{
  "abstract": "Ku-band radar altimeters such as the one onboard CryoSat-2 measure the return-time of backscattered radar pulses to derive sea ice freeboard and thickness. This method relies on the two-way penetration of radar waves through the overlying snow. Early research with a surface-based radar over tank-grown sea ice indicated that most radar power is returned from the sea ice surface rather than the overlying snow, but this has not been replicated by in-situ radars in the field. We present a 24-day timeseries of surface-based radar measurements from young Antarctic sea ice (growing from 20 to 36 cm in thickness), showing a progressive reduction in its normalised radar cross-section (σ0) over time. This is associated with weakening of very strong, single-peaked waveforms associated with specular reflection from the ice surface; these initially swamp the signal from the snow surface but rapidly diminish with snow and ice ageing. Our observations help resolve the apparent contradiction between previous surface-based studies, and are consistent with an early-winter decline in σ0 observed by CryoSat-2. Our results also highlight the suppressing effect of frost flowers on σ0, and the similarity of σ0 evolution between the Ku- and Ka-bands. Our findings are relevant to the capability of the planned Ku/Ka-band CRISTAL altimetry mission, which aims to leverage differential radar penetration through snow on sea ice.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 11,
  "authors": [
    {
      "name": "Robbie Mallett"
    },
    {
      "name": "Vishnu Nandan"
    },
    {
      "name": "Julienne Stroeve"
    },
    {
      "name": "Rosemary Willatt"
    },
    {
      "name": "Thomas Newman"
    },
    {
      "name": "Gaelle Veyssiere"
    },
    {
      "name": "Carmen Nab"
    },
    {
      "name": "Connor Nelson"
    },
    {
      "name": "John Yackel"
    },
    {
      "name": "Amy Macfarlane"
    },
    {
      "name": "Jeremy Wilkinson"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0xc22xpkka8zh.bib",
  "cited_by": 0,
  "doi": "10.1109/jstars.2026.3735896",
  "fulltext_url": null,
  "id": "0xc22xpkka8zh",
  "issns": [
    "1939-1404"
  ],
  "landing_url": "https://hal.science/hal-05820768v1",
  "language": "en",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "hal",
      "0.sdu"
    ],
    [
      "hal",
      "1.sdu.envi"
    ],
    [
      "hal",
      "1.sdu.ocean"
    ],
    [
      "openalex",
      "1902|Arctic and Antarctic ice dynamics"
    ]
  ],
  "openalex": "W7214680052",
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-20",
  "publisher": "IEEE",
  "ris": "https://research.draconitic.com/paper/0xc22xpkka8zh.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:59Z",
      "native_id": "hal-05820768",
      "source": "hal",
      "url": "https://hal.science/hal-05820768v1"
    }
  ],
  "subjects": [
    {
      "field": "earth",
      "origin": "hal:1.sdu.envi",
      "subfield": "environmental-science"
    },
    {
      "field": "earth",
      "origin": "hal:1.sdu.ocean",
      "subfield": "oceanography"
    }
  ],
  "title": "Interpreting the Altimetric Radar Cross Section of Young Sea Ice",
  "title_text": "Interpreting the Altimetric Radar Cross Section of Young Sea Ice",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:17:59Z",
  "url": "https://research.draconitic.com/paper/0xc22xpkka8zh",
  "venue": "IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing",
  "versions": []
}