大气对流边界层发展的模拟研究   总被引：4，自引：0，他引：4  

罗涛  袁仁民  孙鉴泞 《高原气象》2006,25(6):1001-1007

室内水槽模拟是大气边界层研究的一种重要手段。利用室内模拟水槽对大气边界层的发展进行了模拟,通过处理平均温度廓线和光斑图像得到了对流边界层顶部位置h2和边界层高度zi。结果表明,不同测量方法得到的结果一致性很好,与实际大气的边界层发展情况也较为接近。同时,根据试验情况确定初始条件和边界条件,使用边界层参数化模型进行了数值模拟,其结果与室内模拟的结果也较吻合。  相似文献   

大尺度瞬变涡旋经向热量和水沟通量在纬向平均气流形成中的效应     

付超  李维亮 《气象学报》1996,54(3):373-378

在一个纬向平均模式中加入大尺度瞬变涡旋经向热量和水汽通量参数化方案。模拟出涡动通量的空间分布和时间变化。实验表明，涡动通量在中高、纬地区大气能量输送过程中起重要作用。应用上述参数化方案提高了模式的模拟能力。  相似文献   

9406号台风登陆造成华南及长江中游暴雨过程的数值模拟试验     

肖庆农  何德辉 《气象科学》1997,17(1):28-35

本文应用有限区域数值预报模式，并根据不同的积云参数化方案对１９９４年第６号台风登陆后低压的移动规律及其对应降水分布进行了数值模拟试验，结果表明积云对流参数化对于台风移动及其降水分布影响极大，是作出台风暴雨预报的关键过程。  相似文献   

黑风暴的沙尘形成与输送参数化及中尺度数值试验   总被引：21，自引：3，他引：21  

刘春涛  程麟生 《气象学报》1997,55(6):726-739

西北地区典型黑风暴和强沙尘暴都是在特定大尺度环流背景和中尺度系统相互作用下发生和发展的，而中、低空强锋区相伴的强冷锋移经沙源充足的大沙漠区是黑风暴和强沙尘暴形成和发展的必要条件。为了研究黑风暴和沙尘暴的沙尘形成、输送及沉降机制，本文提出了一种沙尘源、汇项的参数化方案和一个沙尘输送方程，进而引入已有的ＭＭ４中尺度数值模式模拟系统；应用这个改进和发展的模式模拟系统基本成功地模拟了“９３．５”黑风暴的天气系统演变及其沙尘浓度的近地层和垂直分布以及沙尘的沉降与输送。模拟结果分析表明，用包括沙尘输送方程及其沙尘源、汇项参数化方案的中尺度数值模式来研究黑风暴的沙尘形成、输送和沉降机制是一种具有应用前景的方法。  相似文献   

有关雪盖模型内部及界面过程的参数化方案的敏感试验   总被引：4，自引：0，他引：4  

Sun Shufen  Li Jingyang 《大气科学进展》2001,18(5):910-928

In order to develop a seasonal snow model of land surface process as accurately as possible for climatic study, it is necessary to fully understand the effects of important snow internal processes and interaction with air and to get an insight into influence of several relevant parameterization schemes with parameters＇ uncertainty to some degree. Using the snow model (SAST) developed by first author and other one and some useful field observation data, this paper has conducted a series of sensitivity studies on the parameterization schemes. They are relative to compaction process, snow thermal conduction, methodology of layering snow pack and to key parameters such as snow albedo, water holding capacity. Then, based on the results from the sensitivity studies, some useful conclusions for snow cover model improvement are ob tained from the analysis of the results.  相似文献   

论中尺度运动对大尺度模式网格平均的次网格垂直通量的影响   总被引：2，自引：2，他引：2  

张强  曹晓彦  胡隐樵 《高原气象》2001,20(4):453-460

较系统地阐述了中尺度运动对大尺度模式网格平均的次网格通量的影响方式和作用机制 ,提出了在大尺度模式中参数化次网格中尺度通量和地表次网格通量中尺度加强的思想方法 ,初步分析了这些参数化方法的缺陷和局限性 ,对几个在参数化中尺度通量和地表次网格通量中尺度加强时应重点考虑的关键因子提出了建议。最后 ,讨论了参数化非均匀大气的网格平均的次网格通量的一些新的想法及相关问题  相似文献   

Parameterization of bedform morphology and defect density with fingerprint analysis techniques     

Adam Skarke  Arthur C. Trembanis 《Continental Shelf Research》2011,31(16):1688-1700

A novel method for parameterizing the morphology of seafloor ripples with fingerprint analysis numerical techniques is presented. This fully automated analysis tool identifies rippled areas in two-dimensional imagery of the seafloor, and returns ripple orientation and wavelength as well as a new morphological parameter, the spatial density of ripple defects. In contrast to widely used manual and spectral parameterization methods, this new technique yields a unique probability distribution for each derived parameter, which describes its spatial variability across the sampled domain. Here we apply this new analysis technique to synthetic and field collected side-scan sonar seafloor images in order to assess the methods capacity to define bed geometry across a wide range of simulated and observed morphological conditions. The resulting orientation and wavelength values compare favorably with those of the existing manual and spectral parameterization methods, and are superior under environmental conditions characterized by low signal to noise ratios as well as high planform ripple sinuosity. Furthermore, the resulting ripple defect density values demonstrate correlation with ripple orientation, wave direction, and the Shields parameter, which is consistent with recent investigations that have theoretically linked this parameter to hydrodynamic forcing conditions. The presented fingerprint analysis method surpasses the capacity of existing methods for ripple parameterization and promises to yield greater insight into theoretical and applied problems associated with the temporal and spatial variability of ripple morphology across a wide spectrum of marine environments.  相似文献   

Sensitivity of simulated wintertime Arctic atmosphere to vertical resolution in the ARPEGE/IFS model     

Øyvind Byrkjedal  Igor Esau  Nils Gunnar Kvamstø 《Climate Dynamics》2008,30(7-8):687-701

The current state-of-the-art general circulation models, including several of those used by the IPCC, show considerable biases in the simulated present day high-latitude climate compared to observations and reanalysis data. These biases are most pronounced during the winter season. We here employ ideal vertical profiles of temperature and wind from turbulence-resolving simulations to perform a priori studies of the first-order eddy-viscosity closure scheme employed in the ARPEGE/IFS model. This reveals that the coarse vertical resolution (31 layers) of the model cannot be expected to realistically resolve the Arctic stable boundary layer. The curvature of the Arctic inversion and thus also the vertical turbulent-exchange processes cannot be reproduced by the coarse vertical mesh employed. To investigate how turbulent vertical exchange processes in the Arctic boundary layer are represented by the model parameterization, a simulation with high vertical resolution (90 layers in total) in the lower troposphere is performed. Results from the model simulations are validated against data from the ERA-40 reanalysis. The dependence of the surface air temperature on surface winds, surface energy fluxes, free atmosphere stability and boundary layer height is investigated. The coarse-resolution run reveals considerable biases in these parameters, and in their physical relations to surface air temperature. In the simulation with fine vertical resolution, these biases are clearly reduced. The physical relation between governing parameters for the vertical turbulent-exchange processes improves in comparison with ERA-40 data.  相似文献   

Numerical Simulation of Effect of Sea Spray on Typhoon ＇Morakot＇ Structure     

《高原气象》2012,31(1)

将海洋飞沫参数化引入到高分辨率、非静力中尺度模式中,并对0908号台风＂Morakot＂进行了数值模拟,研究了海洋飞沫对台风＂Morakot＂结构和强度的影响。结果表明：（1）不论是否考虑海洋飞沫作用,模式均能较好地模拟出台风＂Morakot＂的移动路径,说明海洋飞沫对其移动路径影响不大;（2）引入海洋飞沫参数化后,台风眼墙区域的切向风速、径向风速、垂直速度、涡度、云水混合比、雨水混合比等物理量均增强,表明飞沫对台风结构变化的影响明显;（3）海洋飞沫对台风＂Morakot＂演变的直接影响是在对流层低层,低层风速明显增大,大风速区的影响尤为显著;（4）飞沫的蒸发使台风范围内的潜热和感热通量明显增强,尤其是潜热通量,其大值区对应着台风中心附近的最大风速区。由于水汽和热量输送的增强,使台风眼壁附近的云水量与雨水量增多,因此降水强度明显增加。  相似文献   

海洋飞沫对台风“Morakot”结构影响的数值模拟研究   总被引：1，自引：0，他引：1  

王平  陈葆德  曾智华  范广洲 《高原气象》2012,(1):113-125

将海洋飞沫参数化引入到高分辨率、非静力中尺度模式中,并对0908号台风"Morakot"进行了数值模拟,研究了海洋飞沫对台风"Morakot"结构和强度的影响。结果表明:(1)不论是否考虑海洋飞沫作用,模式均能较好地模拟出台风"Morakot"的移动路径,说明海洋飞沫对其移动路径影响不大;(2)引入海洋飞沫参数化后,台风眼墙区域的切向风速、径向风速、垂直速度、涡度、云水混合比、雨水混合比等物理量均增强,表明飞沫对台风结构变化的影响明显;(3)海洋飞沫对台风"Morakot"演变的直接影响是在对流层低层,低层风速明显增大,大风速区的影响尤为显著;(4)飞沫的蒸发使台风范围内的潜热和感热通量明显增强,尤其是潜热通量,其大值区对应着台风中心附近的最大风速区。由于水汽和热量输送的增强,使台风眼壁附近的云水量与雨水量增多,因此降水强度明显增加。  相似文献