Argo is a key component of the Global Ocean Observing System (GOOS) with an array of about 4,000 autonomous instruments reporting on ocean conditions. These floats collect data on ocean temperature and salinity, and in some cases, additional properties that characterize the ocean’s biological and chemical processes. Established in 1999, Argo represents an international collaboration involving contribution from more than 30 nations. Data from Argo floats are made publicly available within 24 hours of collection time, for free. The data provide valuable information on changes to the Earth's climate and hydrological cycle. They are used for a variety of purposes, such as assessing climate change, improving weather forecasts and developing ocean models. Argo Canada, led by Fisheries and Oceans Canada, has been a key contributor to the International Argo Program since its inception in 2001 . The program has been supported by contributions from Department of Environment and Climate Change Canada, Department of National Defense, Dalhousie University, University of Victoria and Ocean Networks Canada.

The hydrographic 1991 to 2020 climatology for the Maritimes region Atlantic Zone Monitoring Program core transects, Cabot Strait, Louisbourg, Halifax, Browns Bank, and Northeast Channel, are calculated to support annual reporting on seasonal variability. Details on data coverage for these transects and ancillary transects occupied since the inception of the program are provided. Comparisons with the previous climatology period, years 1981 to 2010, are summarized when possible. Cite this data as: Layton, C. Data of: Maritimes Region Atlantic Zone Monitoring Program 1991 to 2020 Hydrographic Transect Climatology. Published: August 2025. Ocean Ecosystems Science Division, Fisheries and Oceans Canada, Dartmouth, N.S. https://open.canada.ca/data/en/dataset/5f9c5d65-3ce1-4bdd-8b43-34086620d1e3

Argo is the largest ocean climate monitoring system in the world. It is an array of over 4,000 free-drifting floats that collects data on ocean temperature and salinity, providing valuable information on changes to the Earth's climate and hydrological cycle. Fisheries and Oceans Canada is proud to be a strong contributor to the international Argo project. Since 2001, Argo Canada has launched 450 Argo floats, 81 of which are still operating. Argo data is publically available for free and is used for a variety of purposes such as assessing climate change, improving weather forecasts and developing ocean models.