A One-dimensional Ensemble Forecast and Assimilation System for Fog Prediction

A probabilistic fog forecast system was designed based on two high resolution numerical 1-D models called COBEL and PAFOG. The 1-D models are coupled to several 3-D numerical weather prediction models and thus are able to consider the effects of advection. To deal with the large uncertainty inherent to fog forecasts, a whole ensemble of 1-D runs is computed using the two different numerical models and a set of different initial conditions in combination with distinct boundary conditions. Initial conditions are obtained from variational data assimilation, which optimally combines observations with a first guess taken from operational 3-D models. The design of the ensemble scheme computes members that should fairly well represent the uncertainty of the current meteorological regime. Verification for an entire fog season reveals the importance of advection in complex terrain. The skill of 1-D fog forecasts is significantly improved if advection is considered. Thus the probabilistic forecast system has the potential to support the forecaster and therefore to provide more accurate fog forecasts.     

相位激电法(偶极-偶极)单频电磁耦合校正方法

主要介绍一种相位激电法(偶极—偶极,以下简称偶极)电磁耦合校正方法,其原理是将视电阻率近似视为均匀大地电阻率,利用均匀大地条件下偶极装置电磁感应响应的正演计算方法,算出电磁感应响应,再将其从观测的总响应中去除,从而达到电磁耦合校正的目的。     

热带太平洋线性海气耦合系统的主模与ENSO

本文利用包含海洋表面边界层、线性海洋大气动力学以及完整的关于不均匀气候态线性化SST预报方程的热带太平洋海气耦合模式， 在真实的气候背景态和参数域内，研究了海气耦合系统的特征值问题，确定了线性耦合系统主模的特征周期及其稳定性特征，进而揭示了主模和ENSO的关系。结果表明:准两年振荡是线性海气耦合系统中的最不稳定模态，且只有该模态类似于ENSO水平结构。因此，准两年振荡很可能是海气耦合系统固有的最根本性的振荡过程。本文也对准两年振荡的形成与年循环的关系以及它在ENSO时间尺度形成中的作用进行了讨论。     

海气耦合气侯模式的依时解

运用量子力学方法，精确地求出了海气耦合随机－动力模式的依时解．对依时解的分析表明：当气候系统处于基态时，系统的行为呈布朗运动形式，由此从理论上证明了Ｈａｓｓｅｌｍａｎｎ关于随机气候模式建立的立足点．当系统处于第一激发态时，系统运动呈随时间衰减的形式；在一定条件下则为周期振荡，主周期长度为２．３年．最后将结果用来讨论二氧化碳浓度倍增时的气候影响．     

A COUPLING THREE DIMENSIONAL BAROCLINIC MODEL OF BIWA LAKE AIR-WATER SYSTEM

I.IntroductionTherearealotofstudiesdealingwithhydrodwiaAncsoflakes,numericalsimulationoflakecurrentsystemst5,7,lO,l31,andwiti1windsystemsoverlakesandnumericalsimulationontheland-lake/seaormountain-valleybreeze[4,6,8].Usually,ti1emodelsinti1eatmosphericboundarylayerandinlakewaterweresimulatedseParately.InfaCt,theprocessesintheatmosphericboundarylayeroverlakesandti1eprocessesinthelakewaterareinteraCtedstronglyeachoti1er.Collecteddatashow,thatalmoStalllargelakes,marginalseas,estuariesandlagoon…     

B-polarization induction in two thin half-sheets coupled to the mantle by a conducting crust—II. Solution by the mode-matching method, the fields above the conductors, and example results

The mode-matching method is used to obtain an exact analytical solution to the problem of B -polarization induction in two adjacent thin half-sheets, lying on a conducting layer that is terminated by a perfect conductor at finite depth. These components of the model represent, respectively, the Earth's conducting surface layers, crust, and mantle. In dimensionless variables, the model has three independent parameters, these being the two thin-sheet conductances and the layer thickness. The mode-matching solution obtained in this paper is shown to be identical lo that derived via the Wiener-Hopf method in a companion paper (Dawson 1996), and so provides additional verification of that solution. As was shown in the companion paper, the solution for the present model contains, as special limiting cases, those for three models considered earlier by various authors. The second part of the present paper addresses the solutions for the electric fields in the non-conducting half-space above the conductors, which represents the atmosphere. In the final part, sample numerical calculations are presented to illustrate the solution.