Grid processed for the purpose of the HR DTMs layer of EMODnet Bathymetry HRSM, October 2020

This composite Digital Terrain Model (cDTM) is a high resolution bathymetry dataset highlighting measurement of depth of water in the ocean. This cDTM covers the Irish Sea around the scallop grounds off the coast of County Wexford in Ireland. The EMODnet high resolution DTM covers bathymetry surveys completed between 2002 and 2016. Bathymetric data collected on board research vessels using multi-beam and single-beam echosounder instrumentation. Raw bathymetry processed within CARIS software to produce bathymetry products subsequently converted to NetCDF cDTM for EMODnet. Acquisition, processing and product delivery follows IHO standard s44 Edition 5. cDTM is composed of two (2) images “merged simply” using GLOBE software. INFOMAR (Integrated Mapping for the Sustainable Development of Ireland’s Marine Resource) is a twenty year programme to map the physical, chemical and biological features of Ireland’s seabed established in 2006. INFOMAR is funded by the Department of Communications, Climate Action and Environment (DCCAE), and delivered by joint management partners Geological Survey Ireland and the Marine Institute. The programme is the successor to the Irish National Seabed Survey (INSS) which ran between 1999 and 2005. INFOMAR concentrates on creating integrated mapping products related to the seabed.

The bathymetry data were collected from the online data source Norge Digitalt (http://www.norgedigitalt.no) established by the Norwegian Mapping Authority, the Hydrographic service (Statens Kartverk Sjø). The original resolution is about 50m on an irregular grid. IMR has interpolated the bathymetry to four 50m x 50m UTM-grids, and simple extrapolation is applied towards a high-resolution coast line, also provided by the Norwegian Mapping Authority.

Multibeam data acquired during the ESSROV-2010 survey. R/V Pourquoi Pas?, 2010, Reson SB7150 multibeam system.

Gridded XBT temperature sections from the SURVOSTRAL project provide a unique multi-decadal observational dataset of temperature across the Southern Ocean from Hobart (Tasmania, 42.9°S, 147.3°E) to Dumont d’Urville (Adelie Land, 66.6°S, 140.0°E), starting in 1992. Gridded temperature sections are based on XBT temperature profiles collected each year during the summer heating cycle from early spring (Oct/Nov) to autumn (Mar), over the depth range from the surface down to 900 m. XBT data were collected aboard the French supply vessel L’Astrolabe, with the support of the French Institut Polaire Emile Victor (IPEV), the LEGOS research laboratory, the CSIRO Marine and Atmospheric Research division. and the National Oceanic and Atmospheric Administration (NOAA). This XBT section is part of the SOP (Ships of Opportunity) network and CLIVAR, and is referred to as section IX28 (https://doi.org/10.18142/172 ). The dataset consists of 25 years (November 1992 to February 2017) of 10238 expendable bathythermograph (XBT) profiles on this section between Hobart, Australia and Dumont d’Urville, Antarctica. Measurements are collected from an average of six transects per year between late October and early March. Depending on ice and weather conditions, XBT measurements are sampled every 35km, with a finer 18km sampling across the energetic polar frontal region from 49°S to 54°S. Temperature profiles extend down to 900 meters depth with a vertical resolution of about 0.7 meters. The XBT temperature profile accuracy is +/-0.1°C. XBT profiles have been corrected for temperature and depth biases depending on the probe type. All corrected XBT measurements can be retrieved from the IMOS website (http://thredds.aodn.org.au/thredds/catalog/IMOS/SOOP/SOOP-XBT/DELAYED/Line_IX28_Dumont-d-Urville-Hobart/catalog.html). Individual XBT profiles are then mapped onto a regular meridional-vertical section from North to South, following the mean path of the Astrolabe’s transect, with 0.5° resolution in latitude (increasing to 0.25° in the polar frontal zone from 49-54°S), with 2m depth resolution down to 800 m depth. XBT profiles sampled further than 3° in longitude from the mean path of the Astrolabe are removed from the analysis. Different types of gridded products are available : 1) Climatological monthly mean temperature sections are calculated for each month during the austral summer ONDJFM period and averaged over 25 years (6 monthly mean temperature sections). 2) Austral summer (NDJF) mean temperature sections are constructed for each year from 1993 to 2017, allowing us to track the interannual temperature evolution (25 annual summer mean temperature sections). 3) Temperature values and anomalies measured for each profile of SURVOSTRAL program, gridded on mean path. Temperature anomaly profiles are constructed by subtracting the climatological monthly mean temperature value at each latitude and depth from each XBT profile. For detalis, see Auger et al. 2021.

This product contains average 10 days & monthly salinity field based on L2P products, mixing ascending and descending orbits. ** This product is no longer available, see below **

Grid processed in the framework of EMODnet Bathymetry HRSM, October 2020

Multibeam data acquired during the Trophal 1 survey. R/V Le Suroit, 2002, EM300 multibeam system.

Multibeam data acquired during the PLA-HANO survey. R/V Thalia, 2006, EM1000 multibeam system.

The bathymetry data were collected from the online data source Norge Digitalt (http://www.norgedigitalt.no) established by the Norwegian Mapping Authority, the Hydrographic service (Statens Kartverk Sjø). The original resolution is about 50m on an irregular grid. IMR has interpolated the bathymetry to four 50m x 50m UTM-grids, and simple extrapolation is applied towards a high-resolution coast line, also provided by the Norwegian Mapping Authority.