András Zénó Gyöngyösi

Sensitivity of WRF-simulated planetary boundary layer height to land cover and soil changes

Planetary boundary layer (PBL) height sensitivity to both so-called single and accumulated land cover and soil changes is investigated in shallow convection under cloud-free conditions to compare the effects. Single land cover type and soil changes are carried out to be able to unequivocally separate the cause and effect relationships. The Yonsei University scheme in the framework of the Weather Research Forecasting (WRF) mesoscale modeling system is used as a research tool. The area investigated lies in the Carpathian Basin, where anticyclonic weather type influence dominated on the five summer days chosen for simulations. Observation-based methods applied for validating diurnal PBL height courses manifest great deviations reaching 500–1300 m. The obtained deviations are somewhat smaller around midday and greater at night. They can originate either from the differences in the measuring principles or from the differences in the atmospheric profiles used. Concerning sensitivity analyses, we showed that PBL height differences caused by soil change are comparable with the PBL height differences caused by land cover change. The differences are much greater in the single than in the accumulated tests. Space averaged diurnal course difference around midday reaching a few tens of meters can be presumably treated as strongly significant. PBL height differences obtained in the sensitivity analyses are, at least in our case, smaller than those obtained by applying different observation based methods. The results may be utilized in PBL height diurnal course analyses.

Development of a complex dynamical modeling system for the meteorological support of unmanned aerial operation in Hungary

Proper, detailed and specific meteorological information is essential in aviation meteorology and may be especially critical in unmanned aerial operations. The aim of the research partially described in the present paper is the development of a weather prediction system that is suitable for the above purpose. The dynamical modeling component of the system was tailored and tested for the special needs of aviation weather forecasting for unmanned aerial operations in the Carpathian basin. Following an extensive technical implementation, the so-called Weather Research and Forecasting limited area model has been applied for this purpose. The applicability of the model system have been investigated on 9 typical weather situations, all of them having aeronautical safety relevance from the weather hazard point of view, all of the selected test case type weather situations are having significant influence on the weather of Hungary. The fine tuning of the model setup included parallel run of 30 different setup model versions, as ensemble members, each of them having different combination of parameterization. Verification of the ensemble members against observation yielded the optimal model version for the present purpose. Furthermore, meteorological measurements with sensors installed on UAV platform have been done. Following the short introduction of the weather prediction system that was applied, results of the case study test runs are compared to observation. The experiences of the first UAV flights are also presented. Results are introduced and the directions towards further development are described.

Weather Forecasting System for the Unmanned Aircraft Systems (UAS) Missions with the Special Regard to Visibility Prediction, in Hungary

Nowadays, Unmanned Aircraft Systems (UAS) systems are playing more and more significant role in military and civil operations in Hungary. The proper, detailed and significant meteorological support system is essential during the planning and executing phases of the different UAS missions. Within such systems, it is very important to generate an accurate short-time visibility prediction. In order to develop a mentioned short-time hybrid visibility forecast, we combined an analog statistical and a high-resolution WRF-based numerical predictions which, are available around the four main airports in Hungary. In our work we show the detailed construction of hybrid visibility forecast. To publish our results we created a special web site where the adequate meteorological predictions can be access in some graphical, text and other forms via (mobile) internet connection.