The Re-intensification of Typhoon Sinlaku (2008)• Observations of the re-intensification of Sinlaku from the TCS-08 / T-PARC field programs comprise a unique data set that has enabled

The Re-intensification of Typhoon Sinlaku (2008)

Elizabeth Sanabia

22 May 2012

Acknowledgments: Patrick Harr, Michael Bell, and Bob Creasey

Typhoon Sinlaku07-22 September 2008

• 6 Targeting– Falcon

• 18/2235 – 19/0725

• 20/0156 – 20/1206

• 20/2205 – 21/0205

• 09/0030 –

09/1045• 09/2100 –

10/1225• 10/2043 –

11/1828

• 12/1138 – 12/2318

• 13/2330 – 14/0555

• 15/2135 – 16/0205

• 16/0500 – 16/0800

• 16/2044 –17/1115

• 17/2224 – 18/0720

• 8 Structure– P-3 – C-130 – DOTSTAR

• 14 ET– P-3– C-130– Falcon

Re-intensification 17-18 September 2008

• 14 ET– P-3 – C-130– Falcon

28 TCS-08 / T-PARC Missions

• 16/0500 – 16/0800

• 16/2044 –17/1115

• 17/2224 – 18/0720

TCS-08 / T-PARC Observation Flights

Typhoon Sinlaku07-22 September 2008

Re-intensification 17-18 September 2008

17 Sep / 0200 UTC 18 Sep / 0200 UTC16 Sep / 1800 UTC

Outline

• Review the large-scale events that led to the re-intensification

• Examine the evolution of the convection preceding the re-intensification

• Identify & analyze the characteristics of the mesoscale circulations within the vicinity of the Sinlaku vortex

• Examine the evolution of the convection and TC during the re-intensification that followed the TC-multivortex interaction.

Objective

Identify physical mechanisms responsible for the

re-intensification of TY Sinlaku

• Aircraft• P-3 ELDORA• WC-130J & P-3 Flight-

level• WC-130J & P-3

Dropsonde

• ECMWF YOTC

• Satellite• MTSAT IR / WV• 85 GHz TRMM• AMSU-A

• NAS16NFS

Data

Observations

Models

ECMWF 200 hPa• Zonal Jet• TC Outflow

ECMWF 500 hPa• Short-wave trough to N• Broad band of southerlies

from the deep tropics to E• Subtropical Ridge to E

13/0230 13/0220

14/1930

15/1830

14/1934

15/1837

R

TC Decay• Land Interaction• Vertical Wind Shear

Ocean Conditions

Conditions at

0000 UTC 16 September 2008

• Kuroshio Current

• West of Okinawa

– OHC > 100 kJ cm-2

– SST > 28oC

Mechanism for TC Intensification & Development of Deep Convection

• Surface Heat Fluxes

Thresholds Favorable to TC Development & Intensification • SST > 26oC (Gray 1968)• OHC > 120 kJ cm-2 (TC moving 2-3 m s-1), and > 65 kJ cm-2 (TC moving 7-8 m s-1)

(Lin et al. 2009)

NRL East Asian Seas Nowcast / Forecast System

Preconditioning

• Elevated OHC and SSTs

• Monsoon moisture & assoc convection

• Increased CAPE W of Okinawa

• TC moving eastward toward monsoon flow

• Convergence of monsoon flow and outer TC circulation

Monsoon Flow

TCcirculation

3 Episodes of Deep Convection

Episode 1

0730 UTC 16 Sep 08

– ESE of the TC center

– Within moist monsoon flow connecting the deep tropics and the midlatitudes

– TC moves ENE toward the developing convection

Episode 21930 UTC 16 Sep 08

– E & SE of the TC center

– 2 concurrent bursts– Shorter duration– TC continues to

move ENE– Episode 1: linear

bands moves NE


– E of the TC center– W side of 2nd

episode– TC slows and turns

NE– Episode 1 continues

to move NE

Movie 1 Movie 2 Movie 3


Episode 1

0730 UTC 16 Sep 08








bands moves NE





to move NE



Episode 1

0730 UTC 16 Sep 08








bands moves NE





to move NE


17 September 2008 0130 UTC

123

Synoptic-scale Processes & Down-

scale Impacts

• TC Decay– Land Interaction– Vertical Wind Shear

• Preconditioning– Monsoon flow– Ocean conditions

• Deep Convection– Convergence of the

outer TC circulation & SW monsoon

– Sheared TC


T-PARC / TCS-08 1st ET Flight

• WC-130 – Blue flight track– Flight level: 300-275 hPa– ~30 minutes ahead of the

NRL P-3• NRL P-3

– Yellow flight track– Flight level: 500 hPa

ELDORA Data • Dual-Doppler collection

– Reflectivity

– Doppler velocity

• Editing process

– Raw sweep files

– EOL - aircraft navigation corrections

– QCd sweep files

– Automated & hand-editing to remove noise, ground clutter

– Edited sweep files

• Processing sequence

– Interpolated to 500-m Cartesian grid

– Reasor et al. (2009)

– Houze et al. (2009)

– Synthesized to 3-D wind and reflectivity fields


– Houze et al. (2009)

– Cloud liquid temperature perturbations


– Roux and Ju (1990)

– Roux et al. (1993)

(modified from Houze et al. 2005)

Edited reflectivity (dBZ)

0140:28 UTC 17 September 2008

QCd reflectivity (dBZ)


123

C

N

C

Plan View Summary

• Two regions of convection

– 3rd convective episode

– linear region of deep convection

– east of the TC LLCC

– 2nd convective episode

– broad region of lower reflectivity

– NE of the TC LLCC

• Three mesoscale vortices

– Sinlaku / Southern vortex

– Deep convective tower

– Tilts ESE with height & becomes centered over the deep convection at 5.5 km

– Cyclonic circulation around the vortex disrupted by flow from 2 mid-level vortices to the NE

– Central vortex

– 5-12 km

– Low reflectivity

– Northern vortex

– 4-6 km

– Medium reflectivity

• Next: Vortex characteristics

– Reflectivity– Vorticity– Convergence /

Divergence– Vertical motion– Thermal characteristics

Vertical motion & temperature perturbations: Reasor et. al 2009

Thermodynamic Characteristics near Sinlaku

• Cloud liquid temperature perturbations determined from the 3-D wind field (Reasor et al. 2009, Roux and Ju 1990, Roux et al. 1993)

• Generally consistent with WC-130J flight-level temperature observations

• Possible issues at very top / bottom of atmosphere and data boundaries

Composite Environmental Sounding

• Houze et al. (2009)

• Minami Daito Jima (ROMD)

– 0000 UTC 17 September 2008

– Downstream from the TC/convective region

– Data through the depth of the atmosphere

• TCS-08 / T-PARC dropwindsondes

– WC-130J 0122 UTC 17 September 2008

– P-3 0141 UTC 17 September 2008

*

*

*

0130 UTC 17 September 2008

Thermal Characteristics• Co-location of warm anomaly

and relative vertical vorticity maximum in base of the deep updraft

• Tilting of the maxima at middle-upper levels

• Possible anomaly issues at very top / bottom of column

C

N

Deep Convection C NNorthern VortexCentral Vortex

Deep Convection

C N

Northern VortexCentral Vortex


Deep Convection

C N


Convection and Re-intensification

Region A

0230 UTC 17 Sep 08

Region B1230 UTC 17 Sep 08

Region C1657 UTC 17 Sep 08


Characteristics common in each case– Convection develops on the downshear side of the TC– As convection develops it moves cyclonically around and inward toward the TC center.– Elongation of cloud tops indicates shearing of the convection and the inward propagation of positive

vorticity associated with latent heat release due to convection– The second convective episode from 16 September 2008 remains east of the TC center


Region A

0230 UTC 17 Sep 08






Region A

Episode 2 from

16Sep08

Region A

Episode 2 from

16Sep08

Region A

Episode 2 from

16Sep08

Region A

Episode 2 from

16Sep08


Region A

0230 UTC 17 Sep 08






Region B

Episode 2 from

16Sep08

Region B

Episode 2 from

16Sep08

Region B

Episode 2 from

16Sep08

Region B

Episode 2 from

16Sep08

Region B

Episode 2 from

16Sep08


Region A

0230 UTC 17 Sep 08






Region C

Episode 2 from

16Sep08

Region C

Episode 2 from

16Sep08

Region C

Episode 2 from

16Sep08

Region C

Episode 2 from

16Sep08

Region C

Episode 2 from

16Sep08

REGION A

REGION B

REGION C

EPISODE 2

PRINCIPAL RAINBAND

Re-intensified TY SinlakuET Flight 2

~0145 UTC 18 September 2008

• Near-symmetric, upright cyclonic circulation 12 km in height

• Eyewall near 40 km in diameter, and contracts two hours later to near 30 km.

• Surface winds in the southwest eyewall were measured at 63 kt by the WC-130J 0118 UTC 18 September 2008 dropwindsonde.

• Cloud liquid perturbations indicate warm core, which is consistent with the near 6oC rise in flight-level temperature in the TC center.

Conclusions• The re-intensification of TY Sinlaku resulted

from the interaction between the TC and 3 mesoscale vortices.

– The vortices were of varying structures and in varying regions of precipitation.

– Vigorously growing deep convective towers and associated vorticity characteristics near TC center

– Mid-level vortex in stratiform region to the northeast of the TC center between second and third episodes

– Hybrid low-level vortex in weak/older convection of second episode

– The merger between the relative vorticity maxima associated with the TC and the western deep convective tower augmented & redistributed positive vorticity within the Sinlaku vortex.

– Convective and mesoscale processes during the re-intensification impacted features and processes on the vortex scale (increasing the intensity of the TC).

Conclusions

• The interaction between the TC and the 3 mesoscale vortices was facilitated by synoptic-scale processes.– TC Decay– Land interaction – Vertical wind shear– Preconditioning– Ocean conditions – Monsoon flow– 3 episodes of deep convection east of Sinlaku on

16 September 2008– Synoptic-scale processes during the decay phase

impacted features and processes on the convective and mesoscale (development of the deep convection and associated vortices)

• Deep convection following the TC-multivortex interaction resulted in the continued re-intensification of the system as the convective regions wrapped cyclonically around and inward toward the TC center, which increased the positive relative vorticity associated with the system.

Conclusions• Observations of the re-intensification of Sinlaku from the TCS-08 / T-PARC field

programs comprise a unique data set that has enabled detailed analysis of the synoptic, mesoscale, and convective-scale processes that define structure change associated with intensification of a TC from a weak tropical storm to near typhoon intensity over a 24-h period.

• Numerical experiments and simulations will extend the results of this research to the more general case.

– Determine which scales and processes (if any) were most critical to the re-intensification.

– Synoptic-scale forcing facilitated the development of deep convection – was it necessary for the re-intensification?

– What if the magnitude of the third convective burst had been smaller – would there still have been the rapid development?

– How critical were the regions of deep convection that rotated into the TC center following the TC-multivortex interaction?

– Clarify the relative roles of the three mesoscale vortices between observation periods.

– Quantify the link between this redevelopment and errors in forecast intensity of the TC during ET and of the subsequent downstream development by the ECMWF and other global numerical models.

Future Work

Questions?

Documents

The Re-intensification of Typhoon Sinlaku (2008)• Observations of the re-intensification of Sinlaku from the TCS-08 / T-PARC field programs comprise a unique data set that has enabled