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ERA5–Drought: Meteorological drought indices from ERA5 reanalyses

This dataset contains a global reconstruction of drought indices from 1940 to today .The dataset and comprises two standardised drought indices:

• the Standardised Precipitation Index (SPI)
• the Standardised Precipitation-Evapotranspiration Index (SPEI).

The SPI measures the precipitation deficit that accumulated over the preceding months and evaluates the deficit with respect to a reference period. The SPEI is an extension of the SPI and incorporates potential evapotranspiration to capture the impact of temperature on drought. SPI and SPEI values are in units of standard deviation from the standardised mean, i.e., negative values indicate drier-than-usual periods while positive values correspond to wetter-than-usual periods. Both indices can be used to identify the onset and the end of drought events as well as their severity.

SPI and SPEI are calculated using precipitation and potential evapotranspiration from ECMWF’s Reanalysis system 5 (ERA5). ERA5 combines model data with observations from across the world, facilitating a global reconstruction of drought indices since 1940. Drought indices are calculated for a range of accumulation windows (1/3/6/12/24/36/48 months) using the reference period from 1991–2020. All data is regridded to a regular grid of 0.25 degrees, making it suitable for many common applications. SPI and SPEI are calculated using both the ERA5 reanalysis (single realisation from the moda stream) and the ensemble of the reanalysis (10 realisations from the edmo stream), enabling uncertainty assessment of drought occurrence and intensity. The quality of the derived indices is evaluated using significance testing.

The dataset currently covers 1940 to near-real time and is updated monthly. The consolidated data set is updated 2-3 months behind real time, while the intermediate data set is updated with 1 month of delay. New versions of the dataset are published as settings, such as the reference period, are updated or bug fixes are applied.

A more detailed description of the the dataset and comparisons to other drought indices can be found in this scientific article (link will be added upon publication). Information on data access and usage examples, e.g. how to calculate the area in drought, are provided in this User Guide.

The dataset is produced by ECMWF in the framework of the CENTAUR project.

Fuel Characteristics dataset.

This dataset can be used to link vegetation changes tofire danger. It also helps in understanding the drivers of fire activity, shifts in vegetation characteristics, and supports risk assessment.

The dataset provides daily estimates of fuel load and fuel moisture content, distinguishing between live and dead vegetation. It combines observations from multiple remote sensing platforms with state-of-the-art land surface models. The dataset will be expanded to incorporate additional observations from upcoming missions and will be periodically updated to cover more recent periods.

The dataset is produced by ECMWF in the framework of the CEMS- Computational center contract  with JRC and in collaboration with ESA through the Fuelity project