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Climate change is likely to alter the runoff regime and its origin in the Nemunas River basin. The changes in runoff volume, seasonality and flood regime might affect hydropower production management, the potential of a forthcoming nuclear power plant and the stability of ecosystems. The water balance model WatBal was used to estimate the changes in the Nemunas River basin hydrology during the periods 1981-2000 and 2081-2100. The monthly air temperature and precipitation projections for the 21st century were estimated using the CMIP 5 model outputs. The two most diverse representative concentration pathways, RCP2.6 and RCP8.5, were analysed in this study to evaluate the spectrum of probable changes in the Nemunas River basin hydrology. The results revealed that the hydrological response to climate change in the Nemunas River basin would be most likely related to the change in snow climate. The projected magnitude of runoff changes during winter and spring is comparable for both scenarios, but the most important distinction is the difference in the cold-season hydrological regime, and especially water supply during winter and spring. According to the climate change scenarios both rain-snow and only rain dominant hydrological regimes are probable in the Nemunas River basin at the end of the 21st century. [ABSTRACT FROM AUTHOR]

In this study, the snow cover dynamics in Lithuania from 1961 to 2010 is analyzed. The spatial distribution of snow cover parameters, as well as intra-seasonal variability and long-term changes are evaluated. Snow survey results in the open field and the forest are compared. The Hess-Brezowski circulation form classification is used to link heavy snow cover accumulation or ablation events in Lithuania with the synoptic situations. The long-term variability of the number of days with snow cover and its connection with large-scale atmospheric circulation patterns (AO and NAO) is also investigated. The decrease in the number of days with snow cover during the study period is determined throughout the whole territory of Lithuania. Meanwhile, changes in the maximum snow depth are not so unambiguous. The study results also show that large-scale atmospheric patterns strongly influence the snow cover regime. [ABSTRACT FROM AUTHOR]

"BalticClimate - Baltic Challenges and Chances for regional and development generated by Climate Change" project is one of The Baltic Sea Region programme 2007-2013projects It helps region municipalities to deal with the climate change issue in a cooperative, integrated and sustainable way. Within the project the complex methodology of adaptation to climate change was created. One of the most important steps of methodology was development of the brand new attitude to territorial vulnerability assessment. Methodological approach based on GIS layers intersections and simple classification of vulnerability categories. The methodology was prepared Panevėžys district, one of the most agrarian areas in Lithuania. 4 general layers sensitive to climate change (typical to all municipalities) were identified: landscape elements, soil typologies, relief slopes and hydrological network; and subject to the municipal peculiarities, specific layers were identified (in this case soil fertility). The following 30-year time periods were identified to assess the municipal territorial vulnerability to climate change: 2011-2040, 2041-2070 and 2071-2100. It was found that Panevėžys district municipality is expected to be the most vulnerable in the time period of 2070-2100. [ABSTRACT FROM AUTHOR]

Data from Road Weather Information Systems (RWIS) automatic stations have been used all over the world for a wider range of purposes than just icy (slippery) road surface forecasts. The aim of this paper was to apply Lithuanian RWIS data to spatial temperature field analysis. The research area is central Lithuania, consisting mainly of Kaunas and the neighboring districts. The data used in the research were obtained from two different types of stations: automatic RWIS stations and meteorological stations. This information was compiled from the archives in Lithuanian Hydrometeorological Service and Lithuanian Road Administration. The chosen time period was 2007 and 2009 (GMT). Firstly, the evaluation of data suitability for spatial analysis was performed. Secondly, the analysis itself was done by drawing two types of maps representing the monthly mean temperature and a map of the yearly amplitude (year 2009). The first mean monthly temperature map type included data only from meteorological stations, whereas the second type was made combining data from both meteorological stations and RWIS. The chosen method for data interpolation was based on spline functions. It was found that if RWIS data is included into temperature field, a vast gradient appears between Babtai and Gynėvė RWIS stations. This results in considerable disparity in temperature zones in the northern area. It was also noted that there is a relatively smaller temperature anomaly in the southern region near Dzūkai Highlands and a slight positive temperature anomaly in the south-eastern part of the region during winter months. It was concluded that RWIS stations represent their background temperature field well and their data can be used in further analyses. Nevertheless, it is recommended to use data from as many stations as possible and to take into consideration the impact of dependency on the local environment and microclimate. [ABSTRACT FROM AUTHOR]

Extreme temperatures seriously impact all aspects of human life. In the 20th century, in Lithuania, the number of extremely hot events tended to increase. The aim of this study was to analyze the frequency of extremely hot day and night events and synoptic conditions during 1961-2010. Data of maximal and minimal temperatures of the warm period (May-September), obtained from 18 meteorological stations were used. Hot weather events were determined using the 95 percentile. Spatial (clustering) and temporal (regression coefficients, Mann-Kendall test) analyse were made. Also, the atmospheric circulation was analyzed using the COST733 action applications. The results have shown that the recurrence time of the highest temperature in the territory is mostly asynchronous. The daily values of extremes have a distribution similar to climatic regions, and for the night-time they become more latitudinal. The number of hot days and nights significantly increased in the second part of the period under analysis, especially during 1998-2010. Circulation analysis has shown that the most persistent types responsible for the development and persistence of hot weather conditions represent anti-cyclonic patterns. However, different circulation types depend on classification methods (GrossWetterType/Litynsky), domain (D00/D05) and event time (day/night), chosen from the COST733 database. [ABSTRACT FROM AUTHOR]

Predictions of heavy precipitation alterations in Lithuania are presented. Annual and seasonal precipitation levels and the repeatability of daily and 3-day precipitation cases were analysed. The CCLM (COSMO - Climate Limited-area Model)???? (Fig. 1), developed in Germany, output data of the period 1971-2000 and the prediction for 2001-2100 periods were used. Predictions were based on A1B and B1 emission scenarios and were divided into three periods (2001-2030, 2031-2060, 2061-2100). Daily precipitation data of 18 meteorological stations from Lithuania (Fig. 1) for the period 1971-2000 were also used. The generalized extreme value (GEV) distribution was used to estimate the probability of heavy precipitation alterations. Annual precipitation will increase by about 22% in the 21st century (Fig. 3). Winter time precipitation will rise extremely due to more frequent warm and moist air mass advections; meanwhile, almost no changes will be expected in summer. The changes will be most pronounced in the Žemaiciai Highlands and coastal lowlands (Fig. 2). Also, the number of days with precipitation will rise (by about 5%), especially in spring. Heavy rain repeatability will increase in the Lithuanian territory (Fig. 5). Mostly, one-day heavy precipitation cases will change in the Žemaiciai Highlands and coastal lowlands (>30%) (Fig. 4). The A1B emission scenario predicts greater changes almost in the whole territory, and only in the northern part greater changes are predicted by the B1 emission scenario. In the western part, the changes will be most significant in autumn, while in East Lithuania in winter. Over the first thirty-year period of the 21st century, the same process will affect the repeatability of three-day heavy precipitation cases (Fig. 6). Both scenarios predict great positive changes (up to 50%) in the east as well as in the west. In autumn, the increase of rains will be more significant. A 10-year and a 100-year probability (Table) of daily and three-day heavy precipitation cases will increase in the western part of Lithuania (A1B scenario). Meanwhile, the B1 scenario predicts a decrease of heavy precipitation of 100-year probability in this area. The other parts will experience no changes versus the period 1971-2000. The 10-year probabilities of three-day precipitation maxima vary slightly (Table). A1B predicts a more significant increase in the west and south-west of Lithuania. The 100-year probability of maxima will increase according to A1B, while the B1 scenario shows a slight decrease. [ABSTRACT FROM AUTHOR]

Climate change impact on hydrological processes in the largest Nemunas river basin of Lithuania has been estimated through combination of results from A1B, A2 and B1 emission scenarios and global climate models (ECHAM5 and HadCM3). Temperature and precipitation simulations from regional climate model were transferred to meteorological station sites using the delta change approach method. These climate scenarios were used as input data for HBV hydrological model. Projections of climate change impacts on hydrological processes were calculated with HBV for the periods 2011-2020, 2031-2040, 2051-2060, 2071-2080, and 2091-2100. The results were compared with baseline period 1975-1984. Projected changes in Nemunas river runoff are linked to changes of temperature and precipitation. [ABSTRACT FROM AUTHOR]

Climate change predictions for the Lithuanian territory according to the latest IPCC Fourth Assessment Report (AR4) issues and climatic models are presented. Predictions of meteorological variables in the 21st century are made for 16 meteorological stations across Lithuania. The prognostic values of variables (zonal (u) and meridional (v) wind component, air temperature, sea level pressure, precipitation) were derived from CERA database. Primary dataset was formed from monthly means of meteorological variables for the years 2001 to 2100. Climate predictions were made according to ECHAM5 and HadCM3 Global Climate Circulation models based on A1B, A2, B1 greenhouse emission scenarios. A linear and multiple regression downscaling procedure was made in order to get a local scale of predictions. Seasonal (for every season) algorithms were made by using the basic period from 1971 to 2000. Grid point data information (monthly means) was obtained from the NCEP / NCAR database. The linear regression method was used for air temperature forecast because data from meteorological stations and NCEP / NCAR data were very similar for all seasons and at all stations (correlation coefficient more than 0.95). Multiple regression algorithms were used for other variables (precipitation, wind speed, sunshine duration). Forecast of air temperature, precipitation, wind speed, sunshine duration was made using these relations for the years 2001 to 2100 for all 16 meteorological stations across the country. Air temperature will rise in the 21st century in Lithuania. The largest increase will be observed in winter seasons (4-8°C), and not so strong in summer (1.5-3.5°C). Based on the ECHAM5 Global Climate model output data, the temperature will tend to rise more by the seaside, and the HadCM3 Global Climate Circulation model shows a more intense air temperature rising in the central part of Lithuania. Regional differences in temperature change would not be very high, only in winter season reaching more than 2°C. A forecast based on A2, B1 greenhouse emission scenarios shows that the mean precipitation amount will rise during the 21st century in all parts of Lithuania. Meanwhile the A1B greenhouse emission scenario shows negative trends. Precipitation will increase in winter and spring and will decrease in summer and autumn. Precipitation type will tend to liquid phase because of rising air temperatures in winter seasons. In July, August and in the beginning of autumn the probability of draughts will rise dramatically. Also, precipitation distribution spatial differences will tend to decrease in spring, summer and autumn. All models show an increase of westerly wind direction frequency which will prevail in the 21st century in Lithuania. Most common wind directions for summer will be north-west and for the rest of seasons south-west. Mean wind speed change will be negligible. It will increase in winter (to 0.3 m/s in the A2 emission scenario) and will decrease in summer (to 0.2 m/s in the A1B emission scenario). Sunshine duration will increase during the 21st century. The modeling based on the A1B emission scenario shows most significant changes. Also, sunshine duration will be most evident from May to September. Meanwhile, a decrease of sunny hours (particularly on February) in winter seasons is expected. Changes will be more significant in the eastern part than on the seaside. [ABSTRACT FROM AUTHOR]