pynldas2.pynldas2#

Get hourly NLDAS2 forcing data.

Module Contents#

pynldas2.pynldas2.get_bycoords(coords, start_date, end_date, coords_id=None, crs=4326, variables=None, to_xarray=False, snow=False, snow_params=None)#

Get NLDAS-2 climate forcing data for a list of coordinates.

Parameters:

  • coords (list of tuples) – List of (lon, lat) coordinates.

  • start_date (str) – Start date of the data.

  • end_date (str) – End date of the data.

  • crs (str, int, or pyproj.CRS, optional) – The CRS of the input coordinates, defaults to EPSG:4326.

  • variables (str or list of str, optional) – Variables to download. If None, all variables are downloaded. Valid variables are: prcp, pet, temp, wind_u, wind_v, rlds, rsds, and humidity and psurf.

  • to_xarray (bool, optional) – If True, the data is returned as an xarray dataset.

  • snow (bool, optional) – Compute snowfall from precipitation and temperature. Defaults to False.

  • snow_params (dict, optional) – Model-specific parameters as a dictionary that is passed to the snowfall function. These parameters are only used if snow is True. Two parameters are required: t_rain (deg C) which is the threshold for temperature for considering rain and t_snow (deg C) which is the threshold for temperature for considering snow. The default values are {'t_rain': 2.5, 't_snow': 0.6} that are adopted from https://doi.org/10.5194/gmd-11-1077-2018.

Returns:

pandas.DataFrame – The requested data as a dataframe.

Return type:

pandas.DataFrame | xarray.Dataset

pynldas2.pynldas2.get_bygeom(geometry, start_date, end_date, geo_crs=4326, variables=None, snow=False, snow_params=None)#

Get hourly NLDAS-2 climate forcing within a geometry at 0.125 resolution.

Parameters:

  • geometry (Polygon or tuple) – The geometry of the region of interest. It can be a shapely Polygon or a tuple of length 4 representing the bounding box (minx, miny, maxx, maxy).

  • start_date (str) – Start date of the data.

  • end_date (str) – End date of the data.

  • geo_crs (int, str, or pyproj.CRS) – CRS of the input geometry

  • variables (str or list of str, optional) – Variables to download. If None, all variables are downloaded. Valid variables are: prcp, pet, temp, wind_u, wind_v, rlds, rsds, and humidity and psurf.

  • snow (bool, optional) – Compute snowfall from precipitation and temperature. Defaults to False.

  • snow_params (dict, optional) – Model-specific parameters as a dictionary that is passed to the snowfall function. These parameters are only used if snow is True. Two parameters are required: t_rain (deg C) which is the threshold for temperature for considering rain and t_snow (deg C) which is the threshold for temperature for considering snow. The default values are {'t_rain': 2.5, 't_snow': 0.6} that are adopted from https://doi.org/10.5194/gmd-11-1077-2018.

Returns:

xarray.Dataset – The requested forcing data.

Return type:

xarray.Dataset