Darko Ogrin

Analysis of monthly, winter, and annual temperatures in Zagreb, Croatia, from 1864 to 2010: the 7.7-year cycle and the North Atlantic Oscillation

Long instrumental records of meteorological variables such as temperature and precipitation are very useful for studying regional climate in the past, present, and future. They can also be useful for understanding the influence of large-scale atmospheric circulation processes on the regional climate. This paper investigates the monthly, winter, and annual temperature time series obtained from the instrumental records in Zagreb, Croatia, for the period 1864–2010. Using wavelet analysis, the dominant modes of variability in these temperature series are identified, and the time intervals over which these modes may persist are delineated. The results reveal that all three temperature records exhibit low-frequency variability with a dominant periodicity at around 7.7 years. The 7.7-year cycle has also been observed in the temperature data recorded at several other stations in Europe, especially in Northern and Western Europe, and may be linked to the North Atlantic Oscillation (NAO) and/or solar/geomagnetic activity.

Climate change and the future of winter tourism in Slovenia.

Climate changes are affecting many activities in modern society all over the world. In Europe, the Alps are among the most affected regions, where rises in temperature and snow lines (Kohler, Maselli, 2009) and changed distribution of precipitation have already brought changes in society. Alpine tourism has undergone changes due to warmer and greener winters, so ski areas face lack of profit, some have even stopped operating, while others have changed their strategy and shifted their offer to all-year activities instead focusing only on winter (Vrtacnik Garbas, 2008). In Slovenia, most of the ski slopes lie at very low elevations compared with other Alpine countries, so most of these centres are even more endangered by global warming. The article focuses on climate trends in the Slovenian mountains, especially in the ski season months, from December to March.

Long-term air temperature changes in Ljubljana (Slovenia) in comparison to Trieste (Italy) and Zagreb (Croatia)

Abstract The cities of Ljubljana, Trieste and Zagreb are proximate in terms of distance but differ in terms of geographical and climatic conditions. Continuous meteorological measurements in these cities began in the mid-19th century. The 100-year trends of changes in mean annual and seasonal air temperatures for these cities are presented here, evaluating the differences between them which result from their different geographical and climatic positions. Differences in trends between Ljubljana and Zagreb that result from different measurement histories and the impact of urban climate are also presented: the impact of city growth on air temperatures in Ljubljana after 1950 was not completely eliminated in the process of data homogenization. The lowest air warming trends occur in the maritime climate of Trieste (mean annual air temperature: + 0.8 °C × 100 yr−1), where measurements were continuously performed in the densely built-up section of the city. The strongest trends occur in Ljubljana, mainly due to city growth (mean annual air temperature: + 1.1 °C × 100 yr−1). Comparing the linear trends in Zagreb-Grič and in Ljubljana, the impact of Ljubljanas urban heat island on the 100-year warming trend was assessed at about 0.2 °C, at 0.3–0.4 °C for the trend after 1950, and if non-homogenized data are used, at about 0.5 °C.

Prenosna infrardeča kamera kot pripomoček pri topoklimatskem raziskovanju

The paper presents some possibilities of application of a portable infrared camera for topoclimatic researches, especially for establishing the differences in temperatures of the so-called active surface layer. Demonstrated is the dependence of surface temperature on surface characteristics, such as land use, morphological features and the time of the day. The results can be useful for establishing topoclimatic units with similar temperature regimes.

Geografija v antiki in prikazi slovenskega ozemlja iz tega časa

The paper presents the development of geography in Classical antiquity by means of combining the findings in foreign and native expert literature. Classical findings, both theoretical and methodological, are the basis which has supported the development of this discipline throughout the following centuries. The broader area of the present-day Slovenian territory was poorly known in Classical antiquity, in particular the inland parts of the countries around the Northern Adriatic Sea.The paper analyses the origin and evolution of the Kysuce landscape from the Mesozoic era until the arrival of humans, identifying the relics of these historical evolutionary stages in the present-day landscape. It presents the most important relics from individual evolutionary time horizons as significant elements of geotourism offer. They are systematised and analysed chronologically, thus allowing geotourists to gain a broader picture of the surveyed region, and bringing them into the focus of geotourists as tangible proof that even a landscape that was formed millions of years ago can continue to stimulate our interest. The paper provides information on authenticity and the opportunity for a potential visitor to “touch” the landscapes’ millions-of-years-old relics in the area of the Kysuce region, Slovakia.

Alexander Georg Supan – v Sloveniji spregledan geograf slovenskega rodu

Paper presents life and work of Alexander Supan, geographer of Slovenian origin, and his influence on global and Slovenian geography. He was one of the more important geographers of the second half of the 19th and at the beginning of the 20th century. His scientific work took place, in contrast to geographers who were then working in present-day Slovenian territory, in accordance with contemporary geographic approaches. He built his career abroad, but he started it in Ljubljana. Because of that and because of his origin, we can consider him one of the more important links in the history of modern geography in Slovenian territory.

Valvasorjevi prikazi vremena in podnebja v Slavi vojvodine Kranjske

Not much is known about the climate and weather conditions on the Slovenian territory before regular and continuous meteorological measurements began to be performed. Some more information exists for the 17th century, particularly for its second half when J. W. Valvasor was active as a renowned Carniolan polymath. Valvasor’s records about weather and climate can be complemented with the records made by the Ljubljana chronicler J. G. Dolnicar. Notwithstanding certain reservations, necessary while using these sources, it is possible to present fairly well with the help of this additional information the weather and climate of that time and their impacts on the social environment.

Prihodnost zimskega turizma na Planini pod Golico v luči globalnega segrevanja

Warmer winters have brought the ski area Spanov vrh near Jesenice in decline. New climate conditions put plans of conventional ski tourism in a different point of a view. The article analysis trends of air temperature and snow conditions in winter months at Planina pod Golico to fnd out if weather conditions assure development of classical winter tourism at ski area Spanov vrh. As alternative to conventional way of tourism, the article recommends some new, more sustainable solutions for development of tourism, which could bring renaissance to Planina pod Golico.

Topoclimatic map of the littoral zone in Slovenian Istria

The paper presents the basic topoclimatic features of the littoral zone in Slovenian Istria which result from general climate features and specific local conditions. The most widely spatially spread topoclimatic units arise from differences in insolation and the combination of local landforms and land use. They are presented on the map at a scale of 1 : 50,000.