Assessing Warming Trends in the Mediterranean Sea: A Workflow-Based Approach

The Mediterranean Sea is warming at a rate faster than the global ocean average, as recent research highlights. This region is particularly vulnerable to climate change due to its distinctive topography and thermohaline circulation patterns. Observational evidence and model-based analyses have revealed considerable shifts in the properties of Mediterranean water masses.

A crucial metric for tracking this phenomenon is the Ocean Heat Content (OHC). This study addresses the challenge of devising a cloud-based workflow to estimate OHC, enabling analysis of its trends across user-defined sub-regions and depth layers within the Mediterranean basin. Developed within the framework of the EU Blue Cloud 2026 project, this application integrates machine-to-machine access to various blue data infrastructures. 

The OHC indicator will be part of a generalized outcome made up of several Marine Environmental Indicators managed by a Virtual Research Environment (VRE) infrastructure that enables users to assess and monitor marine environmental conditions, offering crucial support for informed decision-making in ocean management. By integrating multiple data sources, the future platform will deliver a centralized data analysis service, enabling online computation of indicators through digital tools.

This case study focuses on the use of World Ocean Database temperature data but it can be easily adapted to other data sources such as SeaDataNet, EuroArgo and the Copernicus Marine Service.

The workflow employs the DIVAnd tool to interpolate historical in situ temperature data onto a regular grid, deriving sliding annual and seasonal decadal temperature fields. These fields will be validated with the World Ocean Atlas 2023 and the results will be compared against ocean reanalysis datasets provided by INGV and the Copernicus Marine Service. The primary goal is to uncover OHC trends: this will help to better understand their impact on the regional climate system. 

The anticipated findings will shed light on the spatial heterogeneity of warming trends across different sub-regions and depth layers, emphasizing the intricate relationship between climate change and hydrodynamic processes in shaping the thermal structure of the Mediterranean Sea.

Additionally, the workflow ensures that critical ocean variables are regularly updated and validated using the latest community standards. This advancement will enable rapid and reliable updates of OHC as a key indicator, fostering informed decision-making and efficient responses.