Oelker, Julia; Bergmann, Josy; Frederick, Jennica (2026): Water column raw data (Kongsberg EM 124 entire dataset) of RV MARIA S. MERIAN during cruise MSM140/2 [dataset]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.992612 (DOI registration in progress)

Raw water column data were collected aboard RV MARIA S. Merian during cruise MSM140/2using a Kongsberg EM 124 multibeam echosounder. The expedition took place during 2025-10-17 – 2025-11-05 from Brest (France) to Rio de Janeiro (Brazil) in the Atlantic. The main goal of MSM140/2 was the data collection at times of satellite overpasses for an evaluation of sensor data interpretation and eventual data interpretation improvements. The focus is on recently launched satellites. A particular challenge hereby are underpasses of the ship under the narrow tracks of active remote sensors from space such as of the lidar and the cloud radar on the EarthCare satellite platform. Another scientific focus of MSM140/2 is on investigations of the atmospheric and oceanic environment near tropical convection. In the Inter-Tropical Convergence Zone (ITCZ) continuous remote sensing was complemented by frequently launched radiosondes. The conducted measurements add to data of previous research cruises during other seasons. These measurements help to guide the development and evaluation of a new generation of km-scale global coupled climate models. To complement the atmospheric data set and enhance the suite of satellite products that can be validated with the collected data, near-surface remote sensing of the ocean was added to the work program which encompasses high-spectrally resolved light field measurements of the incoming solar radiation and the water-leaving radiation. Another goal with respect to this radiometric data is to combine information on the light field from different instruments to evaluate the data quality of the permanently installed broadband radiation sensors. The idea is to use this data as part of the project Underway Research Data, coordinated by the German Marine Research Alliance (DAM), to establish a quality control scheme that can be used to routinely provide quality-controlled broadband radiation data for RV Maria S. Merian cruises in the future. Another scientific objective of MSM140/2 is the recording of bathymetric data, amongst others as contribution for the Nippon Foundation-GEBCO Seabed 2030 initiative. Data were recorded solely in international waters. Sound velocity profiles (SVP) were applied on the data for calibration. Please see environmental data and the cruise report for details. The data are unprocessed and can therefore contain incorrect depth measurements (artifacts) if not further processed. Note that refraction errors may occur when no proper SVP is applied. Data acquisition was done by the University of Oldenburg and HafenCity University, provision of the data is supported by the DAM Project Underway Research Data and published according to the FAIR principles.