Ouranosinc/xclim v0.28.0

on GitHub

New features and enhancements

• Automatic load of translations on import and possibility to pass translations for virtual modules.
• New xclim.testing.list_datasets function listing all available test datasets in repo xclim-testdata.
• spatial_analogs accepts multi-indexes as the dist_dim parameter and will work with candidates and target arrays of different lengths.
• humidex can be computed using relative humidity instead of dewpoint temperature.
• New sdba.construct_moving_yearly_window and sdba.unpack_moving_yearly_window for moving window adjustments.
• New sdba.adjustment.NpdfTransform which is an adaptation of Alex Cannon's version of Pitié's N-dimensional probability density function transform. Uses new sdba.utils.rand_rot_matrix. Experimental, subject to changes.
• New sdba.processing.standardize, .unstandardize and .reordering. All of them, tools needed to replicate Cannon's MBCn algorithm.
• New sdba.processing.escore, backed by sdba.nbutils._escore to evaluate the performance of the N pdf transform.
• New function xclim.indices.clausius_clapeyron_scaled_precipitation can be used to scale precipitation according to changes in mean temperature.
• Percentile based indices gained a bootstrap argument that applies a bootstrapping algorithm to reduce biases on exceedance frequencies computed over in base and out of base periods. Experimental, subject to changes.
• Added a .zenodo.json file for collecting and maintaining author order and tracking ORCIDs.

Bug fixes

• Various bug fixes in sdba :

  • in QDM.adjust, fix bug occuring with coords of 'object' dtype and interp='nearest'.
  • in nbutils.quantiles, fix dtype bug when using float32 data.
  • raise a proper error when ref and hist have a different calendar for map_blocks-backed adjustments.

Breaking changes

• spatial_analogs does not support sequence of dist_dim anymore. Users are responsible for stacking dimensions prior to calling spatial_analogs.

New indicators

• biologically_effective_degree_days (with method="gladstones") indice computes degree-days between two specific dates, with a capped daily max value as well as latitude and temperature range swing as modifying coefficients (based on Gladstones, J. (1992)). This has also been wrapped as an indicator.

• An alternative implementation of biologically_effective_degree_days (with method="icclim", based on ICCLIM formula) ignores latitude and temperature range swing modifiers and uses an alternate end_date. Wrapped and available as an ICCLIM indicator.

• cool_night_index indice returns the mean minimum temperature in September (lat >= 0 deg N) or March (lat < 0 deg N), based on Tonietto & Carbonneau, 2004 (10.1016/j.agrformet.2003.06.001). Also available as an indicator (see indices Notes section on indicator usage recommendations).

• latitude_temperature_index indice computes LTI values based on mean temperature of warmest month and a parameterizable latitude coefficient (default: lat_factor=75) based on Jackson & Cherry, 1988, and Kenny & Shao, 1992 (10.1080/00221589.1992.11516243). This has also been wrapped as an indicator.

• huglin_index indice computes Huglin Heliothermal Index (HI) values based on growing degrees and a latitude-influenced coefficient for day-length (based on Huglin. (1978)). The indice supports several methods of estimating the latitude coefficient:

  • method="smoothed": Marks latitudes between -40 N and 40 N with k=1, and linearly increases to k=1.06 at |lat|==50.
  • method="icclim": Uses a stepwise function based on the the original method as presented by Huglin (1978). Identical to the ICCLIM implementation.
  • method="jones": Uses a more robust calculation for calculating day-lengths, based on Hall & Jones (2010). This method is now also available for biologically_effective_degree_days.

• The generic indice day_length, used for calculating approximate daily day-length in hours per day or, given start_date and end_date, the total aggregated day-hours over period. Uses axial tilt, start and end dates, calendar, and approximate date of northern hemisphere summer solstice, based on Hall & Jones (2010).

Internal Changes

• aggregate_between_dates (introduced in v0.27.0) now accepts DayOfYear-like strings for supplying start and end dates (e.g. start="02-01", end="10-31").
• The indicator call sequence now considers "variable" the inputs annoted so. Dropped the nvar attribute.
• Default cfcheck is now to check metadata according to the variable name, using CMIP6 names in xclim/data/variable.yml.
• Indicator.missing defaults to "skip" if freq is absent from the list of parameters.
• Minor modifications to the GitHub Pull Requests template.
• Simplification of some yaml elements for virtual modules.
• Allow injecting freq without the missing checks failing.