The new method proposed in this research is based on the spectral registration of the microwave range radiation by means of a wideband scanning receiver. The experiments have proved its accuracy ...sufficient for the spectrum frequency determination. Sensitivity of 5-6 Hz/nm level is achieved. The obtained spectra are analyzed using a specialized hardware-software complex. The evidence from practice has shown that the method in question, apart from detecting the substances qualitative composition, helps determine the presence and propagation of cracks.
In this paper the spatiotemporal variability of the characteristics of the ocean circulation model, the Nucleus for European Modeling of the Ocean (NEMO), is studied with data assimilation in ...conjunction with the generalized Kalman filtering (GKF) method, previously developed by the authors. In this study, the numerical experiments were carried out with the global version of the NEMO model on the ORCA1 grid using a principally new approach for determining the key parameters of the GKF method. Simulation was carried out on a selected time interval of 1 month of the spatiotemporal variability of the ocean characteristics created by the NEMO model, both using the proposed data assimilation method with the archive of observational data from Argo drifters at different horizons, and without assimilation. The results of the numerical experiments are analyzed.
A technique based on recording radio-wave emission spectra in the microwave region using a scanning wideband receiver is proposed. The obtained spectra are analyzed with a special program using a ...hardware–software complex. It is shown that the technique allows substances to be distinguished with respect to their qualitative and quantitative composition and changes in their structure to be determined. It is found experimentally that the technique allows a sensitivity of 5–6 Hz/nm to be achieved.
Dynamics of the stratosphere and ozone layer are among important sources of atmospheric circulation predictability at subseasonal-to-seasonal time scales. The simulation of the stratospheric dynamics ...with the SL-AV atmospheric general circulation model for the SLAV072L96 seasonal weather prediction configuration is analyzed. The configuration is currently under preoperational testing at the Hydrometcenter of Russia. The model simulates both winter and summer averaged distributions of zonal wind and temperature close to the reanalysis data. The quasi-biennial oscillation of equatorial zonal wind is simulated with a realistic period and amplitude. There is a significant reduction of errors as compared with the previous stratosphere-resolving SL-AV model configuration. It is shown that the stratospheric process simulation enhancement is largely due to the reduction of systematic errors in the simulation of troposphere dynamics. The work on the inclusion of the CHARM photochemical model in the SL-AV model is described. The results of first experiments with the coupled model are given.
A reduced latitude-longitude grid is a modified version of a uniform spherical grid in which the number of longitudinal grid points is not fixed but depends on latitude. A method for constructing a ...reduced grid for a global finite-difference semi-Lagrangian atmospheric model is discussed. The key idea behind the algorithm is to generate a one-dimensional latitude grid and then to find a reduced grid that not only has a prescribed resolution structure and an admissible cell shape distortion but also minimizes a certain functional. The functional is specified as the rms interpolation error of an analytically defined function. In this way, the interpolation error, which is a major one in finite-difference semi-Lagrangian models, is taken into account. The potential of the proposed approach is demonstrated as applied to the advection equation on a sphere, which is numerically solved with various velocity fields on constructed reduced grids.
Development of the multiscale version of the global atmosphere model SL-AV required many improvements in the dynamical core, replacement or refinement of parameterization algorithms and complex ...tuning of the model. These modifications were initially tested with the experiments on modern climate simulation and then incorporated into the model configuration for medium-range numerical weather prediction. The impact of these model improvements on forecast quality is studied in this paper. The increase in accuracy of model climate characteristics has led to the reduction of forecast errors. The comparison of quality for numerical forecasts starting from the initial data of Hydrometcenter of Russia and ECMWF is carried out. The effect of replacing the initial data turned out to be comparable to the effect of multi-year works on model development. This shows the importance and necessity of development and improvement of the Hydrometcenter of Russia data assimilation system.
The global hydrodynamic atmosphere model SL-AV is applied for operational mediumrange weather forecast and as a component of the probabilistic long-range forecast system. The review of the previous ...development of the model is presented and the model features are noted. The existing model versions are described. The unified multi-scale version of the model is developed on the basis of these versions. This version is intended both for numertcal weather prediction and for modeling of climate changes. The numerical experiments on climate modeling with the developed multi-scale version are carried out according to the protocol of the international AMIP2 experiment. First results are pret ented. The pos tibiltty of application of the unified vertion of the SL-AV model for the met dium-range weather forecast, and, after some development, for modeling of climate changes is shown.
Seasonal prediction and climate change modeling are carried out on the basis of the programs incorporating the global model of the atmosphere, ocean model, sea ice and land models, etc. Each ...component of a coupled model has to provide a fairly complete representation of the physical processes in the appropriate medium, while the other components are replaced by reanalysis data. In this paper we present the results of a study aimed at improving the quality of the climate simulation with the SL-AV global atmospheric model where both ocean sur face temperature and ice concentration are prescribed. We also discuss some probtems in tuning the parameterizations of subgrid-scale physical processes and their modifications.
Исследуется пространственно-временная изменчивость характеристик модели циркуляции океана Nucleus for European Modelling of the Ocean (NEMO) с усвоением данных по методу обобщенного фильтра Калмана ...(Generalized Kalman filter (GKF)), ранее разработанному авторами. Проведены численные эксперименты с глобальной версией модели NEMO на сетке ORCA1 и с использованием нового способа определения ключевых параметров метода GKF. Проведено моделирование на выбранном временном интервале в один месяц пространственно-временной изменчивости характеристик океана по модели NEMO как с применением метода усвоения данных GKF с использованием архива данных наблюдений с дрифтеров Argo на различных горизонтах, так и без усвоения. Проанализированы результаты численных экспериментов.
The paper studies the spatiotemporal variability of the characteristics of the ocean circulation model Nucleus for European Modeling of the Ocean (NEMO) with data assimilation in conjunction with the Generalized Kalman filtering (GKF) method, previously developed by the authors. In the present work, numerical experiments were carried out with the global version of the NEMO model on the grid ORCA1 and using a principally new approach for determining the key parameters of the GKF method. Simulation was carried out on a selected time interval of 1 month of the spatiotemporal variability of ocean characteristics created by the NEMO model, both using the proposed data assimilation method with the archive of observational data from Argo drifters at different horizons, and without assimilation. The results of numerical experiments are analyzed.
Results of numerical experiments on the simulation of a flow moving around an isolated mountain are presented. The influence of the sizes of a barrier and of the flow velocity on characteristics of ...wave oscillations is discussed. All calculations are carried out with the authors’ two-dimensional (in the vertical plane) version of a nonhydrostatic dynamic scheme, in which equations of the dry quasi-incompressible atmosphere are solved with a semi-implicit semi-Lagrangian method. This method uses large time steps as compared to explicit-implicit Eurlerian methods. The results of calculations agree with results obtained by other authors, which gives hope for finding physically correct solutions in the simulation of nonhydrostatic processes in the atmosphere.
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