1. Radiosonde Network for IPY
THORPEX-Pacific Asian Regional Campaign/Tropical Cyclone Structure-08 Experiments and Collaborative Efforts
Upgraded Russian
Radiosonde Network for IPY
U.S. (NOAA)
Winter
NOAA G-4 and
Air Force C-130s
U.S.(NSF/ONR), EU,
Japan, Korea,
[DLR Falcon, NRL P-3
WC-130]
U.S.
ONR/NSF
TCS-08
[NRL P-3, WC-130]
WMO
WCRP/WWRP
Asian/Indian
Monsoon
SoWMEX
Typhoon
Landfall
Japan
Palau

2. 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, 13th AF

3. 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 (T-PARC)

4. 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.
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 straight to recurvature, which may be due to the influence of the outer wind structure
TY Tokage: 0000 UTC 14 October 2004
TY Tokage: 1200 UTC 15 October 2004

5. Tropical cyclone formation, structure and structure change: Challenges to Maritime Operations
Midget tropical cyclones often develop in narrow zone along the periphery of a monsoon gyre or in association with an upper-level trough
TS Danas (11W) 1200 UTC 8 Sep 2007
TS Danas (11W) Danger area graphic 0000 UTC 9 Sep 2007
For this small tropical cyclone, the danger area is only 4 deg. in diameter and there is no change in track

6. How does the large-scale atmosphere and ocean environment control the mesoscale environment prior to tropical cyclone formation?
Large-scale modes of variability
Objective: medium-range predictability of the tropical large-scale environmental factors that influence tropical cyclone formation

7. 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?
10o
19o
Pre-Fitow (10W 2007) disturbance Pre-Man-Yi (04W 2007) disturbance
Objective: Increased predictability associated with the location, timing, and rate of tropical cyclone formation over the western North Pacific

8. What are the relative roles of environmentally-induced and vortex-generated mechanisms versus cyclogenesis-determined initial conditions in determining the outer wind structural evolution of western North Pacific tropical cyclones?
Large Tropical Cyclones
Synoptic Type:
Combination type
Large and Small
Tropical Cyclones
Synoptic Forcing
Small Tropical Cyclones
Mesoscale type:
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.

9. Tracks from the JMA ensemble prediction system
What are the key structural aspects of the tropical cyclone and its environment that limit the predictability of recurvature and the start of extratropical transition over the subtropical western North Pacific?
Increase in forecast uncertainty over tropical and midlatitude regions often occurs due to tropical cyclones and the movement of tropical cyclones into the midlatitudes
TY Tokage, October 2004
Tracks from the JMA ensemble prediction system
Tracks supplied by Dr. T. Nakazawa

10. Ensemble Prediction System from the European Center for Medium Range Weather Forecasts (ECMWF)
5-Day Forecasts associated with the Extratropical Transition of TY Maemi (2003)
TY Maemi
Large spread among members
implies decreased predictability
Agreement among members
implies high predictability
Graphic supplied by Prof. S. Jones and D. Anwender

11. Satellite – Aircraft Comparisons
North NW
TMI 85H Z
NOAA Z 10,000’
Hurricane Rita
Graphic supplied by J. Hawkins

12. 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, Japan
Total of 150 research hours
450 dropwindsondes (30 sondes per mission)
USAF Reserve 53rd Weather Squadron (Hurricane Hunter) WC-130J
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

13. Combined missions during tropical cyclone formation
Pre- TY 10W (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

14. T-PARC/TCS-08 Components
TY Nabi, 29 Aug – 8 Sep, 2005
ET characteristics, forcing of downstream impacts, tropical/midlatitude interactions, extratropical cyclogenesis
Extratropical Transition (ET – recurvature),
Downstream Impacts
Midlatitude operating region
NRL P-3, FALCON
Japan, Atsugi, NAF
Subtropical operating region
Driftsonde, NRL P-3,
DOTSTAR, WC-130
TC track characteristics, tropical/midlatitude interaction
TC Intensification and structure change
Recurvature, initiation of ET
Large-scale circulation,
deep convection, monsoon depressions, tropical waves,
TC formation
Tropical Measurements
Tropical operating region
Driftsonde, NRL P-3,
DOTSTAR, WC-130
Okinawa,
Kadena AFB
Guam, Andersen AFB

15. T-PARC and TCS-08: GLOBAL OPERATIONS
Operations center,
Monterey, CA
Driftsonde center,
Boulder, CO
Driftsonde release,
Hawaii
Aircraft locations, and
aircraft operations centers
Guam
Japan
Taiwan
Okinawa

16. 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 TCM93
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
NSB, NOAA SAB, NAS, AMS—Much in common, focus on making progress on intensity
Thorpex—international dialog between researchers and operations with focus on improving global long range forecasts (out to 14 days)
T-Pacific Area Regional Campaign: US/Asian focus on Pacific
lots of Navy participation (NRL, NPS, recently ONR)
4 major problems were ID’d