Vol. 69, No. 1 * Pages 1–72 * January 2024

A symposium was organized by the Hungarian Meteorological Society in November 2023 to pay tribute to Gusztáv Götz. After some memories shared by contemporary colleagues and friends, presentations were given  by a few young colleagues whose publications were honoured with the award of the Society named after Gusztáv Götz. For the event, a scientific quiz was also compiled which was inspired by his widely known book entitled Chaos and Prognostics.

For meteorologist students at the Eötvös Loránd University who intend to work in the area of modelling, the graduate course entitled Numerical Modelling is of key importance. This course dates back to the 1980s; it  explains the theoretical background of the numerical methods applied in meteorology and provides room for practical modelling following the evolution of the area. The lectures are given by modelling practitioners of the meteorological service, who can get in touch with their potential colleagues in this way. The current paper is a summary of the presentation shown in the event organized by the Hungarian Meteorological Society in memory of Dezső Dévényi for his 75th birthday anniversary.

Methane is the most abundant organic compound in the atmosphere. Through its chemical reactions, it plays a major role in the formation of tropospheric ozone, and as a greenhouse gas, it has a non-negligible influence on the Earth's climate. The paper reviews the sources and sinks of atmospheric methane, the chemical processes driven by methane, and the evolution of the atmospheric methane concentration.

The United Nations’ Intergovernmental Panel on Climate Change (IPCC) recently published its Sixth Assessment Report (AR6) in 2021-22. As an important part of AR6, an Interactive Atlas was provided, which collects the available datasets and scenarios used in climate research. We studied the projected changes in the frequency of temperature extremes in the IPCC WGI reference regions using this Atlas. The greatest increase in the frequency of temperature extremes is expected in the Mediterranean Region, following the RCP8.5 scenario (29 days on average in the annual number of very hot days by 2081–2100 compared to  1986‑2005). In general, smaller increases are implied by the lower radiative forcing changes, and in the Northern Europe Region, namely, no changes are projected in the annual number of days with a maximum temperature exceeding 35 °C in the case of RCP2. 6.

The Bükk Plateau sinkholes have a special microclimate that is much colder than their surroundings, due to the cold-air pool (temperature inversion) effect that develops in the sinkholes. These sinkholes can be the cold poles of Hungary. In the summer of 2022, with the cooperation of Institute of Geography and Geoinformatics of University of Miskolc, a new meteorological station was installed in the measuring network on the Bükk Plateau, which was placed in the Mohos sinkhole in Zsidó-meadow. Along with the station operated by Róbert Kerékgyártó and his team in Vörösmeteor sinkhole, two automatic online stations send live data from the bottom of the sinkholes now. With the new data, it is possible to compare the Mohos and Vörösmeteor sinkhole areas of different topography, geometry and plant cover characteristics in the 2022/23 winter season.

Since 2018, Hungarian Meteorological Service has made hail forecasts for the National Chamber of Agriculture. To verify the issued forecasts, we needed to create a weather radar-based method wherewith it is possible to decide with high probability that a convective cell produces hail on the ground or not. By this, hailstorm detection with good frequency and spatial resolution is feasible. Additionally, we examined whether the conditions for the formation of hailstorms can be separated from ordinary storms based on the derived (so-called convective) parameters of the ECMWF fields to gain applicable utilities in forecasting hailstorms. Finally, we present our most significant indices which are used in the verification, and some results from 2023.