Datasets Module¶
CMIP6 Downloader¶
Downloader for CMIP6 daily GCM data.
products_to_download
property
¶
List of all (gcm, ssp, var, year) combinations.
__init__(**kwargs)
¶
Initialize the downloader.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
url_root
|
str
|
Base URL containing CMIP6 data directories. |
required |
download_data(url, fn, output_path)
staticmethod
¶
Download remote file if not already present.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
url
|
str
|
URL of the parent directory. |
required |
fn
|
str
|
Filename. |
required |
output_path
|
Path
|
Directory where file will be saved. |
required |
Returns:
| Type | Description |
|---|---|
Path or None
|
Path to downloaded file or None if failed. |
find_remote_file(gcm, ssp, var, year)
¶
Attempt to locate a remote CMIP6 file matching known naming patterns.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
gcm
|
str
|
|
required |
ssp
|
str
|
|
required |
var
|
str
|
|
required |
year
|
int
|
|
required |
Returns:
| Type | Description |
|---|---|
tuple
|
(url_dir, filename) if found, else (None, None) |
Processing Tools¶
Utility functions for processing climate xarray datasets.
clip_spdata(extent, xrdata=None, xrdata_path=None, rotate=False, chunks='auto')
staticmethod
¶
Clip xarray dataset to a given spatial bounding box.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
extent
|
tuple of float
|
(min_lon, min_lat, max_lon, max_lat). |
required |
xrdata
|
Dataset
|
Dataset already loaded in memory. |
None
|
xrdata_path
|
str
|
Path to dataset on disk. |
None
|
rotate
|
bool
|
If True, shift longitudes from 0–360 → -180–180. |
False
|
chunks
|
str or dict
|
Dask chunking options. |
'auto'
|
Returns:
| Type | Description |
|---|---|
Dataset
|
Spatially clipped dataset. |
preprocess_xrdata(xrdata, variable=None)
staticmethod
¶
Apply variable-specific preprocessing to CMIP6 data.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
xrdata
|
Dataset
|
Dataset containing climate variables. |
required |
variable
|
str
|
Variable name. If None, the first variable is used. |
None
|
Returns:
| Type | Description |
|---|---|
Dataset
|
Preprocessed dataset. |
Notes
- pr: converted to daily precipitation (kg m-2 s-1 → mm/day)
- tasmax, tasmin: convert from Kelvin → Celsius
- rsds: convert radiation (W/m2 → MJ/m2/day)
save_asnc(xrdata, fn)
staticmethod
¶
Save a dataset to a NetCDF file with appropriate encoding.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
xrdata
|
Dataset
|
The dataset to save. |
required |
fn
|
str
|
Output file name. |
required |