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1.
在大洋环流模式中,铅直混合的参数化方法起着关键性的作用。将大洋细结构混合参数化方法首次应用于世界大洋环流模式中。使用中科院大气所(LASG)发展的20层世界大洋环流模式(OGCM)ML20,月平均风场作为强迫场,利用ML20模式在稳定初始状态下运行300a后的计算结果作为本实验进行数值模拟的初始场。该参数化方法对世界大洋环流模式的影响主要表现为:永久性温度跃层的厚度明显变薄;对深层水和底层水的模拟有改进;对南极中层水的模拟比较成功;但是对赤道海区的模拟结果欠佳。  相似文献   

2.
常用海洋数值模式简介   总被引:4,自引:0,他引:4  
OGCM(Ocean General Circulation Model普通海洋环流模式)简单的说就是把海洋原始方程组离散求解的过程.鉴于实际观测资料较少,无法满足研究需求,用数值模式进行数值模拟是实用的研究方法之一,目前海洋学界较为常用的OGCM有POM、FVCOM、HAMSOM、HYCOM等.这些模式有些适用于近岸海域,有些适用于大洋,各有其自身的特点.本文作者在对以上各模式使用与理解的基础上,对这几种模式进行了介绍,并对如何选用一个合适的模式给出了建议.  相似文献   

3.
使用块体混合层模式对一个固定海洋观测站所测的上层海洋之物理特性进行了模拟,结果发现了难以重复观测到的许多物理特征。文章提出了水块混合层模式,着重模拟了扩展湾流体系(EGSS)中的一个水块,在它被海流从佛罗里达海峡(24°N,80°W)带到挪威海(68°N,10°E)的过程中,其物理特性(其中包括温度、盐度、混合层深度和夹卷速度)随时间的变化。模拟结果较好地再现了所观测的物理特性的演化。  相似文献   

4.
使用水块混合层模式模拟上层海洋的季节变化   总被引:3,自引:0,他引:3  
使用块体混合模式对一个固定海洋观测站所测的上层海洋之物理特性进行了模拟,结果发出了难以重复观测到的许多物理特征。文章提出了水块混合层模式,着重模拟了扩展湾流体系中的一个水块,在它被海流从佛罗里达海峡带到挪威海的过程中,其物理特性(其中包括温度、盐度、混合层深度和夹卷速度)随时间的变化,模拟结果较好地再现了所观测的物理特性的演化。  相似文献   

5.
在LICOM模式中,分别使用2种不同的海洋内部垂直混合方案,对气候平均态全球大洋环流进行了数值模拟试验。试验结果的分析比较表明,在添加F方案之后,对全球大洋,尤其是对中高纬度海域的中层水和深层水的温盐状态的模拟有显著的改进;对北冰洋中层水的核心温度及其所在深度的模拟有较大的改进。但是在本文中对于次表层水的模拟在添加F方案后结果欠佳。  相似文献   

6.
全球大洋环流诊断模式研究--流场及流函数   总被引:9,自引:0,他引:9  
基于GFDL的MOM模式建立一个全球大洋环流的诊断模式(R0bust diagnostic model)来研究全球大洋环流.水平空间分辨率1°×1°.垂向分为21层.分别进行月平均和年平均模拟,积分的时间长度为11a.模式水流来自DBDB5(National Geodetic Center,Boulder,Colorado).所用的温度、盐度数据根据Levitus(1994)的资料,表面风应力根据Hellerman and Rosenstem(1983)的全球风场数据插值而来.从模拟结果看,全球大洋中的主要环流结构均得到体现.北太平洋副热带流圈得到合理的模拟,其最大的输运超过50 Sv.北赤道流在12.N附近分为南北两支.北支形成黑潮,而南支为棉兰老海流,在其东边,棉兰老冷涡得到很好的再现.在吕宋海峡有海水进入南海,在南海形成一个气旋式流圈,进而通过南海南部水道流入印度尼西亚海.模拟结果表明南极绕极流和黑潮可以深达底层.湾流则不能深达底层,其下方在1 000~2 000 m深度存在南向的深层流,显示了大西洋深层水的流动.  相似文献   

7.
何云  袁业立  方正 《海洋学报》1993,15(4):19-27
本文采用二层LAGFD-EGGNM模式,模拟出大洋北部中高纬度1 000km×2 000km等深矩形海盆内,由定常风应力驱动的长达65年大洋环流演化过程,对其流函数时间序列结果利用相图分析方法和时间序列分析的方法定量分析海盆内中尺度涡的时间、空间尺度和相速度等特征量,得出在斜压不稳定性和运动不稳定性机制下形成的两种类型涡旋的不同特征量,同时还给出了大洋环流具有低频运动特性的证明。  相似文献   

8.
基于垂向混合坐标系统的海洋模式HYCOM建立了全球大洋气候态环流场.在此基础上与前人研究工作进行对比,分析和讨论了全球风生大洋环流场的季节变化情况.从模拟结果看该模式具有较好的模拟能力,可以合理地模拟南极绕极流、赤道流系、黑潮和湾流等世界各主要大洋流系.从断面温度场、流函数分布和断面流量场等分析显示:南极绕极流堪称世界最强流,湾流整体强于黑潮,3者都具有夏季增强、冬季减弱的特点.HYCOM模式在国外的研究方兴未艾,而在国内的应用尚处在起步阶段.本文通过对该模式的介绍和结果分析,向读者推荐使用该模式.  相似文献   

9.
IPCC耦合模式对北太平洋海-气系统冬季重现的模拟   总被引:1,自引:1,他引:0  
赵霞  杨光 《海洋学报》2019,41(9):114-125
冬季重现(再现)是中高纬度大尺度海表温度重要的持续性特征,是热带外海洋特有的现象。北太平洋大气环流也存在这一现象,它可能会强迫产生这一海域海温的冬季重现。本文利用IPCC 20C3M耦合模式资料,评估了耦合模式模拟北太平洋海–气系统冬季重现的能力。北太平洋海温冬季重现的空间范围是海盆尺度的,中部重现时间比其周围晚。大气环流场的冬季重现主要是在北太平洋中部,它与海温冬季重现关系密切。大多数IPCC耦合模式基本上可以模拟出太平洋海温大范围的冬季重现现象。与重现范围的模拟相比,耦合模式对重现时间地理差异的模拟都比较差。各模式对大气环流冬季重现时空分布特征的模拟较差,大部分模式未能模拟出大气环流场中主要的重现区域。而且,大气环流冬季重现对海温重现的可能影响并没有体现在这些耦合模式中。耦合模式对北太平洋大气冬季重现的模拟还有待改善。  相似文献   

10.
采用日通量距平耦合方案,将中科院大气所最新发展的两个具有较高分辨率的大气和海洋环流模式耦合,并进行了10年以上的耦合积分。为了评估模式的基本性能,对比分析了耦合与未耦合的大气环流模式和海洋环流模式模拟结果,结果显示耦合模式比较成功地控制了"气候漂移",可以较好地模拟平均气候态和季节变化。  相似文献   

11.
A global eddy-permitting ocean-ice coupled model with a horizontal resolution of 0.25 by 0.25 is established on the basis of Modular Ocean Model version 4 (MOM4) and Sea Ice Simulator (SIS). Simulation results are compared with those of an intermediate resolution ocean-ice coupled model with a horizontal resolution of about 1 by 1 . The results show that the simulated ocean temperature, ocean current and sea ice concentration from the eddy-permitting model are better than those from the intermediate resolution model. However, both the two models have the common problem of ocean general circulation models (OGCMs) that the majority of the simulated summer sea surface temperature (SST) is too warm while the majority of the simulated subsurface summer temperature is too cold. Further numerical experiments show that this problem can be alleviated by incorporating the non-breaking surface wave-induced vertical mixing into the vertical mixing scheme for both eddy-permitting and intermediate resolution models.  相似文献   

12.
海洋环流模式中不同近似假设下的海表高度   总被引:1,自引:1,他引:1  
Boussinesq近似是现代海洋环流模式中经常采用的假设,但随着海洋模式的不断发展完善以及气候研究应用的需要,有必要估算Boussinesq近似造成的模式误差。分别利用一个非Boussinesq近似的海洋模式与另一个结构相同且采用Boussinesq近似的模式计算海表高度,并同时利用模式预报的温度、盐度资料计算了比容异常高度。分析结果显示,这3种不同定义的海表高度无论空间结构,还是时间演变,都基本类似,尤其在热带海区最接近,差值≤1cm。Boussinesq近似意味着在模式中以体积守恒代替质量守恒,通常的做法是对其进行简单的质量补偿来保持质量守恒。比较说明,以质量补偿方法进行的高度订正对减小Boussinesq近似带来的误差没有本质的意义。  相似文献   

13.
In light of the pressing need for development and testing of reliable parameterizations of gravity current entrainment in ocean general circulation models, two existing entrainment parameterization schemes, K-profile parameterization (KPP) and one based on Turner’s work (TP), are compared using idealized experiments of dense water flow over a constant-slope wedge using the HYbrid Coordinate Ocean Model (HYCOM). It is found that the gravity current entrainment resulting from KPP and TP differ significantly from one another. Parameters of KPP and TP are then calibrated using results from the high-order nonhydrostatic spectral element model Nek5000. It is shown that a very good agreement can be reached between the HYCOM simulations with KPP and TP, even though these schemes are quite different from each other.  相似文献   

14.
以描述中尺度涡旋对示踪物的输送作用为目的的湍流混合方案GM90经证明对海洋模式的模拟能力较以前的湍流混合方案有较大的提高.该方案涉及到两个主要参数:等密度面扩散系数(AI)和等密度面厚度扩散系数(Aith).该文的目的就是利用中国科学院大气物理研究所(IAP)全球海洋环流模式L30T63研究以上两个系数取值大小对主动示踪物(温盐)以及被动示踪物(CFC-11)海洋分布的影响.实验结果表明这两个系数的取值可明显改变大洋温盐垂直分布以及海洋对CFC-11的吸收,且两个系数在其中起到的作用有很大的差异.从几个剖面的分析结果可知,总的来说,AI的增加使得CFC-11主要储存区的模拟结果更接近观测资料,而Aith的增大使得模拟结果变差.  相似文献   

15.
特征线计算格式下共轭方程两种导出途径的比较   总被引:1,自引:0,他引:1  
共轭方程的导出是建立资料同化模型的关键,其导出方式有两种途径:AFD形式与FDA形式。在特征线计算格式基础上针对一类较广泛海洋动力控制方程分析了其两种共轭方程(AFD形式与FDA形式)之间的关系,并将理论结果应用于波谱共轭方程的讨论。  相似文献   

16.
The results of simulations performed by the CORE-II scenario using the two Russian OGCMs, INMOM and INMIO, are presented. The models use different coordinate systems in the basic set of primitive equations and different numerical techniques. Both models are used as oceanic components of the INM RAS coupled models. Simulations have shown that reproducing ocean circulation using both models agrees with observations and simulations by other models. In general, the INMOM slightly underestimates the meridional heat transport in the ocean when compared to the INMIO model and climatic estimations. However, the INMIO yields a higher bias in temperature than the INMOM.  相似文献   

17.
Intercomparison of three South China Sea circulation models   总被引:2,自引:1,他引:1  
1IntroductionTheSouthChinaSeaisthelargesttropicalmarginaldeepsealocatingbetweenthewesternPacificOceanandtheeasternIndianOcean.AsapartofAsia-Australiamaritimecontinent,monsoonisaprimaryfactorforcingtheSouthChinaSeaCurrent(SCSC)variation.Drivenbynortheasterlymonsooninwinterandsouth-westerlymonsooninsummer,respectively,theSCSCbehavesacyclonicgyreandananticy-clonicgyre,correspondingly(Wyrtki,1961;Xuetal.,1982).Owingtotheshortageandexpen-sivenessofdirectobservationsintheSCS,fur-therunder…  相似文献   

18.
A new three-dimensional numerical model is derived through a wave average on the primitive N-S equations, in which both the"Coriolis-Stokes forcing" and the"Stokes-Vortex force" are considered. Three ideal experiments are run using the new model applied to the Princeton ocean model (POM). Numerical results show that surface waves play an important role on the mixing of the upper ocean. The mixed layer is enhanced when wave effect is considered in conjunction with small Langmuir numbers. Both surface wave breaking and Stokes production can strengthen the turbulent mixing near the surface. However, the influence of wave breaking is limited to a thin layer, but Stokes drift can affect the whole mixed layer. Furthermore, the vertical mixing coefficients clearly rise in the mixed layer, and the upper ocean mixed layer is deepened especially in the Antarctic Circumpolar Current when the model is applied to global simulations. It indicates that the surface gravity waves are indispensable in enhancing the mixing in the upper ocean, and should be accounted for in ocean general circulation models.  相似文献   

19.
《Ocean Modelling》2007,16(1-2):76-94
The question of whether mean flow generation by eddies interacting with sloping bathymetry significantly influences World Ocean circulation is approached by examining output from two near-global circulation models, OFES and the LANL/NPS POP model, having ∼1/10° lateral resolution. In each of these vigorously eddying models, the mean currents over sloping bathymetry tend preferentially to align with the direction of topographic Rossby wave propagation, in accordance with theories of eddy-topographic interaction. This tendency, which is particularly strong near the ocean bottom and at abyssal depths, prevails both globally and within a variety of circulation regimes including the subpolar and subtropical gyres and the extra-equatorial tropics. By contrast, two coarser (∼1–2°), non-eddying models exhibit flow alignments throughout much of the abyssal ocean that are oppositely directed. This result suggests that eddies play an essential role in determining the direction of mean circulation over slopes, and that non-eddying models could benefit from a parameterization of this effect.  相似文献   

20.
A global spectral barotropic ocean model is introduced to describe the depth-averaged flow. The equations are based on vorticity and divergence (instead of horizontal momentum); continents exert a nearly infinite drag on the fluid. The coding follows that of spectral atmospheric general circulation models using triangular truncation and implicit time integration to provide a first step for seamless coupling to spectral atmospheric global circulation models and an efficient method for filtering of ocean wave dynamics. Five experiments demonstrate the model performance: (i) Bounded by an idealized basin geometry and driven by a zonally uniform wind stress, the ocean circulation shows close similarity with Munk’s analytical solution. (ii) With a real land–sea mask the model is capable of reproducing the spin-up, location and magnitudes of depth-averaged barotropic ocean currents. (iii) The ocean wave-dynamics of equatorial waves, excited by a height perturbation at the equator, shows wave dispersion and reflection at eastern and western coastal boundaries. (iv) The model reproduces propagation times of observed surface gravity waves in the Pacific with real bathymetry. (v) Advection of tracers can be simulated reasonably by the spectral method or a semi-Langrangian transport scheme. This spectral barotropic model may serve as a first step towards an intermediate complexity spectral atmosphere–ocean model for studying atmosphere–ocean interactions in idealized setups and long term climate variability beyond millennia.  相似文献   

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