Wyniki wyszukiwania - BazTech

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Precipitation estimation and nowcasting at IMGW-PIB (SEiNO system)

Szturc J., Jurczyk A., Ośródka K., Wyszogrodzki A., Giszterowicz M.

Meteorology Hydrology and Water Management. Research and Operational Applications

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2018

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Vol. 6, Iss. 1

1--12

EN

A System for the Estimation and Nowcasting of Precipitation (SEiNO) is being developed at the Institute of Meteorology and Water Management – National Research Institute. Its aim is to provide the national meteorological and hydrological service with comprehensive operational tools for real-time high-resolution analyses and forecasts of precipitation fields. The system consists of numerical models for: (i) precipitation field analysis (estimation), (ii) precipitation nowcasting, i.e., extrapolation forecasting for short lead times, (iii) generation of probabilistic nowcasts. The precipitation estimation is performed by the conditional merging of information from telemetric rain gauges, the weather radar network, and the Meteosat satellite, employing quantitative quality information (quality index). Nowcasts are generated by three numerical models, employing various approaches to take account of different aspects of convective phenomena. Probabilistic forecasts are computed based on the investigation of deterministic forecast reliability determined in real time. Some elements of the SEiNO system are still under development and the system will be modernized continuously to reflect the progress in measurement techniques and advanced methods of meteorological data processing.

2

Operational setup of the soil-perturbed, time-lagged Ensemble Prediction System at the Institute of Meteorology and Water Management – National Research Institute

Duniec G., Interewicz W., Mazur A., Wyszogrodzki A.

Meteorology Hydrology and Water Management. Research and Operational Applications

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2017

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Vol. 5, Iss. 2

43--51

EN

The usage of Ensemble Prediction System (EPS)-based weather forecasts is nowadays becoming very popular and widespread, because ensemble means better represent weather-related risks than a single (deterministic) forecast. Perturbations of the lower boundary state (i.e., layers of soil and the boundary between soil and the lower atmosphere) applied to the governing system are also believed to play an important role at any resolution. As a part of the research project of the Consortium for Small-scale Modelling (COSMO) at the Institute of Meteorology and Water Management – National Research Institute (IMWM-NRI), a simple and efficient method was proposed to produce a reasonable number of valid ensemble members, taking into consideration predefined soil-related model parameters. Tests, case studies and long-term evaluations confirmed that small perturbations of a selected parameter(s) were sufficient to induce significant changes in the forecast of the state of the atmosphere and to provide qualitative selection of a valid member of the ensemble members. Another important factor that added a significant increment to ensemble spread was the time-lagged approach. All these aspects resulted in the preparation of a well-defined ensemble based on the perturbation of soil-related parameters, and introduced in the COSMO model operational setup at the IMWM-NRI. This system is intended for the use in forecasters’ routine work.

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Towards petascale simulation of atmospheric circulations with soundproof equations

Piotrowski Z., Wyszogrodzki A., Smolarkiewicz P.K.

Acta Geophysica

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2011

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Vol. 59, no. 6

1294-1311

EN

This paper highlights progress with the development of a petascale implementation of general-purpose high-resolution (nonoscillatory) hydrodynamical simulation code EULAG [Prusa et al. 2008, Comput. Fluids 37, 1193]. The applications addressed are anelastic atmospheric flows in the range of scales from micro to planetary. The new modeldomain decomposition into a three dimensional processor array has been implemented to increase model performance and scalability. The performance of the new code is demonstrated on the IBM BlueGene/L and Cray XT4/XT5 supercomputers. The results show significant improvement of the model efficacy compared to the original decomposition into a two-dimensional processor array in the horizontal - a standard in meteorological models.

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Macroscopic impacts of cloud and precipitation processes in shallow convection

Grabowski W., Slawinska J., Pawlowska H, Wyszogrodzki A.

Acta Geophysica

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2011

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Vol. 59, no. 6

1184-1204

EN

This paper presents application of the EULAG model combined with a sophisticated double-moment warm-rain microphysics scheme to the model intercomparison case based on RICO (Rain in Cumulus over Ocean) field observations. As the simulations progress, the cloud field gradually deepens and a relatively sharp temperature and moisture inversions develop in the lower troposphere. Two contrasting aerosol environments are considered, referred to as pristine and polluted, together with two contrasting subgridscale mixing scenarios, the homogeneous and the extremely inhomogeneous mixing. Pristine and polluted environments feature mean cloud droplet concentrations around 40 and 150 mg¯¹, respectively, and large differences in the rain characteristics. Various measures are used to contrast evolution of macroscopic cloud field characteristics, such as the mean cloud fraction, the mean cloud width, or the height of the center of mass of the cloud field, among others. Macroscopic characteristics appear similar regardless of the aerosol characteristics or the homogeneity of the subgrid-scale mixing.

5

Activation of cloud droplets in bin-microphysics simulation of shallow convection

Wyszogrodzki A., Grabowski W., Wang L.-P.

Acta Geophysica

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2011

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Vol. 59, no. 6

1168-1183

EN

This paper describes implementation of the warm-rain bin microphysics in a LES model based on the EULAG fluid flow solver. The binmicrophysics EULAG is applied to the case of shallow nonprecipitating tropical convection to investigate the impact of the secondary activation of cloud droplets above the cloud base. In a previous study applying the EULAG model with the double-moment bulk warm-rain microphysics scheme, the in-cloud activation was shown to have significant implications for the mean microphysical and optical characteristics of the cloud field. By contrasting the simulations with and without in-cloud activation as in the previous study, we show that the in-cloud activation has qualitatively similar but quantitatively smaller effect. In particular, the concentration of cloud droplets in the bin simulation without in-cloud activation decreases with height not as strongly as in corresponding simulations applying the double-moment bulk scheme.