Multicloud Model Research Articles

The line-of-sight velocity fields of the flare loops of 1989 August 17∼: Dun Jin-ping, Gu Xiao-ma and Xuan Jia-yu Yunnan Observatory, CAS, Kunming 650011

The multi cloud model (MCM) is an effective method for dealing with asymmetric profiles of spectral lines formed by active objects on the Sun. An application of this method is given in the paper. From the H β spectra of the flare loops observed with the SSHG at Yunnan Observatory in 1989 August 17, the line of sight velocity fields of the loops are obtained and discussed.

Multi-cloud model (MCM) method and its applications to the study on asymmetric spectral profiles

A method of 'multi-cloud model' (MCM) is proposed in this paper in order to research asymmetric profiles of spectral line formed by solar discrete active objects aligned along the line-of-sight direction. Based on the MCM method, under the conditions of certain assumptions and approximations, the line-of-sight velocity V and three other physical parameter approximation values, (i.e. Doppler width Delta lambda(D), source function S and optical depth at line center tau(O)) within different 'clouds' may be derived simultaneously by fitting both profiles theoretical and observational. An application example of the method with m = 3 shows that MCM method is suitable to measure the velocity fields of multi-object at the same time from their non-Gaussian profiles of complex. The V and Delta lambda(D) derived from the method are reliable, S and tau(O) are approximation. An influence of the variations of initial values in the parameter on the solution is given as well.

The multi-cloud model and its application to the study of asymmetrical line profiles: Gu Xiao-ma, Li Ke-jun & Lin JunYunnan Observatory, Kunming 650011

The multi-cloud model and its application to the study of asymmetrical line profiles: Gu Xiao-ma, Li Ke-jun & Lin JunYunnan Observatory, Kunming 650011

A Method on Measurements of Solar Velocity Fields

AbstractA new method of ‘multi-cloud model’(MCM) is proposed and two application examples are given in the paper.

A stochastic multicloud model for tropical convection

A stochastic model for representing the missing variability in global climate models due to unresolved features of organized tropical convection is presented here. We use a Markov chain lattice model to represent small scale convective elements which interact with each other and with the large scale environmental variables through convective available potential energy (CAPE) and middle troposphere dryness. Each lattice site is either occupied by a cloud of a certain type (congestus, deep or stratiform) or it is a clear sky site. The lattice sites are assumed to be independent from each other so that a coarse-grained stochastic birth-death system, which can be evolved with a very low computational overhead, is obtained for the cloud area fractions alone. The stochastic multicloud model is then coupled to a simple tropical climate model consisting of a system of ODEs, mimicking the dynamics over a single GCM grid box. Physical intuition and observations are employed here to constrain the design of the models. Numerical simulations showcasing some of the dynamical features of the coupled model are presented below.