5115f69c-414a-49b7-b8cc-6b5d57bc0458 2026-02-24T10:24:22.399589Z ISO 19115-3 - SEXTANT 1.0 [OLD TEMPLATE] Sea Ice Freeboard, Thickness and Snow Depth (Arctic and Antarctic) 2017-11-17 publication https://sextant.ifremer.fr/record/5115f69c-414a-49b7-b8cc-6b5d57bc0458 These data contain monthly mean gridded seaice products from altimetry including the following parameters over Arctic and Antarctic areas: - radar freeboard (direct Ku measurement) - ice freeboard (radar freeboard corrected from Ku speed propagation in Snow Depth) - snow depth (SD) - sea ice thickness (Sea Ice Thickness(SIT), using SD) The survey of these high latitudes requires satellite altimeters with high latitude orbits : Saral/AltiKa, Cryosat-2 and Envisat. CTOH, LEGOS AVISO+ CTOH ctoh_products@legos.obs-mip.fr distributor Sara Fleury sara.fleury@legos.obs-mip.fr author Florent Garnier florent.garnier@legos.obs-mip.fr author https://sextant.ifremer.fr/geonetwork/srv/api/records/5115f69c-414a-49b7-b8cc-6b5d57bc0458/attachments/CTOH_Glace_epaisseur_arctic2.png CTOH_epaisseur_glace /Imagerie/Imagerie satellitale Thèmes Sextant 2024-07-26 publication geonetwork.thesaurus.local.theme.sextant-theme Caractéristiques géographiques océanographiques GEMET - INSPIRE themes, version 1.0 2018-07-27T14:39:48 publication geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme CDS-SAT-AVISO Centre de données ODATIS 2024-07-26 publication geonetwork.thesaurus.local.theme.odatis_centre_donnees Variables ODATIS 2023-10-13 publication geonetwork.thesaurus.local.theme.odatis_variables /Données d'observation/satellite Type de jeux de donnée ODATIS 2024-07-26 publication geonetwork.thesaurus.local.theme.type_jeux_donnee freeboard, snow depth, density, sea ice thickness SNO-CTOH Services Nationaux d'Observation 2024-07-26 publication geonetwork.thesaurus.local.theme.SNO Glace de mer ODATIS aggregation parameters and Essential Variable names 2024-06-13 publication geonetwork.thesaurus.external.theme.NVS.OD1 Aucune condition ne s’applique “The data used in this study (doi 10.6096/CTOH_SEAICE_2019_12) were developed, validated by the CTOH/LEGOS, France and distributed by Aviso +”. grid 12 utf8 oceans -180.00 180.00 -82.00 88.00 2002-01 2019-12 ftp://ftp-access.aviso.altimetry.fr/altimetry-sea-ice/ctoh WWW:LINK Accès authentifié aux données https://www.aviso.altimetry.fr/en/data/products/altimetry-ice-products/altimetry-sea-ice-products-from-ctoh.html WWW:LINK Plus d'information sur AVISO+ https://www.aviso.altimetry.fr/fileadmin/documents/data/tools/hdbk_AltimetrySeaIce_CTOH.pdf WWW:LINK Manuel utilisateur https://tds-odatis.aviso.altimetry.fr/thredds/catalog/dataset-auxilary-seaice-ctoh/catalog.html WWW:DOWNLOAD TDS fileserver Sea Ice Freeboard, Thickness and Snow Depth http://ctoh.legos.obs-mip.fr/data/sea-ice-products/sea-ice-thickness DOI Sea ice and its snow coverage has important effects on the global climate. Sea ice thickness (SIT) measurement relies on the “Freeboard” method. It consists in calculating the height difference between the floes (range above the ice) and the leads (range above the water in ice fractures). Alti Snow Depth (SD) : The difference of the scattering properties of the AltiKa Ka-band (on Saral/AltiKa) and the Siral Ku-band (on Cryosat-2) altimeters provides a good proxy of the snow depth using an adapted processing chain. According to the selected product, the Snow Depth could have 3 origins: - Modified Warren99 climatology (in Arctic only) - AMSR (for now in Antarctic only) - Altimetry Snow Depth (ASD ou KaKu) for both hemisphere but only for 2013-2019 as it uses Saral Ka altimeter. For each data, an estimation of uncertainties is also provided. More detail on computation will be described soon in an handbook. All months are concatened in one netcdf file. File names are built as follow: SIT_{HEMISPHERE}_{start_year}_{end_year}_{SATELLITE}_Snow{snow_origin}.ease2_{pixel_size}_smth{filtering_radius}.nc with: - {HEMISPHERE} in [NH, SH] - {SATELLITE} in [ENV, CS2] for Envisat or CryoSat-2 - {snow_orgin} in [W99m, AMSR, KaKu] This Snow Depth is the one used to compute the Sea Ice Thickness - {filtering_radius} in [25000, 50000] which are the radius in meters References: - For Envisat and CryoSat-2 FB and SIT : Guerreiro, K., Fleury, S., Zakharova, E., Kouraev, A., Rémy, F., Maisongrande, P., 2017. Comparison of CryoSat-2 and ENVISAT radar freeboard over Arctic sea ice: toward an improved Envisat freeboard retrieval. The Cryosphere 11, 2059–2073. https://doi.org/10.5194/tc-11-2059-2017 - For the Snow Depth : - Garnier, F., Fleury, S., Garric, G., Bouffard, J., Tsamados, M., Laforge, A., Bocquet, M., Fredensborg Hansen, R. M., and Rémy, F.: Advances in altimetric snow depth estimates using bi-frequency SARAL/CryoSat-2 Ka/Ku measurements, The Cryosphere Discuss. [preprint], https://doi.org/10.5194/tc-2021-79 , in review, 2021. - Guerreiro, K., Fleury, S., Zakharova, E., Rémy, F., Kouraev, A., 2016. Potential for estimation of snow depth on Arctic sea ice from CryoSat-2 and SARAL/AltiKa missions. Remote Sensing of Environment 186, 339–349. https://doi.org/10.1016/j.rse.2016.07.013