This dataset comprises a time series of measurements of water current, temperature, conductivity, and pressure from instruments deployed at various depths in the Orkney Passage from 2007 onwards. The instruments were deployed in sub surface oceanographic moorings at fixed locations, in order to monitor the transport of Weddell Sea Deep Water (ESDW), a precursor to Antarctic Bottom Water (AABW), flowing northward from the Weddell Sea into the Scotia Sea. For 2007-2011 data are typically at hourly resolution; in subsequent years, most instruments are sampling at 10 minutes' resolution. The moorings are deployed in water depths ranging between approx. 1750 and 3670 metres, with instrument depths between 1250 and 3660 metres. This time series originally started out as part of the British Antarctic Survey's Long-Term Monitoring and Survey (LTMS) programme, led by Keith Nicholls; from 2016 it is continuing as part of the Ocean Regulation of Climate by Heat and Carbon Sequestration and Transports (ORCHESTRA) project, led by Emily Shuckburgh (British Antarctic Survey) and Dynamics of the Orkney Passage Outflow (DyNOPO) led by Alberto Naveira Garabato (National Oceanography Centre). Additional support for mooring instrumentation has come from NOAA through their Ocean Climate Observation Program, Weddell Sea Moorings project, PI's Bruce Huber and Arnold Gordon, Lamont-Doherty Earth Observatory, Columbia University. The mooring work is currently led and coordinated by Povl Abrahamsen at the British Antarctic Survey. The data are subject to a two year organisational moratorium from collection after which they become publically available.

The GEBCO Grid is a global terrain model for oceans and land at 30 arc-second intervals which was developed and first released in 2009 by the General Bathymetric Chart of the Oceans (GEBCO) as GEBCO 08. The current release is GEBCO 2014, released in December 2014 and updated in March 2015. GEBCO is an international group of experts who work on the development of a range of bathymetric (accurate mapping of the sea floor) data sets and data products. The bathymetric portion of the grid is largely based on a database of ship-track soundings with interpolation between soundings guided by satellite-derived gravity data. Data sets developed by other methods are also included where they improve the grid. The land portion of the grid is largely based on the US Geological Survey's SRMT30 data set, developed with data from the US National Aeronautics and Space Administration (NASA) Shuttle Radar Topographic Mission (SRTM). For the area around Antarctica, the land data are taken from the Bedmap2 data set. The grid is accompanied by a Source Identifier (SID) Grid which identifies which cells in the GEBCO Grid are based on soundings or existing grids and which have been interpolated. The data sets are updated as new bathymetric compilations are made available. Both grids are freely available to download, in netCDF; data GeoTiff and Esri ASCII raster formats, from the web. Free software is available for viewing and accessing data from the grids in netCDF and ASCII data formats. The grids are also included as part of the GEBCO Digital Atlas DVD.

The joint UK (NERC) and Chile (CONICYT) ICEBERGS project investigated the physical processes and feedbacks implicated in rapid climate-induced warming deglaciation of three west Antarctic Peninsula tidewater glacier systems, and the impacts of this deglaciation on benthic communities in the adjacent fjords between 2017 and 2020. The project involved three research cruises on the RRS James Clark Ross, JR17001 (ICEBERGS1, November-December 2017), JR18003 (ICEBERGS2, December 2018-January 2019) and JR19002 (ICEBERGS3, January-February 2020). The data from JR19002 are compiled here. The project focused on three sites, Marian Cove (King George Island), Börgen Bay (Anvers Island) and Sheldon Cove (Adelaide Island). Multidisciplinary deployments characterised each cruise, involving: CTD, multi-beam swath bathymetry, TOPAS, water sampling (salinity, oxygen isotopes), LADCP, VMADCP, EK80, Hamon grab, multicore, shelf underwater camera system (SUCS), Agassiz trawl and N70 plankton nets.

The data set comprises full tidal analyses for over 800 current meter records collected at 400 sites in the seas around the British Isles, covering the continental shelf area and the shelf slope. The vast majority of the analyses in this data set are based on harmonic analyses, where the amplitude and phases of the tidal constituents are determined by a least squares fit. The data were selected from the BODC Current Meter Databank so as to provide representative coverage over the shelf areas - only good quality series were selected.

This dataset comprises hydrographic sections, together with measurements collected by ocean gliders and moored instrumentation deployed during the UK Overturning In the Subpolar North Atlantic Programme (UK-OSNAP). UK-OSNAP is the UK contribution to the International OSNAP Programme. The dataset also includes modelling output informed by the observations. OSNAP observations are focused on two lines: i) OSNAP West, extending from south Labrador to southwest Greenland and ii) OSNAP East from southeast Greenland to Scotland. Data collection commenced June 2014 and is ongoing. UK-OSNAP consists of cruises JR302, PE399, DY053, DY054, two alternating glider deployments, current meter moorings (five at Cape Farewell and three in the Rockall trough) and ADCPs in the Rockall Trough Shelf Edge Current. The model data addresses the Subpolar Gyre circulation and fluxes using data assimilation and theoretical analysis. The datasets assembled as part of UK-OSNAP provide a continuous record of full-depth, trans-basin mass, heat, and freshwater fluxes in the North Atlantic Subpolar Gyre. These, coupled with the associated modelling exercises help improve the understanding of the circulation and fluxes of the North Atlantic Subpolar Gyre. UK-OSNAP, funded by the Natural Environment Research Council (NERC) is led by the National Oceanography Centre (NOC). UK-OSNAP is a partnership between NOC, Scottish Association for Marine Science (SAMS), University of Oxford and the University of Liverpool. It is part of international OSNAP that is led by USA and includes 10 further partner groups in Canada, France, Germany, the Netherlands and China. Investigators: National Oceanography Centre (NOC): Dr Penny Holliday, Dr Sheldon Bacon, Dr Chris Wilson, Neill Mackay. Scottish Association for Marine Science (SAMS): Dr Stuart Cunningham, Prof Mark Inall, Loic Houpert. University of Oxford: Prof David Marshall, Dr Helen Johnson. University of Liverpool: Prof Ric Williams, Dr Vassil Roussenov. The full dataset is still being assembled and currently consists of near real time glider measurements, mooring data and cruise data. NERC have added an extension to UK-OSNAP, until October 2024. This will result in the UK-OSNAP-Decade: 10 years of observing and understanding the overturning circulation in the subpolar North Atlantic (2014-2024).

The Changing Arctic Ocean (CAO) oceanographic dataset comprises data collected in the Arctic Ocean, including the Barents Sea and Fram Strait, as part of the Changing Arctic Ocean programme. The data were collected over multiple research cruises starting in June 2017. The majority of these cruises were conducted during the Arctic summer on board the RRS James Clark Ross, with further winter cruises completed in collaboration with the Nansen Legacy project on board the RV Helmer Hanssen. Shipboard data collection included the deployment of conductivity-temperature-depth (CTD) packages, ocean seagliders, mulitcorers, grabs, nets, trawls, and a shelf underwater camera system. The CAO programme aims to understand the changes in Arctic marine ecosystem in a quantifiable way, enabling computer models to help predict the consequences of these changes on, for example; surface ocean productivity; species distributions; food webs; and ecosystems, and the services they provide (ecosystem services). It was initially a Natural Environment Research Council (NERC) funded programme comprising four projects: Arctic PRIZE (Arctic productivity in the seasonal ice zone), led by Finlo Cottier (Scottish Association for Marine Science - SAMS); ARISE (Can we detect changes in Arctic ecosystems?), led by Claire Mahaffey (University of Liverpool); ChAOS (The Changing Arctic Ocean Seafloor), led by Christian Maerz (University of Leeds) and DIAPOD (Mechanistic understanding of the role of diatoms in the success of the Arctic Calanus complex and implications for a warmer Arctic), led by David Pond (University of Stirling). Additional projects were added to the programme in July 2018 through funding provided by NERC and the German Federal Ministry of Education and Research (BMBF). The majority of data are held by the British Oceanographic Data Centre (BODC) but a proportion of the data, primarily biological, are stored at the British Antarctic Survey Polar Data Centre (polardatacentre@bas.ac.uk) and any BMBF funded data are held by Pangaea (https://www.pangaea.de/).

The Rapid Climate Change (RAPID) data set comprises a diverse collection of oceanographic and benthic observations, including profiles of temperature, salinity, dissolved gases and currents. The dataset also includes discrete measurements of plankton, stable isotopes, dissolved metals, chlorofluorocarbons (CFCs) and nutrients in the water column, sediment grain size parameters and geochemistry, and atmospheric concentrations of inorganic halogens. The RAPID data were collected from numerous locations in the North Atlantic, North Sea, Greenland and Europe via over 30 cruises between 2004 and 2008. Many of the oceanographic data resulted from an extensive mooring array in the North Atlantic devoted to monitoring the Atlantic overturning circulation. These mooring arrays are continuing to return data in the follow-on programmes, Rapid Climate Change - Will the Atlantic Thermohaline Circulation Halt? (RAPID-WATCH, 2008-2015) and RAPID - Atlantic Meridional Overturning Circulation (RAPID-AMOC, 2015 onwards) which will result in a decadal time series spanning the North Atlantic. RAPID, RAPID-WATCH and RAPID-AMOC aim to investigate and understand the causes of rapid climate change, with a primary (but not exclusive) focus on the role of the Atlantic Ocean thermohaline circulation. A Rapid Climate Change project office has been established at the National Oceanography Centre, Southampton. The cruise and mooring data are managed by the British Oceanographic Data Centre and are supplemented by atmospheric model output held at the British Atmospheric Data Centre (BADC).

The Impacts of Deglaciation on Benthic Marine Ecosystems in Antarctica (ICEBERGS) dataset comprises of physical oceanography, marine geology, habitat mapping, community structure and seabed sediment data. The data were collected from CTD deployments, multi-beam swath bathymetry surveys, TOPAS sub-bottom profiling, shallow underwater camera system deployments, plankton net deployments, Agassiz trawls, Hamon grabs and multi-corer deployments during three seasonal cruises around the West Antarctic Peninsula beginning 2017 and scheduled to end in 2021. The data were collected as part of the ICEBERGS project to investigate the impacts of physical disturbance arising from climate-warming induced deglaciation on benthic communities around the West Antarctic Peninsula. The ICEBERGS project is part of the joint funded NERC-CONICYT Initiative and involves collaboration between the University of Exeter, University of Bangor, British Antarctic Survey (BAS) and Universidad Católica de la Santísima Concepción. The physical data will be managed by the British Oceanographic Data Centre (BODC) with the remainder of the data being submitted to the Polar Data Centre (BAS-PDC).

This dataset contains 201 measurements (188 from CTD rosette, 13 from underway) of seawater dissolved inorganic carbon (DIC) and total alkalinity (TA) from the Celtic Sea (50 N, 8 W). The samples were collected during RRS Discovery cruise DY033 in July-Aug 2015, as part of the UK Shelf Sea Biogeochemistry research programme (UK-SSB), in order to constrain the interior DIC and TA inventories. Measurements were carried out using VINDTA 3C instruments (#024 and #038, Marianda, Germany) at the University of Southampton (UK). Updated from v1 (doi:10.5285/50fbe4de-f777-1cde-e053-6c86abc0a855) on 17-07-2017 to include an additional 44 measurements (44 from CTD rosette, 2 from underway). Bad results resulting from technical issues during analysis have been removed from these results, so there are no recognised issues. The data were collected as part of the SSB research programme in the CaNDyFloSS: Carbon and Nutrient Dynamics and Fluxes over Shelf Systems (NE/K00185X/1) research programme component. SSB was co-funded by the Natural Environment Research Council (NERC) and the Department for Environment, Food and Rural Affairs (Defra). The programme took a holistic approach to the cycling of nutrients and carbon and the controls on primary and secondary production in UK and European shelf seas, to increase understanding of these processes and their role in wider biogeochemical cycles. The British Oceanographic Data Centre (BODC) created the metadata entry and is responsible for holding master copies of the data.

The data set comprises temperature and salinity hydrocasts collected across the North Atlantic Ocean between 1910 and 1990. The measurements were collected by nine North Atlantic Ocean Weather Ships (OWS): OWS Alpha (1954 – 1974); OWS Bravo (1928 – 1974); OWS Charlie (1910 – 1982); OWS Echo (1910 – 1979); OWS India (1957 – 1975); OWS Juliet (1950 – 1975); OWS Kilo (1949 – 1973); OWS Lima (1948 – 1990); OWS Mike (1948 – 1982). This data set also includes measurements collected close to the general positions prior to the stationing of the Weather ships for the OWS Bravo, Charlie and Echo stations. Data from OWS Alpha, Bravo, Echo, India, Juliett and Kilo have been taken from the US National Oceanographic Data Center (NODC) compilations whereas those from OWS Charlie, Lima and Mike have been constructed from both the US NODC and International Council for the Exploration of the Seas (ICES) data holdings. In addition a daily averaged data set for OWS Charlie is available for the period 1975 - 1985 (supplied by Syd Levitus). This data set was supplied to the British Oceanographic Data Centre (BODC) by ICES. Additional files and more recent data can be acquired from the ICES website.

The UK Argo program is an active contributor to the international Argo program, offering a comprehensive data set vital for supporting global oceanographic research. The data set includes a mixture of near-real-time and delayed-mode data collected by profiling floats, quality controlled to operational ocean forecasting standards and to climate research standards respectively. Real-time data are available within 24 hours of the float surfacing, while delayed-mode data become available within 12 months of the profile date. UK Argo floats data are typically managed by the British Oceanographic Data Centre. Argo floats operate in profiling ‘cycles’, normally repeated every 10 days throughout their lifetime. As part of a cycle, floats drift at their parking depth of approximately 1000m for 5 or 10 days, then sink to 2000m before starting their ascent to the surface, taking temperature and conductivity measurements at regular intervals. Since 2012, biogeochemical sensors have gradually been rolled out across a portion of the UK Argo fleet, reflecting the broadening research focus of the international Argo program. The UK Argo data set now includes measurements of dissolved oxygen, chlorophyll fluorescence, optical backscatter, pH, nitrate and irradiance. Moreover, an array of Deep Argo floats have recently been adding observations as deep as 6000m, and deployments have ventured to higher latitudes. The UK Argo data set has a variety of uses, including assimilation into operational weather forecasts in near-real-time to climate and ocean biogeochemistry research with the delayed mode data. In addition to its national efforts, the British Oceanographic Data Centre manages floats deployed by partner nations including Mauritius, Saudi Arabia, Ireland, and Portugal. This collaboration underscores the cross-border cooperative nature of the program, which is fundamental to its world-wide success.

Multibeam bathymetry data were collected in the Clarion-Clipperton Zone (CCZ), Northeast Pacific Ocean, using a hull-mounted Kongsberg EM122 multibeam echosounder during RRS James Cook Cruise JC241 from 06/02/2023 to 25/03/2023, and JC257 from 08/02/2024 to 19/03/2024. Data acquisition began upon exiting the Costa Rican Econoic Exclusion Zone (EEZ), suspended within the Clipperton Island EEZ, and resumed upon exiting the Clipperton Island EEZ. Data were then acquired throughout the CCZ. This suspension was repeated on the return journey. The data were recorded using Kongsberg’s Seafloor Information System (SIS) in .all format, and CTD and model-derived sound velocity profiles were subsequently applied. The data were manually cleaned using swath and subset editors in CARIS HIPS and SIPS software version 10.4. A zero tide file was also applied. The data were collected to obtain a better insight in the biodiversity patterns and benthic habitat distributions within the CCZ, by scientists from the National Oceanography Centre, Southampton, UK as part of the NERC-funded Seabed Mining And Resilience To EXperimental impact (SMARTEX) project (NE/T003537/1).

The Ocean Regulation of Climate by Heat and Carbon Sequestration and Transports (ORCHESTRA) data set comprises hydrographic data, including measurements of temperature, salinity and currents, complemented by bathymetric, meteorological and stable isotope data. The study area was the South Atlantic Ocean and Southern Ocean, including the Weddell and Scotia Seas and Drake Passage. The data were collected by research cruises, beginning March 2016. Shipboard data collection involved the deployment of conductivity-temperature-depth (CTD) packages and Lowered Acoustic Doppler Profilers (LADCP) in the study area. Continuous measurements of current velocities (using vessel mounted ADCPs, VMADCPs), bathymetry and surface ocean and meteorological properties were collected throughout each cruise. The ORCHESTRA programme aims to advance the understanding of, and capability to predict, the Southern Ocean's impact on climate change via its uptake and storage of heat and carbon. It represents the first fully unified activity by the Natural Environment Research Council (NERC) institutes as part of the Long-Term Multi-centre Science (LTMS) along with other UK research institutes, more specifically the British Antarctic Survey (BAS), National Oceanography Centre (NOC), British Geological Survey (BGS), Plymouth Marine Laboratory (PML), Sea Mammal Research Unit (SMRU), Centre for Polar Observation and Modelling (CPOM) and the Met Office Hadley Centre. The programme was divided into three Work Packages with the following Principal Investigators for each: WP1 (Interaction of the Southern Ocean with the atmosphere), led by Liz Kent from NOC; WP2 (Exchange between the upper ocean mixed layer and the interior), led by Dave Munday from BAS and WP3 (Exchange between the Southern Ocean and the global ocean), led by Yvonne Firing from NOC. The overall programme is led by Andrew Meijers from BAS. The majority of the data will be managed by the British Oceanographic Data Centre (BODC), with a minority of data sets being submitted to the BAS Polar Data Centre (BAS-PDC) and atmospheric data from MASIN aircrafts submitted to the Centre for Environmental Data Analysis (CEDA).

This data collection consists of data collected as part of the Commonwealth Marine Economies Programme (1st April 2016 to 31st March 2020). The data includes two AWAC moorings off the east coast of St. Vincent (July to October 2018 and January to March 2019) and a number of discrete water and underway measurements taken around Belize using a semi autonomous surface platform, "C-worker", owned and managed by the National Oceanography Centre, UK. The AWAC data consists of current profile and water level data, whilst the Belize data consists of biogeochemical and hydrographic data as well as sediment biogeochemical data for blue carbon assessments. This work was funded by the UK Foreign Commonwealth and Developmen Office (FCDO).

This dataset comprises a variety of physical oceanographic measurements collected under the CarTRidge project between 25th February and 26th March 2025. These data were collected on RRS James Cook cruise JC275 in the South Atlantic ocean. The data included are from: 53 Conductivity Temperature Depth (CTD) and Lowered Acoustic Doppler Current profiles (LADCP), 2 Wirewalker moorings, and 3 glider deployments. These data will be used to link internal tidal waves to patterns of carbon export. The data were funded under Natural Environment Research Council (NERC) Discovery grant "Enhanced carbon export driven by internal tides over the mid-Atlantic ridge (CarTRidge)" (grant number NE/X013758/1).

The fundamental dataset consists of full water column temperature and salinity profiles, with discrete inorganic nutrient data added later on. Between 1975 and January 1996 there were usually multiple occupations, in a single year, of a section between the Scottish shelf and the Rockall Channel. Many of these occupations targeted only a selection of the 35 stations collectively recognised as the Ellett Line. Over the years various names were used to describe the hydrographic section (or components of it): The Rockall Section, The Anton Dohrn Seamount Section, The Shelf-Edge-Sound of Mull Section. These are collectively termed the Ellett Line, after the scientist David Ellett, who coordinated much of this early work. The Extended Ellett Line consisted of 58 identified stations between the North West coast of Scotland and Iceland, crossing the Scottish shelf, Rockall Channel and Iceland Basin. The Extended Ellett Line was occupied at least annually from 1996 to 2018. The water column profiles were collected using STDs/CTDs at recognised fixed stations along the section. The discrete inorganic nutrient data were obtained from water bottles fired at multiple depths on each profile, although these data are absent (or more limited) in the earlier stages of the time series. In 2018, the Extended Ellett Line became the Ellett Array. The Ellett Array consists of moorings, gliders and CTD sections in the Rockall Trough and Hatton-Rockall Basin. The overall Ellett Line/Extended Ellett Line/Ellett Array dataset is recognised as a key oceanographic time series. Several important water masses are captured within it – water masses that help drive ocean thermohaline circulation and consequently regulate climate on a global scale. The multi-decadal nature of the dataset provides a rare opportunity for scientists to monitor changing ocean circulation patterns. Ellett Line occupations were first carried out by the Scottish Marine Biological Association (SMBA), now the Scottish Association for Marine Science (SAMS). From 1996 there was a move to joint maintenance, with Southampton Oceanography Centre (SOC), now the National Oceanography Centre (NOC), sharing the responsibility with SAMS. Data collection as part of the Ellett Array is an ongoing activity. Some of the data are subject to a two-year embargo upon generation, after which they become available as part of this growing unrestricted data collection.

This dataset consists of 1148 measurements of micromolar nutrient concentrations made on samples collected during the Atlantic Meridional Transect programme cruise 25 (AMT25 JR15001) between 18th September and 2nd November 2015. The cruise track between UK and Chile passed through both north and south Atlantic gyres. This dataset contributes to the AMT time-series of core oceanographic measurements along a north-south transect of the Atlantic Ocean. Samples were collected on a daily basis at 10 to 18 depths, usually in the upper 500m but up to 5000m, using a CTD rosette with 24 x 20 L OTE (Ocean Test Equipment) bottles. Samples were analysed within 3-4 hours of collection for nitrate+nitrite, nitrite, phosphate and silicate using a 5-channel Bran and Luebbe AAIII segmented flow, colourimetric, auto-analyser (Brewer and Riley (1965) for nitrate, Grasshoff (1976) for nitrite, Kirkwood (1989) and Mantoura and Woodward (1983) for phosphate and silicate). Established, proven analytical protocols were used.

The project objectives are to follow long-term trends. The project began in 1991 and each year about 20 samples were collected per station. A complete monitoring series is available from station NB1, while at station US5b and F9 the programme were interrupted between July 1992 and July 1993.The data has been quality inspected. Simultaneous biological sampling is stored in Biomad at the Department of Systems Ecology.

The dataset contains 39148 years of sea level data from 1355 station records, with some stations having alternative versions of the records provided from different sources. GESLA-2 data may be obtained from www.gesla.org. The site also contains the file format description and other information. The text files contain headers with lines of metadata followed by the data itself in a simple column format. All the tide gauge data in GESLA-2 have hourly or more frequent sampling. The basic data from the US National Atmospheric and Oceanic Administration (NOAA) are 6-minute values but for GESLA-2 purposes we instead settled on their readily-available 'verified hourly values'. Most UK records are also hourly values up to the 1990s, and 15-minute values thereafter. Records from some other sources may have different sampling, and records should be inspected individually if sampling considerations are considered critical to an analysis. The GESLA-2 dataset has global coverage and better geographical coverage that the GESLA-1 with stations in new regions (defined by stations in the new dataset located more than 50 km from any station in GESLA-1). For example, major improvements can be seen to have been made for the Mediterranean and Baltic Seas, Japan, New Zealand and the African coastline south of the Equator. The earliest measurements are from Brest, France (04/01/1846) and the latest from Cuxhaven, Germany and Esbjerg, Denmark (01/05/2015). There are 29 years in an average record, although the actual number of years varies from only 1 at short-lived sites, to 167 in the case of Brest, France. Most of the measurements in GESLA-2 were made during the second half of the twentieth century. The most globally-representative analyses of sea level variability with GESLA-2 will be those that focus on the period since about 1970. Historically, delayed-mode data comprised spot values of sea level every hour, obtained from inspection of the ink trace on a tide gauge chart. Nowadays tide gauge data loggers provide data electronically. Data can be either spot values, integrated (averaged) values over specified periods (e.g. 6 minutes), or integrated over a specified period within a longer sampling period (e.g. averaged over 3 minutes every 6 minutes). The construction of this dataset is fundamental to research in sea level variability and also to practical aspects of coastal engineering. One component is concerned with encouraging countries to install tide gauges at locations where none exist, to operate them to internationally agreed standards, and to make the data available to interested users. A second component is concerned with the collection of data from the global set of tide gauges, whether gauges have originated through the GLOSS programme or not, and to make the data available. The records in GESLA-2 will have had some form of quality control undertaken by the data providers. However, the extent to which that control will have been undertaken will inevitably vary between providers and with time. In most cases, no further quality control has been made beyond that already undertaken by the data providers. Although there are many individual contributions, over a quarter of the station-years are provided by the research quality dataset of UHSLC. Contributors include: British Oceanographic Data Centre; University of Hawaii Sea Level Center; Japan Meteorological Agency; US National Oceanic and Atmospheric Administration; Puertos del Estado, Spain; Marine Environmental Data Service, Canada; Instituto Espanol de Oceanografica, Spain; idromare, Italy; Swedish Meteorological and Hydrological Institute; Federal Maritime and Hydrographic Agency, Germany; Finnish Meteorological Institute; Service hydrographique et oceanographique de la Marine, France; Rijkswaterstaat, Netherlands; Danish Meteorological Institute; Norwegian Hydrographic Service; Icelandic Coastguard Service; Istituto Talassographico di Trieste; Venice Commune, Italy;

Sea level measurements initially started around 1774, to investigate why the sea water disappeared. At present, sea level is recorded from 34 stations in all seas surrounding Sweden. Once every hour the data are evaluated and one value is stored. The data is manually controlled. The benchmarks are controlled once a year. The purpose of collecting sea level data is to provide a basis for forecasting, mathematical modelling (forcing), statistics, planning and validation of models. In the future there is a need for assimilation of the model High Resolution Oceanographic Model for the Baltic Sea (HIROMB).