Making Ice Penetrating Radar More Accessible A tool for ﬁnding, downloading, and visualizing georeferenced radargrams within the QGIS ecosystem NSF: 2209726 PI: Laura Lindzey Abstract Ice Penetrating Radar has been a fundamental tool for understanding polar ice sheets since the ﬁrst ﬂights in the 1960’s. The US alone has spent many tens of millions of dollars on direct grants to enable the acquisition and analysis of radar data, and even more on related infrastructure and support costs. The QIceRadar project tries to make these critical datasets more FAIR. It will index data that is distributed across multiple international data centers (ﬁndability) and will provide a consistent interface to the many diﬀerent formats this data is published in (interoperability). We chose to build this functionality as a QGIS plugin because QGIS is already used by much of the polar community: Quantarctica and QGreenland have rapidly become indispensable data indices for researchers, making diverse data sets readily available. Thus, with no additional work on our part, QIceRadar will enable interpreting radargrams in context with many map- view datasets. Ice Penetrating Radar As an aircraft ﬂies above the ice sheet, the radar system emits VHF pulses. After each pulse, it records the intensity of reﬂected echoes, which correspond to the air/ice surface, features within the ice, and the ice/bed interface. Radargram Interpretation Data Availability QIceRadar Left: QGIS screencap showing existing radargrams over Thwaites Glacier. Other active layers show the MODIS mosaic [1] included in Quantarctica [2] and hypothesized active lake outlines from [3]. Above: Segment of radargram THW/X63a [4] corresponding to the orange line in the map. The yellow dot in the map view corresponds to the location of the vertical red line in the radargram. [1] Scambos, Ted A., et al. "MODIS-based Mosaic of Antarctica (MOA) data sets: Continent-wide surface morphology and snow grain size." Remote sensing of environment 111.2-3 (2007): 242-257. [2] Matsuoka, Kenichi, et al. "Quantarctica, an integrated mapping environment for Antarctica, the Southern Ocean, and sub-Antarctic islands." Environmental Modelling & Software 140 (2021): 105015. [3] Smith, Benjamin E., et al. "Connected subglacial lake drainage beneath Thwaites glacier, west Antarctica." The Cryosphere 11.1 (2017): 451-467. [4] Chu, W., Culberg, R., Hilger, A., Jordan, T., Schroeder, D., Seroussi, H., et al. (2021) "Radar Sounding Observations of the Amundsen Sea Embayment, 2004-2005" U.S. Antarctic Program (USAP) Data Center. unavailable unsupported supported Intensity Time since transmission Air Ice Rock Polar ice penetrating radar data is collected by over a dozen countries/research groups, all of which utilize diﬀerent data centers and formats. Both Antarctica and Greenland / the Canadian Arctic are included in our index, and our viewer will work with data formats from every major provider. Unfortunately, much of Bedmap 3’s data [5] are not available as radargrams. Our project includes a database of all known polar ice penetrating radar datasets, provided as a geopackage, and a plugin that enables visualizing them in context with other map-view datasets. In the radargram above, there is likely a deep valley where the bed was not observed, so an ice ﬂow model based on smoothed interpreted horizons (shown in red) and observed surface velocities may not converge. Modeling subglacial drainage networks is also sensitive to this eﬀect. AGAP A38b [6] Radargrams contain far more information than the proﬁle and gridded ice sheet geometry that is currently readily available. In the radargram above, there is an additional bright reﬂector above the bedrock reﬂection. [7] interpreted this to be a buried ash layer, corresponding to historical volcanism in West Antarctic and enabling the eruption to be dated to 8 kya. THW/Y53a [4] ICP3/F56T03a [8] Englacial layers observed in radargrams can be traced between core sites, inf