[12 ( ), ],, [13 ] [14, ], ;,, 1 6 [15 ], ( ) [1618 ], Blackmon [16,19 ],,, [20, ],, ;,,, ( ), [8,9 ], Mak [21 ] [22,23 ],? ( )?, Orlanski [24

28 6 2004 11 Chinese Journal of Atmospheric Sciences Vol128 No16 Nov1 2004 3 1) 2) 1) 1) (, 266003) 2) (, 100029),,,,,,, :,, :, ;,, : ; ; ; ; 100629895 (2004) 0620901224 P433 A 1 :, [1,, ], [26 ] [7,8,? ],,,, [9,10 ],, Cai Mak [11 ], 2003204228, 2003212225 3 4017019340275025 40325016

902 28 [12 ( ), ],, [13 ] [14, ], ;,, 1 6 [15 ], ( ) [1618 ], Blackmon [16,19 ],,, [20, ],, ;,,, ( ), [8,9 ], Mak [21 ] [22,23 ],? ( )?, Orlanski [24 ],? Mak Cai [25 ] 2 [8,9, ],, :,,, : (1) ; (2),

6 : 903,, 5 5 t ( 2 < + y - F r <) + J ( <, 2 < + y - F r <) = F s, (1), <, = ( L 2 / U) 0, 0,, F r = ( L/ R 0 ) 2, R 0, F s, L = 1000 km U = 10 m s - 1 : < = - guy + +, (2), <, gu,,, (1) : 5 5 t + gu 5 5 x ( 2- = - J (, 5 5 t + gu 5 5 x ( = - J ( F r ) + (+ F r gu) 5 5 x 2 ) p - J ( 2 ) p - J (, 2 ) p - J (, 2 ) p, (3) 2 - F r ) + (+ F r gu) 5 5 x, 2 ) s - J (, 2 ) s - J (, 2 ) s + F, (4) (3) (4), p, s, 14, 516 (3) (4), J [ (+ ), 2 ( + ) ], J [ (+ ), 2 ( + ) ] = J (, 2 ) + J ( 2 ) + J (, 2 ) + J (, 2 ), J (, 2 ) = J (, 2 ) p, J (, 2 ) = J (, 2 ) p + J (, 2 ) s, J (, 2 ) = J (, 2 ) p + J (, 2 ) s, J (, 2 ) = J (, 2 ) p + J (, 2 ) s, (3) (4) ( - guy) ( ) - guy + = 2 2 L y A 0 sech (019A 0 ) cos ( kx) sin ( my), (5), k = 2 / 2L x, m = 2/ ( L y / 2) L x L y, A 0, 017 1a 0, : x, (0, y, t) = 0. (6) = ( L x, y, t), (0, y, t) = ( L x, y, t) ; [10 y ] :

904 28 5 2 g( y, t) 5 y5 t 5 2 ( y, t) 5 y5 t y = 52 g( y, t) 0 = 0, 5 5 y5 t y = L y 5 x = 0, y = 52 g ( y, t) 0 = 0, 5 5 y5 t y = L y 5 x = 0,, g( y, t ) ( y, t ) x,,,,, F s = 2 a 0 exp [ ( - 2 ( x + x 0 ) 2 ][cos ( k 1 x - t) - cos ( k 2 x - t) ]sin my 2,, k 1 = 2 / 14L x, k 2 = 2 / 15L x, a 0, 0175, x 0,, (1b), 1 (a) (b),, [26 ] 2, h = h 0 cos( kx) sin my 2,, h 0, 015, [26 ], (3) (4),

6 : 905 5 5 t + gu 5 5 x ( = - J (, 5 5 t + gu 5 5 x ( 2 2+ h - = - J ( 011,, F r ) + (+ F r gu) 5 5 x + gu 5 h 5 x 2+ h) p - J (, 2+ h) p - J (, 2 ) p - J (, 2 ) p, (7) 2 - F r ) + (+ F r gu) 5 5 x, 2+ h) s - J (, 2 ) s - J (, 2 ) s, (8) (6), - guy +,,,, (3) (4) (7) (8), (3) (4) (7) (8),,,, Mak [21 ] (1) (4),,,, 3, Pierrehumbert [27 ] (absolute instability), WKB ( Wentzel2Kramers2Bril2 louin) ( ), (local mode), (convective instability), ( ), Mak [21 ]

906 28, Pierrehumbert, y ( x ) [28 ],, [29 ], [30 ], Mak [21 ],,??,,, [25 ], ( ) 4,,,, 411 41111, Shutts [2 ] Shutts,, [8,9 ],,

6 : 907 Shutts,, Shutts, 3 4, 3,, 3eh,,,,, 4ad,,, 41112 D E 5 ( 27, 44 ), ( D ) ( E ), D [25 ] D = 5 U 5 x - 5V 5 y,5v 5 x + 5 U 5 y, x, y E [25 ] E = 1 2 ( v 2 - u 2 ), ( - u v ), E, x, y Orlanski [23 ] E x, y : ( - u v ) ( u v ), 5a c, D,,, 5bd E ;, y E y, 6 E y,,,,,,,,,,,,

908 28 3 111927 38 (a) (d), : - 0115-4105, : 0115

6 : 909 3 (1) (e) (h)

910 28 3 (2) (i) (l), : - 012-410, : 012

6 : 911 4 303644 50, (a) (d), : - 012-410, : 012

912 28 4 (1) (e) (h)

6 : 913 4 (2) (i) (l), : - 012-410, : 012

914 28 5 27 44 D E : (a) (c) D, (b) (d) E :,,,, 41113 7 8 7

6 : 915 7 ( ) (a), : - 0115-4105, : 0115 ; (b), : - 012-410, : 012

916 28 8 (a) (b) ; (c) (d),

6 : 917 8a, 8c, 25 ( ),, 2,, 8b 8a 10 25 ( ), ( ), ( ) 8a,, 5 E, [2,8 ] 8c, 25, 50 (50 ) 8d 8c,,, 8a 34, 27 44,, 34 8, 20, 13,,,,,, 8,,,,, 412 [25,, ] : K t = E D - ( V K ) - ( v p (1) ), (9), K = (1/ 2) ( u 2 + v 2 ), E = [ (1/ 2) ( v 2 - u 2 ), ( - u v ) ], D, D = [ ( 5 U/ 5 x - 5 V/ 5 y), ( 5 V/ 5 x + 5 U/ 5 y) ] ; p = ( p/u 2 ) dim, p (1) p, p (0) x p (1) : p = p (0) + p (1), = v (0), p y = - u Ro Ro, Ro = U fl. 2 p (1) = - 4 u x U x - 2 u y V x - 2 v x U y, (10) : x, y

918 28 (9), : (1) ( E D) ; (2) [ - ( V K ) ] ; (3) [ - ( v p (1) ) ] (9) E D, D E,, 5, D E, E, 6 E y (9), (9), 41211 9, 9a,, ( y > 21 y < 9),, 9b,,,, 9c ( ),,,,,,,,, 9d,,, ;,,,,, ;, 41212 10,,,,,, ( y > 21),,,

6 : 919 9 27,, (a) ( 0103) ; (b) ( 011) ; (c) ( 0105) ; (d) ( 011)

920 28 ;,,,, ;,,,,,,,,,,,,,,,, 9 10,,, (8),,, Orlanski [24 ], ( ) ( ) Orlanski,,?, Orlanski,,,,,, :, ;,,,, :,,,,,

6 : 921 10 44,, (a) ( 0102) ; (b) ( 011) ; (c) ( 0105) ; (d) ( 011)

922 28 5,,, : (1), E,,,,,,,,, (2) : ;, (3) :,,,,,,,, :, 1 Rex, D. F., Blocking action in the middle troposphere and its effect upon regional climate : an aerological study of blocking cc2 tion, Tellus, 1950, 2, 196211. 2 Shutts, G. J., The propagation of eddies in diffluent jet streams : eddy vorticity forcing of blocking flow fields, Quart. J. Roy. Meteor. Soc., 1983, 109, 737761. 3 Haines, K., and J. C. Marshall, Eddy2forced coherent structures as a prototype of atmospheric blocking, Quart. J. Roy. Meteor. Soc., 1987, 113, 681704. 4, 1980,, 1994, 52 (3), 308319. 5,,, 1998, 56 (6), 665680. 6,,, 2001, 25 (3), 289302. 7,, :, 1999, 113 pp.

6 : 923 8 Luo Dehai, Planetary2scale baroclinic envelope Rossby solitons in a two2layer model and their interaction with synoptic2scale ed2 dies, Dyn. Atmos. Oceans, 2000, 32, 2774. 9,, :, 2000, 248 pp. 10 Luo, D., F. Huang, and Y. Diao, Interaction between antecedent planetary2scale envelope soliton blocking anticyclone and synoptic2scale eddies : Observations and theory, J. Geophys. Res., 2001, 106, 3179531815. 11 Cai, M., and M. Mak, Symbiotic relation between planetary and synoptic waves, J. Atmos. Sci., 1990, 47, 29532968. 12,,, 2001, 46 (9), 753757. 13 Rex, D. F., Blocking action in the middle troposphere and its effect upon regional climate : the climatology of blocking action, Tellus, 1950, 2, 275301. 14 Hansen, A., and T. C. Chen, A spectral energeties analysis of atmospheric blocking, Mon. Wea. Rev. 1982, 110, 1146 1159. 15 Lejengs, H., and H. gkland, Characteristics of Northern Hemisphere blocking as determined from a long time series of observa2 tional data, Tellus, 1983, 35A, 350362. 16 Blackmon, M. L., J. M. Wallace, N. 2C. Lau et al., An observational study of the northern Hemisphere wintertime circula2 tion, J. Atmos. Sci., 1977, 34, 10401053. 17 Blackmon, M. L., Y. 2H. Lee, and J. M. Wallace, Horizontal structure of 500 mb height fluctuations with long, intermedi2 ate and short time scales, J. Atmos. Sci., 1984, 41, 961979. 18 Hoskins, B. J., and P. J. Valdes, On the existence of storm2tracks, J. Atmos. Sci., 1990, 47, 18541864. 19 Blackmon, M. L., A climatological spectral study of the 500mb geopotential height of the Northern Hemisphere, J. Atmos. Sci., 1976, 33, 16071623. 20 Chang, E. K. M., S. Lee, and K. L. Swanson, Storm track dynamics, J. Climate, 2002, 15, 21632183. 21 Mak, M., Wave packet resonance : instability of a localized barotropic jet, J. Atmos. Sci., 2002, 59, 823836. 22 Chang, E. K. M., and I. Orlanski, On the dynamics of a storm track, J. Atmos. Sci., 1993, 50 (7), 9991015. 23 Lee, S., and I. M. Held, Baroclinic wave packets in models and observations, J. Atmos. 1428. 24 Orlanski, I., Poleward deflection of storm tracks, J. Atmos. Sci., 1998, 55 (16), 25772602. 25 Mak, M., and M. Cai, Local barotropic instability, J. Atmos. Sci., 1989, 46, 32893311. Sci., 1993, 50 (10), 1413 26 Luo, D., Near resonant topographically forced envelope Rossby solitons in a barotropic flow, Geophys. Astrophys. Fluid. Dyn., 1999, 90, 161188. 27 Pierrehumbert, R. T., Local and global baroclinic instability of zonally varying flow, J. Atmos. Sci., 1984, 41, 2141 2162. 28 Bretherton, F. P., Critical layer instability in baroclinic flows, Quart. J. Roy. Meteor. Soc., 1966, 92, 325334. 29 Hoskins, B. J., M. E. McIntyre, and A. W. Robertson, On the use and significance of isentropic potential vorticity maps, Quart. J. Roy. Meteor. Soc, 1985, 111, 877946. 30 Mak, M., Non2hydrostatic barotropic instability : applicability to non2supercell tornadogenesis, J. Atmos. Sci., 2001, 58, 19651977.

924 28 A Dynamic Study of the Interaction bet ween Transient Eddies and Blocking Diao Yina 1), Li Jianping 2), and Luo Dehai 1) 1) ( Department of Atmospheric Sciences, Ocean University of China, Qingdao 266003) 2) ( State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029) Abstract Using a channel barotropic model, the paper discusses the interaction between the transient synoptic2 scale eddies and the blocking, and investigates the role played by thetype blocking in offecting the moving trace of the storm track. An equation describing the changing rate of the local energy is applied to analysing the details of the energy budget of the transient eddies when they interact with the blocking flow. The results show that the initial weak planetary scale ridge can develop into a strong and steady blocking flow under the energy and the vorticity forc2 ing of the synoptic eddies coming from upstream. The energy budget analysis of the synoptic eddies shows that in the blocking area the synoptic eddies lose energy while in the northern and southern vicinity of the blocking area eddies gain energy and move downstream along the northern and southern edges of the blocking area. Thus the upstream ed2 dies are transformed from one train into two trains under the feedback of the blocking flow. Interacting with two differ2 ent types of the blocking flow is considered in this paper, the transient synoptic eddies show the different traveling traces : when the background planetary scale the blocking flow is a dipole type, the trace of the eddies distribute sym2 metrically along the southern and northern edges of the blocking area ; when the blocking flow is the type, the traveling eddies show an asymmetric trace, viz the northern train is strong and the southern one is very weak. The re2 sults are consistent with the phenomenon showed by the observational data that the winter storm track is always deflect2 ing northward. Key words : blocking ; transient eddy ; storm track ; interaction ; dynamic study