Thesis TopicsThesis TopicsProf. C.-P. ChangProf. C.-P. Chang

Tropical and Monsoon MeteorologyTropical and Monsoon Meteorology

Focus on the area of Indian Ocean-Asia-Focus on the area of Indian Ocean-Asia-Australia-PacificAustralia-Pacific

All topics on Weather and Climate in this areaAll topics on Weather and Climate in this area(all spatial and time scales)(all spatial and time scales)

Data Analysis (NWP analysis, satellite data)Data Analysis (NWP analysis, satellite data)

General Circulation Model SimulationGeneral Circulation Model Simulation

Current FocusesCurrent Focuses

East Asian Summer Monsoon (Meiyu weather East Asian Summer Monsoon (Meiyu weather system in China/Japan/Korea and vicinitysystem in China/Japan/Korea and vicinity

East Asian Winter Monsoon, particularly on East Asian Winter Monsoon, particularly on Maritime Continent Rainfall (Local, seasonal Maritime Continent Rainfall (Local, seasonal and climate variations of rainfall over and climate variations of rainfall over Malaysia/Indonesia and vicinity)Malaysia/Indonesia and vicinity)

Equatorial Tropical CyclonesEquatorial Tropical Cyclones

East Asian Summer East Asian Summer MonsoonMonsoon

Convective systems

Onset of phased Monsoon rainbelt

Subtropical High

MJOSCS Monsoon Onset

East Asian Winter East Asian Winter MonsoonMonsoon

MJO

Subtropical High

Convective systems

Cold Surges

EQ

110E

SINGAPORE

KUALA LUMPUR

105E

EQ

5N 5N

BORNEO ISLAND

SUMATRA ISLAND

GMS V 12/27/2001 0232 UTC

Equatorial TC: Typhoon Equatorial TC: Typhoon Vamei 2001Vamei 2001

center at 1.5N, lowest center at 1.5N, lowest latitude record latitude record

Chang et Chang et al 2003, al 2003, See See Poster Poster outside outside R251R251

A classic formation criterion: 5 degrees away A classic formation criterion: 5 degrees away from equator (e.g., Gray, 1968, Anthes, 1982)from equator (e.g., Gray, 1968, Anthes, 1982)

No TC Formation at the No TC Formation at the Equator?Equator?

The lowest latitude of previously recorded The lowest latitude of previously recorded development: Typhoon Sarah in 1956 (3.3°N)development: Typhoon Sarah in 1956 (3.3°N)

Vffdt

d )()(

Reason: Coriolis effect needed for initial spin-Reason: Coriolis effect needed for initial spin-upup

NOGAPSNOGAPS 850hPa Wind and 850hPa Wind and VorticityVorticity

(red +, green -)

+

12N

10N

8N

6N

4N

2N

EQ

2S 102E 104E 106E 108E 110E 112E

12/26/2001 22:32 UTC

BORNEO ISLAND

SUMATRA ISLAND

MALAY

PENNINSULA

QuikSCAT WindsQuikSCAT Winds

Topic on Equatorial Tropical Topic on Equatorial Tropical CycloneCyclone

Will more frequent development be Will more frequent development be observed with increased remote sensing? observed with increased remote sensing?

Can equatorial formation occur Can equatorial formation occur elsewhere? (Surges are strongest in the elsewhere? (Surges are strongest in the South China Sea). South China Sea).

Mechanism of development. Mechanism of development.

ApproachApproach

NWP gridded data: NOGAPS, NCEP, NWP gridded data: NOGAPS, NCEP, ECMWFECMWF

Scatterometer Ocean surface winds: Scatterometer Ocean surface winds: QuikSTATQuikSTAT

Satellite Data: Hourly IR, MODIS images, Satellite Data: Hourly IR, MODIS images, TRMM PR TRMM PR

– – Analyze recently observed Analyze recently observed equatorial vortices:equatorial vortices:

Typhoon Agni 2004Typhoon Agni 2004

Typhoon Agni 2004Typhoon Agni 2004

EQEQ

60E

NOGAP 1000 hPa WindNOGAP 1000 hPa Wind

EQ EQ

70E