Drought Metrics following Martin (2018)

Compares SPI/SPEI data from models with observations/reanalysis.

Description

This diagnostic applies drought characteristics based on Martin (2018) to data produced by spei.R. These characteristics and differences to a reference dataset or between different time periods are plotted for each dataset and multi-model mean. The calculated frequency, duration and severity of drought events are saved to netcdf files for further use. It expects multiple datasets for a particular index as input. The reference dataset can be specified with reference_dataset and is not part of the multi-model mean.

Note

Previous Version: With ESMValTool v2.12 and previous, multiple collect_drought_*.py diagnostics and a collect_drought_func.py diagnostic existed in the droughtindex folders. Those have been archived and replaced by this diagnostic in v2.13.

Configuration options

indexname: str

The indexname is used to generate filenames, plot titles and captions. Should be SPI or SPEI.

reference_dataset: str

Dataset name to use for comparison (excluded from MMM). With compare_intervals=True this option has no effect.

threshold: float, optional (default: -2.0)

Threshold for an event to be considered as drought.

compare_intervals: bool, false

If true, start and end of the time periods are compared instead of models and reference. The lengths of start and end period is given by comparison_period.

comparison_period: int

Number of years from start and end of the full period to be compared. Should be < (end_year - start_year)/2. If compare_intervals=False this option has no effect.

plot_models: bool, false

Save plots for each individual model, in addition to multi-model mean.

start_year: int

This option is used to select the time slices for comparison if compare_intervals=True.

end_year: int

This option is used to select the time slices for comparison if compare_intervals=True.