不同辐射参数化方案对南京地区大雾过程数值模拟的影响

为了比较不同长、短波辐射参数化方案对江苏省大雾过程的模拟效果,本文利用WRF模式,通过设计不同长、短波辐射参数化方案,对江苏省2015年5月18—21日和12月20—21日2次典型大雾过程进行了数值模拟,讨论了模式中不同长、短波辐射参数化方案对江苏省大雾过程的模拟影响。采用平均绝对误差(MAR)、均方根误差(RMSE)、皮尔逊相关系数(r)及中国气象局颁布的雾区预报规定,评价得到不同条件的最优模拟方案。结果表明:(1)热力条件与水汽条件,模拟最优方案为长波GFDL方案与短波RRTMG方案组合。(2)动力条件,最优辐射参数化方案组合为CAM方案与FLG方案组合。(3)雾区的模拟,效果最好的方案为长波GFDL方案与短波RRTMG方案的组合。     

WRF-Solar模式对山东太阳总辐射的模拟效果检验

利用专门为太阳能资源评估应用的 WRF-Solar数值模式系统,结合 MODIS 气溶胶光学厚度（AOD550 nm）数据,设置了5种山东区域总辐射模拟方案,使用山东济南、福山、吉县3个太阳辐射站总辐射观测数据,对晴天、阴天、雨天以及四季代表月等逐时总辐射模拟结果进行了对比检验。 结果表明：WRF-Solar数值模式对总辐射模拟能力在晴天和少云天最好,阴雨天较差,四季代表月中,天气过程较少的秋季和冬季模拟效果较好,春季次之,夏季相对较差;晴天和少云天、阴天和雨天以及不考虑天气过程的四季代表月所有日条件下,长、短波辐射方案分别采用RRTMG方案、new Goddard 方案,积云对流参数化方案均采用Grell 3D集合方案,同时使用AOD550 nm的气溶胶数据的总辐射模拟能力最强;WRF-Solar模式中加入 MODIS 气溶胶光学厚度资料后,山东区域晴天总辐射模拟结果明显改善,秋季、冬季代表月亦明显改善,但阴天和雨天总辐射模拟结果改善不明显,低能见度日总辐射模拟结果有所改善。     

基于CWRF的中国近海热带气旋集合模拟及其对物理参数化方案的敏感性研究

为评估CWRF模式的降尺度能力和其热带气旋模拟对物理参数化方案的敏感性,本文利用ERI再分析资料驱动CWRF在30km网格上对1982-2016年中国近海热带气旋开展了一次集合模拟.结果表明:CWRF与ERI均能模拟出热带气旋的季节变化和年际变化形势且均存在低估,但相较ERI,CWRF的降尺度技术和集合模拟可以再现更多的热带气旋,显著减少低估.年际变化结果提升最为明显,它对积云方案最为敏感,其次是边界层,陆面和辐射方案,对云和微物理方案较弱.该研究为应用CWRF理解和预报热带气旋提供了参考.     

WRF模式不同微物理过程对东北降水相态预报的影响

为了研究不同微物理过程对中尺度模式降水相态预报的影响,利用中尺度模式WRF（V3.1）和NCEP再分析资料,采用WSM 6方案、Goddard方案和New Thompson方案等3种不同微物理过程参数化方案,对2006-2008年东北地区存在降水相变的11次降水过程进行了敏感性试验。通过对降水和云微物理特征影响的分析,了解不同方案间的预报差异。结果表明：不同微物理方案对降水落区和强度预报影响不明显,而降水相态对微物理参数化方案较为敏感,主要表现在对雨区和雨夹雪区预报影响显著。从总体预报效果来看Goddard方案表现较好。选用不同微物理参数化方案模拟的底层大气云微物理特征存在较大的差别,正是这种差别直接导致了降水相态预报间的差异。     

NASA/Goddard长波辐射方案在GRAPES_Meso模式中的应用研究

本文将NASA（National Aeronautics and Space Administration）/Goddard长波辐射方案引入到GRAPES_ Meso（Global/Regional Assimilation and PrEdiction System_Meso）模式中,对2006年4月中国地区进行了一个月的模拟试验,并与相应的NCEP（National Centers for Environmental Prediction）再分析资料进行了对比分析。试验结果表明:在模拟区域内,使用GRAPES_Meso模式进行24 h、48 h预报得到的晴空大气顶向外长波辐射通量（the clear sky outgoing longwave radiation flux,OLRC）、地面接收到向下长波辐射通量（the clear sky downward longwave radiation flux at ground,GLWC）分布形势与NCEP再分析资料具有较好的对应关系;模式预报24 h、48 h OLRC和NCEP再分析资料月平均误差百分比控制在－10%～＋10%以内,GLWC月平均误差百分比比OLRC略大,但总体上两者误差都在合理和可接受范围之内。OLRC和GLWC 24 h、48 h的预报和NCEP再分析资料的逐日距平相关系数及标准误差的对比显示,模式24 h预报OLRC、GLWC的距平相关系数月平均值分别为0.96、0.98,标准误差月平均值分别为24.54 W m-2、27.23 W m-2;模式48 h预报OLRC、GLWC的距平相关系数月平均值分别为0.9521、0.9804,标准误差月平均值分别为22.43 W m-2、27.64 W m-2。总体上,模式24 h、48 h预报OLRC和GLWC的距平相关系数都在0.93以上,标准误差都在31 W m-2以内,且GLWC预报和NCEP再分析资料的相关性比OLRC略好,OLRC预报与NCEP再分析资料的的标准误差比GLWC略小。通过和RRTM长波辐射方案对比可知,两者的预报水平基本一致。本文研究结果表明,引入NASA/Goddard长波辐射方案后的GRAPES_Meso模式整体上能够较好地预报OLRC和GLWC,该辐射方案可以作为模式GRAPES_Meso的备选辐射方案之一。     

北京地区一次空气重污染过程的气象条件模拟参数化敏感性试验

气象预报是影响大气重污染预报精度的关键所在。针对2016年12月16～21日北京市一次重污染过程,开展了中尺度气象模式WRF的参数化方案配置敏感性试验。对微物理过程、长波辐射过程、短波辐射过程、陆面过程、边界层过程、近地面过程以及积云对流参数化过程进行组合优选,共设计51组参数化方案组合,分析不同模拟方案下北京市8个气象站点温度、相对湿度、10 m风速的模拟精度及其敏感性。试验结果表明:温度模拟对长波过程参数化方案最为敏感,集合离散度达2.4～7.4°C,再次是短波过程参数化方案;相对湿度模拟也对长波过程参数化方案最敏感,再次是陆面过程;风速模拟对不同过程参数化方案的敏感性程度差异不大。通过模拟结果与观测的统计对比,优选出模拟误差最小的方案组合为Lin微物理方案、RRTMG长波方案、RRTMG短波方案、Tiedtke积云对流方案、Noah陆面方案、MYNN 3rd边界层方案和MYNN近地面方案,并将其与集合平均、基准方案进行对比。对于集合平均来说,其温度模拟与观测相关系数为0.69,高于基准方案,其模拟偏差与均方根误差比基准方案低25%和11%;集合平均的相对湿度和风速模拟相比基准方案变化较小。与集合平均相比,优选方案能同时改进温度、相对湿度和风速模拟,使温度模拟偏差和均方根误差比基准方案下降35%和17%,使相对湿度模拟偏差和均方根误差下降43%和13%,使风速模拟偏差和均方根误差下降33%和24%。以上结果表明,参数化方案的敏感性试验和优选能显著减小重污染期间气象要素的模拟误差,重污染预报改进需重点关注参数化方案模拟上的不确定性。本研究也发现MYNN3rd边界层方案在这次重污染过程的气象要素模拟上具有良好性能,可为未来重污染预报改进提供参考。     

Asian monsoon simulations by Community Climate Models CAM4 and CCSM4

This study examines the ability of Community Atmosphere Model (CAM) and Community Climate System Model (CCSM) to simulate the Asian summer monsoon, focusing particularly on inter-model comparison and the role of air–sea interaction. Two different versions of CAM, namely CAM4 and CAM5, are used for uncoupled simulations whereas coupled simulations are performed with CCSM4 model. Ensemble uncoupled simulations are performed for a 30 year time period whereas the coupled model is integrated for 100 years. Emphasis is placed on the simulation of monsoon precipitation by analyzing the interannual variability of the atmosphere-only simulations and sea surface temperature bias in the coupled simulation. It is found that both CAM4 and CAM5 adequately simulated monsoon precipitation, and considerably reduced systematic errors that occurred in predecessors of CAM4, although both tend to overestimate monsoon precipitation when compared with observations. The onset and cessation of the precipitation annual cycle, along with the mean climatology, are reasonably well captured in their simulations. In terms of monsoon interannual variability and its teleconnection with SST over the Pacific and Indian Ocean, both CAM4 and CAM5 showed modest skill. CAM5, with revised model physics, has significantly improved the simulation of the monsoon mean climatology and showed better skill than CAM4. Using idealized experiments with CAM5, it is seen that the adoption of new boundary layer schemes in CAM5 contributes the most to reduce the monsoon overestimation bias in its simulation. In the CCSM4 coupled simulations, several aspects of the monsoon simulation are improved by the inclusion of air–sea interaction, including the cross-variability of simulated precipitation and SST. A significant improvement is seen in the spatial distribution of monsoon mean climatology where a too-heavy monsoon precipitation, which occurred in CAM4, is rectified. A detailed investigation of this significant precipitation reduction showed that the large systematic cold SST errors in the Northern Indian Ocean reduces monsoon precipitation and delays onset by weakening local evaporation. Sensitivity experiments with CAM4 further confirmed these results by simulating a weak monsoon in the presence of cold biases in the Northern Indian Ocean. It is found that although the air–sea coupling rectifies the major weaknesses of the monsoon simulation, the SST bias in coupled simulations induces significant differences in monsoon precipitation. The overall simulation characteristics demonstrate that although the new model versions CAM4, CAM5 and CCSM4, are significantly improved, they still have major weaknesses in simulating Asian monsoon precipitation.     

Sensitivity of the WRF model simulation of the East Asian summer monsoon in 1993 to shortwave radiation schemes and ozone absorption

Sensitivity of the Weather Research and Forecasting (WRF) model simulation of the East Asian summer monsoon (EASM) in 1993 to solar radiation parameterizations and ozone absorption was investigated. Three numerical experiments were conducted using the National Centers for Environmental Prediction/Department of Energy (NCEP/DOE) and the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis data as time-varying surface and lateral boundary forcings, respectively: (a) a control run (“CTL”) with the Dudhia radiation scheme and the model top placed at 50 hPa, (b) the “SWG” experiment which is the same as the CTL except the Goddard radiation scheme, and (3) the “SWT” run which is the same as the SWG but the model top was raised to 5 hPa and the vertical levels increased from 31 to 35. The use of the Goddard scheme results in considerable improvement in reproducing the model’s thermal structures, such as zonal mean air temperature, its latitudinal gradient and vertically integrated temperature. This leads to better agreements in the simulation of the upper tropospheric zonal winds through the thermal wind relationship which, in turn, rectifies the lowlevel circulations through dynamical coupling between the upper and lower troposphere. The Taylor diagram analysis quantitatively indicates that the SWT and the SWG are discernable from each other with slightly improved simulations in the SWT. This suggests a nontrivial role of ozone absorption and accompanied stratospheric heating in EASM simulation.     

WRF模式对2013年1月华北一次大雾的数值对比试验

采用WRF模式系统模拟了2013年1月22—23日华北大雾天气过程,针对不同的边界层方案、微物理方案和陆面方案,设计了三组数值试验方案,并利用地面观测资料对其模拟效果进行了对比分析,找出了部分最适合于此次大雾过程模拟的参数化方案,它们分别是TEMF边界层方案、Goddard微物理方案和RUC陆面方案。此次数值试验结果还表明,WRF模式对大雾天气地面风速风向的模拟能力较好,其他气象要素存在一定的误差,用10 m液态水含量和10 m相对湿度指标共同诊断大雾天气能有效提高大雾判识准确率。     

CWRF-based ensemble simulation of tropical cyclone activity near China and its sensitivity to the model physical parameterization schemes: 基于CWRF的中国近海热带气旋集合模拟及其对物理参数化方案的敏感性研究

To evaluate the downscaling ability with respect to tropical cyclones (TCs) near China and its sensitivity to the model physics representation, the authors performed a multi-physics ensemble simulation with the regional Climate–Weather Research and Forecasting (CWRF) model at a 30 km resolution driven by ERA-Interim reanalysis data. The ensemble consisted of 28 integrations during 1979–2016 with varying CWRF physics configurations. Both CWRF and ERA-Interim can generally capture the seasonal cycle and interannual variation of the TC number near China, but evidently underestimate them. The CWRF downscaling and its multi-physics ensemble can notably reduce the underestimation and significantly improve the simulation of the TC occurrences. The skill enhancement is especially large in terms of the interannual variation, which is most sensitive to the cumulus scheme, followed by the boundary layer, surface and radiation schemes, but weakly sensitive to the cloud and microphysics schemes. Generally, the Noah surface scheme, CAML(CAM radiation scheme as implemented by Liang together with the diagnostic cloud cover scheme of Xu and Randall(1996)) radiation scheme, prognostic cloud scheme, and Thompson microphysics scheme stand out for their better performance in simulating the interannual variation of TC number. However, the Emanuel cumulus and MYNN boundary layer schemes produce severe interannual biases. Our study provides a valuable reference for CWRF application to improve the understanding and prediction of TC activity.摘要为评估CWRF模式的降尺度能力和其热带气旋模拟对物理参数化方案的敏感性, 本文利用ERI再分析资料驱动CWRF在30km网格上对1982-2016年中国近海热带气旋开展了一次集合模拟.结果表明:CWRF与ERI均能模拟出热带气旋的季节变化和年际变化形势且均存在低估, 但相较ERI, CWRF的降尺度技术和集合模拟可以再现更多的热带气旋, 显著减少低估.年际变化结果提升最为明显, 它对积云方案最为敏感, 其次是边界层, 陆面和辐射方案, 对云和微物理方案较弱.该研究为应用CWRF理解和预报热带气旋提供了参考.     

基于不同微物理过程的广西沿海南风型暖区暴雨的数值模拟研究

基于WRFV3.6.1,利用其8个云微物理参数化方案对2010—2016年华南汛期（4—9月）的6个南风型暖区暴雨个例进行数值模拟与多方案集成试验,并采用基于对象的诊断评估方法（MODE）对模拟结果进行评估。结果发现对于大多数个例,WRF模式都能较好地模拟出暖区暴雨的降水带,对暖区降水带模拟最好的参数化方案是WSM6方案,其次是Lin方案;模拟效果较差的参数化方案为CAM5.1与NSSL 2-mon方案。选取模拟结果较好的个例进行诊断分析,发现不同参数化方案得到的动力学特征以及云微物理特征相关变量存在较大差异,导致模拟降水的差异。在单方案模拟的基础上,开展多方案集成试验,发现多方案集成方法能够有效降低模式模拟的不确定性,产生更稳定的模拟结果。     

我国近20年太阳辐射时空分布状况模式评估

利用NCAR/PSU联合研发的第5代中尺度气象模式(MM5),结合最优插值方法,模拟获得高时空分辨率的我国太阳辐射分布特征。MM5模式模拟中采用敏感性分析方法挑选参数化方案,结合1975—1997年辐射日平均值资料验证模拟效果,采用最优插值方法优化辐射的模拟效果,并导入GIS平台进行统计分析。分析表明:最优插值后辐射模拟平均标准绝对误差由原来的24.4%下降到8.5%,平均标准偏差由20.6%下降到3.5%。模拟获得的全国平均年太阳辐射总量为5648.6 MJ·m~(-2),空间分布上,呈现以内蒙中西部—宁夏—甘肃西北部—四川西部—云南西北部为分界线的西高东低特征,分界线以西太阳辐射在6000 MJ·m~(-2)以上,东部以华北太阳辐射为最高;1975—1997年年太阳辐射总量呈现上升—下降—上升的变化趋势,1978年太阳辐射最高,1989年最低。此外,基于Arc GIS 8.3统计获得各省份平均年太阳辐射总量,对各省份太阳辐射丰富程度进行等级划分,统计结果表明:西藏、青海、新疆是太阳辐射最丰富的省份,其中,西藏平均年太阳辐射总量在6900MJ·m~(-2)以上。     

辐射参数化方案对一个海气耦合模式云和辐射模拟的影响

比较Morcrette辐射方案和Fu_Liou辐射方案对NCC/IAP T63海气耦合模式云和辐射模拟的影响, 结果表明:两种方案模拟的大气顶入射辐射存在明显的差异; 晴空大气Fu_Liou方案的短波吸收能力在全球普遍较Morcrette方案低; 在60°S~60°N之间, Fu_Liou方案模拟的行星反照率更接近于ERBE卫星观测; 在对大气顶净辐射的模拟上, 除了冬季的太平洋和大西洋东岸云量明显减少的部分地区外, Fu_Liou方案对大气顶净辐射的模拟总体上较Morcrette方案有了较为明显的改善; Fu_Liou方案模拟的海洋低层云显著减少, 而热带地区高云的模拟明显增加; 由于采用了“二元云量”算法, 尽管云量有所减少, Fu_Liou方案模拟的云短波吸收作用仍有所增强, 一定程度上改进了Morcrette方案云的短波吸收作用偏弱的现象。     

WRF4.0模式陆气耦合对不同物理参数化方案的敏感性初探

模式的不同参数化方案会对模拟的天气和气候产生影响,但如何影响陆气耦合还不是很清楚。利用WRF 4.0模式设计了一组16种不同参数化方案组合的集合试验,对华北地区2013年夏季气候进行模拟。结果表明,不同积云对流参数化方案对模拟的降水平均态影响较大,其次是短波辐射方案,而微物理方案影响较小。进一步利用潜热通量(LH,Latent Heat flux)和土壤湿度(SM,Soil Moisture)、抬升凝结高度(LCL,Lifting Condensation Level)的相关系数R_(SM,LH)和R_(LH,LCL)表征陆气耦合过程,评估了陆气耦合对不同参数化方案的敏感性。模式模拟的R_(SM,LH)在不同区域随着平均降水、相对湿度的增加以及平均短波辐射的减少而减小,而R_(LH,LCL)的变化正好相反。它们内在的物理机制类似,与气候态的干湿变化密切相关,即随着土壤湿度趋于饱和,蒸散发过程逐渐受太阳辐射的限制,陆面对大气的影响减弱。另外,陆气耦合强度受积云对流方案、微物理方案和短波辐射方案的影响而产生差别,这与不同参数化方案模拟的气候态的不同密切相关,因此本研究对于WRF 4.0模式中参数化方案特别是积云对流方案的选择同样有着重要的指导意义。     

Effects of heterogeneous vegetation on the surface hydrological cycle

Using the three-layer variable infiltration capacity (VIC-3L) hydrological model and the successive interpolation approach (SIA) of climate factors, the authors studied the effect of different land cover types on the surface hydrological cycle. Daily climate data from 1992 to 2001 and remotely-sensed leaf area index (LAI) are used in the model. The model is applied to the Baohe River basin, a subbasin of the Yangtze River basin, China, with an area of 2500 km2. The vegetation cover types in the Baohe River basin consist mostly of the mixed forest type (85%). Comparison of the modeled results with the observed discharge data suggests that: (1) Daily discharges over the period of 1992–2001 simulated with inputs of remotely-sensed land cover data and LAI data can generally produce observed discharge variations, and the modeled annual total discharge agrees with observations with a mean difference of 1.4%. The use of remote sensing images also makes the modeled spatial distributions of evapotranspiration physically meaningful. (2) The relative computing error (RCE) of the annual average discharge is ?24.8% when the homogeneous broadleaf deciduous forestry cover is assumed for the watershed. The error is 21.8% when a homogeneous cropland cover is assumed and ?14.32% when an REDC (Resource and Environment Database of China) land cover map is used. The error is reduced to 1.4% when a remotely-sensed land cover at 1000-m resolution is used.     

太阳辐射预报滚动订正方法研究

利用2013年1月至2014年12月北京南郊观象台逐时观测总辐射以及BJ-RUC模式系统预报的该站未来24h逐时总辐射、云量、水汽混合比、云水、云冰含量等14个气象要素数据,运用多种线性订正方案对总辐射预报值进行订正,重点分析了不同方法、不同季节、不同样本数的订正效果差异。结果表明:1不同季节辐射订正的影响因素不尽相同,需采用不同的组合订正因子,其中总辐射、2m比湿、2m相对湿度、低云量、中云量、高云量、总云量、云水雨冰雪霰混合比、水汽混合比可作为推荐因子;2最优样本数选取时需考虑季节差异;3逐时滚动订正方案的订正效果较好,明显优于非滚动方案。订正后总辐射误差显著减小,而且79%的时刻有改进,明显减小了预报偏大的系统误差;4冬春季订正效果优于夏秋季,这与云的宏观和微观物理量预报效果的季节差异有关。本文研究结果可为太阳能资源评估、总辐射和光伏电站发电量预报提供有效的改进方法。     

A source of hail embryos

Abstract

The sensitivity of the annual cycle of ice cover in Baffin Bay to short‐wave radiation is investigated. The Princeton Ocean Model (POM) is used and is coupled with a multi‐category, dynamic‐thermodynamic sea‐ice model in which the surface energy balance governs the growth rates of ice of varying thickness. During spring and summer the short‐wave radiation flux dominates other surface heat fluxes and thus has the greatest effect on the ice melt. The sensitivity of model results to short‐wave radiation is tested using several, commonly used, shortwave parameterizations under climatological, as well as short‐term, atmospheric forcing. The focus of this paper is short‐term and annual variability. It is shown that simulated ice cover is sensitive to the short‐wave radiation formulation during the melting phase. For the Baffin Bay simulation, the differences in the resulting ice area and volume, integrated from May to November, can be as large as 45% and 70%, respectively. The parameterization of the effect of cloud cover on the short‐wave radiation can result in the sea‐ice area and volume changes reaching 20% and 30%, respectively. The variation of the cloud amount represents cloud data error, and has a relatively small effect (less then ±4%) on the simulated ice conditions. This is due to the fact that the effect of cloud cover on the short‐wave radiation flux is largely compensated for by its effect on the net near‐surface long‐wave radiation flux.     

Solar Radiation Climatology of Alaska

Summary There are only six locations in Alaska for which global radiation data of more than a year in duration are available. This is an extremely sparse coverage for a state which covers 1.5×10&⁶ km² and stretches over at least three climatic zones. Cloud observations are, however, available from 18 stations. We used fractional cloud cover and cloud type data to model the global radiation and thus obtain a more complete radiation coverage for Alaska. This extended data set allowed an analysis of geographic and seasonal trends. A simple 1-layer model based on Haurwitz’s semi-empirical approach, allowing for changes in cloud type and fractional coverage, was developed. The model predicts the annual global radiation fluxes to within 2–11% of the observed values. Estimated monthly mean values gave an average accuracy within about 6% of the measurements. The estimates agree well with the observations during the first four months of the year but less so for the last four. Changing surface albedo might explain this deviation. Previously, the 1993 National Solar Radiation Data Base (NSRDB) from the National Renewable Energy Laboratory (NREL) modeled global radiation data for 16 Alaskan stations. Although more complete and complex, the NREL model requires a larger number of input parameters, which are not available for Alaska. Hence, we believe that our model, which is based on cloud-radiation relationship and is specifically tuned to Alaskan conditions, produces better results for this region. Annual global solar radiation flux measurements are compared with results from global coverage models based on the International Satellite Cloud Climatology Project (ISCCP) data. Contour plots of seasonal and mean annual spatial distribution of global radiation for Alaska are presented and discussed in the context of their climatic and geographic settings. Received July 16, 1997 Revised May 18,1998     

中国积雪气候调节服务价值评估

文中通过长时间中国雪深序列数据集、ERA-5的反照率数据,以及CESM-CAM5的辐射数据,分析了1988—2016年中国积雪的辐射强迫,并通过DICE/RICE模型计算其大气碳当量,进而对中国年均积雪气候调节服务价值进行了核算,同时分析其时空变化,由此得到功能分区。结果表明,中国积雪对于全球的辐射强迫贡献等价于-0.22 (±0.01) W/m²,相当于减少大气碳当量17 (±1) Gt C带来的降温效应,从能源转变的替代成本角度出发,其气候调节服务价值可达到3.9 (±2.1)万亿元。同时发现,由于积雪减少趋势引起的中国积雪气候调节服务衰减,相当于碳当量以0.67亿t/a的速率减少,这相当于每年气候调节服务衰减造成的替代成本达到150 (±12)亿元,在29年间累积损失可达4100 (±328)亿元。最后基于评估结果对中国积雪气候调节服务功能进行了分区讨论。     

外强迫对热带季节内振荡影响的模拟研究

应用经过修改的NCAR CCM3模式和CAM2模式进行的数值实验结果以及NCEP的GFS模式的输出结果讨论了海温等外强迫作用对热带季节内振荡的影响.结果表明,热带季节内振荡是热带大气固有的内部变率.它是由大气内部过程的相互作用决定的.但外强迫对热带季节内振荡的强度、传播方向等有明显的影响.当外强迫没有变化时,模式可以模拟出与观测近似的低频振荡.当作为外强迫的海温和太阳辐射有年内季节变化时,模式模拟的季节内振荡则明显减弱.当海温与辐射不仅有季节变化而且有年际变化时,模式模拟的季节内振荡会进一步减弱.具有长周期的外强迫还会削弱季节内振荡中东移波动的能量而增加静止波的强度.在与海洋模式耦合的状态下,模式不受来自海洋的外强迫影响,而是与海洋构成一个耦合系统,可以产生最强的季节内振荡.