Main Parameters of the Global Climate Change Background in the Eastern Part of the Black Sea Region

The results of assessment the reservoir's impact on climate include serious errors. The reason for this is that there is no method or other means to separate the regional and local climate parameters of a reservoir from the background parameters created by global climate change.

Implementation of this problems requires solving two tasks: a) choosing a method for calculating the numerical characteristics of regional and local climate characteristics; b) using the results of the joint impact of the reservoir and climate variations, select the numerical values of the background parameters of climate change.

The Eastern Black sea region was chosen as a demonstration of the implementation of the problem, since there is enough territory free from the impact of the reservoir, and they border on areas where the impact of the reservoir on the Environment occurs against the background of climate change. Moreover, the number of meteorological and oceanographic points on both sections and the duration of observations (1874–2019) are sufficient for statistical accuracy of monitoring.

The following operations were performed to analyze the monitoring results:

a) Statistical temporal series of average annual meteorological and oceanographic data elements have been created for each of the following types of time series:

X₁, X₂, X₃,...X_n-1, X_n n=1, 2, 3,...

where, X₁ is the indirect observational data of any hydrometeorological element (t, p, h, w, etc.).

b) According to the time of the Black Sea level rise (modern eustasy), the starting period of the beginning of current climate change was determined (1900-1905);

c) According to this timeline, the rows were divided into two fragments. The first fragment incorporates the data before that date (1905), the second after this term, ie 1906-2019:

{X_i}_i=1^k, {X_i}_i=k+1ⁿ, i=1,2,3,..,k,k+1,..,n. k=1905, n=2019

Analysis of these fragments was performed using statistical methods known as the "least squares method" and "long rows method". Temporal changes in meteorological and Oceanographic elements (air temperature, precipitation, surface water temperature, and sea level) are most accurately represented by the following third-order polynomial equations:

Y = Ax³ + Bx² + Cx + D

The results of the analysis show that the current climate change in 1900-2019 is characterized by an upward trend. The graphic depiction of its first period is a sinusoid, which lasted from the 1900s to 1990 and had a maximum value in the 1940s. The second, current period began in 1985-1990. However, according to the monitoring analysis, background of climate change has been so strong since the 1980s that in 2015-2019 air and sea water temperatures have risen by 1.1-1.2 ºC, sea levels have risen 10-12 cm due to climate warming, and annual precipitation decreased by 15-17%.