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It is important to investigate the hydrological consequences of current climate change. Hydrological responses to climate warming and wetter conditions include changes in discharge (frequency, amplitude, and volume). This paper describes current climate change and its impact on hydrological flow within the Horyn River basin. Daily air temperature and precipitation data obtained from the 17 meteorological stations located in and nearby the Horyn River basin, in combination with hydrological data (such as daily water discharges obtained from 9 water gauges), were used for the analysis of climate variability and its hydrological consequences. Analyses of meteorological variables and water discharges are crucial for the assessment of long-term changes in the river regime. Thiessen polygons were used to determine the area of influence of assigned specific meteorological stations, which affect the river's catchments within the Horyn River basin. As a result of the trend analysis, it was observed that discharge within the Horyn River basin decreased over time. These results were congruent with the trends of precipitation data and air temperature data of the stations determined by the Thiessen polygons and basin boundaries. To understand current changes in the daily flow in the basin, changes in air temperature and precipitation for the period 1991-2020 were compared with the period of the climatic norm (1961-1990). A similar analysis was done for daily water discharges. Increasing air temperature and decreasing precipitation in the current period led to a significant decrease in discharges in the Horyn River basin, especially during the spring flood period. [ABSTRACT FROM AUTHOR]

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Of particular current importance in the general problem of global climate change is the regional manifestation of this process. The focus of this paper is concentrated on the transitional natural zones: forest tundra (st. Salekhard), and forest-steppe (st. Omsk) of the West Siberian Plain. The study is based on data for ground air temperatures and precipitation at the mean-daily and mean annual level, covering the time interval from 1936 to 2012. The observations are grouped in three periods: from 1936 to 1970, from 1971 to 2006, and from 2001 to 2012 thus making it possible to identify trends in the behavior of mean annual indicators, examine the intra-annual and seasonal changes, and to carry out a typification according to thermal regime and humidification regime. Regional changes in mean annual air temperatures at st. Salekhard and st. Omsk are representative of the general features of temperature variation over the entire observing period. In the Subarctic, however, the warming period became more pronounced in 2001, whereas it started in the 1970s in the forest-steppe, which is borne out by an increase in the recurrence frequency of warm and normal (according to thermal regime) years during the aforementioned periods. The southern part of the West Siberian Plain has experienced a more intense warming than in the north. Analysis of the intra-annual behavior of mean daily temperatures at st. Omsk showed their steady increase during the time interval from 1971 to 2012; this is especially true in regard to a warm season. At st. Salekhard the dynamics of temperatures is more complicated in character. Observation showed comparable (in duration) time spans with alternating increases and decreases in air temperature. The annual precipitation amounts for the time intervals used in the comparison indicated that their mean long-term value in the zones under consideration has increased for the last 35 years by 26 mm at st. Salekhard, and by 15 mm at st. Omsk. Considerable changes of climate have been observed since the 1970s; in high and mid-latitudes, they differ greatly and have influence on phenological phenomena, the structure of seasonal rhythms, the conditions of functioning of landscapes, and on human economic activity. [ABSTRACT FROM AUTHOR]

This paper focuses on evaluation of climatic data obtained at Meteorological Observatory GPI SAS Stará Lesná according to the classical daily observations carried out for period 1988-2013. Location is situated at the foothills of the High Tatra Mts. and represents submontane climate zone favourable for temperate coniferous and mixed forest vegetation. According to observations climate of Star´a Lesná is characterized by average annual air temperature 5.9 °C that seasonally varies from -3.5 °C (DJF) to 15.2 °C (JJA). Air-temperature extremes range between -26.5 and 34.2 °C. Daily air temperature maxima and derived indices such as the number of summer days indicate moderate warming during last decade. Growing season length is about 195 days. Average annual precipitation is 744 mm, seasonal comparison shows nearly twice more precipitation amount in summer than winter half year. Snow depth is 35 cm on average, extraordinary over 50 cm. Relative air humidity is about 78%. Wet periods lasted from 5 to 13 consecutive wet days; substantially longer are dry periods from 14 to 39 days. Average sunshine duration is 1806 hours per year. The number of sunny days is clearly lower than the number of cloudy days. Surface air pressure 920.4 hPa relates to altitudinal position of site. Wind blows mostly from the more open southern side. Although average wind speed is rather low (2.1 m/s), occurrence of strong wind gusts above 40 m/s can cause such a spatial destruction of natural environment as in November 2004 [ABSTRACT FROM AUTHOR]

The paper presents a concise overview of the theoretical framework on which climate classifications are based. Beside short review of climate classifications, namely climatic regionalization for Serbia (or wider area including Serbia), main deficiency of these research was ascertained (which primarily relate to the period on the basis of which climate regionalization was carried out). The criteria of the Köppen climate classification are presented, on the basis of which the climate regionalization of Serbia has been carried out. The methodology of making maps of air temperatures and precipitation amounts has been described, on the basis of which a map of the climate regions of Serbia has been created. Spatial distribution of the types and subtypes of the climates in Serbia has been briefly described. It has been pointed to the constraints of the climate regionalization that arise from the theoretical bases of the climate classifications, but also from nature of the collected data and the applied methodology. [ABSTRACT FROM AUTHOR]

Mongolia's Selenga sub-basin of the Lake Baikal basin is spatially extensive, with pronounced environmental gradients driven primarily by precipitation and air temperature on broad scales. Therefore, it is an ideal region to examine the dynamics of the climate and the hydrological system. This study investigated the annual precipitation, air temperature, and river discharge variability at five selected stations of the sub-basin by using Mann-Kendall (MK), Innovative trend analysis method (ITAM), and Sen's slope estimator test. The result showed that the trend of annual precipitation was slightly increasing in Ulaanbaatar (Z = 0.71), Erdenet (Z = 0.13), and Tsetserleg (Z = 0.26) stations. Whereas Murun (Z = 2.45) and Sukhbaatar (Z = 1.06) stations showed a significant increasing trend. And also, the trend of annual air temperature in Ulaanbaatar (Z = 5.88), Erdenet (Z = 3.87), Tsetserleg (Z = 4.38), Murun (Z = 4.77), and Sukhbaatar (Z = 2.85) was sharply increased. The average air temperature has significantly increased by 1.4 °C in the past 38 years. This is very high in the semi-arid zone of central Asia. The river discharge showed a significantly decreasing trend during the study period years. It has been apparent since 1995. The findings of this paper could help researchers to understand the annual variability of precipitation, air temperature, and river discharge over the study region and, therefore, become a foundation for further studies. [ABSTRACT FROM AUTHOR]

The total glacial area of the Cordillera Blanca, Peru, has shrunk by more than 30% in the period of 1930 to the present with a marked glacier retreat also in the recent decades. The aim of this paper is to assess local air temperature and precipitation changes in the Cordillera Blanca and to discuss how these variables could have affected the observed glacier retreat between the 1980s and present. A unique data set from a large number of stations in the region of the Cordillera Blanca shows that after a strong air temperature rise of about 0.31°C per decade between 1969 and 1998, a slowdown in the warming to about 0.13°C per decade occurred for the 30years from 1983 to 2012. Additionally, based on data from a long-term meteorological station, it was found that the freezing line altitude during precipitation days has probably not increased significantly in the last 30years. We documented a cooling trend for maximum daily air temperatures and an increase in precipitation of about 60mm/decade since the early 1980s. The strong increase in precipitation in the last 30years probably did not balance the increase of temperature before the 1980s. It is suggested that recent changes in temperature and precipitation alone may not explain the glacial recession within the thirty years from the early 1980s to 2012. Glaciers in the Cordillera Blanca may be still reacting to the positive air temperature rise before 1980. Especially small and low-lying glaciers are characterised by a serious imbalance and may disappear in the near future. [ABSTRACT FROM AUTHOR]

As knowing the impact of weather phenomena and their effects on agriculture represents a primary necessity, at present the importance of agro-meteorological information for economy, in general, and for the agriculture sector, in particular, involves a complex approach of the relation environment--plant. The agro-climatologic resource's assessment is multi-way needed: to choose the product and to cultivate varieties; for different phyto-technical interventions used to improve soil fertility; it is also economically fundamental in order to obtain optimum yields. This article frames an analysis and a synthesis of the main agro-climatic parameters, the air temperature and the precipitation for the region of Muntenia, considering the period between 1961- 2009. As this region has the largest agricultural land in Romania, is it useful and necessary for everyone who aims to carry on agricultural business or studies to be well informed on the agro-climatologic potential that characterizes it. [ABSTRACT FROM AUTHOR]

Abstract: This work focuses on estimation of global solar radiation and, in particular, it explores the effect of precipitation and temperature on solar radiation profile of Kathmandu (Nepal). An accurate knowledge of solar radiation distribution in each particular geographical location is crucial for the promotion of solar energy technology. The best way of knowing the amount of global solar radiation is to install quality instruments at many locations in the given region. This requires their day to day maintenance, recording and calibration, which is very costly in developing countries like Nepal. Thus, the alternative approach is to correlate meteorological measurements with appropriate models and investigate the key parameters. For the research activities the RadEst program has been used. It includes, for evaluating the daily global solar radiation values at a given latitudes, four models which estimate the atmospheric transmissivity by measurements of daily temperature range and precipitations. The model parameters are fitted in 2years data by iterative procedures. The values obtained by these models are, then, compared with measured radiation data. The paper reports graphical and statistical evaluations suggesting that among the four models, the Modular DCBB is the best model for Kathmandu area. This result is useful for designing solar panels able to maximize the harvesting of solar energy and to reduce the chronic shortage of hydrocarbon fuel that Nepal imports in a significant amount each year. [Copyright &y& Elsevier]

This paper analyses the present Egyptian Mediterranean coast (EMC) climate and the response of its climate variables to global changes. First, the accuracy of the ERA-Interim dataset (1979-2010) for the studied region is examined by comparing these data with available independent observations. Second, the qualities of six global climate models (GCMs), together with the ensemble mean of multiple model realisations of the A1B scenario, are examined by comparing these with the ERA-Interim dataset. Finally, GCM simulations are used to describe the uncertainties in future climate change along the EMC. The results indicate that the observations are in good agreement with the ERA-Interim data. The data for the EMC, 1979-2000, display a significant positive trend for 2-m air temperature together with significant negative trends for total precipitation and sea level pressure. The climate model that best describes the present EMC climate is the CGCM 3.1 model, which is used to describe the future climate of the study area. The CGCM 3.1 model indicates that the EMC area will experience significant warming, substantial droughts, and a weak decrease in sea level pressure in the end of the current century. [ABSTRACT FROM AUTHOR]

Despite the widespread application of statistical downscaling tools, uncertainty remains regarding the role of model formulation in determining model skill for daily maximum and minimum temperature (Tmax and Tmin), and precipitation occurrence and intensity. Impacts of several key aspects of statistical transfer function form on model skill are evaluated using a framework resistant to model overspecification. We focus on: (a) model structure: simple (generalized linear models, GLMs) versus complex (artificial neural networks, ANNs) models. (b) Predictor selection: Fixed number of predictors chosen a priori versus stepwise selection of predictors and inclusion of grid point values versus predictors derived from application of principal components analysis (PCA) to spatial fields. We also examine the influence of domain size on model performance. For precipitation downscaling, we consider the role of the threshold used to characterize a wet day and apply three approaches (Poisson and Gamma distributions in GLM and ANN) to downscale wet‐day precipitation amounts. While no downscaling formulation is optimal for all predictands and at 10 locations representing diverse U.S. climates, and due to the exclusion of variance inflation all of the downscaling formulations fail to reproduce the range of observed variability, models with larger suites of prospective predictors generally have higher skill. For temperature downscaling, ANNs generally outperform GLM, with greater improvements for Tmin than Tmax. Use of PCA‐derived predictors does not systematically improve model skill, but does improve skill for temperature extremes. Model skill for precipitation occurrence generally increases as the wet‐day threshold increases and models using PCA‐derived predictors tend to outperform those based on grid cell predictors. Each model for wet‐day precipitation intensity overestimates annual total precipitation and underestimates the proportion derived from extreme precipitation events, but ANN‐based models and those with larger predictor suites tend to have the smallest bias. [ABSTRACT FROM AUTHOR]

Bright sunshine duration (BSD) is of singular importance for estimating solar irradiance, and its data base is small in comparison. This paper reports a generic algorithm that captures global variation in monthly BSD data in relation to temperature, precipitation and geographic location. The algorithm depicts BSD in terms of reduction from daylength as a negative exponential function of standard station pressure, with the exponential reduction rate as proportional to the product of a series of multiplicative functions reflective of global generalities and regional idiosyncrasies. The algorithm is parameterized byregression fitting to monthly climate normal data for 729 stations worldwide. It accounts statistically for 85% of the variance in the BSD data, with a root mean square error of 1.0 hr, or 15% of the data mean. The data fitting tends to be least robust for tropical humid climates or for tropical and subtropical monsoonal Asia. The spatially-based algorithm projects with a reasonable accuracy 5-yr sequential monthly BSD data for five stations representative of the climate regimes in the conterminous United States: the absolute error is within +/-1.5 hr for 70% to 93% of the 60 monthly mean BSD values for each of the stations. [ABSTRACT FROM AUTHOR]

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The aim of the present research work is to bring to better understanding the recent climate change at regional scale. The tendencies of many-years variability of air temperature and precipitation in Northeastern Bulgaria are determined. In order to determine future tendencies in air temperature and precipitation variability the data from regional climate models are analyzed. The occurrence of extreme monthly temperature and precipitation totals are investigated by calculation of 10th and 90th percentiles of the empirical distribution in the reference period 1961-1990. The main result of present work is that there are a positive tendency in changes of air temperature and negative in precipitation. The regional climate model data show increasing of extreme hot and dry months which is considerable for the second part of 21th century. [ABSTRACT FROM AUTHOR]

Presented is the review of the modern knowledge of the Arctic Oscillation (AO). Demonstrated is the relation of air temperature and precipitation in Northern Eurasia to this dominant type of wintertime atmospheric variability at northern extratropical latitudes. It is demonstrated that AO is a result of the coupling between the troposphere and stratosphere. The attention is paid to the long-range forecasting of AO index and to the factors complicating the forecasting. Given are the new results of the authors' research. Used is the wintertime AO index computed by the authors from the 20th Century Reanalysis dataset. The high- and low-frequency components of AO index variability and the periods of statistically significant trends are analyzed using the 112-year series (1901-2012). Demonstrated is the key impact of wintertime AO phase on the anomalies of air temperature and precipitation in Northern Eurasia at the time scale of years and decades. This impact is manifested in the northern part of Northern Eurasia in the prevalence of warmer and wetter winters at the positive AO phase and of colder and drier winters at the negative AO phase. The precipitation anomalies of opposite sign prevail in the southern part of Northern Eurasia. It is demonstrated that the winter AO phase affects the terms of the springtime air temperature transition to positive values. [ABSTRACT FROM AUTHOR]

Copyright of Zemdirbyste-Agriculture is the property of Lithuanian Research Centre for Agriculture & Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Climate change affects seasonal weather patterns, but little is known about the relative importance of seasonal weather patterns on animal population vital rates. Even when such information exists, data are typically only available from intensive fieldwork (e.g., mark-recapture studies) at a limited spatial extent. Here, we investigated effects of seasonal air temperature and precipitation (fall, winter, and spring) on survival and recruitment of brook trout ( Salvelinus fontinalis) at a broad spatial scale using a novel stage-structured population model. The data were a 15-year record of brook trout abundance from 72 sites distributed across a 170-km-long mountain range in Shenandoah National Park, Virginia, USA. Population vital rates responded differently to weather and site-specific conditions. Specifically, young-of-year survival was most strongly affected by spring temperature, adult survival by elevation and per-capita recruitment by winter precipitation. Low fall precipitation and high winter precipitation, the latter of which is predicted to increase under climate change for the study region, had the strongest negative effects on trout populations. Simulations show that trout abundance could be greatly reduced under constant high winter precipitation, consistent with the expected effects of gravel-scouring flows on eggs and newly hatched individuals. However, high-elevation sites would be less vulnerable to local extinction because they supported higher adult survival. Furthermore, the majority of brook trout populations are projected to persist if high winter precipitation occurs only intermittently (≤3 of 5 years) due to density-dependent recruitment. Variable drivers of vital rates should be commonly found in animal populations characterized by ontogenetic changes in habitat, and such stage-structured effects may increase population persistence to changing climate by not affecting all life stages simultaneously. Yet, our results also demonstrate that weather patterns during seemingly less consequential seasons (e.g., winter precipitation) can have major impacts on animal population dynamics. [ABSTRACT FROM AUTHOR]

Predisposition of drought occurrence is based on combined evaluation of above-normal temperatures and below-normal precipitation. According to the weight of the individual categories of extremity, the five degrees of predisposition to drought were determined (degree 1 is the lowest risk, degree 5 is the highest risk). Evaluation of temperature extremity is based on the determination of abnormality in comparison with average value and standard deviation. Individual categories of extremity of precipitation are determined by comparing the individual monthly data with percentile values. Monthly data of homogenized technical series of the Czech Hydrometeorological Institute were evaluated for the years 1961-2010 in two climatologically dry areas (Breclav and Kladno county in the Czech Republic). Fourty-two months were rated risky in Breclav county and fourty-four in Kladno county. The evaluation shows an increase of predisposition to drought, especially after 1990. The highest incidence of degree 5 was recorded in 2001 to 2010 in vegetation season. Subsequently the drought variability as a mean variance of years/season and drought severity as a sum of degree of predisposition to drought of years/season were assessed. A gradual increase of variability and severity from 1961-1970 to 2001-2010 is visible. The lowest values of variability (maximum 2) and severity (maximum 3) in both counties were recorded in winter. [ABSTRACT FROM AUTHOR]

The results of meteorological ground-based observations in Moscow (mainly at Moscow State University (MSU)) in summer 2010 are discussed. It is shown that the anomalous heat of 2010 has no analogs in the history of meteorological observations in the Russian capital in either the record-breaking values themselves or in their duration. Both the secular records of the monthly mean air temperatures in July and August over the past 230 years and the absolute temperature maximum over the past 130 years were exceeded. For the first time in the history of regular meteorological measurements, the maximal air temperature in Moscow exceeded +38°C, the diurnal mean temperature exceeded +30°C, the monthly mean temperature exceeded +26°C, the soil surface temperature exceeded +60°C, and the deficit of water vapor saturation exceeded 50 hPa. On the whole, the tropical air, which dominated in Moscow, was to a larger degree anomalously hot than anomalously dry. The least relative humidity during the catastrophic heat (16%) only approached the historical minimum (15%). For the first time in the history of measurements for July, the amount of precipitation in July 2010 was only 7.4 mm. In total, these conditions were responsible for the appearance of mass ignition centers in the Moscow region and, as a consequence, of dense smog. The record-breaking ground temperatures over the past 45 years associated with the catastrophic heat were observed at a depth of 320 cm up to the end of 2010. [ABSTRACT FROM AUTHOR]

In grassland areas where herbage production has no economic value, the cut grass is often left on the sward surface where its decomposition is influenced by weather conditions. Although the influence of temperature and humidity on decomposition has been investigated under controlled lab conditions, experimentation has generally been under ideal moisture conditions that have not tested the combinations of climatic limitations that might occur in the field. The decomposition of mown turfgrass clippings deposited at different times of vegetation period was studied in situ using nylon bags during the first 8 weeks after deposition to investigate the effect of weather conditions (the air temperature, relative humidity, precipitation) on decomposition. Decomposition is the highest in the case of high air humidity and temperature of 10°C. Limiting factors for decomposition at temperatures above 10°C is the air humidity and below 10°C the air temperature. The general tendency was that the rate of decomposition increased with increasing air temperature up to 10°C, but with further increases of air temperature the decomposition rate slowed down. Relative air humidity had a variable impact (at the beginning of the decomposition process (weeks 1–2) the influence was negative, during weeks 3–8 of the decomposition process the effect was positive), and hence had no generalized relationship with decomposition over the studied decomposition period (weeks 1–8). The most significant influence of weather conditions on the decomposition rate was recorded directly after cutting. If the cutting was done during hot weather conditions, the material was drying fast and therefore decomposed slowly. Our results indicate that for fast decomposition of clippings it is important to maintain the freshness of material. Lower decomposition rates occurred during conditions of hot and dry weather, and also cooler (temperature near to 0°C) weather, and can be compensated as soon as favourable weather arrives. [ABSTRACT FROM AUTHOR]

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Analysis of numbers of invasive species (insects, plants, plant diseases) in each of Chinese provinces and the world’s climatic zones respectively, demonstrated positive correlations between diversity of bioinvasion and air temperature and precipitation (the two main criteria for classifying world climate types). When the air temperature is within the range of 1–25°C, the degree of diversity of invasive alien species increases exponentially with air temperature. However, when the air temperature falls outside the range of 1–25°C, the diversity of harmful invasive alien species changes with air temperature in a parabolic pattern, showing a “mid-latitude bulge”. Namely, when air temperatures are too high or too low, a lower average invasion frequency of harmful alien species is observed. Invasion by harmful invasive alien species is more weakly related to precipitation. Different climatic zones showed dramatic differences in resistance to the invasion of invasive alien species due to their different characteristic climatic factors, mainly including air temperature and precipitation. [ABSTRACT FROM AUTHOR]

The article presents a study on the long-term monotonic trend and abrupt changes for major climate variables at 23 meteorological stations in the headwater catchment of the Yellow River basin in China from 1960 to 2001 on the basis of mean air temperature, precipitation, sunshine duration and pan evaporation. It states that the abrupt changes have been examined in terms of a five-year moving averaged annual series using the moving t-test (MTT) method, Yamamoto method and Mann-Kendall method. The results indicated that the annual air temperature has increased by 0.80 degrees Celsius in the headwater catchment of the Yellow River basin during the past 42 years.

Series of annual and seasonal temperature and precipitation representing respectively northern and southern Italy are compared for trend,interannual variability and periodicity in the period 1866-1995. Temperature and precipitation trends are almost always anticorrelated except in winter in the North where an anomalous behavior is evident till about 1980. The result is that the Italian climate has become warmer and drier especially in the South since about 1930.The interannualvariability does not present significant maxima, but only minima that cannot be related to the start of a trend either for temperature orfor precipitation. The power spectra of the series show broad significant peaks containing the quasi-biennial oscillation and other well known periodicities probably due to solar cycles or to the North Atlantic ocean-atmosphere oscillation (NAO). [ABSTRACT FROM AUTHOR]