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 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, SSP3-7.0 (r1)	baseline / projections	LUMI	high/standard
IFS-NEMO – control, historical (r1), SSP3-7.0 (r1)	baseline / projections	MN5	high/standard
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 Climate Models. The data portfolio, including available variables and output frequencies, is described in 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).

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")

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.

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:

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