These data were aquired with a Terrestrial Radar Interferometer overlooking the grounding zone of Priestley Glacier, Antarctica. The time series contains differential interferograms with a 12h temporal baseline covering an approximately 8 day period in November 2018. Tidal modulation of ice streams and their adjacent ice shelves is a real-world experiment to understand ice-dynamic processes. We observe the dynamics of Priestley Glacier, Antarctica, using Terrestrial Radar Interferometry (TRI) and GNSS. Ocean tides are predominantly diurnal but horizontal GNSS displacements oscillate also semi-diurnally. The oscillations are strongest in the ice shelf and tidal signatures decay near-linearly in the TRI data over >10 km upstream of the grounding line. Tidal flexing is observed >6 km upstream of the grounding line including cm-scale uplift. Tidal grounding line migration is small and <40 % of the ice thickness. The frequency doubling of horizontal displacements relative to the ocean tides is consistent with variable ice-shelf buttressing demonstrated with a visco-elastic Maxwell model. Taken together, this supports previously hypothesized flexural ice softening in the grounding-zone through tides and offers new observational constraints for the role of ice rheology in ice-shelf buttressing. Time series of line-of-sight flowfields averaged over approximately three hours. Data were taken with a Terrestrial Radar Interferometer in November 2018 at the grounding zone of Priestley Glacier, Antarctica – The Zip Archive contains 288 Geotiff in South polar stereographic projection – Each raster has 4027 x 4746 entries – The file name details the approximately 3h time inverval of aquisition with Stack_YYYYMMDD_HHMMSS_YYYYMMDD_HHMMSS marking the beginning and end of the time interval, respectively. – The line of sight velocities are given in meters per year Related Publication: Drews, R., Wild, C. T., Marsh, O. J., Rack, W., Ehlers, T. A., Neckel, N., & Helm, V. (2021). Grounding-zone flow variability of Priestley Glacier, Antarctica, in a diurnal tidal regime. Geophysical Research Letters, 48, e2021GL093853. https://doi.org/10.1029/2021GL093853 GET DATA: https://doi.org/10.1594/PANGAEA.935702

In Antarctica, ice shelves such as the Ross Ice Shelf (RIS) fringe 75% of the coastline and cover over 1.5 million km2, creating distinct and largely unexplored marine environments. It is fundamental to characterize the communities under these shelves to understand their biogeochemical role and predict how they might respond to future ice-shelf collapse 1,2. While historical studies suggested the RIS harbors active microorganisms 3–5, nothing is known about the composition of these communities. In this study, we profiled the composition, function, and activities of microbial communities in three seawater samples (400, 550, 700 m depth) underlying the shelf interior. We combined rate measurements with multi-omics (i.e. single-cell genomics, metagenomics, metatranscriptomics, and metaproteomics). Overall, below-shelf waters harbour microbial communities of comparable abundance and diversity to deep pelagic waters. Based on the meta-omic data, the community is inferred to be sustained by dark carbon fixation using ammonia, nitrite, and sulfur compounds as electron donors. In turn, these chemolithoautotrophs are predicted to support the aerobic heterotrophic majority and various trophic interactions. Consistently, this study and previous activity measurements suggest that dark carbon fixation is sufficient to sustain prokaryotic heterotrophic production, making the waters below the RIS presumably the largest chemolithotrophic system in the global ocean. Further details are provided at https://doi.org/10.1038/s41467-021-27769-5 GET DATA: https://www.ebi.ac.uk/ena/browser/view/PRJEB35712 GET DATA: https://www.ncbi.nlm.nih.gov/bioproject/?term=PRJNA593264

Here, we present new, transient, GCM-forced ice-sheet simulations validated against proxy reconstructions. This is the first time such an evaluation has been attempted. Our empirically constrained simulations indicate that the AIS contributed 4 m to global mean sea level by 126 ka BP, with ice lost primarily from the Amundsen, but not Ross or Weddell Sea, sectors. We resolve the conflict between previous work and show that the AIS thinned in the Wilkes Subglacial Basin but did not retreat. We also find that the West AIS may be predisposed to future collapse even in the absence of further environmental change, consistent with previous studies. There are two files, for Termination 1 ('T1') and Termination 2 ('T2'). They contain spatial fields for ice thickness, ice surface elevation, bedrock elevation, surface and basal velocity, and mask. The T1 outputs are every 500 years, whereas the T2 outputs are every 100 years. The spatial resolution of both is 20 km. Sea-level-equivalent mass loss can be calculated from these outputs, but is also provided here in a text file for convenience. RELATED PUBLICATION: Golledge, N.R., Clark, P.U., He, F., et al. (2021). Retreat of the Antarctic Ice Sheet During the Last Interglaciation and Implications for Future Change. Geophysical Research Letters, 48(17). https://doi.org/10.1029/2021GL094513 GET DATA: https://doi.org/10.17605/OSF.IO/GZB3H

This is GNSS data of four stations covering the grounding zone of Priestley Glacier Antarctica. Tidal modulation of ice streams and their adjacent ice shelves is a real-world experiment to understand ice-dynamic processes. We observe the dynamics of Priestley Glacier, Antarctica, using Terrestrial Radar Interferometry (TRI) and GNSS. Ocean tides are predominantly diurnal but horizontal GNSS displacements oscillate also semi-diurnally. The oscillations are strongest in the ice shelf and tidal signatures decay near-linearly in the TRI data over >10 km upstream of the grounding line. Tidal flexing is observed >6 km upstream of the grounding line including cm-scale uplift. Tidal grounding line migration is small and <40 % of the ice thickness. The frequency doubling of horizontal displacements relative to the ocean tides is consistent with variable ice-shelf buttressing demonstrated with a visco-elastic Maxwell model. Taken together, this supports previously hypothesized flexural ice softening in the grounding-zone through tides and offers new observational constraints for the role of ice rheology in ice-shelf buttressing. Related Publication: Drews, R., Wild, C. T., Marsh, O. J., Rack, W., Ehlers, T. A., Neckel, N., & Helm, V. (2021). Grounding-zone flow variability of Priestley Glacier, Antarctica, in a diurnal tidal regime. Geophysical Research Letters, 48, e2021GL093853. https://doi.org/10.1029/2021GL093853 GET DATA: https://doi.pangaea.de/10.1594/PANGAEA.936090

Diatom census counts were used to quantitatively estimate summer sea-surface temperatures (SST) over the last 40,000 years in core MD11-3353, collected in 2011 on board the R.V. Marion Dusfresne west of Kerguelen Island, Southern Ocean. The transfer function used to reconstruct summer (January to March) SST is the Modern Analog Technique that here uses 249 surface sediment samples (modern analogs), the relative abundances of 32 diatom species and the chord distance to select the five most similar modern analogs (Crosta et al., 2020). This method yields a root mean square error of prediction of ~1 °C. The core chronology is detailed in Thöle et al. (2019). RELATED PUBLICATION: Civel-Mazens, Matthieu; Crosta, Xavier; Cortese, Giuseppe; Michel, Elisabeth; Mazaud, Alain; Ther, Olivier; Ikehara, Minoru; Itaki, Takuya (2021): Impact of the Agulhas Return Current on the oceanography of the Kerguelen Plateau region, Southern Ocean, over the last 40 kyrs. Quaternary Science Reviews, 251, 106711, https://doi.org/10.1016/j.quascirev.2020.106711

Polar regions are experiencing some of the most dramatic effects of climate change resulting in large-scale changes in sea ice cover. Despite this, there are relatively few long-term studies on polar species that evaluate the full scope of these effects. Over the last two decades, this team has conducted globally unique demographic studies of Adélie penguins in the Ross Sea, Antarctica, to explore several potential mechanisms for population change. This five-year project will use penguin-borne sensors to evaluate foraging conditions and behavior and environmental conditions on early life stages of Adélie penguins. Results will help to better understand population dynamics and how populations might respond to future environmental change. To promote STEM literacy, education and public outreach efforts will include multiple activities. The PenguinCam and PenguinScience.com website (impacts of >1 million hits per month and use by >300 classrooms/~10,000 students) will be continued. Each field season will also have ‘Live From the Penguins’ Skype calls to classes (~120/season). Classroom-ready activities that are aligned with Next Generation Science Standards will be developed with media products and science journal papers translated to grade 5-8 literacy level. The project will also train early career scientists, postdoctoral scholars, graduate students and post-graduate interns. Finally, in partnership with an Environmental Leadership Program, the team will host 2-year Roger Arliner Young Conservation Fellow, which is a program designed to increase opportunities for recent college graduates of color to learn about, engage with, and enter the environmental conservation sector. Further details are provided at: Morandini, V., Dugger, K. M., Schmidt, A. E., Varsani, A., Lescroël, A., Ballard, G., Lyver, P. O., Barton, K., & Ainley, D. G. (2024). Sex-specific recruitment rates contribute to male-biased sex ratio in Adélie penguins. Ecology and Evolution, 14, e10859. https://doi.org/10.1002/ece3.10859 GET DATA: https://doi.org/10.15784/601444

Data of apparent ice thickness from airborne electromagnetic (AEM) surveys of fast ice in McMurdo Sound, Antarctica, carried out in Nov/Dec 2009, 2011, 2013, 2016, and 2017. Values are given for apparent thicknesses derived from both, in-phase and quadrature signals. The difference between both thicknesses is a scaled measure of sub-ice platelet layer thickness. Data are from east-west transects across McMurdo Sound, at fixed latitudes. Data were smoothed and interpolated onto a regular longitude grid (0.001 degree increments). More information can be found in Haas et al. (2021). Related Publication: Haas, C., Langhorne, P. J., Rack, W., Leonard, G. H., Brett, G. M., Price, D., Beckers, J. F., and Gough, A. J.: Airborne mapping of the sub-ice platelet layer under fast ice in McMurdo Sound, Antarctica, The Cryosphere, 15, 247–264, https://doi.org/10.5194/tc-15-247-2021, 2021

Radiolarians (holoplanktonic Protozoa) found in marine sediments are commonly used in Southern Ocean as palaeoclimate proxies. Generating such reconstructions of past climate based on radiolarian abundances requires a spatially and environmentally comprehensive reference dataset of modern radiolarian census counts. The Southern Ocean RADiolarian (SO-RAD) dataset includes census counts for 237 radiolarian taxa from 228 surface sediment samples located in the Atlantic, Indian and South-west Pacific sectors of the Southern Ocean. This compilation is the largest radiolarian census dataset derived from surface sediment samples in the Southern Ocean. The SO-RAD dataset may be used as a reference dataset for palaeoceanographic reconstructions, or for studying modern radiolarian biogeography and species diversity. RELATED PUBLICATION: https://doi.org/10.5194/essd-13-5441-2021

These data were aquired with a Terrestrial Radar Interferometer overlooking the grounding zone of Priestley Glacier, Antarctica. The time series contains differential interferograms with a 12h temporal baseline covering an approximately 8 day period in November 2018. Tidal modulation of ice streams and their adjacent ice shelves is a real-world experiment to understand ice-dynamic processes. We observe the dynamics of Priestley Glacier, Antarctica, using Terrestrial Radar Interferometry (TRI) and GNSS. Ocean tides are predominantly diurnal but horizontal GNSS displacements oscillate also semi-diurnally. The oscillations are strongest in the ice shelf and tidal signatures decay near-linearly in the TRI data over >10 km upstream of the grounding line. Tidal flexing is observed >6 km upstream of the grounding line including cm-scale uplift. Tidal grounding line migration is small and <40 % of the ice thickness. The frequency doubling of horizontal displacements relative to the ocean tides is consistent with variable ice-shelf buttressing demonstrated with a visco-elastic Maxwell model. Taken together, this supports previously hypothesized flexural ice softening in the grounding-zone through tides and offers new observational constraints for the role of ice rheology in ice-shelf buttressing. Related Publication: Drews, R., Wild, C. T., Marsh, O. J., Rack, W., Ehlers, T. A., Neckel, N., & Helm, V. (2021). Grounding-zone flow variability of Priestley Glacier, Antarctica, in a diurnal tidal regime. Geophysical Research Letters, 48, e2021GL093853. https://doi.org/10.1029/2021GL093853 GET DATA: https://doi.org/10.1594/PANGAEA.935707