Relationship between the Tibetan Plateau Heating and

East Asian Summer Monsoon Rainfall

許晃雄 (Huang-Hsiung Hsu) 劉新 (Xin Liu)台灣大學大氣科學系 (NTU)

洪志誠 (Chi-Cherng Hong)台北市立師範學院自然科學教育系

(Taipei Municipal Teachers College)

(1st part: GRL, in press)

Major rainfall pattern in EASM

（ 1993 ， 1994 ，2003 ）

Affecting Taiwan（ 1993 ， 1994 ，

2003 ）

Mechanism ：• SST ： PJ pattern correlation ~ 0.3• Tibetan Plateau forcing?• ?

澇（旱）

旱（澇）

Heating index&1st PC

Correlation HTP(JJA)Vs. JJA Heaitng

Correlation HTP(MAM)Vs. JJA Heaitng

Heating index: vertically-integrated diabatic heating (above 3 Km)

Rainfall Composites (strong - weak)

1st EOF (JJA precipitation)

Vorticity Composites200 hPa

500 hPa

Patterns reproduced by SVD analysis

Numerical experiments: Barotropic model

Basic flow： 200hPa zonal-mean zonal flow in JJA

Forcing： divergence over the Tibetan Plateau

4

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( ) ( )

t

v f f v k r F

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Basic flow: Climatological mean flow

Simulation1. Same forcing2. Basic flow (strong HTP) – Basic flow (weak HTP)

Observation

Strong - Weak

Simulation

Observation

1993 (S) – 1994 (W)

zonal-mean U

zonal-mean U

PV gradient

PV gradient

strongweak

19931994

wave guide

wave guide

[U] JJA

1993 1994

1993 - 1994HTP(S)-HTP(W)

JJA []

1993 - 1994

1993 1994

HTP(S)-HTP(W)

Corr(Precip.EOF1,SST)JJA

Corr.(TPH, Precip)

Part. Corr.(TPH, Precip|WNPSST)

Corr.(WNPSST, Precip)

Part. Corr.(WNPSST, Precip|TPH)

Indian Ocean Dipole SST(50~70E, 10S~10N) – SST(90~110E, 0~10S)

Corr.(TPH, Precip)

Part. Corr.(TPH, Precip|Nino3.4)

Corr.(Nino3.4, Precip)

Part. Corr.(TPH, Precip|TPH)

JJA rainfall in Taiwan

-61.60-75.04

280.57

102.23

-89.09

-344.39

-136.20-104.46

-180.10-160.94

21.73

338.13

-179.53

-15.69

-139.49

-59.86

-170.13

1.16

62.29

-4.21

-24.30

111.57

-158.64

-2.53

-213.94

-253.81

-25.70

353.07

52.81

-148.84

156.00

85.71

-113.60

-319.23

349.67

11.19

282.09

-43.83-29.40

41.5342.10

-26.77

260.20

153.70

80.79

27.89

413.56

-156.74

133.37104.96

174.13

-119.51

51.70

-2.21

378.43

-196.51

50.59

-205.21

139.09

282.54

-196.91

-112.73

-277.91

-114.89

-5.61

54.29

-35.21

39.21

-54.59

-102.67

-232.24

204.14184.14

163.86

278.07

-81.51

264.61

-69.61

85.54

-317.49

-51.86-60.00

-140.89

195.84

148.39

3.81

-208.80

-29.56

-283.19

225.59

-101.47-77.23

-150.89

194.80

-86.50

-234.87

246.26

53.74

149.56

39.39

-76.23

-159.91

-49.76

-400

-300

-200

-100

0

100

200

300

400

500

1900 1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

年份

月雨量距平值

(mm)

7 ( )1901-2003 6-8個測站 台北、花蓮、澎湖、台南、台中、恆春、台東 年 月降雨時序

558.857 mm平均值：170.746 mm標準差：

HTP(S) – HTP(W)

1993-1994

[U]

HTP(S) - HTP(W)

[]

1993-1994