Heat waves and warm spells are extreme meteorological events that generate a significant number of casualties in temperate regions, as well as outside of temperate regions. For the purpose of this paper, heat waves and warm spells were identified based on daily maximum temperatures recorded at 27 weather stations located in Romania over a 55-year period (1961–2015). The intensity threshold was the 90th percentile, and the length of an event was of minimum three consecutive days. We analyzed 111 heat wave and warm spell events totaling 423 days. The classification of synoptic conditions was based on daily reanalysis at three geopotential levels and on the online version of a backward trajectories model. The main findings are that there are two major types of genetic conditions. These were identified as: (i) radiative heat waves and warm spells (type A) generated by warming the air mass due to high amounts of radiation which was found dominant in warm season; and (ii) advective heat waves and warm spells (type B) generated mainly by warm air mass advection which prevails in winter and transition seasons. These major types consist of two and three sub-types, respectively. The results could become a useful tool for weather forecasters in order to better predict the occurrence of heat waves and warm spells.

Due to its complex role within the radiation budget of the Earth, cloud cover plays an important role in climate variability at local, regional or continental scale. Consequently, there is a need for better understanding the causes and feedbacks of changes in cloud cover. We aim at investigating the response of cloud cover to changes in atmospheric circulation for 1981–2014. This is done based on the application of automated weather type classification from COST733 synoptic classifications software, which helps in identifying a variety of atmospheric circulation types for selected domains. Two major spatial changes in cloud cover over Europe are identified, in connection with atmospheric circulation, associated with the latitudinal shift towards the north of the westerly circulation. The first one is related to a decrease of the cloud cover over the inner continent and especially in the East of Europe in connection with an increase of circulation types associated with high pressures centers development over the central and northern part of the continent. The second one, which is weaker in intensity, indicates an increase of cloud cover in the south‐western part of Europe as a result of a decrease in circulation types induced by the development of the Azores High and its northeastward ridges. The changes in cloud cover distribution and also in radiation fluxes, imposed by these shifts in atmospheric circulation over the continent, are higher in the Eastern and Central Europe.

The aim of this study was to evaluate the frequency and severity of drought over the arable lands of Romania using the Normalized Difference Drought Index (NDDI). This index was obtained from the Moderate Resolution Imaging Spectro-Radiometer (MODIS) sensor of the Terra satellite. The interval between March and September was investigated to study the drought occurrence from the early stage of crop growth to its harvest time. The study covered a long period (2001–2020), hence it is able to provide a sound climatological image of crop vegetation conditions. Corine Land Cover 2018 (CLC) was used to extract the arable land surfaces. According to this index, the driest year was 2003 with 25.6% of arable land affected by drought. On the contrary, the wettest year was 2016, with only 10.8% of arable land affected by drought. Regarding the multiannual average of the period 2001–2020, it can be seen that drought is not a phenomenon that occurs consistently each year, therefore only 11.7% of arable land was affected constantly by severe and extreme drought. The correlation between NDDI and precipitation amount was also investigated. Although the correlations at weekly or monthly levels are more complicated, the annual regional mean NDDI is overall negatively correlated with annual rainfall. Thus, from a climatic perspective, we consider that NDDI is a reliable and valuable tool for the assessment of droughts over the arable lands in Romania.

During the last 30 years, the Romanian economy has faced different challenges due to structural readjustments, overcoming crisis and globalization. The share of primary and secondary sectors in the gross domestic product have strongly decreased, while the services have taken off. The main objective for this study is to observe how these economic readjustments can be assessed and measured using the Corine Land Cover datasets from 1990, 2000, 2006, 2012 and 2018 (with special observation on the range 2006 and 2018, after Romania was included in European Union). Despite some of the methodological limitations (like the minimum surface change), the Corine Land Cover turned out to be a powerful tool and it allowed us to detect an intense correlation between the socioeconomic and the structural trends in land use, in specific spatial contexts. The artificial surfaces are constantly increasing and this trend is rather visible as a distance function to the major Romanian cities. The most interesting changes occurred in the case of the agricultural polygons. The main trend emphasized by our analysis regards the redeployment of large farms in areas of agronomic and environmental territorial optimum. Such is the case for vineyards (after a decline during 2000–2006) and for annual cultures. All these changes in land-use patterns are too complex to be encompassed by a single methodology, which is why we used different tools, ranging from spatial analysis to geo-economic modeling, in order to detect how the Corine Land Cover datasets might be used for a better understanding of the Romanian economic readjustments.