pycontrails.datalib.ecmwf.HRES¶

class pycontrails.datalib.ecmwf.HRES(time, variables, pressure_levels=-1, paths=None, cachepath=None, grid=0.25, stream='oper', field_type='fc', forecast_time=None, cachestore=<object object>, url=None, key=None, email=None)¶

Bases: ECMWFAPI

Class to support HRES data access, download, and organization.

Requires account with ECMWF and API key.

API credentials set in local ~/.ecmwfapirc file:

{
    "url": "https://api.ecmwf.int/v1",
    "email": "<email>",
    "key": "<key>"
}

Credentials can also be provided directly url key, and email keyword args.

See ecmwf-api-client documentation for more information.

Parameters:

time (datalib.TimeInput | None) – The time range for data retrieval, either a single datetime or (start, end) datetime range. Input must be a datetime-like or tuple of datetime-like (datetime, pandas.Timestamp, numpy.datetime64) specifying the (start, end) of the date range, inclusive. If forecast_time is unspecified, the forecast time will be assumed to be the nearest synoptic hour: 00, 06, 12, 18. All subsequent times will be downloaded for relative to forecast_time. If None, paths must be defined and all time coordinates will be loaded from files.
variables (datalib.VariableInput) – Variable name (i.e. “air_temperature”, [“air_temperature, relative_humidity”]) See pressure_level_variables for the list of available variables.
pressure_levels (datalib.PressureLevelInput, optional) – Pressure levels for data, in hPa (mbar) Set to -1 for to download surface level parameters. Defaults to -1.
paths (str | list[str] | pathlib.Path | list[pathlib.Path] | None, optional) – Path to CDS NetCDF files to load manually. Can include glob patterns to load specific files. Defaults to None, which looks for files in the cachestore or CDS.
grid (float, optional) – Specify latitude/longitude grid spacing in data. Defaults to 0.25.
stream (str, optional) – “oper” = atmospheric model/HRES, “enfo” = ensemble forecast. Defaults to “oper” (HRES),
field_type (str, optional) – Field type can be e.g. forecast (fc), perturbed forecast (pf), control forecast (cf), analysis (an). Defaults to “fc”.
forecast_time (DatetimeLike, optional) – Specify forecast run by runtime. Defaults to None.
cachestore (cache.CacheStore | None, optional) – Cache data store for staging data files. Defaults to cache.DiskCacheStore. If None, cache is turned off.
url (str) – Override ecmwf-api-client url
key (str) – Override ecmwf-api-client key
email (str) – Override ecmwf-api-client email

Notes

MARS key word definitions

class: in most cases this will be operational data, or “od”
stream: “enfo” = ensemble forecast, “oper” = atmospheric model/HRES
expver: experimental version, production data is 1 or 2
date: there are numerous acceptible date formats
time: forecast base time, always in synoptic time (0,6,12,18 UTC)
type: forecast (oper), perturbed or control forecast (enfo only), or analysis
levtype: options include surface, pressure levels, or model levels
levelist: list of levels in format specified by levtype levelist
param: list of variables in catalog number, long name or short name
step: hourly time steps from base forecast time
number: for ensemble forecasts, ensemble numbers
format: specify netcdf instead of default grib, DEPRECATED format
grid: specify model return grid spacing

Local paths are loaded using xarray.open_mfdataset(). Pass xr_kwargs inputs to open_metdataset() to customize file loading.

Examples

>>> from datetime import datetime
>>> from pycontrails import GCPCacheStore
>>> from pycontrails.datalib.ecmwf import HRES

>>> # Store data files to local disk (default behavior)
>>> times = (datetime(2021, 5, 1, 2), datetime(2021, 5, 1, 3))
>>> hres = HRES(times, variables="air_temperature", pressure_levels=[300, 250])

>>> # Cache files to google cloud storage
>>> gcp_cache = GCPCacheStore(
...     bucket="contrails-301217-unit-test",
...     cache_dir="ecmwf",
... )
>>> hres = HRES(
...     times,
...     variables="air_temperature",
...     pressure_levels=[300, 250],
...     cachestore=gcp_cache
... )

__init__(time, variables, pressure_levels=-1, paths=None, cachepath=None, grid=0.25, stream='oper', field_type='fc', forecast_time=None, cachestore=<object object>, url=None, key=None, email=None)¶

Methods

`__init__`(time, variables[, pressure_levels, ...])
`cache_dataset`(dataset)	Cache data from data source.
`create_cachepath`(t)	Return cachepath to local data file based on datetime.
`create_synoptic_time_ranges`(timesteps)	Create synoptic time bounds encompassing date range.
`download`(**xr_kwargs)	Confirm all data files are downloaded and available locally in the `cachestore`.
`download_dataset`(times)	Download data from data source for input times.
`generate_mars_request`([forecast_time, ...])	Generate MARS request in MARS request syntax.
`is_datafile_cached`(t, **xr_kwargs)	Check datafile defined by datetime for variables and pressure levels in class.
`list_from_mars`()	List metadata on query from MARS.
`list_timesteps_cached`(**xr_kwargs)	Get a list of data files available locally in the `cachestore`.
`list_timesteps_not_cached`(**xr_kwargs)	Get a list of data files not available locally in the `cachestore`.
`open_dataset`(disk_paths, **xr_kwargs)	Open multi-file dataset in xarray.
`open_metdataset`([dataset, xr_kwargs])	Open MetDataset from data source.
`set_metadata`(ds)	Set met source metadata on `ds.attrs`.

Attributes

`server`	Handle to ECMWFService client
`stream`	stream type, "oper" = atmospheric model/HRES, "enfo" = ensemble forecast.
`field_type`	Field type, forecast ("fc"), perturbed forecast ("pf"), control forecast ("cf"), analysis ("an").
`forecast_time`	Forecast run time, either specified or assigned by the closest previous forecast run
`url`
`key`
`email`
`grid`	Lat / Lon grid spacing
`hash`	Generate a unique hash for this datasource.
`is_single_level`	Return True if the datasource is single level data.
`paths`	Path to local source files to load.
`pressure_level_variables`	ECMWF pressure level parameters.
`pressure_levels`	List of pressure levels.
`single_level_variables`	ECMWF surface level parameters.
`step_offset`	Difference between `forecast_time` and first timestep.
`steps`	Forecast steps from `forecast_time` corresponding within input `time`.
`supported_pressure_levels`	Get pressure levels available from MARS.
`supported_variables`	Parameters available from data source.
`timesteps`	List of individual timesteps from data source derived from `time` Use `parse_time()` to handle `TimeInput`.
`variable_ecmwfids`	Return a list of variable ecmwf_ids.
`variable_shortnames`	Return a list of variable short names.
`variable_standardnames`	Return a list of variable standard names.
`variables`	Variables requested from data source Use `parse_variables()` to handle `VariableInput`.
`cachestore`	Cache store for intermediates while processing data source If None, cache is turned off.

create_cachepath(t)¶

Return cachepath to local data file based on datetime.

Parameters:: t (datetime) – Datetime of datafile
Returns:: str – Path to cached data file

classmethod create_synoptic_time_ranges(timesteps)¶

Create synoptic time bounds encompassing date range.

Extracts time bounds for synoptic time range ([00:00, 11:59], [12:00, 23:59]) for a list of input timesteps.

Parameters:: timesteps (list[pd.Timestamp]) – List of timesteps formatted as pd.Timestamps. Often this it the output from pd.date_range()
Returns:: list[tuple[pd.Timestamp, pd.Timestamp]] – List of tuple time bounds that can be used as inputs to HRES(time=...)

download_dataset(times)¶

Download data from data source for input times.

Parameters:: times (list[:class:`datetime]`) – List of datetimes to download and store in cache datastore

email¶

field_type¶: Field type, forecast (“fc”), perturbed forecast (“pf”), control forecast (“cf”), analysis (“an”).

forecast_time¶: Forecast run time, either specified or assigned by the closest previous forecast run

generate_mars_request(forecast_time=None, steps=None, request_type='retrieve', request_format='mars')¶

Generate MARS request in MARS request syntax.

Parameters:

forecast_time (datetime, optional) – Base datetime for the forecast. Defaults to forecast_time.
steps (list[int], optional) – list of steps. Defaults to steps.
request_type (str, optional) – “retrieve” for download request or “list” for metadata request. Defaults to “retrieve”.
request_format (str, optional) – “mars” for MARS string format, or “dict” for dict version. Defaults to “mars”.

Returns:

str | dict[str, Any] – Returns MARS query string if request_format is “mars”. Returns dict query if request_format is “dict”

Notes

Brief overview of MARS request syntax

property hash¶

Generate a unique hash for this datasource.

Returns:: str – Unique hash for met instance (sha1)

key¶

list_from_mars()¶

List metadata on query from MARS.

Returns:: str – Metadata for MARS request. Note this is queued the same as data requests.

open_metdataset(dataset=None, xr_kwargs=None, **kwargs)¶

Open MetDataset from data source.

This method should download / load any required datafiles and returns a MetDataset of the multi-file dataset opened by xarray.

Parameters:

dataset (xr.Dataset | None, optional) – Input xr.Dataset loaded manually. The dataset must have the same format as the original data source API or files.
xr_kwargs (dict[str, Any] | None, optional) – Dictionary of keyword arguments passed into xarray.open_mfdataset() when opening files. Examples include “chunks”, “engine”, “parallel”, etc. Ignored if dataset is input.
**kwargs (Any) – Keyword arguments passed through directly into MetDataset constructor.

Returns:

MetDataset – Meteorology dataset