of WP TCs – Utilize the post-CBLAST coupled ocean-wave-atmosphere modeling system as a testbed to gain understanding of the processes as informed and constrained by the field data • Expected accomplishments: – Increase the predictability of the environmental forcing, formation, outer wind structure and intensity of TCs over the western North Pacific – Leverage several international efforts – GOAL: to reduce errors in TC structure and intensity forecasts by 50% within a decade – will also increase warning times and improve ocean and wave forecasts