Atlantic meridional transect. AMT 21 cruise report. 29 September – 14 November 2011

Abstract

The Atlantic Meridional Transect – AMT (www.pml.ac.uk/amt) is a multidisciplinary programme which undertakes biological, chemical and physical oceanographic research during an annual voyage between the UK and destinations in the South Atlantic - previously the Falkland Islands and South Africa, and for this cruise Punta Arenas, Chile. This transect crosses a range of ecosystems from sub-polar to tropical and from euphotic shelf seas and upwelling systems to oligotrophic mid-ocean gyres. The programme was established in 1995 and this was the 21st in the series of research cruises which have involved over 200 scientists from 20 countries. AMT has proved to be a long-term multidisciplinary ocean observation programme, which is a platform for national and international scientific collaboration, a training arena for the next generation of oceanographers and an ideal facility for validation of novel technology. AMT continues to contribute to science and policy development, including the social and economic understanding of the marine environment and services it delivers. The main deliverable of AMT is an unique time series (1995-2012) of spatially extensive and internally consistent observations on the structure and biogeochemical properties of planktonic ecosystems in the Atlantic Ocean that are required to validate models addressing questions related to the global carbon cycle. Data sets include: • Vertical CTD profiles and continuous underway data • Optical characteristics of the water column • Biogeochemical measurements on water samples including nutrients, pigments, dissolved gases and particulate carbon and nitrogen • Primary, new production and respiration measurements