Seasonal Variation and Test of Qinghai-Tibetan Plateau H

eating and Its Profile

Zhong Shanshan , He JinhaiKey Laboratory of Meteorological Disasters of Jiangsu,Nanjing University of Information Scie

nce & Technology

NANJING UNIVERSITY OF INFORMATION SICENCE & TECHNOLOGY

1. Introduction

2. Data and Methodology

3. Seasonal Variation and Test of Tibetan

Plateau Heating and Its Profile

4. Summary

Outlines

• height is the highest

• acreage is the largest

• surface feature is more complicated

• exerts pronounced effects on atmospheric circulations and climate worldwide

Qinghai-Tibetan Plateau

(QTP)

introduction

1

the QTP as a heat source is so great that it influences global atmospheric and oceanic circulations .

(Krishnamurti T. N. et al., 1973; Ye D. Z. ,1998; Zhao P , 2000 ; Zhao P., 2001 )

the strongest heat source Q1 in summer Asia is not over the QTP but in the northern Bay of Bengal and the South-China Sea – western Pacific.

( Chen L. X., W. L. Li, 1981)

the QTP heating effect is pronounced.

the QTP heating strength is not very pronounced.

How reasonable ?

How strong ?

1961-2001 ECMWF daily reanalysis data （ ERA for short ） 1961-2001 NCEP/NCAR daily reanalysis data

1979-2001 daily OLR ( Outgoing Longwave Radiation)

1979-2001 GPCP(Global Precipitation Climatology Project)

1998-2006 monthly 3A12 data obtained from TRMM µwave Imager (TMI) ： 1.surface rain; 2.latent heat

1979-2001 monthly precipitation form 231 station in China (included 71station on tibetan plateau)

Jun 4th-14th in 1998 ， relative humidity from the radiosonde data at Anduo were obtained by GAME/Tibet project

Data and methodology

11

1 s

t

p

pQ Q dp

g Vertical integration

10

k

p

pQ C V

p t p

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atmospheric heating source (Yanai, et al.,1992 ) :

.

Seasonal variation and test of Qinghai-Tibetan plateau heating and its profile

Distribution of the 23-yr mean (1979-2001) vertically integrated heat source in summer by (a) ERA; (b) NCEP I

Summer (ERA) Summer (NCEP)

（ a ） 1979 ～ 2001 GPCP （ b ） 1998 ～ 2006 rain of 3A12 （ c ） 1979 ～ 2001 OLR （ d ） 1979-2001 precipitation in China

Summer (OLR) Summer Observed Rain

Summer (GPCP) Summer (3A12 )

left ： ERA

right ： NCEP

Monthly mea

n <Q1> distri

bution in hor

izontal over t

he QTP. (Unit

s: W/m2 )

Jan ERA Jan NCEP

Apr NCEP

Jul NCEP

Oct NCEP

Apr ERA

Jul ERA

Oct ERA

ERA

NCEP

Regional averaged monthly <Q1> (W/m2) over the QTP

in 1979-2001

Mean heating rate at≥3000m level over the QTP during 1979-2001 （ Units ：℃ /day ）

ERA NCEP

 

May Jun

Jul Aug Sep

Mar AprNCEP

ERA

The vertical profile of monthly mean Q1 at ≥ 3000 m level over the

QTP from March to September in 1979-2001 ( /day)℃

Mar Apr May Jun

Jul Aug Sep

Monthly mean Latent heat profile of 3A12 at ≥ 3000 m level over the QTP from

March to September in 1998-2006 ( /day) ℃

Latent heat

June 4th -14th 1998, Anduo’s vertical profile of left: heating rate Middle: relative humidity Right: latent heat

Relative humidity

latent heat

the precipitation of Anduo during June

4th-14th in 1998 （ unit ： mm ）

date 4 5 6 7 8 9 10 11 12 13 14

rainfall 0 0 1 0 42 0 0 0 0 0 0

The location of Anduo : 91°.06′E ， 32°.21′N ， 4801m)

Comparison of relative humidity with heating rate of A

nduo during June 7th-9th 1998

L.RH （ %） ; M.ERA （℃ /d ） ; R.NCEP （℃ /d ）

Comparison of relative humidity with heating rate of Anduo on June 10th and 12th 1998a 、 RH （ % ） ; b 、 ERA （℃ /d ） ; c 、 NCEP （℃ /d ）

The distribution of maximum heating level over Qinghai-Tibetan Plateau and its nearby regions in June during 1979-2001

ERA

400hPa

500hPa

600hPa

600hPa 500hPa

The distribution of heating rate on the maximum heati

ng level in June ( /day)℃

As far as the calculated heat sources are concerned, NCEP- and ERA- based summer thermal sources clearly show the surface heavy rainfall centers of the Asian monsoon region. As a result, the findings are rational for the data used.

For the two kinds of reanalysis data, their vertical profiles are similar during the period from March to September. However, the ERA is superior to NCEP , which is tested by the radiosonde data at Plateau station.

summary

The thickness and intensity of heat source over the plateau change with season. The heating rate of the plateau which is comparable to the Bay of Bengal’s, is remarkable at the maximum heat source layer.

Aknowledgement

• The radiosonde data at Anduo were obtained by GAME/Tibet project, which was GAME-Tibet project supported by the MEXT, FRSGC, NASDA of Japan, Chinese Academy of Science, and Asian Pacific Network.

Thanks!