Study of thunderstorm activity in Volyn Region and in Ukraine using the data of Blitzortung online resource

The article contains the results of statistical and graphical analysis of thunderstorm activity in Ukraine and within Volyn Region, in particular, following the study of the dynamic maps archive available at the online resource Blitzortung.org (lightnings and thunderstorms in real time). It describes the principles and results of activities of Blitzortung.org, a community of lightning direction sensors owners and users, and presents the developed algorithm of the methodology of reading dynamic maps available at this resource. Regional analysis of the archival maps on the website Blitzortung.org for 2008-2019 for the territory of Volyn Region made it possible to establish the following changes of the thunderstorm activity dynamics: the total number of thunderstorm days more than doubled (from 30 to 68.3 days on average); the number of thunderstorms increased in April (it was a rare phenomenon earlier); the number of thunderstorms increased significantly in May, for some years the number of thunderstorm days in May reached certain summer months (June and July); most thunderstorms are of frontal origin, storm fronts come from the west, north and southwest. The number of frontal thunderstorms tends to increase, therefore indicating increased atmospheric instability and the number of natural meteorological phenomena associated with such instability; the average monthly number of thunderstorm days in Volyn Region also increased for all months of the year with no exception. The analysis of storm activity within the whole territory of Ukraine during the period of 2018-2019 indicated the presence of clear regional features and differences. The increase in thunderstorm activity is observed in the western (50-100%) and southern (15-50%) regions of the country, and partly in the north. The number of thunderstorm days in the eastern part of Ukraine is close to the climatic normal. At the same time, the analysis needs to be clarified and detailed throughout the whole network of meteorological stations of Ukraine whose data can be compared with the results of the study of archival maps available at Blitzortung.org.

Evaluating Recent and Future Climatic Suitability for the Cultivation of Norway Spruce in the Czech Republic in Comparison with Observed Tree Cover Loss between 2001 and 2020

The high portion of secondary Norway spruce in Central European forests constitutes a major problem because a significant part of these forests is moving further away from their original bioclimatic envelope. The precise evaluation and prediction of climatic suitability are needed for the implementation of forest adaptation strategies. We evaluated climatic suitability for the cultivation of Norway spruce in the Czech Republic forests, making use of the Random Forest combined learning statistical method. The evaluation presented was based on a comparison with the climatic normal period 1961–1990; change analysis was carried out for the period 1991–2014 and projected for 2021–2040 and 2041–2060. We found that suitable conditions for Norway spruce will remain only in 11.3% by area of Czech forests in the period 2041–2060 vs. 46.0% in the period 1961–1990. We also compared tree cover loss data (using Global Forest Watch) from 2001 to 2020 with statistics on salvage logging. In the period, the cover loss affected 19.5% of the area with more than 30% Norway spruce. The relationships between relative tree cover loss and the percentage of salvage logging caused by insects were conclusive and statistically significant.

Analysis of Air Temperature and Precipitation in Nitra, Slovakia in 2005–2019

High air temperatures and low amount of precipitation occur more and more frequently in Slovakia. The aim of this work is to evaluate the temperature conditions and total precipitation during the period 2005–2019 and to compare it with the 50-year climatic normal 1951–2000. Also, there was calculated the probability of summer days, tropical days, super-tropical days, frost days and ice days occurrence. Annual temperature is higher by 0.9 °C (1.1 °C during vegetation period) than normal. Rainfall, especially in the last 5 years, has a decreasing character (-75 mm.year−1) with frequent fluctuations. New phenomena – super-tropical days has occurrence of up to 20% between July and August. This study provides information based on which adaptation measures to the climate change need to be taken.

Long-term dynamics of the atmospheric and soil climate of humid subtropics of Russia

Aim. Identify patterns of temporal changes in the parameters of the atmospheric and soil climates of humid subtropics. Methods. The dynamics of air and soil temperature and precipitation are analyzed in the long-term and seasonal cycles with respect to the climatic normal, which is considered as a quantitative characteristic of the conditions of pedogenesis and climate variability over time. Results. The data on air temperature, precipitation and soil temperature yellow soils, formed in a subtropical wet-forest soil bioclimatic area are analyzed. It is shown that the average annual air temperature in 2001 - 2018 exceeded the climatic normal by 0,7°C, the annual precipitation increased by 104 mm. Modern warming leads to a change in the temperature regime of yellow soils. The average annual soil temperature at the beginning of the XXI century increased from 0,5°С at the depth of 320 cm to 0,9°С at the depth of 20 cm. The sum of active soil temperatures above 10°С at the depth of 20 cm increased by 283°С. Main conclusions. In the modern period, a change in the atmospheric and soil climate towards warming is observed in the zone of distribution of yellow soils of humid subtropics of Russia, accompanied by an increase in precipitation. Warming is most pronounced in the summer season and is practically not observed in the winter season. It is characterized by an increase in air and soil temperature throughout its profile, an increase in the sum of active temperatures. The revealed climate changes make it possible to re-evaluate the soil and agroclimatic resources of the Russian subtropics for agriculture and forestry.

The Evolution of Climate Changes in Portugal: Determination of Trend Series and Its Impact on Forest Development

Climate changes are a phenomenon that can affect the daily activities of rural communities, with particular emphasis on those directly dependent on the agricultural and forestry sectors. In this way, the present work intends to analyse the impact that climate changes have on forest risk assessment, namely on how the occurrence of rural fires are affecting the management of the forest areas and how the occurrence of these fires has evolved in the near past. Thus, a comparative analysis of the data provided by IPMA (Portuguese Institute of the Sea and the Atmosphere), was carried out for the period from 2001 to 2017 with the climatic normal for the period between 1971 to 2000, for the variables of the average air temperature, and for the precipitation. In this comparative study, the average monthly values were considered and the months in which anomalies occurred were determined. Anomalies were considered in the months in which the average air temperature varied by 1 °C than the value corresponding to the climatic norm, in at least 50% of the national territory. The same procedure was repeated for the variable precipitation, counting as anomaly the occurrence of a variation in precipitation of 50%, also in 50% of the national territory. Then the calculation of the moving averages for cycles of 3, 5 and 7 periods were applied, and the trend lines were projected. Subsequently, the relationship between the results obtained and the occurrence of rural fires as well as the spatial distribution of forest area, species and structure were analyzed. From the results obtained it was possible to confirm the existence of a tendency for the occurrence of climatic anomalies, highlighting the occurrence of an increasing number of months with temperatures higher by at least 1 °C. It was possible to foresee the relation between the occurrence of rural fires and the periods of anomaly and absence of precipitation. From the results obtained it is also possible to infer that, analyzing the tendency for these phenomena to occur, it can be necessary to change the “critical period of rural fires”, since it is verified that what is currently in use does not covers the entire period where anomalies occur and where large-scale rural fires potentially can happen.