**1. Introduction**

Operational forecasting is now a reality in most ocean areas around the world. It follows the example of weather forecasting [1] and provides products that are crucial for the sustainable development of activities at sea and along the coasts.

The operational quality of the products has steadily improved since the late 1990s, when only a few centers around the world were engaged in ocean analysis and forecasting [2]. The operational system assessment allows Earth System Science to estimate the quality and fitness of the numerical ocean model for purpose of the observing system.

Operational forecasting in the Black Sea region is part of the data production architecture of the Copernicus Marine Environment and Monitoring Service (CMEMS, https://marine.copernicus.eu/ accessed on 29 December 2021, [3]). The Black Sea Monitoring and Forecasting Center (BS-MFC) has been operative since 2016. The center provides

**Citation:** Ciliberti, S.A.; Jansen, E.; Coppini, G.; Peneva, E.; Azevedo, D.; Causio, S.; Stefanizzi, L.; Creti', S.; Lecci, R.; Lima, L.; et al. The Black Sea Physics Analysis and Forecasting System within the Framework of the Copernicus Marine Service. *J. Mar. Sci. Eng.* **2022**, *10*, 48. https:// doi.org/10.3390/jmse10010048

Academic Editor: Carlos Guedes Soares

Received: 14 December 2021 Accepted: 30 December 2021 Published: 2 January 2022

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**Copyright:** © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

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regular, systematic and operational marine information, such as numerical analyses, forecasts and reanalyses for the main physical parameters (temperature, salinity, sea level, currents), together with biogeochemical and wave products.

The Black Sea operational analysis and Forecasting System (BSFS), within BS-MFC, is devoted to providing near real-time information of the physical ocean state in the basin. It is implemented in the Black Sea region, covering the area shown in Figure 1.

**Figure 1.** BSFS spatial domain and bathymetry (expressed in meters, from 0 to −2200 m).

The system is based on three major components: collection of upstream data, including atmospheric forcing and observations, the numerical ocean model, and a variational data assimilation scheme. Together with the Mediterranean Sea forecasting system, which began operation in 1998 [4,5], the Black Sea one completed the operational capacity in the Southern Regional European Seas [6]. These operational products also reconstruct the past state of the Black Sea, thus providing the optimal data set to study the ocean climate variability and in general the Black Sea general circulation. We are currently at the third generation of forecasting systems, and this paper analyzes the accuracy of the first ocean forecasting system for the Black Sea physics.

This study presents the numerical setup, operational implementation and product quality assessment for the period January 2018 to December 2020, using observations from in-situ (temperature and salinity profiles) and satellite (sea surface temperature and sea level anomaly) platforms, provided by CMEMS Thematic Assembly Centers (TAC) [3].

The paper is organized as follows: Section 2 presents the system, including the ocean model, the data assimilation method used for the forecasting cycle and the processing chain; Section 3 describes the operational products and discusses the product quality; Section 4 presents the conclusions and future evolutions of the BSFS.
