热带大气季节内振荡的季节性特征及其在SAMIL-R42L9中的表现
SEASONAL VARIATIONS OF THE TROPICAL INTRASEASONAL OSCILLATION AND ITS REPRODUCTION IN SAMIL-R42L9
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摘要: 分析了NCEP资料和SAMIL-R42L9中热带大气季节内(30~60天)振荡(ISO)的季节变化特征及其与平均气候场季节变化的关系。NCEP资料的分析表明:热带地区大气ISO在空间分布上存在明显的季节变化,大气ISO的季节变化与平均背景场的季节变化有明显的一致性。在空间分布上,热带大气ISO的活动对暖的SST、强的对流活动、西风、强的降水和低层水汽辐合有很强的依赖性。大气环流模式SAMIL-R42L9基本能够再现热带大气ISO空间分布上的季节转换特征,尤其在动力场(纬向风)上表现得最为明显。但对基本气候态季节变化的模拟,对不同的物理量有明显的差异。模式结果表明:热带大气ISO动力因子的季节性比热力因子的季节性对平均背景场的依赖性更大,模式不能很好地反映NCEP资料表现出来的ISO对平均背景场的强依赖性,同时也说明热带大气ISO的季节性可能并不完全依赖于平均背景场的季节变化。
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关键词:
- 热带大气季节内振荡(ISO) /
- 季节变化 /
- 气候背景 /
- 大气环流模式
Abstract: Seasonal variations of the tropical intraseasonal oscillation(ISO) and relationship to seasonal variation of the climate background are studied by using NCEP/NCAR reanalysis data and output of SAMIL-R42L9. Analysis of NCEP data shows that spatial distribution of the tropical ISO has obvious seasonal variations,which are well consistent with the seasonal variation of climate background. The activity of the tropical ISO is,to a great extent,dependent on warm SST,strong convection,zonal western wind,strong precipitation and low-level moisture convergence. Main characteristics of the seasonal variations of the tropical ISO are captured by SAMIL-R42L9. Simulations of seasonal variation of climate background vary greatly with different variables. Results of SAMIL-R42L9 indicate that the seasonal variations of the tropical ISO in dynamical fields are more depended on climate background than in heating fields and SAMIL-R42L9 cannot represent well the strong dependence of the ISO on the climate background present in NCEP/NCAR reanalysis data. It also suggests that seasonal variations of the ISO do not completely depend on that of climate background.-
Key words:
- tropical intraseasonal oscillation /
- seasonal variation /
- climate background /
- GCM
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[1] MADDEN R A,JULIAN P R.Detection of a 40-50 day oscillation in the zonal wind in the tropical Pacific[J].J Atmos Sci,1971,28(5):702-708. [2] MADDEN R A,JULIAN P R.Description of global scale circulation cells in the tropics with 40-50 day period[J].J Atmos Sci,1972,29(6):1109-1123. [3] MURAKAMI T,NAKAZAWA T,HE J H..On the 40-50 day oscillation during 1979 northern hemisphere summer,Part (:Phase propagation[J].J Meteor Sor Japan,1984,62(3):440-468. [4] LAU K M,CHAN P H.Aspects of the 40-50 day oscillation during the northern winter as inferred from outgoing longwave radiation[J].Mon WeaRev,1986,114(7):1354-1367. [5] LAU N C,LAU WK-M.The structure and propagation of 40-50 day oscillations appearing in a GFDL general circulation model[J].J Atmos Sci,1986,43(19):2023-2047. [6] KNUSTON T R,WEICKMANN K M.30-60 day atmospheric oscillation:Composite life cycles of convection and circulation anomalies[J].Mon Wea Rev,1987,115 (7):1407-1436. [7] 李崇银.大气中的季节内振荡[J].大气科学,1990,14(1):32-45. [8] LI Chongyin,LI Guilong.Evolution of intraseasonal oscillation over the tropical western Pacific/South China Sea and its effect to the summerprecipitation in Southern China[J].Advances Atmos Sci,1997,14(2):246-254. [9] 翟盘茂,郭艳君,李晓燕.1997/1998年ENSO过程与热带大气季节内振荡[J].热带气象学报,2001,17(1):1-9. [10] 徐国强,朱乾根.1998年南海夏季风低频振荡特征分析[J].热带气象学报,2002,18(4):309-316. [11] 薛洪斌,钟中,薛峰.对流凝结加热的垂直分布与低纬大气的30~60天低频振荡[J].热带气象学报,2003,18(4):397-404. [12] 李崇银,龙振夏.大气季节内振荡及其重要作用[J].大气科学,2003,27(4):518-535. [13] 何志学,贺懿华,熊秋芬,等.1998年夏季热带内外大气低频振荡特征分析[J].热带气象学报,2004,19(1):51-63. [14] 李崇银.大气季节内振荡研究的新进展[J].自然科学进展,2004,14(7):734-741. [15] 林爱兰,梁建茵,李春晖.南海夏季风对流季节内振荡的频谱变化特征[J].热带气象学报,2005,21(5):542-548. [16] 琚建华,赵尔旭.东亚夏季风区的低频振荡对长江中下游旱涝的影响[J].热带气象学报,2005,21(2):163-171. [17] MADDEN R A.Seasonal variation of the 40-50day oscillation in the tropics[J].J Atmos Sci,1986,43(24):3138-3158. [18] HARTMANN D L,GROSS J R.Seasonal variability of the 40-50 day oscillation in wind and rainfall in the tropics[J].J Atmos Sci,1988,45(18):2608-2702. [19] GUTZLER D S,MADDED R A.Seasonal variations in the spatial structure of intraseasonal tropical wind fluction[J].J Atmos Sci,1989,46(5):641-660. [20] SALBY M L,HENDON H H.Intraseasonal behavior of clouds,temperature,and winds in the tropics[J].J Atmos Sci,1994,51(15):2207-2224. [21] 董敏,张兴强,何金海.热带季节内振荡时空特征的诊断研究[J].气象学报,2004,62(6):821-830 [22] ZHANG Chidong,DONG Min.Seasonality in the Madded-Julian oscillation[J].J Climate,2004,17 (16):3169-3180. [23] HENDEN H H,LIEBMANN B,NEWMAN M,et al.Medium range forecasts errors associated with active episodes of the Madden-JulianOscillation[J].Mon Wea Rev,2000,128(1):69-85. [24] SLINGO J M,SPERBER K R,BOYLE J S,et al.Intraseasonal oscillation in 15 atmospheric general circulation models:Results from an AMIPdiagnostic subproject[J].Climate Dyn,1996,12(5):325-357. [25] 贾小龙,李崇银,周宁芳.热带大气季节内振荡的一个数值模拟研究[J].气象学报,2004,62(6):725-739. [26] 李薇,俞永强.大气季节内振荡的耦合模式数值模拟[J].大气科学,2001,25(1):118-131. [27] XUE Y,SELLERS P J,KINTER J L,et al.A simplified biosphere model for global climate studies[J].J Climate,1991,4(3):345-364. [28] SLINGO J M.The development and verification of a cloud prediction scheme for the ECWMF model[J].Quart J Roy Meteor Soc,1987,113(7):899-927. [29] MANABE S,SMAGORINSKY J,STRICKLER R F.Simulated climatology of a general circulation model with a hydrologic cycle[J].Mon WeaRev,1965,93(12):769-798.
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