The breeding method has been widely used in studies of data assimilation, predictability and instabilities. The bred vectors （BVs）, which are the nonlinear difference between the control and perturbed runs, represen...The breeding method has been widely used in studies of data assimilation, predictability and instabilities. The bred vectors （BVs）, which are the nonlinear difference between the control and perturbed runs, represent the time-evolving rapidly growing errors in dynamic systems. The Lorenz （1963） model （hereafter Lorenz63 model） has chaotic dynamics similar to weather and climate. This study investigates the features of BVs of the Lorenz63 model and its impact on regime prediction of the Lorenz63 model. The results show that the Lorenz63 model has two different BVs for each breeding cycle, and the two BVs approach being identical when growth rate is high. The duration of the current and next regime is associated with the relative directions between the BV with high growth rate and the model trajectory.展开更多
The study of water and salt movement in soil is of vital importance to the prevention of secondary salinization, the reclamation of salt-affected soil and the scheduling of rational irrigation and drainage. In this pa...The study of water and salt movement in soil is of vital importance to the prevention of secondary salinization, the reclamation of salt-affected soil and the scheduling of rational irrigation and drainage. In this paper, on the basis of numerical simulation, the processes of salt accumulation and leaching of salts in soils under the conditions of evaporation, rainfall infiltration and irrigation are studied. The numerical methods for the prediction of water and salt regime are investigated.展开更多
基金supported by the ONR(Office of Naval Research)(Grant No.N00014-10-1-0557)the Civil,Mechanical and Manufacturing Innovation Division of the NSF(National Science Foundation)(Grant No.CMMI112585)NASA(National Aeronautic and Space Administration)(Grant No.5069UMNASAMI3G)
文摘The breeding method has been widely used in studies of data assimilation, predictability and instabilities. The bred vectors （BVs）, which are the nonlinear difference between the control and perturbed runs, represent the time-evolving rapidly growing errors in dynamic systems. The Lorenz （1963） model （hereafter Lorenz63 model） has chaotic dynamics similar to weather and climate. This study investigates the features of BVs of the Lorenz63 model and its impact on regime prediction of the Lorenz63 model. The results show that the Lorenz63 model has two different BVs for each breeding cycle, and the two BVs approach being identical when growth rate is high. The duration of the current and next regime is associated with the relative directions between the BV with high growth rate and the model trajectory.
文摘The study of water and salt movement in soil is of vital importance to the prevention of secondary salinization, the reclamation of salt-affected soil and the scheduling of rational irrigation and drainage. In this paper, on the basis of numerical simulation, the processes of salt accumulation and leaching of salts in soils under the conditions of evaporation, rainfall infiltration and irrigation are studied. The numerical methods for the prediction of water and salt regime are investigated.
