.. _data_structure: Data Structure and Keys ======================= All three access methods (Polytope, Insula Code, HDA) use the same dictionary-based ``request`` syntax. This page describes the data structure, available keys, and provides example requests. .. note:: The `Climate DT Explorer notebooks `_ can also be used to generate these working requests. Example notebooks for accessing and working with Climate DT data on the HEALPix grid are available in the `Polytope examples repository `_. The table below summarises, for each group of simulations, the ``activity`` metadata used during the data query, the data bridge hosting the data, and the available output resolutions on the HEALPix grid. See :ref:`Data Keys ` for a detailed explanation of the different keys. +--------------------------------------------+-----------------------+------------------+---------------------------+ | Simulations | Activity | Data Bridge | HEALPix output resolution | +============================================+=======================+==================+===========================+ | ICON – control, historical, SSP3-7.0 (r1) | baseline / projections| LUMI | high/standard | +--------------------------------------------+-----------------------+------------------+---------------------------+ | IFS-FESOM – control, historical, | baseline / projections| LUMI | high/standard | | SSP3-7.0 (r1) | | | | +--------------------------------------------+-----------------------+------------------+---------------------------+ | IFS-NEMO – control, historical (r1), | baseline / projections| MN5 | high/standard | | SSP3-7.0 (r1) | | | | +--------------------------------------------+-----------------------+------------------+---------------------------+ | IFS-FESOM – storyline simulations (r1–r5) | story-nudging | MN5 | high/standard | | | | | | +--------------------------------------------+-----------------------+------------------+---------------------------+ For a full list of available simulations, including model details, temporal extent, and experiment IDs, see :ref:`models_simulations_intro`. The data portfolio, including available variables and output frequencies, is described in :ref:`data_catalogue`. The **Generic State Vector (GSV)** ensures that all three coupled models produce output with consistent variable names and output frequencies. Beyond the model name, the primary differences between models when retrieving data are the vertical coordinate systems used for ocean variables, which remain heterogeneous across models. As the three models use different native grids, output is interpolated onto a common `HEALPix `_ mesh to provide a unified spatial representation. Output is provided at two spatial resolutions: ``high`` (H1024 for the 5 km runs, H512 for the 10 km run) and ``standard`` (H128, around 50 km). Atmospheric variables are available at hourly and monthly frequency, while ocean and sea-ice variables are available as daily and monthly means. Further details on the GSV concept and the Climate DT data infrastructure are described in `Doblas-Reyes et al. (2025) `_. .. _data_keys: .. _data_example_request: **Example request**:: #Request for 1 month of 1 hourly data, 2m temperature request = { 'activity': 'baseline', 'class': 'd1', 'dataset': 'climate-dt', 'experiment': 'hist', 'expver': '0001', 'model': 'ifs-fesom', 'generation': '2', 'realization': '1', 'resolution': 'high', 'date': '20140101/to/20140131', 'time': '0000/to/2300', 'stream': 'clte', 'type': 'fc', 'levtype': 'sfc', 'param': '167' } data_1hourly = earthkit.data.from_source( "polytope", "destination-earth", request, stream=False, address="polytope.lumi.apps.dte.destination-earth.eu") #Request for 1 month of monthly data, 2m temperature request = { 'activity': 'baseline', 'class': 'd1', 'dataset': 'climate-dt', 'experiment': 'hist', 'expver': '0001', 'model': 'ifs-fesom', 'generation': '2', 'realization': '1', 'resolution': 'high', 'year' : '2014', 'month': '01', 'time' : '0000', 'stream': 'clmn', 'type': 'fc', 'levtype': 'sfc', 'param': '167' } data_monthly = earthkit.data.from_source( "polytope", "destination-earth", request, stream=False, address="polytope.lumi.apps.dte.destination-earth.eu") .. _finding_the_data: Data Keys --------- Climate DT data stored in the DestinE data bridges and served via the DestinE Platform can be requested using a combination of keys and values. The table below lists the available keys and their meaning. Keys are case-insensitive. .. list-table:: :header-rows: 1 :widths: 15 35 50 * - Key - Relevant values - Description * - activity - story-nudging, baseline, projections - The type of activity the simulation corresponds to * - date - YYYYMMDD (YYYYMMDD/to/YYYYMMDD) - Date or dates for which the data is required (Valid only for clte stream) * - experiment - cont, hist (baseline or story-nudging), ssp3-7.0 (projections) - Experiment name (in parenthesis, the associated activity related to each experiment) * - levtype - sfc, pl, o2d, o3d, hl, sol - Level type depends on variable (sfc=surface, pl=pressure levels, o2d=ocean 2D, o3d=ocean 3D, hl=height levels in the atmosphere, sol=soil levels) * - level - lev1/lev2/lev3 - Present only in the case of levtype=pl, o3d, hl or sol * - model - ifs-fesom, ifs-nemo, icon - Available models in Climate DT * - param - paramid (167/235/...) - `ParamID `_. The correspondence between the param, the long name and the levtype is available in the portfolio documentation * - realization - 1 or ensemble number - Number of the ensemble member * - resolution - high or standard - HEALPix resolution: high=closest to the model native resolution (H1024 for 5 km, or H512 for 10 km depending on simulation), standard=interpolated to H128 (~50 km) * - stream - clte, clmn - clte: Hourly instantaneous or daily mean values, clmn: monthly mean values * - time - HHMM or HHMM/HHMM/HHMM - Select a specific time (Valid only for clte stream) * - year - YYYY - To select a specific year (Valid only for the clmn stream) * - month - MM - To select a specific month (Valid only for the clmn stream) The following keys are fixed for all simulations in this documentation: .. list-table:: :header-rows: 1 :widths: 15 35 50 * - Key - Relevant values - Description * - class - d1 - The data originates from Destination Earth * - dataset - climate-dt - Selects the Climate DT data from Destination Earth * - expver - 0001 - Experiment version for operational simulations * - type - fc - All Climate DT data uses type forecast * - generation - 2 - Climate DT generation