# Presentation: 677774

## TROPICAL CYCLONE STRUCTURE (TCS08) FIELD EXPERIMENTIN THE WESTERN NORTH PACIFIC DURING 2008

**Russell L. Elsberry (Naval Postgraduate School)****Ronald J. Ferek (Office of Naval Research)****Simon Chang (Naval Research Laboratory)****Daniel Eleuterio (Naval Research Laboratory)****Patrick A. Harr (Naval Postgraduate School)**
**SPONSORS**
**Office of Naval Research****Naval Research Laboratory****Air Force*****National Science Foundation**
*** With thanks to LCOL Kurt Brueske**

- 62nd Interdepartmental Hurricane Conference, Charleston, SC, 3-7 March 2008

## 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 or inhibition due to ventilation
- 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)**

- 62nd Interdepartmental Hurricane Conference, Charleston, SC, 3-7 March 2008

## FORMATION:  SCIENCE HYPOTHESES

- 62nd Interdepartmental Hurricane Conference, Charleston, SC, 3-7 March 2008

**Science hypotheses**Mesoscale processes determine the location and timing of tropical cyclone formation within the favorable environment Top-down:  MCV near center merges with monsoon depression circulation  Bottom-up:  Low-level cyclonic vortices form from intense convection      in “sweet spot”Environmental processes lead to amplification of the secondary circulation that spin-up the tropical cyclone, but may inhibit via ventilation
**Concept of operations**Global model forecasts for potential cloud clustersRegional model forecasts for likely mesoscale organizationSatellite (geostationary and polar-orbiting for continual monitoring, cross-checking against model output, and aircraft briefing and in-flight support)

## STRUCTURE:  SCIENCE HYPOTHESES

- 62nd Interdepartmental Hurricane Conference, Charleston, SC, 3-7 March 2008

**Environmental dominance:**Outer wind** **structure evolves only slowly from the structure determined at the time of formation
**Internally determined:**Dynamic and thermodynamic imbalances in the inner region generate outward-and-upward-propagating Rossby waves that modify the outer wind structure
**Super-intensity:**Frequent dropwindsonde releases through the eyewall of typhoons will detect structures leading to super-intensity

## SPECIAL TCS08 RESOURCES

- 62nd Interdepartmental Hurricane Conference, Charleston, SC, 3-7 March 2008

**AIRCRAFT****     Naval Research Laboratory P-3**           ELDORA (Doppler Radar)           Dropwindsondes           Flight-level meteorological variables           Doppler wind lidar     **Air Force C-130 reconnaissance aircraft**           Stepped frequency microwave radiometer (SFMR)           Dropwindsondes           Flight-level meteorological variables           Airborne Expendable BathyThermographs     **Air Force support aircraft**           Ocean buoy deployment     **Taiwan DOTSTAR** (if operating near Taiwan)

## Combined missions during tropical cyclone formation 

- _[Combined missions during tropical cyclone formation ](slide10.xml)_
- Use of Eldora to measure characteristics associated with deep convection
- Doppler Wind Lidar for inflow measurements
- Use of WC-130 to measure the environmental characteristics
**BASE OF OPERATIONS AT ANDERSEN AFB, GUAM**

- 62nd Interdepartmental Hurricane Conference, Charleston, SC, 3-7 March 2008

## Pre-Pabuk

- Tropical Wave

- Lawnmower
- Pattern

**PGUM**

## Butterfly Pattern

**Man Yi**

_**Tropical Storm WC-130J Survey:**_
_**BUTTERFLY**_
**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:**_
**7 sondes per leg +3 = 24 total**
**(eyewall multi-sonde ~5 per leg**
**= +15; 39 total)**
_**AXBTs:**_
**7 AXBTs per  leg +2 diagonals x4 = 29 total**

**1944 UTC 10 July 2007**
**TMI 85 GhZ  H**

**PGUM**

**Track**

**Targeting Option**

**Notes:**
Fig. 5. Sample following day inner core structure pattern for genesized tropical storm with dropsonde deployment for 3-D inner core kinematic and thermodynamic structure plus detailed eyewall inflow layer and lower troposphere vertical structure. Deployment of AXBT and GPS sonde pairs provides 3-D ocean thermal structure and bulk air-sea flux input.

## Man Yi

**0030 UTC 12 July 2007**

**0430 UTC 12 July 2007**
**amsre 89 GhZ  H**

**PGUM**

**RODN**

**Typhoon WC-130J Survey **
**700 mb, 220 kt IAS **
**110 nm radius legs, 7.5 hr duration**
**7 sondes per profile x 4 = 28 total**
**(eyewall multi-sonde: +5 per profile**
**x 2 = +10 = 38 total; or x 4 = +20 = **
**48 total); no creep**
**7 AXBTs per profile x 4 = 28 total**

**Man Yi**

**Notes:**
Fig. 3. Sample typhoon inner core structure pattern for mature TC on Day 4 following deployment to forward operating base (flying basic Fig4 inner core pattern in route on Day 3) with dropsonde deployment for 3-D inner core kinematic and thermodynamic structure plus detailed eyewall inflow layer and lower troposphere vertical structure. Deployment of AXBT and GPS sonde pairs provides 3-D ocean thermal structure and bulk air-sea flux input. Optional deployment of drift buoy array of 5 buoys along each of two green lines normal to storm track (10 buoys total) using C-130J on day 3 following WC-130J enroute transit to forward operating base for 4-D ocean mixed layer fine structure.

## SPECIAL TCS08 RESOURCES

- 62nd Interdepartmental Hurricane Conference, Charleston, SC, 3-7 March 2008

**SATELLITE****     MTSAT****          **Continual monitoring during all phases of operations           Rapid scan – desirable during all flight operations       Polar-orbiters           Microwave for convective structure           Scatterometers
**NUMERICAL MODEL ANALYSES AND FORECASTS****     **Global models (NOGAPS, GFS, UKMO, ECMWF)           Environmental conditions in all phases           Focus attention on cloud clusters     Mesoscale models           Naval Research Lab COAMPS           Central Weather Bureau NFS and WRF

## VALIDATION OF SATELLITE ALGORITHMS

- 62nd Interdepartmental Hurricane Conference, Charleston, SC, 3-7 March 2008

- 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)

## U.S. FUNDING SOURCE INTERESTS AND REQUIREMENTS(TCS08-specific but affects other science objectives)

- 62nd Interdepartmental Hurricane Conference, Charleston, SC, 3-7 March 2008

**    ****Office of Naval Research (ONR)                 Air Force (AF)****    Naval Research Laboratory (NRL)             National Science Foundation (NSF)**
-    _PLATFORM_		_SPONSOR_	_%_	  SCIENCE						_OBJECTIVES_
-    P-3 ELDORA		ONR/NRL	50	Formation, Structure			NSF		50	Extratropical transition  P-3 Wind Lidar		ONR		100	All  C-130 Flight hours	AF		50	Satellite evaluation			ONR/NRL	50	 Formation, Structure    c-C-130 Dropsondes	AF		100	All          Ocean buoys	ONR		100	Structure (intensity)

## T-PARC/TCS-08 Components

- Subtropical operating region
- Driftsonde, NRL P-3,
- DOTSTAR, WC-130

- Japan, Yokota  AFB

**Large-scale circulation, **
**deep convection, monsoon depressions, tropical waves, **
**TC formation**

**TC track characteristics, tropical/midlatitude interaction**

**ET characteristics, forcing of downstream impacts, tropical/midlatitude interactions, extratropical cyclogenesis**

- Extratropical Transition (ET – recurvature),
- Downstream Impacts

- Tropical Measurements

- TC Intensification and structure change
**Recurvature, initiation of ET**

- Okinawa,
- Kadena AFB

- Midlatitude operating region
- NRL P-3, FALCON

- Guam, Andersen AFB

- Tropical operating region
- Driftsonde, NRL P-3,
- DOTSTAR, WC-130

**TY Nabi, 29 Aug – 8 Sep, 2005**

## 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

**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?**

- 62nd Interdepartmental Hurricane Conference, Charleston, SC, 3-7 March 2008