The Southern Ocean Freshwater Input from Antarctica (SOFIA) Initiative aims to improve our understanding of the simulated response to Antarctic freshwater input, and in particular the model uncertainty. The initiative has developed an experimental protocol and is engaging with modelling groups from around the world to run this common set of experiments using a variety of coupled climate and ocean-only models. Data from this international multi-model ensemble is openly shared for analysis, and is being synthesized into a series of publications by SOFIA participants. Full details are provided at https://doi.org/10.5194/gmd-16-7289-2023 GET DATA: https://sofiamip.github.io/data-access.html

Here we provide data from the Ross Ice Shelf ocean cavity. The HWD2 Camp was established in October of 2017 at (-80 39.497, 174 27.678) where the ice is moving seaward at around ~600 m a-1 and is sourced from the Transantarctic Mountains. Profiling Instruments - Profiling was primarily conducted with an RBR Concerto CTD (conductivity-temperature depth) profiling instrument, and this was cross-calibrated against irregular profiles with an RBR Duet (pressure and temperature only), a SBE37 MicroCat CTD as well as moored SBE37 MicroCat CTDs. The RBR unit is small and has suitable sensor capability (temperature and conductivity accuracies of ±0.002°C and ±0.003 mS cm-1). Its conductivity cell design is not prone to fouling by ice crystals, making it ideal for work in the sometimes crystal-laden borehole conditions. We were inconsistent in how we mounted the CTD on its protective frame and this appeared to make small difference in the conductivity signal (resulting in an ~0.03 psu variation). This was post-corrected based on the essentially invariant mooring data from the lower water column as well as SBE37 cross-calibration profile data. Because of the potential for sediment contamination of the sensors, the profiles were mostly conservative in their proximity to the sea floor. On several occasions, profiles were conducted all the way to the sea floor. The temperature and salinity are presented in EOS-80 in order to compare with available data. Eighty-three profiles are provided here (ctd_HWD2_*.dat). In addition, limited microstructure profiling was conducted to provide insight into some of the mixing details. The profiles were conducted by lowering the instrument to the ice base then commencing a sequence of three up-down “yo-yos” before returning to the surface and downloading. A data segment is included here (VMP_HWD2.dat). There were some challenges registering the vertical coordinate for the profiles. The melting of the borehole generates a trapped pool of relatively fresh water. The interface between this and the ocean should be near the base of the hole or a little higher – with seawater intrusion. However, there were some instances where the interface was at a higher pressure (i.e. apparently in the open water column). The best explanation for this is that the water in the borehole is not at static equilibrium for some period after initial melting. We use 34.3 psu as a cut-off, in addition to a pressure criterion to identify the top of the useful oceanic profile. It is also not inconceivable that water was being ejected from the hole, but it is unlikely that this would have impacted in the consistent observed pattern. Instrumented Mooring - The mooring instruments at HWD2-A comprised 5 Nortek Aquadopp single point current meters in titanium housings reporting to the surface (30-minute interval, Table SI-Three) via an inductive modem to a Sound-9 data logger and Iridium transmitter. The current meter measurements were corrected to account for the 138° magnetic declination offset (i.e. the south magnetic pole is to the north-west of the field site). Five files are provided here (HWD2_Init_rcm*.dat4). Stevens Craig, Hulbe Christina, Brewer Mike, Stewart Craig, Robinson Natalie, Ohneiser Christian, Jendersie Stefan (2020). Ocean mixing and heat transport processes observed under the Ross Ice Shelf control its basal melting. Proceedings of the National Academy of Sciences, 117 (29), 16799-16804. https://doi.org/10.1073/pnas.1910760117

Contained in this folder are the raw and processed data files for data collected with the underwater robot Icefin in the ocean cavity beneath Ross Ice Shelf, near the grounding line of Kamb Ice Stream. Most of these data are located within a basal crevasse. They were collected in December 2019 as part of the Aotearoa New Zealand Antarctic Science Platform and Victoria University of Wellington Hot Water Drilling initiative, and the NASA RISEUP grant (NNX16AL07G, PI B. E. Schmidt). The code that converted raw data files to processed can be found at https://zenodo.org/record/8338529. Direct questions to Peter Washam at pwasham@cornell.edu. RELATED PUBLICATION: https://doi.org/10.1126/sciadv.adi7638 GET DATA: https://doi.org/10.15784/601733

The mooring was deployed from February 2017 through February 2018 at 74.97° S, 163.96° E, approximately 7km east of the Nansen Ice Shelf in a region of TNB. The purpose of this study was to utilize data from a uniquely positioned and densely instrumented mooring to calculate HSSW production rates in TNB from continuous, in-situ observations. Moored instrumentation consisted of 7 SeaBird Electronics conductivity and temperature (SBE37-SM/SMP MicroCAT) sensors at depths of 47, 95, 119, 144, 168, 219, and 360 m and an upward-facing 600 kHz Nortek Acoustic Wave and Current (AWAC) profiler at 37 m depth, collecting both current velocity profiles in the upper ~35 m of the water column as well as Acoustic Surface Tracking (AST) measurements. Temperature and salinity measurements were validated against a shipboard conductivity-temperature-depth (CTD) cast performed upon deployment of the mooring. Temperature and salinity at 47 m and 95 m were additionally validated against a CTD cast performed upon recovery of the mooring. Full details of methods can be found in https://doi.org/10.1038/s41467-023-43880-1 GET DATA: ukm2103@columbia.edu

This work was primarily funded by the NASA-funded RISE-UP: Ross Ice Shelf & Europa Underwater Probe (PI Britney E. Schmidt) project. Field work at the KIS-1 site during the 2019-2020 season was completed through international collaboration between NASA, NSF/USAP, and Antarctica New Zealand, funded by the Aotearoa New Zealand Antarctic Science Platform (ANTA1801) Antarctic Ice Dynamics Project (ASP02101), and the NZARI-funded Aotearoa New Zealand Ross Ice Shelf Programme, “Vulnerability of the Ross Ice Shelf in a Warming World” (grant no. 2014-11). The data contained in this directory are merged and calibrated data files from three missions conducted with ROV Icefin through a borehole drilled through Ross Ice Shelf at KIS1 (-82.78410, -155.26267), near the Kamb Ice Stream grounding zone. Missions were conducted in 2019 on December 16th, 18th, and 21st (UTC). For questions or assistance working with the data please contact Britney Schmidt (britneys@cornell.edu) and Justin Lawrence (jdl287@cornell.edu). Related Publication: https://doi.org/10.1038/s41561-023-01129-y GET DATA: https://doi.org/10.15784/601625

Data from a measurement campaign examining the oceanic connection between an ice shelf cavity and sea ice. Here we present data from the ocean boundary-layer in an Ice Shelf Water outflow region from the Ross/McMurdo Ice Shelves. From a fast ice field camp during the Spring of 2015, we captured the kinematics of free-floating relatively large (in some cases 10s of mm in scale) ice crystals that were advecting and then settling upwards in a depositional layer on the sea ice underside (SIPL, sub-ice platelet layer). Simultaneously, we measured the background oceanic temperature, salinity, currents and turbulence structure. At the camp location the total water depth was 536 m, with the uppermost 50 m of the water column being in-situ super-cooled. Tidal flow speeds had an amplitude of around 0.1 m s-1 with dissipation rates in the under-ice boundary layer measured to be up to e=10-6 W kg-1. Acoustic sampling (200 kHz) identified backscatter from large, individually identifiable suspended crystals associated with crystal sizes larger than normally described as frazil. Crystal sizes in the SIPL were also measured. RELATED PUBLICATION: https://doi.org/10.3389/fmars.2023.1103740 GET DATA: https://doi.org/10.17882/90432

This set is a compilation of raster imagery at various scales. All data contained is available for download from the LINZ Data Service. THIS DATA DOES NOT REPLACE NAUTICAL CHARTS AND MUST NOT BE USED FOR NAVIGATION. Note: This set contains charts at a variety of scales. Use of LDS web map tile services for this set is not recommended as the scaled charts overlap. The hydrographic raster data made available through the LINZ Data Service is based on the Paper Navigational Charts published and maintained by the New Zealand Hydrographic Authority at Land Information New Zealand (LINZ). The online New Zealand Chart Catalogue provides more detailed and the most up to date information about New Zealand charts: [New Zealand Chart Catalogue] (http://www.linz.govt.nz/sea/charts/paper-charts/nz202-chart-catalogue). Information on symbols and abbreviations used on nautical charts: [Symbols and Abbreviations] (http://www.linz.govt.nz/sea/charts/paper-charts/symbols-terms-abbreviations-used-charts). Hydrographic standards and specifications for nautical charts and publications: [Standards and Specifications] (http://www.linz.govt.nz/sea/charts/hydrographic-standards-technical-specifications).

This set is a compilation of raster imagery at various scales. All data contained is available for download from the LINZ Data Service. THIS DATA DOES NOT REPLACE NAUTICAL CHARTS AND MUST NOT BE USED FOR NAVIGATION. Note: This set contains charts at a variety of scales. Use of LDS web map tile services for this set is not recommended as the scaled charts overlap. The hydrographic raster data made available through the LINZ Data Service is based on the Paper Navigational Charts published and maintained by the New Zealand Hydrographic Authority at Land Information New Zealand (LINZ). The online New Zealand Chart Catalogue provides more detailed and the most up to date information about New Zealand charts: [New Zealand Chart Catalogue] (http://www.linz.govt.nz/sea/charts/paper-charts/nz202-chart-catalogue). Information on symbols and abbreviations used on nautical charts: [Symbols and Abbreviations] (http://www.linz.govt.nz/sea/charts/paper-charts/symbols-terms-abbreviations-used-charts). Hydrographic standards and specifications for nautical charts and publications: [Standards and Specifications] (http://www.linz.govt.nz/sea/charts/hydrographic-standards-technical-specifications).

This layer contains depth information in gridded format captured by multibeam sonar in 2016/17 as part of HS52 - Approaches to Auckland. The data was collected for Toitū Te Whenua Land Information New Zealand (LINZ) and for which the survey took place from 26 October 2016 to 17 February 2017. Data management and distribution is by LINZ. Data comprises a gridded depth model as tif or ascii tiles in UTM projection. Vertical accuracy is +/- 0.2m (95%) Horizontal accuracy is +/- 0.5m (95%) Vertical datum is Approximate Lowest Astronomical Tide. The source data used to create the depth model may be of a higher resolution/density than the model. This data can be supplied on request and resolutions be discovered through the [NZ Bathymetric Surface model Index](https://data.linz.govt.nz/layer/95574-nz-bathymetric-surface-model-index/).

This set is a compilation of raster imagery at various scales. All data contained is available for download from the LINZ Data Service. THIS DATA DOES NOT REPLACE NAUTICAL CHARTS AND MUST NOT BE USED FOR NAVIGATION. Note: This set contains charts at a variety of scales. Use of LDS web map tile services for this set is not recommended as the scaled charts overlap. The hydrographic raster data made available through the LINZ Data Service is based on the Paper Navigational Charts published and maintained by the New Zealand Hydrographic Authority at Land Information New Zealand (LINZ). The online New Zealand Chart Catalogue provides more detailed and the most up to date information about New Zealand charts: [New Zealand Chart Catalogue] (http://www.linz.govt.nz/sea/charts/paper-charts/nz202-chart-catalogue). Information on symbols and abbreviations used on nautical charts: [Symbols and Abbreviations] (http://www.linz.govt.nz/sea/charts/paper-charts/symbols-terms-abbreviations-used-charts). Hydrographic standards and specifications for nautical charts and publications: [Standards and Specifications] (http://www.linz.govt.nz/sea/charts/hydrographic-standards-technical-specifications).