AMT25 Cruise Report

The highlights of AMT25 were as follows:

• Eighty-one CTD profiles at stations spaced approximately 200nM apart measuring key physical and biogeochemical parameters including: temperature, salinity, chlorophyll, oxygen, nutrients, total alkalinity, dissolved inorganic carbon, phytoplankton abundance and microbial dynamics;
• Thousands of underway bio-optical and biogeochemical measurements covering a 100° range in latitude and vastly contrasting ocean biomes;
• Underway radiometry combined with hyperspectral in-water Inherent Optical Property measurements, particularly pertinent for satellite calibration validation. Both hyperspectral and multi-spectral data were taken independently;
• Launch of 7 Argo floats, on behalf of the UK and German Met Offices, in the tropical and south Atlantic;
• Recovery a deep (5000m) sediment trap mooring in the South Atlantic Gyre for NOC, which had previously been deployed in October 2014 (AMT24) and the construction and deployment of a single sediment trap mooring at the same location. The entire operation was achieved in less than 18 hours;
• Automated processing chain, partly developed and designed on AMT24/25, to seamlessly send coarse resolution CTD data to the UK Met Office for assimilation into atmosphere/ocean forecasts. Of particular interest was the real-time ingestion to FOAM of a deep CTD cast (>5000m) in the northern Atlantic;
• Continuous operation of acoustic sensors to probe positions of marine creatures;
• Continuous swath bathymetry and ADCP data;