- No. 1(3) 2023
«Meteorology. Hydrology. Environmental monitoring»
“SOLAR RADIATION DURING COLD SEASON DROUGHT FOR THE YEARS 1991–2020 IN UKRAINE
Drought is a dangerous natural phenomenon that has often been observed during the last thirty years. In certain months of the cold period of the year, droughts were observed at the end of autumn (November), at the end of winter and at the beginning of spring (February-March). The purpose of the work is to evaluate the changes in the components of the radiation regime of solar radiation during droughts or their prerequisites for the cold period of the year in 1991-2020 in Ukraine. During some cold periods, the prerequisites for the development of droughts were noted. The latest in the cold period of the year are droughts or the prerequisites for them, in particular some in the larger territory of Ukraine, which are caused by a special state of the atmosphere with the anticyclonic nature of the atmospheric circulation and the transformation of slow-moving air masses in large areas. According to a complex of dynamic processes that cause the development of this phenomenon, there is an increase in the duration of sunlight and short-wave radiation, which leads to an increase in air temperature during a period without rain or precipitation. In the conditions of changes in atmospheric circulation in 1990-2020 relative to 1961-1990, which led to an increase in clear and cloudless weather, deviations of individual components of the radiation regime of solar radiation were observed in certain months of the cold period. In the cold period of the last three decades, during droughts or the conditions for them, an increase in the duration of sunshine, the flow of direct and total solar radiation was observed, which was accompanied by a decrease in scattered radiation. The set of dynamic processes during droughts or the prerequisites for them leads to an increase in the energy potential of the active surface. Changes in the components of the radiation regime of solar radiation during droughts or prerequisites for them during the cold period of the year and their comparison relative to the average values for the years 1991-2020 in Ukraine are given. The conducted studies are important in the direction of monitoring climate change anomalies, which determine the solution of applied problems of adaptation of agricultural production in conditions of droughts or prerequisites for them during the cold period.
“HOMOGENIZATION OF PRECIPITATION TIME SERIES: MAIN MODERN APPROACHES AND SOFTWARE TOOLS
In our work, we analyzed modern software products that are frequently used for quality control and homogenization of long climatological time series of different variables, in particular, atmospheric precipitation. Based on our analysis, the HOMER software was selected to perform quality control and homogenization procedures for time series of monthly precipitation sums. The advantages of using HOMER include the possibility for the researcher to make a decision on confirming the breakpoints at the stage of joint comparison (joint detection), which allows considering the available information about the natural variability of atmospheric precipitation in the region and preventing oversmoothing of their values. The HOMER homogenization procedure was applied to monthly atmospheric precipitation time series collected in Ukraine for the period 1946-2020. Possible areas of inhomogeneity of the series (break points) were established and it was determined that the value of the shift amplitude is 0.1-0.7 (in relative units of standard deviation). The correction of the time series of the monthly precipitation sums for the studied period was carried out and it was calculated that their change depends on the magnitude and sign of the shift amplitude and is 10-20% of the initial amounts of precipitation. The considered methodological techniques and approaches to data quality control and their homogenization using the HOMER software can be applied in further precipitation studies.
“DATA RESCUE AND QUALITY CONTROL OF DAILY TIME SERIES OF AIR TEMPERATURE (MEAN, MAXIMUM AND MINIMUM) AND ATMOSPHERIC PRECIPITATION IN UKRAINE
This paper presents the results of the digitization of hard copies (meteorological tables) containing records of daily values of mean (TM), maximum (TX) and minimum (TN) surface air temperatures and atmospheric precipitation sums (RR). The daily values of TM, TX and TN obtained at 176 meteorological stations of the national hydrometeorological monitoring network were digitized. The largest number of stations (178) were processed for digitizing atmospheric precipitation data. The total number of digitized values is 3,571,778. The digitized values fill in the gaps in the digital database of daily values of the essential climatic variables (TM, TX, TN and RR), which was created at the Ukrainian Hydrometeorological Institute. The quality control of the digital database was carried out using state-of-the-art, well-tested dedicated software INQC and Climatol. The number of detected gross errors is 3,933 and ranges from 9 to 2015, depending on the meteorological parameter (however, not more than 0.04% of the total set of values of each variable). A slightly larger number of values were recorded that fell into the category of probable errors, outliers, suspicious values, and collectively suspicious values. The percentage of such values from the total amount of values for each dataset reaches up to 0.14%. Based on the results of the quality control procedure, all identified errors were checked and corrected in correspondence with the data in the original hard copies.
“LOGICAL-APRIORI ANALYSIS IN HYDROGEOLOGICAL RESEARCH
The article demonstrates with examples that due to the lack of input information, logical a priori analysis can be effectively applied to solve not too complex hydrogeological problems: in regional studies, for the analysis of observation data on the groundwater regime, in the design of underground water intakes, dissection of river hydrographs, selection calculation parameters for modeling, etc. Nowadays, this method of analysis is replaced by methods of information processing using artificial intelligence, which does not require deep knowledge of the subject and significant experience of the researcher. It is shown that the logical a priori analysis can be an effective auxiliary method when performing hydrodynamic calculations. Thus, with its help, it was found that the most representative parameter, which manifests and controls the dependence of the groundwater recharge on precipitation, is the weighted average annual coefficient of infiltration recharge. This indicator can also be used to correct unknown filtering parameters, since it has a narrow range of variability, which in turn is controlled by the actual amount of annual precipitation.
“HEAT FLOW COEFFICIENTS AT THE LONG-TERM FORECASTING OF THE ICE PHENOMENA APPEARANCE DATES AT THE DNIPRO CASCADE RESERVOIRS
Reliable and efficient water management is impossible without information on the current and future condition of river basins. Timely informing stakeholders about the future development of hydrological processes is based on a system of hydrological forecasts. Long-term forecasts of ice phenomena are of great importance, as they are used to plan the end of navigation and the crossing of economic facilities to winter regime. Reliable and lead-time forecasts of appearance dates of ice phenomena and freeze-up on reservoirs are essential for the rational use of water resources and for establishing reservoir operation regimes that take into account the requirements and interests of various economic sectors: hydropower, shipping, fisheries, utilities, etc. The appearance dates of floating ice are one of the most important characteristics of autumn ice phenomena. In recent years, the frequency of warm seasons in autumn and pre-winter has increased, and the process of ice formation is often protracted. In such conditions, it is of great importance to forecast the appearance dates of stable ice and the dates of freeze-up, as these characteristics determine the most effective hydrological strategy in the autumn-winter period. The paper investigates the relationship between heat flow coefficients and the appearance dates of ice phenomena in the reservoirs of the Dnipro cascade. The received forecasting dependencies revealed very weak and moderate correlations, and the efficiency of the forecasting equations was 60 % or less. Thus, the use of heat flow coefficients as predictors of atmospheric processes is very limited. That is why the search for predictors of atmospheric processes should be expanded for long-term forecasting of the appearance dates of ice phenomena in space and time.
“CAN CORRELATIONS BE AN EVIDENCE, THAT CHANGES IN THE COUNT RATE OF RADIOACTIVE DECAY SIGNALS ARE DUE TO CHANGES IN TEMPERATURE?
In recent years, there has been a debate in the scientific literature about the possibility of variability in the rate of radioactive decay under the influence of external factors, as evidenced by separate experiments. However, since such effects are in sharp conflict with the basic principles of nuclear physics, there is also a strong criticism, which converges to that all such experiments are incorrect. At the same time, one way or another, everything converges to that the observed effects are the result of the response of the measurement equipment to external weather conditions, that is, caused by changes in temperature, humidity, etc. And these effects are not changes of the actual measured physical quantity. In this work, the possibility of influence of such a factor as temperature is carefully considered. A correlation was found between regular series of measurements of temperature and gamma background level in the exclusion zone of the Chornobyl nuclear power plant, which is contaminated by fuel fallouts from the destroyed power unit. The assumption was made regarding the mechanism of formation of features in gamma background signals. The revealed relation may indicate the existence of a common global factor (cause) of the variability of the gamma background signals and temperature, which should be sought beyond trivial assumptions about the influence of meteorological conditions on the operation of the equipment.
