This dataset provides an estimation of the climate feedback parameter and the climate sensitivity developed in collaboration by Magellium and LEGOS. It is based on the publication of Meyssignac et al., (2023, https://doi.org/10.1038/s43247-023-00887-2) . The product is a crucial study on Effective Climate Sensitivity (ECS), focusing on the time variation of the climate feedback parameter (λ). Understanding λ is fundamental as it quantifies the Earth’s radiative response to changes in global average temperature. A less negative λ directly implies a greater climate sensitivity to greenhouse gas concentrations. The product addresses the high uncertainty in ECS by providing an observational estimate of λ temporal variations since 1970. Estimates are derived from the global energy balance equation, regressing the radiative response against temperature over periods longer than 25 years. Users are primarily interested in the time series of λ and its associated uncertainties. The input data for computing λ is provided in a secondary "extended product" for transparency, allowing users to rebuild the indicators. The final product, available as a NetCDF file, can be downloaded in open access and is licensed for any project or study.

The general objective of the PEACETIME cruise is to study the fundamental processes and their interactions at the ocean-atmosphere interface, occurring after atmospheric deposition (especially Saharan dust) in the Mediterranean Sea, and how these processes impact the functioning of the pelagic ecosystem. During the proposed 33 days cruise in the western and central Mediterranean Sea in May 2017, we will study the impact of atmospheric deposition on the cycles of chemical elements, on marine biogeochemical processes and fluxes, on marine aerosols emission and how ongoing changes will impact the functioning of Mediterranean Sea communities in the future. The cruise is designed to explore a variety of oligotrophic regimes. Combining in situ observations both in the atmosphere and the ocean, and in situ and minicosm-based on-board process studies, the 40 embarking scientists from atmosphere and ocean sciences will characterize the chemical, biological and physical/optical properties of both the atmosphere and the sea-surface microlayer, mixed layer and deeper waters. The PEACETIME strategy (season and cruise track) associated to a combination of dust transport forecasting tools and near real-time satellite remote sensing is designed to maximize the probability to catch a Saharan dust deposition event in a stratified water column in order to follow the associated processes in-situ. This coordinated multidisciplinary effort will allow us to fill the current weaknesses/lacks in our knowledge of atmospheric deposition impact in the ocean and feedbacks to the atmosphere in such oligotrophic systems. As a key joint-project between MERMEX and CHARMEX : The PEACETIME project comes in the scope of the regional multidisciplinaryprogramme MISTRALS (Mediterranean Integrated STudies at Regional And Local Scales ), which aims at predicting the evolution of this region following strong expected changes in climate and human pressures. In this framework, the PEACETIME project constitutes a key joint project between the ChArMEx (the Chemistry-Aerosol Mediterranean Experiment) and MERMEx (Marine Ecosystems Response in the Mediterranean Experiment) initiatives, enabling to gather communities of atmospheric chemists and marine biogeochemists around the common question of assessing the impact of atmospheric deposition on the marine biogeochemical processes and air-sea exchanges.