21 12 2006 12 ADVANCES IN EARTH SC IENCE Vol. 21 No. 12 Dec., 2006 : 100128166 (2006) 1221273210 3 1, 2, 2, 3 (1., 100085; 2., LASG, 100029; 3., 100082) : NCEP /NCAR,,,,,,,, : ; ; ; : P434 : A 1, [ 1 ] Flohn [ 2 ], 70% [ 3 ],, 1 2,, 18 [ 4 ] 1961 1970 10,,,, [ 5 ] [ 6 ], [ 7 ] [ 8 ], 1979 5 8 FGGE,, Kuo [ 8 ], 3 : 2006210211; : 2006211202. 3 : ( : KZCX32SW 2231) ; ( : 2005CB422000) ; ( : 40475027). : (19552),,,,. E2ma il: lx@ itpcas. ac. cn
1274 21 Chen [ 10 ],, [ 8 ],,, 2, 1 7, 12UTC ( 18 ), 00UTC ( 06 ) NCAR / NCEP, (1) LH = C w RR (1) LH, C w, 1 10 ( 1986 1995) : ( a) 12UTC ; ( b) 00UTC ; ( c) 12UTC ; ( d) 00UTC ; ( e) 12UTC ; ( f) 00UTC F ig. 1 10 years m ean ( 198621995) July 12UTC d iaba tic hea ting com pare w ith 00UTC
12 : 1275 RR 1 a b 1986 1995 7 12UTC 00UTC,, 150 W /m 2, 250 W /m 2,,, - 20 W /m 2 H 12 3 000 m 200 W /m 2 1c d 12Z 00Z 12UTC, H 00 00UTC, 10 7, 2 500 W / m 2, 50 W /m 2,,,, - 100 W /m 2 ( ), ( 1e), 2 7 1,,, 4 ( 1f),,,, ( 1e f),, 200 600 W /m 2, - 150 50 W /m 2 1e f 350 W /m 2 2 10 ( 1986 1995 ) 7 ( :W /m 2 ) F ig. 2 10 years m ean ( 198621995) July d iurna l var ia tion of d iaba tic hea ting over the T ibetan pla teau( Un it: W /m 2 ), 3 000 m 12UTC 00UTC,, H TP H m ean, : H TP = H 12 - H 00 (2) H m ean = ( H 12 + H 00 ) /2 (3) 3 3 200 hpa 3a 10 7, 7,, 3b 10 12UTC 00UTC,, 600 hpa ( 4a), ( 4b),
1276 21 3 7 200 hpa ( 10 5 / s) ( a. ( 1986 1995) ; b. 12UTC 00UTC ) F ig. 3 200 hpa July stream line and vortic ity ( 1025 / s) ( a. 10 years m ean ( 198621995) ; b. the d ifference of 12UTC and 00UTC) 4 7 600 hpa ( 10 5 / s) ; ( a. ( 1986 1995) ; b. 12UTC 00UTC ) F ig. 4 A s f ig. 3 but for 600 hpa, 5a 10 7 200 hpa,, ( 5b),,, 35,, 35 N,, ;, 7, ( 1e) ( 1a),,, 6 5, 600 hpa, ( 6a),,
12 : 1277,,,, 5 7 200 hpa ( 10 gpm ) ( Pa / s) ; ( a. ( 1986 1995) ; b. 12UTC 00UTC ) F ig. 5 200 hpa July geopoten tia l he ight ( 10 gpm ) and vertica l veloc ity ( Pa / s) ( a. 10 years m ean ( 198621995) ; b. the d ifference of 12UTC and 00UTC) 6 7 600 hpa ( 10 gpm ) ( Pa / s) ; ( a. ( 1986 1995) ; b. 12UTC 00UTC ) F ig. 6 A s f ig. 5 but for 600 hpa 7 ( 1986 1995) 7 ( K) 30 N ; ( a. 12UTC; b. 00UTC) F ig. 7 The cross section of 10 years m ean ( 198621995) July poten tia l tem pera ture ( K) and w ind vector a long 30 N( a. 12UTC; b. 00UTC)
1278 21,, 7 8 30 N 90 E 30 N 7a 10 12UTC ( 18 ) ( 10 3 ),,, 00UTC ( 7b ), 12UTC, 00UTC 00UTC ( 7b; 6 ),, 8 ( 1986 1995) 7 ( K) 90 E ; ( a. 12UTC ; b. 00UTC) F ig. 8 A s f ig. 7 but a long 90 E 8a 12UTC 90 E,,, 8b, 8b,, (45 N ) 8b,,,,, 4, [ 11 ],, 5W 5t + g gvw = g Sa g g + gf g (4) g = d d t, gf, W = P = g a g, g s, g a, D D t = 5 + g gv 5t,
12 : 1279 (4),,, -, : g gv W = g a g g + R (5) R = gf g + g a g g + g gv W (6) (5), 12 12UTC 00UTC 12UTC 00UTC (5), 12UTC 00UTC, g gv W = a g g + R (7) a b c 9 (7) = 0. 4357 ( 10-6 TU s; 1TU = 10-6 K/ (m s 2 ) 250 hpa,,, a, b 9e 12UTC 00UTC ( (7) a ), a, 12UTC 00UTC 9f 12UTC 00UTC ( (7) b ), a 7, a b, 9 ( 1986 1995) 7 = 0. 4357 ( 7) a b F ig. 9 The 10 years m ean ( 198621995) ca lcula ted the item a and b of the equa tion 7 on = 0. 4357 level
1280 21, ( 9a, b) ( 9c, d),,,, 10 = 0. 995 (7) ( 10-4 TU s) 10a 12UTC 00UTC ( 7 a ),, 10b,,,, ( ),,, [ 12 ], ( 12 h) ( c ) 5,, 7 400 W /m 2 500 W /m 2,,,, 350 W /m 2 550 W /m 2, : 10 ( 1986 1995) 7 = 0. 995 F ig. 10 A s f ig. ( 7) a b c 9 but on the = 0. 995 level (1), 35, 20 (2),, ( 45 N ) (3),
12 : 1281 60%,, (4),,,,,,, ( References) : [ 1 ] Ye Duzheng, Gao Youxi. Meteorology of the Q inghai2xizang Plat2 eau[m ]. Beijing: Science Press, 1979. [,. [M ]. :, 1979. ] [ 2 ] Flohn H. Contributions to a Meteorology of the Tibetan H ighlands [M ]. A tmospheric Science Paper, No. 130, Corolado State Uni2 versity, Ft. Collins, 1968. [ 3 ] Shen Zhibao. The temperature over Tibetan p lateau and its sur2 rounding areas[ C ] Ye Duzheng, ed. Meteorology of the Q ing2 hai2xizang Plateau. Beijing: Science Press, 1979: 10222. [. [ C ] / /.. :, 1979: 10222. ] [ 4 ] Tang Maocang. A ir p ressure and wind[ C ] Ye Duzheng, ed. Me2 teorology of the Q inghai2xizang Plateau. Beijing: Science Press, 1979: 23238. [. [ C ].. :, 1979: 23238. ] [ 5 ] Shen Zhibao. The hum idity over Tibetan Plateau and its surround2 ing areas[ C ] Ye Duzheng, ed. Meteorology of the Q inghai2xi2 zang Plateau. Beijing: Science Press, 1979: 39248. [. [ C ].. :, 1979: 39248. ] [ 6 ] Yin Daosheng. The local diabatic frontogenesis in the central of the Tibetan Plateau [ J ]. Acta M eteorological S inica, 1979, 37: 16225. [. [ J ]., 1979, 37: 16225. ] [ 7 ] Ma Henian, L iu Zichen, Q in Ying, et al. Study on the transforma2 tion p rocess of the thermal low in Q inghai p rovince[ C ] The Col2 lected Papers of the Meteorological Sciences Exam ination over the Q inghai2xizang Plateau. Beijing: Science Press, 1984: 2622272. [,,,. [ C ]. :, 1984: 2622 272. ] [ 8 ] Yang W eiyu. The D iagnosis of the Heating and Circulation over Tibetan Plateau in Summer[ D ]. Beijing: The Institute of A tmos2 pheric Physics, Chinese Academy of Sciences, 1988: 1632207. [. [ D ]. :, 1988: 1632207. ] [ 9 ] Kuo H L, Q ian Y F. Influence of the Tibetan p lateau on cumula2 tive and diurnal changes of weather and climate in summer [ J ]. M onthly W eather R eview, 1981, 109: 2 33722 356. [ 10 ] Shuyi S Chen, Houze R A. D iurnal variation and life2cycle of deep convective system s over the trop ical Pacific warm pool[ J ]. Quarterly Jounal of RoyalM eteorological Society, 1997, 123: 3572 388. [ 11 ] W u Guoxiong, L iu Yim in. Thermal adap tation, overshooting, dispersion and subtrop ical anticyclone, I: Thermal adaptation and overshooting[ J ]. Chinese Journal of A tm ospheric, 2000, 24 (4) : 4332446. [,. I: [ J ]., 2000, 24 (4) : 4332446. ] [ 12 ] Guoxiong W u, Yim in L iu, Jiangyu Mao, et al. Adap tation of the A tmospheric Circulation to Thermal Forcing over the Tibetan Plat2 eau [M ]. Observation, Theory andmodeling ofa tmospheric Vari2 ability. Sigapore: World Scientific Publishing Company, 2004: 922114. The D iurnal Variation of the Atmospheric C irculation and D iabatic Heating over the Tibetan Plateau L IU Xin 1, 2, WU Guo2xiong 2, L IW ei2p ing 3 (1. Institu te of Tibetan P lateau R esearch, Chinese A cadem y of Sciences, B eijing 100085, China; 2. S tate Key L abora tory of N um erica l M odeling for A tm ospheric Sciences and Geophysical F luid D ynam ics, Institute of A tm ospheric Physics, Chinese A cadem y of Sciences, B eijing 100029, China; 3. N ationa l C lim ate Center, B eijing 100081, China) Abstract: The NCEP /NCAR reanalysis data are emp loyed to analyze the diurnal variation of the diabatic heat2 ing and atmospheric circulation over the Tibetan Plateau and it s surrounding areas. The atmosphere over the TP is
1282 21 most sensitive to the diurnal change of heating, and it results in the vivid diurnal change feature over the TP and its surrounding areas. Its diurnal change is consistent w ith that of the heating field s, especially w ith diurnal change of the solar heating. Because the m ass of the atmospheric column over the TP is much lighter than other regions, the diurnal change of solar radiation heating causes more significant circulation variation over the TP. The equation of the potential vorticity is emp loyed to diagnose the dynam ics of diurnal circulation variation in the paper. The result show s while the solar radiation gradually enhanced in the daytime, the positive vorticity of lower level atmosphere and negative vorticity of high level atmosphere over the TP is increase. A ll these lead to the most significant circula2 tion and weather diurnal changes over the TP and its surrounding areas. The features of the diurnal change of the atmospheric circulation are in accordance w ith both theory and data analysis results in their phase and circulation patterns. Key words: Tibetan Plateau ( TP) ; D iabatic heating; D iurnal change; Potential vorticity. 973 1997 6 4,, ( 973 ),,, 1998 2006,, 297, 44,, 28, 72, 24. 2% 973,, 2005 11 973, 2006 12 13 15,, 973,, 973, 973 : (1), (2), (3),,,,,, : : linhai@mail. nsfc. gov. cn linh@ igsnrr. ac. cn : 8 730000 adearth@ lzb. ac. cn 973,,,, (1 12 ) 973 2006 12