Long term dynamics of some meteorological and agrometeorological indicators according to the Luhansk meteorological station

Abstract

The results of the analysis of the dynamics of the average monthly values of hydrothermal climatic indicators on the territory of the Luhansk region (Northern Steppe of Ukraine) in the conditions of long-term climatic changes in precipitation (1882-2020) and air temperature (1837-2020) are presented. Statistical models — regression equations for determining temporary changes in the studied indicators are developed. Statistical analysis was carried out and patterns of dynamics of parameters of hydrothermal indicators were revealed within the framework of such stages: year, growing season; sowing periods of spring crops (April); harvest formation (May-June); post-harvest (July–August); sowing of winter cereals (September-October); cold period (November-March). A general trend towards an increase in the average annual precipitation and a high variability (CV > 25%) of the average monthly values in certain stages of the growing season were revealed. Probabilistic analysis of long-term data, using the method of constructing empirical and theoretical (analytical) security curves, revealed that the average monthly temperature during the sowing periods of early spring and winter crops 11-14 ℃ corresponds to 10% probability level, and 8.0–11.5 ℃ — 50%. In the same period, precipitation of 58-60 mm corresponds to a 10% probability level, and 30-40 mm corresponds to 50%. By analyzing the angles of inclination of trend lines, the dynamics of the average monthly values of precipitation and air temperature in the study area was studied and the distribution of the rate of increase or decrease in precipitation and temperature change was obtained. The generalization showed that the angle of inclination of trend lines is associated with the stage of the growing season. Fluctuations in average monthly temperatures correspond to fluctuations in the average monthly precipitation and are most noticeable in the periods of early spring sowing, crop formation and post-harvest. The average annual temperature in 1845-1935 on the territory of the region it is kept at the level of 8 ℃, and from 1935 to nowadays time it has been steadily increasing to 10 ℃. The revealed features of changes in the amount of precipitation over time can be used for further studies of the unevenness of atmospheric soil moisture, flood forecasting, changes in erosion activity, and the like.