Coupling of high-resolution meteorological and wave models over the Gulf of Thailand Presented by...

Coupling of high-resolution meteorological and wave models over the Gulf of Thailand

Presented byDr.Wattana Kanbua

Director, Marine Meteorological CenterThai Meteorological Department

The Fourth Session of the Joint WMO-IOC Technical Commission for Oceanography and Marine Meteorology (JCOMM-4),

To be held on 23-25 May, 2012 at EXPO2012 Yeosu Korea.

Outline

• Introduction• WAM Model• WIND Models• Results• Conclusions



Introduction• Third Regional Workshop on Storm Surge and Wave Forecasting - A Hands on Forecast Training Laboratory, Beijing, China, 25-29 July

2005.

• Fourth Regional Workshop on Storm Surge and Wave Forecasting - A Hands on Forecast Training Laboratory, Manila, Philippines,11 - 15 September 2006.

• Jamboree-II (Combined Modeling and Data Management Training Workshop), Held at IODE, Oostende, Belgium, 8-14 October 2006.

• Jamboree-III (MetOcean Modelling Workshop), Held at IODE, Oostende, Belgium, 19-23 October 2009.



Dr. Johannes GUDDAL http://www.wamwatt.tmd.go.th

http://www.wamwatt.tmd.go.th/

Introduction• Thailand has located in tropical zone and The change of

weather in Thailand has been influenced by the monsoon. • The north-east monsoon winds has blown from the north-

east it travels across the Gulf of Thailand, This usually means that along the eastern coastline of southern part of Thailand and offshore islands can receive significant rainfall and huge waves between November and January.

• There was severely eroded by strong wind and huge waves. Hence, the destructive force from the wind and sea waves is diminished.

• There was coincidence when a cyclone had occurred in the Indian Ocean. The wind system induced a northeast monsoon winds which was stronger than normal. It caused high waves hit hundreds of houses in southern provinces.

• Waves estimated at nearly four-metre struck the southern provinces of Prachuap Khiri Khan, Chumpon and Surat Thani, prompting residents to evacuate. Some people panicked, as such an incident has not happened in half a century. An initial survey found three houses destroyed by giant waves. Other houses are under water during 25 – 28 December 2011.



Introduction• Cyclone-1 THANE had occurred during 25-30 December

2011. It took place at 9.80 N Latitude and 87.70 E Longitude on 25 December 2011 at 18UTC, the sustain winds was 35 knots, the status was tropical depression and there was developing and became Cyclone-1 at 12.10 N latitude and 84.80 E Longitude on 28 December 2011 at 06UTC, the sustain winds was 65 knots. It was moving westward go to India. It was weak at 11.70 N Latitude and 79.10 E Longitude on 30 December 2011 at 06UTC, the sustain winds was 40 knots, the status was tropical depression.



WAM Model • It is a third generation wave model that integrates the basic transport

equation describing the evolution of a two-dimensional ocean wave spectrum without additional ad hoc assumptions regarding the spectral shape.

• The three source functions describing – The wind input– Nonlinear transfer– White-capping dissipation

They are prescribed explicitly.




WAM Model


THE ENERGY BALANCE EQUATION

WAM PHYSICS

• SOURCE TERMS S = Sin + Snl + Sds + Sbottom

– WIND INPUT SOURCE TERM Sin • CYCLE 1-3 BASED ON SYNDER (1981)• CYCLE 4 BASED ON JANSSEN (1991)

– NON-LINEAR SOURCE TERM Snl • BASED ON HASSELMANN’S THEORIES ON WAVE-

WAVE INTERACTIONS– DISSAPATION SOURCE TERM Sds

• BASED ON HASSELMANN’S THEORY OF DISSAPATION DUE TO WHITE CAPPING. TUNING TERM

– BOTTOM FRICTION SOURCE TERM Sbottom • ONLY APPLIES IN SHALLOW WATER



WAM Model

• WAVE PROPAGATION– WAVES ARE PROPAGATED AT THERE GROUP SPEED

USING A 1st ORDER UPWINDING SCHEME. – CHARACTERIZED BY HIGH NUMERICAL DIFFUSION– WAVE REFRACTION AND SHOALING

WAM PHYSICS


WAM Model


• WIND INPUT

– U10

– U-STAR (FRICTION VELOCITY)– WIND STRESS

WAM INPUTS


WAM Model


• TOPOGRAPHY– ETOPO5 (5MIN RESOLUTION)

NOGAPS1x1 degree

WRF5x5km

0.083x0.083 degree

9.2x9.2km

WAM OUTPUT


WAM Model


• OUTPUT – DIRECTIONAL FREQUENCY SPECTRA– SIGNIFICANT WAVE HEIGHT– PEAK WAVE DIRECTION– PEAK WAVE PERIOD– SEA AND SWELL HEIGHT– WAVE STRESS

MODEL SETUP


WAM Model


COARSE GRID FINE GRID

0

90

25

115

5

95

15

105

COARSE GRID


WAM Model


FINE GRID


WAM Model


NOGAPS winds

WRF winds

1x1 degree

5x5 km.

Note: 1 degree = 111 km

WIND MODELS- NOGAPS IS GLOBAL MODEL.- THE RESOLUTION IS 1X1 DEGREE- DOWNLOAD FROM WEBSITE :

http://usgodae.org/pub/outgoing/fnmoc/models/nogaps



- WRF IS MESOSCALE MODEL.- THE RESOLUTION IS 5X5 KM- RUN AT MARINE METEOROLOGICAL CENTER BY

DOWNLOAD GLOBAL MODEL FROM NCEP AND DOWNSCALING INTO SMALL AREA AS THE GULF OF THAILAND.



NOGAPS DOMAIN

Run WAM for Coarse Grid frame



WRF DOMAIN

Run WAM for Fine Grid frame

WRF modeling flowchart

การผสานข้�อมู�ล

ไมู�ผ�านข้บวนการผสานข้�อมู�ล



Computational run WRF Model on Marine Meteorological Center

Internet

Computing Node

Computing Node

Computing Node

Computing Node

Front-endGigabit Switch

User

192.168.0.2

192.168.0.3

192.168.0.4

192.168.0.5

-Archive output-download GFS data-Visualize wrf output-convert to graphic-convert to others/web

Visualize ftp

ftp

ftp

ftp

vdomain

192.168.0.6

192.168.0.1

โดเมนสำ��หรั�บก�รัปรัะมวลผล



VirtualWeather3DThe Fourth Session of the Joint WMO-IOC Technical Commission for Oceanography and Marine Meteorology (JCOMM-4),


Results • Winds and waves field are reasonable

with extreme event.• The north east monsoon winds which

was blowing over the Gulf of Thailand, was abnormal when the tropical depression in Indian Ocean was progress and stronger and became tropical storm.

• The spiral band of Cyclone had connected with the monsoon winds, and induced north east monsoon to be strongly. The strong winds had built huge waves hit along the eastern coastline of southern part of Thailand during December 25 - 28, 2011



NOGAPS-WAM

WRF-WAM

Results



WAM-WRF WAM-NOGAPS WAM-WRF WAM-NOGAPS WAM-WRF WAM-NOGAPS

WAM-WRF WAM-NOGAPS WAM-WRF WAM-NOGAPS WAM-WRF WAM-NOGAPS

Conclusions• When comparison the results

of the WAM which used low resolution winds from NOGAPS as 1x1 degree latitude and longitude and high resolution winds from WRF as 5x5 km.

• WAM using wind data from the WRF will produce waves that are more finer than the results of the WAM using wind data from NOGAPS.

• High-resolution winds reflected sea state near the coast, more than low-resolution winds, when input to ocean wave model.



Further work



http://www.oceansky.tmd.go.th

Marine Meteorological Disaster Warning System Project

HF Radar

http://www.oceansky.tmd.go.th/



HF radar in Thailand

Acknowledgements- This paper is supported jointly by Thai Meteorological Department, and JCOMM.

- Thanks to Dr.Songkran Agsorn and Director – General of Thai Meteorological Department for their encouragement and

- Thanks to Dr. David Meldrum for information and suggestion.

- Thanks to Korean local staff s for helping and kindness.



Thank you for attention.



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