Russian Journal of Earth Sciences Russian Journal of Earth Sciences Russian Journal of Earth Sciences 1681-1208 48757 10.2205/2021ES000779 ОРИГИНАЛЬНЫЕ СТАТЬИ ORIGINAL ARTICLES ОРИГИНАЛЬНЫЕ СТАТЬИ Data analysis for variational assimilation of the surface temperature of the Black and Azov Seas Data analysis for variational assimilation of the surface temperature of the Black and Azov Seas Zakharova N. B. Zakharova N. B. Parmuzin E. I. Parmuzin E. I. Marchuk Institute of Numerical Mathematics RAS Россия Marchuk Institute of Numerical Mathematics RAS Russian Federation Marchuk Institute of Numerical Mathematics RAS Россия Marchuk Institute of Numerical Mathematics RAS Russian Federation 04 02 2022 04 02 2022 21 6 1 8 05 10 2021 28 10 2021 https://rjes.ru/en/nauka/article/48757/view

The paper considers sensing data on the state of the Black and Azov Seas, provided by the shared use center “IKI-Monitoring” and their application in the data assimilation problems. Observation data on the sea surface temperature are obtained from various satellites (Aqua, Terra, SNPP) and instruments (MODIS, VIIRS), measured at different moments and received irregularly and often cover only a part of the investigated water area due to weather conditions and the characteristics of measuring instruments. The paper describes the specifics of the data obtained, the difficulties that had to be faced in the data processing for their correct use in the problems of mathematical modeling of the sea dynamics. An analysis of observation data was carried out which showed the presence of errors in the data. An algorithm is proposed based on the determination of weight coefficients characterizing the proximity of observation data to known verified “reference” values. The weight coefficients are constructed taking into account the received fields of observation data and an additional set of average daily data from the European Copernicus Marine Service. The calculated matrix of weight coefficients is used in the algorithm of variational assimilation of observation data for the numerical model of thermodynamics of the Black and Azov Seas. The results of numerical experiments on variational assimilation of observational data using the constructed weight coefficients are presented. The results of assimilation are compared with near-real time in situ quality control observations. KEYWORDS: Data analysis; observation data; data errors; variational assimilation; sea surface temperature; optimality system.

The paper considers sensing data on the state of the Black and Azov Seas, provided by the shared use center “IKI-Monitoring” and their application in the data assimilation problems. Observation data on the sea surface temperature are obtained from various satellites (Aqua, Terra, SNPP) and instruments (MODIS, VIIRS), measured at different moments and received irregularly and often cover only a part of the investigated water area due to weather conditions and the characteristics of measuring instruments. The paper describes the specifics of the data obtained, the difficulties that had to be faced in the data processing for their correct use in the problems of mathematical modeling of the sea dynamics. An analysis of observation data was carried out which showed the presence of errors in the data. An algorithm is proposed based on the determination of weight coefficients characterizing the proximity of observation data to known verified “reference” values. The weight coefficients are constructed taking into account the received fields of observation data and an additional set of average daily data from the European Copernicus Marine Service. The calculated matrix of weight coefficients is used in the algorithm of variational assimilation of observation data for the numerical model of thermodynamics of the Black and Azov Seas. The results of numerical experiments on variational assimilation of observational data using the constructed weight coefficients are presented. The results of assimilation are compared with near-real time in situ quality control observations. KEYWORDS: Data analysis; observation data; data errors; variational assimilation; sea surface temperature; optimality system.

 Data analysis; observation data; data errors; variational assimilation; sea surface temperature; optimality system. Data analysis; observation data; data errors; variational assimilation; sea surface temperature; optimality system. The work was supported by the Russian Science Foundation (project 19- 71-20035, Informational Computational System for Variational Data Assimilation ”INM RAS – Black Sea” and its integration with the hardware-software complex of the CKP ”IKI-Monitoring”). The work was supported by the Russian Science Foundation (project 19- 71-20035, Informational Computational System for Variational Data Assimilation ”INM RAS – Black Sea” and its integration with the hardware-software complex of the CKP ”IKI-Monitoring”).

Agoshkov, V. I., N. R. Lezina, T. O. Sheloput (2019),Domain Decomposition Method for the Variational Assimilation of the Sea Level in a Model of Open Water Areas Hydrodynamics, Journal of Marine Science and Engineering, 7, 195, Crossref Agoshkov, V. I., N. R. Lezina, T. O. Sheloput (2019),Domain Decomposition Method for the Variational Assimilation of the Sea Level in a Model of Open Water Areas Hydrodynamics, Journal of Marine Science and Engineering, 7, 195, Crossref Lebedev, S. A., A. G. Kostianoy, D. M. Soloviev, et al. (2020), On a relationship between the rive runoff and the river plume area in the northeastern Black Sea, International Journal of Remote Sensing,41, No. 15, 5806-5818, Crossref Lebedev, S. A., A. G. Kostianoy, D. M. Soloviev, et al. (2020), On a relationship between the rive runoff and the river plume area in the northeastern Black Sea, International Journal of Remote Sensing,41, No. 15, 5806-5818, Crossref Proshin, A. A., M. A. Burtsev, I. V. Balashov, et al.(2020), ”IKI-Monitoring” shared use center sup-port and development - possible solutions, Problems in Remote Sensing of the Earth from Space, 17, No.6, 51-55, Crossref Proshin, A. A., M. A. Burtsev, I. V. Balashov, et al.(2020), ”IKI-Monitoring” shared use center sup-port and development - possible solutions, Problems in Remote Sensing of the Earth from Space, 17, No.6, 51-55, Crossref von Schuckmann, Karina, Pierre-Yves Le Traon, et al. (2021), Copernicus Marine Service Ocean State Report, Journal of Operational Oceanography, 14, No. 5, 1-185, Crossref von Schuckmann, Karina, Pierre-Yves Le Traon, et al. (2021), Copernicus Marine Service Ocean State Report, Journal of Operational Oceanography, 14, No. 5, 1-185, Crossref Sheloput, T. O. (2018), Numerical solution of the problem of variational assimilation of the sealevel on the liquid (open) boundary in the Baltic Sea hydrothermodynamics model, Problems in Re-mote Sensing of the Earth from Space, 15, No. 7,15-23, (in Russian) Crossref Sheloput, T. O. (2018), Numerical solution of the problem of variational assimilation of the sealevel on the liquid (open) boundary in the Baltic Sea hydrothermodynamics model, Problems in Re-mote Sensing of the Earth from Space, 15, No. 7,15-23, (in Russian) Crossref Shutyaev, V. P., E. I. Parmuzin (2021), Numerical solution of the problem of variational data assimilation to restore heat fluxes and initial state for the ocean thermodynamics model, Russ. J. Numer. Anal. Math. Modelling, 36, No. 1, 43-53, Cross-ref Shutyaev, V. P., E. I. Parmuzin (2021), Numerical solution of the problem of variational data assimilation to restore heat fluxes and initial state for the ocean thermodynamics model, Russ. J. Numer. Anal. Math. Modelling, 36, No. 1, 43-53, Cross-ref Stepanov, V. N., Yu. D. Resnyanskii, et al. (2021), Evaluating Effects of Observational Data Assimila-tion in General Ocean Circulation Model by Ensemble Kalman Filtering: Numerical Experiments with Synthetic Observations, Russian Meteorology and Hydrology, 46, No. 2, 94-105, Crossref Stepanov, V. N., Yu. D. Resnyanskii, et al. (2021), Evaluating Effects of Observational Data Assimila-tion in General Ocean Circulation Model by Ensemble Kalman Filtering: Numerical Experiments with Synthetic Observations, Russian Meteorology and Hydrology, 46, No. 2, 94-105, Crossref Zakharova, N. B. (2016), Verification of the sea sur-face temperature observation data, Problems in Re-mote Sensing of the Earth from Space, 13, No. 3,106-113, Crossref Zakharova, N. B. (2016), Verification of the sea sur-face temperature observation data, Problems in Re-mote Sensing of the Earth from Space, 13, No. 3,106-113, Crossref Zalesny, V. B., N. A. Diansky, V. V. Fomin, et al. (2012), Numerical model of the circulation of the Black Sea and the Sea of Azov, Russ. J. Numer. Anal. Math. Modelling, 27, No. 1, 95-111 Zalesny, V. B., N. A. Diansky, V. V. Fomin, et al. (2012), Numerical model of the circulation of the Black Sea and the Sea of Azov, Russ. J. Numer. Anal. Math. Modelling, 27, No. 1, 95-111