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The North Atlantic Oscillation (NAO) and that Artic (AO), respectively, are by considerable importance to make the short-time weather forecast (until three days), followed by those of middle range and long time (until two weeks). To analyzing the ‘Hess-Brezowsky’ weather patterns associated with the NAO and AO during 19 years (2000 to 2018), has highlighted some aspects over the weather kind in the north part of Moldova. The zonal air-masses’ movements such as northwestern and western, both of them into the anti-cyclonic and cyclonic regime, were deployed in a predominately positive phase of NAO and AO. In the case of NWA type, NAO was 0.17 and AO 0.60, and for WA, NAO was 0.12 and AO 0.71. From NWZ, the NAO shown values around of 0.03 and AO 0.08. Exceptionally, NAO was into a negative phase in the case of WZ, with a value of around -0.13. Instead, for WZ, the AO was positive, with a yearly average of 0.08. Such air-masses movements are associated with a mild weather pattern, especially during the wintertime. Then, over the southern part of Europe, it’s set up the ‘Omega’ ridge. In doing so, the amounts of the precipitations are low at the studied area’s level. By a more significant interest is the southwesterly air-masses movement into a cyclonic regime (SWZ) who shown values of NAO of -0.16 and 00.26 for AO. Also, negative values for NAO were in the case of TRM (Trough over Central Europe), with -0.04 and HNFZ (High over Scandinavia-Iceland, Trough over Central Europe), with -0.64. For the same synoptically contexts (TRM and HNFZ), the AO was of -0.23, respectively, -1.31. Associated with the negative phases of NAO and AO, the planetary waves have shown an undulatory tendency. In such a case, there are development areas with extreme weather. For the studied region, the negative phases of NAO and AO were associated with severe weather events, such as blizzards, storms, and floods.

The paper presents the temporal variability of surface ozone (O3) and its precursors (oxides of nitrogen - NOx) from January 2012 to December 2015. In the same time, this study is aimed to explore the influence of the weather elements on these two major atmospheric pollutants in the area of Iași city. The maximum record of nitrogen oxides reached during the 4 analyzed years was 1200 μ/m-3 on October 27, 2015, a period of the year when atmospheric stability prevails. During the warm season (considered from May to September) the highest concentration of ozone was recorded at 155 μ/m-3. The winds direction from SSE or NNW and the winds speed greater than 2 m/s can significantly increase the concentration of the O3 and NOx respectively. Also, the stable atmospheric conditions can increase especially the concentration of the nitrogen dioxides. The statistical results illustrate a strong Pearson's correlation of surface ozone with solar radiation/maximum air temperature (r >0.5). The correlations were strongest during the summer months. Using the composite method, between warm season and cold season a difference of the pollutants concentration greater than 30 units for NOx was observed. Synoptic conditions associated with high pollution are also described.

This study is based on 3 years of hourly observations of global solar radiation (2014-2016), at a new weather station installed in the region of Central Moldavian Plateau, at Mădârjac (47.05°N, 27.25°E, 270 m). The main characteristics of annual, monthly and daily regime of global radiation were emphasized using for comparison similar data from Iașioficial weather station. Smaller annual amount of global solar radiation than those observed in previous studies were observed, reaching 4734 MJ/m2 in Iași and 4454 MJ/m2 in Mădârjac. An altidudinal gradient of global solar radiation close to 140 MJ/m2 was identified for the hilly region of Moldova. Despite the overall higher values in Iași, 30% of days indicates higher values of this parameter at Mădârjac weather station. These results can be used for the evaluation of the photo-voltaic potential in the region, but also to understand the altitudinal differences of solar radiation in the hilly region in Moldavia, since the only long-range actinometric stations from this part of Romania, Iași and Galați, are located at low altitudes.

This paper aims to present the evolution of the meteorological terminology, from the 17th century Grigore Ureche’s chronicle and bishop Amfilohie Hotiniul's manuscript on Physics (Moldavia, late 18th Century) to the mid 19th century writings of Teodor Stamati (Moldova) and Julius Barasch (Wallachia), also considering pop science literature, newspapers, such as “Albina Românească” and weather superstitions published in various calendars, and disputed by intelectuals like Mihail Kogălniceanu.

The air temperature variability and locally global warming impact, in the North Eastern Carpathians, have analyzed, namely in the high area of the Massif Rarău, as the environmental implications of these changes. Also taking into account the touristic potential of this area, some aspects of thermal regime change have been highlighted, with implications for tourism. For this study the string climate data have been used from the meteorological station Rarău, currently belonging to the Faculty of Geography and Geology, University Alexandru Ioan Cuza. The yearly average of air temperature at the meteorological station Rarău was 2.5°C over the period 1958-2015. The annual variations were from -1.3°C in comparition with the annual average in 1980 to +1.7°C in 2015. The lowest monthly average was in January, 6.7°C, the highest in July, 11.8°C and annual average amplitude was 18.5°C.

In the present work has been studied weather types that have characterized the North of Moldavia over the last 20 years and the role of synoptic conditions which stood behind them. In this study, we will show the role of airsynoptical conditions which give the look of the weather characterized during this period, a frequency of types of circulations to highlight a general trend, the induced effects on air temperature and in the weather and climate risks, that resulted (scattered thunderstorms phenomena associated with a high termic contrast, dryness, freezing phenomena, early, in the final of August and September and later, in April-May.

During the cold semester , most representative of climate risks are the thermal ones, specifically, on the base of a depression area, apprearance of thermal inversions. Amid this feature mentioned, the coldest temperatures were recorded in the lowlands,in the hearth's depression,as the municipe Câmpulung Moldovenesc, here being registered and the lowest temperature from the area studied,-31.7°C. All these thermal inversions that occur in transitional periods (spring and autumn) are producing the early frosts,late respectively, these being the most damaging for local agriculture. This stability of the atmosphere, in conjunction with cold air, which is garrisoned on the’s hearth depression, leads to atmospheric pollution with pollutants, resulting from transport and heating, because we are talking about an area in woodland, and consequently, wood is the main source of heating, especially in outlying areas of the city Câmpulung Moldovenesc,where court houses predominate, with their own heating systems.

Component part of the Carpathian-Danubian-Pontic space, the interfluve area between Prut and Dniester is subject to the regional process of climate evolution and change. In what regards the concept of human-influenced pedogenesis, the role of the biological factor is significantly reduced. As a consequence the direction and intensity of the elementary landscape and pedogenetic processes are determined by the relations between climate and the geomorphological factor. In the conditions of a relative stability of the geomorphological factor, the determining role is held by climate. To this is added soil vulnerability to the implications of climate changes, determined by the degree of soil physical degradation but also by a series of intrinsic and external (drainage) factors. This implies the idea of the control and management of the landscape and pedogenetic implications of climate changes by improving soil physical characteristics.

Temperature inversions represent complex phenomena, specific for depression forms of relief which introduce changes in vertical zoning (Apăvăloae, Apostle, Pîrvulescu, 1986 by stable air stratification (Erhan, 1981), because of their morphological features, this is due to the interdependence of general movement and characteristics of the active surface, being the cause of their production (Apăvăloae, et. al., 1984, 1986, 1987). The generation of thermal inversions, their intensity and frequency is a consequence of altitude topography, morphology, fragmentation, orientation and degree of closure to external drives. (Apăvăloae, Apostle, Pîrvulescu, 1988). Thermal inversions represent complex phenomena, specific to depression landforms that introduce changes within the vertical zoning (Apăvăloae, Apostol, Pîrvulescu, 1986) by stable air stratification (Matveev, 1958, Erhan, 1981, Yinghui Liu, 2002) where vertical thermal gradient is negative (Matveev, 1958), due to their morphological features, also as a consequence of the interdependance of general circulation and characteristics of the active surface, the cause of their generation (Apăvăloae, et. al., 1984, 1986, 1987).

Synoptic conditions associated with strong winds and snowfalls on January 2014 in Bulgaria and Romania are investigated in this paper. The Romanian authorities established the orange and red codes while the Bulgarian ones the orange code. A first peak was recorded in northern and especially northeastern Bulgaria and south-eastern Romania on January 25-26 and a second one on January 29 2014. The purpose is to understand what regulates the duration and intensity of these events. For their study, NCEP-500/700/850 and SLP analyses, different model outputs and soundings as well as data from 12 weather stations have been used.

Due to climate change, important attention was paid to the precipitations amounts over Moldavia's northern part. To point out the rainy air-circulation types was used the ‘Hess-Brezowsy’ Grosswetterlagen system (HBGWL) with 29 types of classifying European synoptic regimes of the 2000 to 2018 period at the reference weather stations of Bacău (184 m), Botoșani (161 m), Ceahlău-Toaca (1897 m), Iași (102 m), and Suceava (350 m). The highest amounts of precipitations annually from 2000 to 2018 in Romania's northeastern part were associated with the retrogressive cyclones. Therefore, on a background of the northeastern, cyclonic type (NEZ), there were recorded 53.45 mm, followed by High Scandinavia-Iceland, the ridge over Central Europe (HNFA), with 48.14 mm, and those from East in cyclonic type, with 44.03 mm. All the high over Central Europe (HM) weather types were associated with the lowest precipitations, only 1.71 mm. Also, small amounts of precipitations in the southwestern and south background, both of them into an anti-cyclonic type (SWA, SA), with 2.56 mm, respectively, 2.92 mm. Semestrial, the most important amounts of precipitations in the northeastern part of Romania were attributed to the retrogressive cyclones in the Eastern part of Romania and the ridges over the northern part of Europe. So, associated with EZ, during the 2000 to 2018 period, in the cold semester were recorded 28.43 mm and 27.66 mm within NEZ. During the warm semester, the highest amounts of precipitations were recorded within the HNFA type, with 42.75 mm, followed by Highs over the British Isles (HB) – 25.44 mm. The lowest values were associated with the southerly and southwesterly, both into an anti-cyclonic type (SA, SWA). [ABSTRACT FROM AUTHOR]

Snow water equivalent (SWE) and snow depth (SD) is estimating using Snow 17 model for several meteorological mountain stations from Romania. The model uses air temperature as the sole index to determine the energy exchange across the snow-air interface. In addition to temperature, the only other input variable needed to run the model is precipitation. The estimating values was validated with measurements values from respective point stations. It was observed that depending on the elevation station the values estimated have different errors. It is a strong correlation between estimating and observed values of SWE for Sinaia station (r = 0.96), Balea Station (r = 0.92), whereas for Vf. Omu station the correlation is weaker (r = 0.82). Regarding the SD values, the negligible difference can be found between modelled and observed data. Importantly, this study validates a model applied to the several meteorological stations from Romania. [ABSTRACT FROM AUTHOR]

Hail represents a phenomenon among other dangerous phenomena. All of these take place in the warm period of the year. Clouds which are able to generate hail’s falls are the convective cells. The agricultural sector is the most sensible in the path of hail’s falls. Moldova, where the farm sector prevails, is one the most exposed areas to damages generated by hail’s falls. Within the framework of the studied area, seen on atmospherically types movements, the most favorable in the occurrence of hail are those from North-Easterly and North-Westerly, both in the cyclonic pattern. Linked to them in the time interval studied (2000 to 2018) was recorded a frequency from North-East in the cyclonic mode (NEC) by 22.7%. Next, the North-Westerly air-mass movements in a cyclonic way (NVC) were about 21.8%. Significant weights were also during South-Westerly cyclonic (SVC) with 16.8% and Westerly cyclonic (VC) with 11.8%, respectively. The Westerly air-mass movements with its subdivisions (South-Westerly and North-Westerly) are those who generate the most severe convective developments. As a result, the North-Westerly airmasses movements in the cyclonic pattern are those who produced throughout time, the most significant dimensions of hail. In this study, we found that the sizes of hail during North-Westerly movements were between 40 and 60 mm in diameter. As a frequency, the most favorable period with hail at the ground’s level is valuable in May (29.4%), followed by June (26.1%), and July (21.8%). [ABSTRACT FROM AUTHOR]

The paper presents the temporal variability of surface ozone (O3) and its precursors (oxides of nitrogen - NOx) from January 2012 to December 2015. In the same time, this study is aimed to explore the influence of the weather elements on these two major atmospheric pollutants in the area of Iași city. The maximum record of nitrogen oxides reached during the 4 analyzed years was 1200 μ/m-3 on October 27, 2015, a period of the year when atmospheric stability prevails. During the warm season (considered from May to September) the highest concentration of ozone was recorded at 155 μ/m-3. The winds direction from SSE or NNW and the winds speed greater than 2 m/s can significantly increase the concentration of the O3 and NOx respectively. Also, the stable atmospheric conditions can increase especially the concentration of the nitrogen dioxides. The statistical results illustrate a strong Pearson’s correlation of surface ozone with solar radiation/maximum air temperature (r >0.5). The correlations were strongest during the summer months. Using the composite method, between warm season and cold season a difference of the pollutants concentration greater than 30 units for NOx was observed. Synoptic conditions associated with high pollution are also described. [ABSTRACT FROM AUTHOR]

Nowadays, the functional maintenance of narrow gauge railways, which still exist, with a very old infrastructure, is costly taking into consideration their low economic profitability. Competition and facilities offered by road transport, infrastructure development of forest roads which are easier to maintain, uncontrolled deforestation over the regenerative capacity of forest, economic conversion of many mining regions have also contributed to the disappearance of many forestry and mining railways. Saving the last lines that still exist in Europe, located in Romania is an obligation of mountain communities; one of the easiest ways of economic viability is the railway tourism and the arranged museums of old railway technique. In Romania, there is still in operation the only narrow gauge forest railway in Europe. [ABSTRACT FROM AUTHOR]

The central part of the Romanian Plain, more precisely the region delimited by the rivers Prahova and Mostistea to the East and Olt to the West, is characterized from a climatic point of view by more significant precipitation amount than the areas of the West and East, being named by Bordei-Ion (1988) as an air masses convergence area of directions from NE and E with directions from W. This area, due to the higher amount of precipitation, is evidenced by the characteristics of the physicogeographic factors such as, the types of vegetation, the characteristics of the soil cover, the use of the land or the presence of the steppes and the forests. The present work was realized using ROCADA data base (Bîrsan et al., 2014), from which all days with atmospheric precipitation values greater than 10 mm between 1981-2013 were extracted. This data was analyzed from a synoptic point of view using the available synoptic maps in the archive of the GFS forecasting model (Global Forecast System) available on www.wetter3.de. Thus, of the 3552 days analyzed, most days were asociated with high atmospheric instability specific for cold air advections in the form of long-wave troughs with a total of 1433 (40.3%). This is followed by Mediterranean cyclones with a total number of 1008 days (28.2%) with different trajectories according to the classification of Bordei-Ion (1983), of which cyclones with a type I track in 148 days (4.1%), cyclones with a type II track that acted in 653 days (18.4%) and those with trajectory IV that acted in 208 days (5.7%). The third place in the hierarchy of pluviogenetic causes is represented by the cyclones of Atlantic origin, with a total number of 436 days (12.3%). Cyclones with retrogressive trajectory had a 50 day (1.4%) and cut-off-low altitude cyclones in 469 days (13.4%). And last, warm air advections in anticyclonal regime acted in a number of 156 days (4,4%). [ABSTRACT FROM AUTHOR]