Analyzing and measuring the surface temperature of Qinghai2Tibet Plateau

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1 CHINESE JOURNAL OF GEOPHYSICS Vol. 49, No. 2 Mar., 2006,,.,2006,49 (2) : Jiang H, Cheng G D, Wang K L. Analyzing and measuring the surface temperature of Qinghai2Tibet Plateau Chinese J. Chinese),2006,49 (2) : Geophys. ( in,,, cm,.,, :, 4, - 2 ;, 16, - 3.,,.,,,,,, (2006) P , Analyzing and measuring the surface temperature of Qinghai2Tibet Plateau J IANG Hao, CHENG Guo2Dong, WANG Ke2Li Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou , China Abstract For Qinghai2Tibet Plateau 0 cm temperatures are measured by mercury thermometer at weather stations. Also they can be obtained by upward and downward long2wave radiation and the differences between both temperatures are analyzed in this paper. The results show that, because the limitation of the measure method used mercury thermometer on the weather station observation field, there is an measuring error for the surface temperature measured by this method. On the bare surface, the difference in day can be over 4 in the summer, and the negative difference at night can be about - 2. On the dense vegetation surface, the highest difference in day can be over 16, and the negative difference at night can be about - 3. Because the differences are discrete and non2proportional, the representation of the surface temperature measured by mercury thermometer is very bad even make the average or integral process. With the more high accuracy and reliability are requested, it is important and necessary to popularize the surface temperature measure method based on the surface radiation. Keywords Qinghai2Tibet Plateau, Surface temperature, Mercury thermometer temperature, Radiation temperature, Surface temperature measure method ( KZCX12SW204) ( ).,,1953,, -. E2mail : ac. cn

2 392 (Chinese J. Geophys. ) , - [1 4 ]. :,. ( ) ( ),,.,,,. -,,, ,. 2,, : R u = T 4 g + (1 - ) R d, (1) R u,, stefan2boltzmann, T g, R d. (1) T g = R u - (1 - ) R d 1 4. (2) (2),, = 1,, [ 5 ], 20, ,, (2) :, 0,., [6 ],,, ;,,.,, ; 0cm ( ). 10, 00 : : : : : : :00 16 :00 18 :00 20 :00, , ,4,7,10. 1, : ( 1a),, ; ( 1b 1c), ; ( 1d),,. 1,

3 2 : (a), (b), (c) (d) ( T 0 ) ( T g ) Fig. 1 Distribution of correlation between surface mercury thermometer temperature ( T 0 ) and surface radiation temperature ( T g ) at Gerze (a), Garze (b), Lhasa (c) and Nagqu (d) on the Qinghai- Tibetan Plateau Table 1 Correlation ratio of surface mercury thermometer temperature and surface radiation temperature ,,,. 1a,, 1, 1 1. ( ),,,,, ;,, ,,,., 312,

4 394 (Chinese J. Geophys. ) 49,,,, 3,,,, ( 1b). ( ),, ;,.,,,. 1, 20 %, 70 %.,, ;,,,. 313,,,, 30cm,. ( 1c), 1, ; ( ) ; ( ), %,, 1173.,, 314,, ( 1d),,. ( ),,, 1 1.,,,.,, 1 1,.,,, 1-20 %,,,.,,, 5 %, 20 %.,, 70 %, 20 % , :,,,.,,,,. 3 4 ( 3a),,,, 4 ;,, - 2. ( 3b),, 6, 11., - 3. ( 3c),,,, 13.,,

5 2 : Jan., 4 Apr., 7 Jul., g 10 Oct.,,,. Hollow symbol as surface mercury thermometer temperature, solid symbol as surface radiation temperature, Unit :. 2 (a), (b), (c) (d) ( T 0 ) ( T g ) Fig. 2 Diurnal variation of surface mercury thermometer temperature ( T 0 ) and surface radiation temperature ( T g ) at Gerze (a), Garze (b), Lhasa (c) and Nagqu (d) on the Qinghai- Tibetan Plateau 16., - 3. ( 3d),,.,, ,,,,,,., 4, - 2., 16, , ,4,7,10, 2,,.,.,.,,,

6 396 (Chinese J. Geophys. ) 49 1 Jan., 4 Apr., 7 Jul., 10 Oct., 3 (a), (b), (c) (d) ( T e ) Fig. 3 Diurnal variation of difference ( T e ) between surface mercury thermometer temperature and surface radiation temperature at Gerze (a), Garze (b), Lhasa (c) and Nagqu (d) on the Qinghai- Tibetan Plateau,,,,.,, 10,,,. 6 (1) 2 4 ( ) Table 2 Mean discrepance, daily amount discrepance and root2mean2square error of surface mercury thermometer temperature relative to surface radiation temperature (Unit : )

7 2 : , 5 %, 20 %,,, ;, 70 %, 20 %,,. (2),,., 4, - 2 ;, 16, - 3. (3),, ;,,,,. (4),,,,., (References) [ 1 ],,.., 2003, 25 (6) : Cheng G D, Jiang H, Wang KL, et al. Thawing index and freezing index on roadbed surface in permafrost regions. Journal of Glaciology and Geocryology (in Chinese), 2003, 25(6) : [ 2 ] Jiang H, Wang K. Analysis of the surface temperature on the Tibetan Plateau from satellite. Advances in Atmospheric Science, 2001, 18 (6) : [ 3 ],,., 1997, 16 (3) : Jiang H, Wang KL, Wu G X. Effects of surface temperature and its taking values on atmospheric longwave radiation cooling over the Qinghai- Xizang. Plateau. Plateau Meteorology (in Chinese), 1997, 16(3) : [ 4 ],.., 1995, 53 (1) : Wang K L, Zhong Q. The relationship between the planetary and surface net radiation over the Qinghai- Xizang Plateau. Acta Meteorologica Sinica (in Chinese), 1995, 53 (1) : [ 5 ],.., 1992, 16(4) : Jiang H, Zhong Q. The theoretical analysis and experiment of the method for measuring natural surface emissivity. (in Chinese), 1992, 16 (4) : Atmospheric Sinica [ 6 ].. :, 2003 China Meteorological Administration. The Ground Meteorological Observation Criterion. Beijing : Meteorology Press, 2003 ( )