GEOSFP_A3dyn

{
  "kind": "grid",
  "source": {
    "url_template": "https://geos-chem.s3-us-west-2.amazonaws.com/GEOS_0.25x0.3125/GEOS_FP/{date:%Y}/{date:%m}/GEOSFP.{date:%Y%m%d}.A3dyn.025x03125.nc"
  },
  "temporal": {
    "start": "2013-01-01T01:30:00Z",
    "file_period": "P1D",
    "frequency": "PT3H",
    "records_per_file": 8,
    "time_variable": "time"
  },
  "reference": {
    "citation": "GEOS-FP A3dyn collection. NASA GMAO.",
    "url": "http://geoschemdata.wustl.edu/ExtData/"
  },
  "metadata": {
    "tags": [
      "geos_fp",
      "dynamics",
      "wind",
      "3-hourly",
      "3d"
    ],
    "earthscidata_source": "src/geosfp.jl::GEOSFPFileSet (filetype=A3dyn), geosfp_staggering()",
    "filetype": "A3dyn",
    "domain": "0.25x0.3125",
    "staggering_note": "geosfp_staggering() returns (true,false,false) for U, (false,true,false) for V, (false,false,true) for OMEGA; all others (false,false,false). The runtime de-staggers to cell centres before spatiotemporal interpolation.",
    "omega_extrapolation_note": "OMEGA uses zero extrapolation (extrapolate_type=0.0) vs Flat() for all others. This is encoded in per_variable.OMEGA.extrapolation='zero'.",
    "time_center_note": "A3dyn record times are centered: 01:30, 04:30, ..., 22:30 UTC (Delta_Time=030000).",
    "native_resolution_deg": {
      "longitude": 0.3125,
      "latitude": 0.25
    },
    "native_extent": {
      "longitude": [
        -180.0,
        180.0
      ],
      "latitude": [
        -90.0,
        90.0
      ],
      "lev_layer_index": [
        1,
        72
      ]
    },
    "regridding_provenance": "Former co-located data_loaders.regridding block (fill_value=0.0, extrapolation=clamp) removed in the 0.6.0 hard break; regridding is now declared per-variable on the GEOSFP model `regrid` (RFC pure-io-data-loaders §4.1/§5.2).",
    "crs_provenance": "Former DataLoaderSpatial.crs '+proj=longlat +datum=WGS84 +no_defs' is now the structured GDD grid.crs {projection: longlat, datum: WGS84}.",
    "merged_from": "components/earthsci_data/geosfp_a3dyn_loader.esm",
    "merge_note": "Merged from the standalone pure-I/O file components/earthsci_data/geosfp_a3dyn_loader.esm, which is deleted by the same commit. The 0.x `X.esm` + `X_loader.esm` split existed only because a loader was a COMPONENT and a {\"ref\"} target had to contain exactly one component. At esm 1.0.0 a data source is NOT a component, not a coupling endpoint and not a scoped-name path root, and `data_sources` no longer counts toward a file's top-level system count — so one file may hold a model AND the data_sources that model consumes and still be mountable by {\"ref\"}. This registry entry is byte-identical to the one the deleted file declared (it was already mirrored here so this document would validate), and the deleted file's own top-level metadata — name, description, tags, created, authors, references — is preserved verbatim in `merged_file_metadata` so no provenance, citation or migration note is lost.",
    "merged_file_metadata": {
      "name": "GEOSFP_A3dyn_loader",
      "description": "Pure-I/O data loader for GEOS-FP (A3DYN collection): 3-hourly time-averaged 3-D dynamics fields (winds, omega, RH, detrainment) on the native 0.3125°×0.25° global longitude/latitude grid, from the GEOS-Chem GEOS_FP 0.25x0.3125 archive.\n\nThis is one loader half of the geosfp loader+regridding-model split (RFC pure-io-data-loaders §4.1/§7; bead esm-3nc.2, following the esm-3nc.1 era5/wrf pattern). It is PURE I/O: it declares its source (url_template), the file variables it reads (with units), its temporal cadence, and its NATIVE grid expressed as a GDD Grid with a geographic (longlat/WGS84) crs descriptor. It performs NO reprojection and NO regridding — those are per-variable concerns of the regridding model (components/earthsci_data/geosfp.esm), which references this file as a subsystem via {\"ref\": \"./geosfp_a3dyn_loader.esm\"} under the subsystem key GEOSFP_A3dyn.\n\nThe removed co-located blocks: the old DataLoaderSpatial block (proj4 crs string / grid_type / staggering / resolution / extent) is replaced by the GDD `grid` (family + crs + dimensions + extents); the old per-loader `regridding` block (fill_value / extrapolation) is gone — regridding is declared per-variable on the model (geosfp.esm `regrid`). Because a `temporal` block is present, this loader seeds DISCRETE cadence (ess-v9a.5): the runtime refreshes the file buffers on its update schedule.\n\nMigrated from EarthSciData.jl@830435a065f27e99f10bba91107ca1730322cc6b:src/geosfp.jl (GEOSFPFileSet, filetype=A3DYN). Split out of the pre-migration components/earthsci_data/geosfp.esm (esm-1c6s).",
      "tags": [
        "earthsci_data",
        "meteorology",
        "geos_fp",
        "global",
        "data_loader",
        "pure-io",
        "longlat"
      ],
      "created": "2026-06-25T00:00:00Z",
      "authors": [
        "NASA GMAO / GEOS-Chem",
        "EarthSciModels migration (esm-3nc.2)"
      ],
      "references": [
        {
          "citation": "GEOS-FP data archived for GEOS-Chem classic. NASA Global Modeling and Assimilation Office (GMAO). AWS S3 mirror: s3://geos-chem/GEOS_{domain}/GEOS_FP/. See http://geoschemdata.wustl.edu/ExtData/ for current domain and file-type options.",
          "url": "http://geoschemdata.wustl.edu/ExtData/"
        },
        {
          "citation": "Molod, A., Takacs, L., Suarez, M., and Bacmeister, J. (2015). Development of the GEOS-5 atmospheric general circulation model: evolution from MERRA to MERRA2. Geosci. Model Dev., 8, 1339–1356.",
          "doi": "10.5194/gmd-8-1339-2015"
        },
        {
          "citation": "GEOS-Chem vertical grid documentation: https://wiki.seas.harvard.edu/geos-chem/index.php/GEOS-Chem_vertical_grids",
          "url": "https://wiki.seas.harvard.edu/geos-chem/index.php/GEOS-Chem_vertical_grids"
        },
        {
          "citation": "Source: EarthSciData.jl@830435a065f27e99f10bba91107ca1730322cc6b:src/geosfp.jl (GEOSFPFileSet, GEOSFP constructor, Ap/Bp hybrid grid coefficients, geosfp_staggering). Test: test/geosfp_test.jl. Docs: docs present in pinned commit."
        }
      ]
    }
  }
}