Verification of cmems bs-biogeochemistry re-analysis data of ph value in the black sea based on the results of direct measurements

A.B. Polonsky, E.A. Grebneva

Institute of Natural and Technical Systems, RF, Sevastopol, Lenin St., 28

DOI: 10.33075/2220-5861-2024-1-112-118

UDC 551.464.6/465.7(262.5)                                  


Verification of pH data from the CMEMS BS-Biogeochemistry re-analysis is carried out based on the results of direct measurements of the pH value in the Black Sea. pH measurement data were obtained by employees of the Institute of Natural and Technical Systems (IPTS) during expeditionary research in April – May and December 2019, as well as in September – October 2020. A comparison of the average daily pH values calculated from two samples at individual nodes of a regular grid is made, the consistency of the spatial structure of the hydrogen index fields constructed from different types of data is analyzed, and a correlation analysis is performed. It is shown that the spatiotemporal variability of average daily pH values, estimated from two samples, demonstrates a high degree of consistency. When analyzing the difference in average daily pH values at the nodes of a regular grid, calculated using two types of data, a significant overestimation of the measured pH values was revealed in the period from April 18 to April 28, 2019. Possible causes of the identified systematic error are analyzed, including methodological errors in the measurement process.

Keywords. Black Sea, surface layer, pH value, re-analysis, data verification.

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