819f5ea3-6897-4e64-b599-cfb98d6c963e Jullien Swen IFREMER PDG-DGDS-ODE-LOPS-SIAM 02 98 22 41 29 Swen.Jullien@ifremer.fr pointOfContact 2026-01-19T12:32:27.386471Z ISO 19115-3 - SEXTANT 1.0 0 2 0 1440 0.25 721 0.25 false EPSG:4326 Blended wind and pressure fields (ERA5 + parametric TCs) 2025-11-01 publication 2026-01-19 revision FRE-330-715-368-00032_WORLD_OCEAN_ATLAS_ARGO_INFERRED_STATS DOI:10.12770/819f5ea3-6897-4e64-b599-cfb98d6c963e This dataset provides global surface winds and pressure fields on a 0.25° resolution horizontal grid with hourly frequency, based on the global ERA5 reanalysis but with enhanced realistic TCs, built from a parametric wind formulation fitted to SAR high-resolution observations. TC wind structures in ERA5 are indeed known to be strongly biased. The methodology, developed in Herry et al. (2025) and applied here, is to replace ERA5 underestimated winds in TCs by the parametric wind formulation of Wood et al. (2013) with optimized parameters (fitted to SAR data), while keeping ERA5 wind field elsewhere. The wind profile and the transition area between the parametric and ERA5 winds are adjusted for each TC, according to its intensity and size. This blended product manages to represent a variety of realistic TC structures, and ensure an asymmetry associated to the synoptic flow for each case. This work was supported by the SPC-Climate-FLAGSHIP project, the ANR OROWSHI project (https://www.france-energies-marines.org/projets/orowshi, grant No. ANR-10-IEED-0006-34), the PPR FUTURISKS Project ‘Un Océan de Solutions’, managed by the National Research Agency, under France 2030 [grant No.ANR-22-POCE-0002]. It used the HPC resources from GENCI-IDRIS (Grant A0010107661) and the Pôle de Calcul et de Données Marines (PCDM; https://pcdm.ifremer.fr/). The researchers were supported by Ifremer and IRD. IFREMER sismer@ifremer.fr publisher Jullien Swen IFREMER PDG-DGDS-ODE-LOPS-SIAM 02 98 22 41 29 Swen.Jullien@ifremer.fr author Jullien Swen IFREMER PDG-DGDS-ODE-LOPS-SIAM 02 98 22 41 29 Swen.Jullien@ifremer.fr pointOfContact https://sextant.ifremer.fr/geonetwork/srv/api/records/819f5ea3-6897-4e64-b599-cfb98d6c963e/attachments/TC_sextant_database.png /Physical Environment Thèmes Sextant 2025-12-09 publication geonetwork.thesaurus.local.theme.sextant-theme Oceanographic geographical features GEMET - INSPIRE themes, version 1.0 2018-07-27T14:39:48 publication 2018-07-27 publication geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme tropical cyclones Wind Pressure ODATIS aggregation parameters and Essential Variable names 2025-07-29 publication geonetwork.thesaurus.external.theme.NVS.OD1 Simulation data Type de jeux de donnée ODATIS 2025-12-09 publication geonetwork.thesaurus.local.theme.type_jeux_donnee Cersat - Metadata convention 2025-12-09 publication geonetwork.thesaurus.local.theme.cersat_metadata_convention CC-BY (Creative Commons - Attribution) grid 0.25 utf8 oceans climatologyMeteorologyAtmosphere disaster -180.00 180.00 -90.00 90.00 1980-01-01 2024-06-30 /home/ref-atmos-forcing-public/ERA5_CYCLO_PARAM NETWORK:LINK Download (visible path) https://data-dataref.ifremer.fr/atmos-forcing-public/ERA5_CYCLO_PARAM/ WWW:DOWNLOAD Download link https://gitlab.ifremer.fr/lops-public/toolbox_era5_tc WWW:LINK Adresse internet (URL) https://doi.org/10.12770/819f5ea3-6897-4e64-b599-cfb98d6c963e DOI Digital Object Identifier (DOI) RÈGLEMENT (UE) N o 1089/2010 DE LA COMMISSION du 23 novembre 2010 portant modalités d'application de la directive 2007/2/CE du Parlement européen et du Conseil en ce qui concerne l'interopérabilité des séries et des services de données géographiques 2010-12-08 publication See the referenced specification The full methodology to build this dataset is detailed in Herry et al. (2025). In short: * The ERA5 wind field is first filtered within a 200km-radius from the TC track, using an 11-day low-pass filter designed to remove the underestimated ERA5 TC, but keeping the synoptic flow. * The parametric wind field is computed over a 1/4° grid from the Wood et al. (2013) parametric formulation, and best-track TC parameters, Vmax, Rmax, and the latitude. The coefficient of the parametric formulation are expressed as a function of best-track parameters also, following a fit to SAR data detailed in Herry et al. (2025). * Then the blending is performed between two radii R1 and R2. Within R1 of the TC track position, the zonal and meridional wind components of the symmetric parametric vortex are added to the asymmetric ERA5 filtered wind field. Between R1 and R2, the wind transition from that to ERA5 wind with a linear weighting. Out of R2, the ERA5 wind field remains unchanged. R1 and R2 are adjusted for each TC position: - if an 34-kt wind radius (R34) can be found in ERA5 and the ratio Rmax/R34 is less than 1/3, then the blending is performed between R1 = R34/2 and R2 = R34, - if that ratio is greater than 1/3, then R1 = 2.Rmax and R2 = R34 - if no R34 can be found, the transition zone is defined between 100 km and 200 km. The pressure field is similarly blended. The parameterization of the pressure profile is derived from Knaff and Zehr (2007) and Holland (1980).