Vol. 35, No. 2

1.  Molinari, I., I. DasoviŠ, J. StipŔeviŠ, V. ęipka, E. Kissling, J. Clinton, S. Salimbeni, S. Prevolnik, D. Giardini, S. Wiemer, the AlpArray-CASE Field Team and the AlpArray-CASE Working Group: Investigation of the Central Adriatic lithosphere structure with the AlpArray-CASE seismic experiment.

The tectonics of the Adriatic microplate is not well constrained and remains controversial, especially at its contact with the Dinarides, where it acts as the lower plate. While the northern part of the Adriatic microplate will be accurately imaged within the AlpArray project, its central and southern parts deserve detailed studies to obtain a complete picture of its structure and evolution. We set-up the Central Adriatic Seismic Experiment (CASE) as a AlpArray Complementary Experiment with a temporary seismic network to provide high-quality seismological data as a foundation for research with state-of-the-art methods and high-precision seismic images of the controversial area. The international AlpArray-CASE project involves four institutions: the Department of Earth Sciences and the Swiss Seismological Service of ETH ZŘrich (CH), the Department of Geophysics of the Faculty of Science at the University of Zagreb (HR), the Republic Hydrometeorological Service of the Republic of Srpska (BIH) and Istituto Nazionale di Geofisica e Vulcanologia (I). The established temporary seismic network will be operational for at least 18 months. It combines existing permanent and temporary seismic stations operated by the involved institutions together with newly deployed temporary seismic stations, installed in November and December 2016, managed by ETH ZŘrich and INGV: five in Croatia, four in Bosnia and Herzegovina and one in Italy. We present our scientific aims and network geometry as well as newly deployed stations sites and settings. In particular, the new stations show favourable noise level (power spectral density estimates). The new network improves considerably the theoretical ray coverage for ambient noise tomography and the magnitude threshold shown in the Bayesian magnitude of completeness threshold map.

Keywords: AlpArray, Adriatic microplate, Dinarides, lithosphere, seismic networks, noise level

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Vol. 35, No. 1

2.  Kendzierski, S., B. Czernecki, L. Kolendowicz and A. Jaczewski: Air temperature forecasts' accuracy of selected short-term and long-term numerical weather prediction models over Poland.

The article discusses the results of air temperature forecasts from four short-term and two long-term forecasts of numerical weather prediction models. The analysis covered the results of model simulations from January 2015 to January 2016 and compared them at 14 meteorological stations in Poland. The comparison was made based on the most commonly used measures for continuous parameters i.e., ME (mean error), MAE (mean absolute error), RMSE (root mean square error), MSE (mean square error), BIAS and Pearson correlation. In the short time horizon, the best results in the context of the MAE, RMSE, MSE and correlation values were obtained by the Unified Model, although the diagnosed differences between the models are small. All models in the 0-72 h projection horizon reached a correlation of 0.95-0.97 and an MAE in the range of 1.5 ░C to 2.1 ░C. In the case of long-term forecasts, the HIRLAM model was slightly better than the GFS model. Clearly, in both cases, there is a marked decrease in quality after the fourth and in the following forecast lead days.

Keywords: verification, weather forecast, numerical weather prediction, NWP, long-term forecast, short-term forecast, air temperature, Poland

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3.  Sridevi, C., A. Kumar, K. K. Singh, V. R. Durai and P. Suneetha: Rainfall forecast skill of Global Forecasting System (GFS) model over India during summer monsoon 2015.

The Indian summer monsoon is one of the most important phenomenon that bring vital rain to India, so the Indian summer monsoon forecast and its verification is always of great interest and it effects India's agriculture. In the present study the categorical (Yes/No) and quantitative verification of rainfall forecast of the Global Forecasting System model running at India Meteorological Department, i.e., IMD GFS T574 (25 km resolution) and National Centre for Environmental Prediction, NCEP GFST1534 is done over Indian domain against 0.25░ gridded rainfall observations during summer monsoon season 2015. A detailed verification study for rainfall forecast at 0.25░ Î 0.25░ grid for Indian Window (0-40 ░N and 60-100 ░E) is conducted using two models output; both the / models are indicating that skill of the rainfall forecast is good for all parts of the country except high terrain regions. Regional verification also carried over 5 homogeneous regions of India, i.e., North India, West Coast India, North East India, Central India and Peninsular India using both model outputs. Results show that, in general, both the GFS T1534 and GFS T574 forecasts are skillful to capture climatologically heavy rainfall regions. However, the accuracy in prediction of location and magnitude of rainfall fluctuates considerably. The results documented are expected to be useful to the operational forecasters in day-to-day weather forecasting over Indian monsoon regions.

Keywords: GFS T1534L64, T574L64, NWP, global model, rainfall analysis, Indian summer monsoon, rainfall prediction skill, forecast verification

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4.  Ki║i, Í., C. A. G. Santos, R. M. da Silva and M. Zounemat-Kermani: Trend analysis of monthly streamflows using ¬en's innovative trend method.

Trend analysis of monthly mean streamflows is essential for better water resources management and planning. In this study, Mann Kendall (MK), ¬en's method and ¬en's innovative trend method (ITM) were employed in order to examine the possible trends of monthly streamflows obtained from nine stations from three basins (Yakabasi and Derecikviran in Western Black Sea Basin; Durucasu, Sutluce, Kale and Gomeleonu in Yesilirmak Basin; Simsirli, Tozkoy and Topluca in Eastern Black Sea Basin) located in Black Sea Region of Turkey. Based on the MK, streamflow data of Tozkoy Station which is located in western part of the Eastern Black Sea Region showed a significantly increasing trend while a significantly decreasing trend was found for the Yakabasi, Derecikviran, Durucasu and Sutluce stations which are situated in western part of the Black Sea Region. According to the ¬en's trend method, a significantly decreasing trend was seen in Durucasu, Sutluce, Yakabasi and Derecikviran stations while Tozkoy station showed significantly increasing trend. According to the ITM, low-medium values of Tozkoy Station indicated slightly increasing trend while low and medium streamflow values of Yakabasi, Derecikviran, Durucasu and Sutluce stations showed a decreasing trend. High streamflow values of Derecikviran and Sutluce stations showed a decreasing trend while corresponding values of Yakabasi, Simsirli and Tozk÷y stations indicated an increasing trend. It was showed that trends of low, medium, and high data can be easily identified by ITM which has some advantages (having no assumption such as serial relationship, nonnormality, test number) over the ¬en's method and Mann-Kendall test.

Keywords: monthly mean streamflows, trend analysis, Mann-Kendall, ¬en's method, innovative trend method

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5.  IvanŔiŠ, I., D. Herak, M. Herak, I. Allegretti, T. Fiket, K. Kuk, S. Marku╣iŠ, S. Prevolnik, I. SoviŠ, I. DasoviŠ and J. StipŔeviŠ: Seismicity of Croatia in the period 2006-2015.

During the ten-year period from 2006 to 2015 a total of 36 733 earthquakes were located in Croatia and its surrounding areas, with 37 main events registering magnitudes from 4.0 to 4.9. Seismically the most active was the coastal part of Croatia confined to two seismically distinguished areas. The NW domain was seismically less active, with almost 10 000 located events (seven were of magnitude ML ≥ 4.0), among which were the three strongest events that occurred in Croatia during the observed period. Two of them occurred in the Senj epicentral area, the first one on 5 February 2007 at 8:30 UTC (ML = 4.9, Imax = VII ░MSK) and the second one on 30 July 2013 at 12:58 UTC, (ML = 4.8, Imax = VI ░MSK). The third event occurred near Kornati Islands on 18 July 2007 at 10:54 UTC (ML = 4.8). The SE domain experienced the highest number of earthquakes (over 19 000 located events, with 24 events of magnitude ML ≥ 4.0, among which the strongest one was of magnitude ML = 4.9 with the epicentre in Bosnia and Herzegovina near the Croatian border). The seismicity in the continental part of Croatia was weak-to-moderate, with earthquakes of magnitudes ML ≤ 4.1. Focal mechanisms were obtained for 31 earthquakes with magnitudes ML ≥ 4.0, and individual earthquakes have also been macroseismically analysed. Low current moment release rates for both regions (continental and coastal) as compared to long-term averages, indicate the regions are currently in the strain accumulation phase.

Keywords: Croatia, fault-plane solutions, earthquake catalogue, macroseismic maps

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6.  VlŃdu■, A., N. Nikolova and M. Licurici: Evaluation of thermal continentality within southern Romania and northern Bulgaria (1961-2015).

The assessment of continentality and oceanity of the climate at a global level or within particular regions has lately gained in importance on the background of global warming and its impact on food and water resources. Aiming at understanding these influences, there were analysed the spatial distribution (based on the data from 27 meteorological stations) and temporal variability of four indices (for 19 meteorological stations with complete data series covering the interval 1961-2015). In specialized literature, there are used different continentality and oceanity indices. We studied four of them, but the results indicate that three of these are redundant, as they deliver almost the same information. Consequently, only the results based on Gorczy˝ski Continentality Index (GCI) and Kerner Oceanity Index (KOI) are presented and discussed in greater detail. These indices emphasize the continental character of the climate in the region, except for a narrow strip along the Black Sea Coast, which displays a maritime climate. There did not emerge a clear intensification of continentality (the trends were not statistically significant), in spite of the increase of air temperature in the region during the last two decades. However, a good correlation was obtained between three of the analysed indices (GCI, II and KOI) and North Atlantic Oscillation Index (NAOI).

Keywords: thermal continentality, Johansson Continentality Index (JCI), Ivanov Index of Thermic Continentality (II), Kerner Oceanity Index (KOI), Marsz Oceanity Index (MOI), Romania, Bulgaria

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