####### Title

Performance metrics for CMORPH V1.0, IMERG V07A and MSWEP V2.8 over the Iberian Mediterranean Basin

####### Description

Correlation Coefficient (CC), relative Total bias (rBias), Probability of Detection (POD) and False Alarm Ratio (FAR) for CMORPH V1.0, IMERG V07A and MSWEP V2.8 satellite precipitation products (SPPs) over the Iberian Mediterranean Basin along the 2001-2020 period using AEMET ground gauges as reference.

Performed within the framework of the Spanish national research project Tool4Extreme PID2020-118797RB-I00, supported by MCIN/AEI/10.13039/501100011033, and within the project PROMETEO/2021/016, supported by Generalitat Valenciana.

####### Methodology

Following the methodology described in [1]:

AEMET ground gauges daily precipitation dataset (which is an extension of that explained in [2]) was transformed into two grids: one at ~25 km (CMORPH resolution) and other one at ~10 km (IMERG and MSWEP resolution), in both cases by averaging gauge data that fell in each pixel. Then the aforementioned metrics were computed for the three SPPs (using the corresponding grids) along the 2001-2020 period, without further data agroupation.

CC, POD and FAR were computed following the usual definitions, while rBias was computed as accumulated Total bias (as defined in [3]) divided by accumulated AEMET precipitation, for easier comparison across regions with very different annual accumulated precipitation.

####### Technical information

The data is provided in three netCDF files (one per SPP), each one containing latitude ('lat'), longitude ('lon') and four bands whose names indicate the corresponding metric. All metrics are already provided in percentage value (%) instead of absolute value.

Pixels with NaN correspond to pixels that did not contain any ground gauge, as every original dataset (gauge dataset and the three SPPs) had no missing values along the study period.

####### References

[1] García-Ten, A., Niclòs, R., Valor, E., Caselles, V., Estrela, M. J., Miró, J. J., Luna, Y., & Belda, F. (2025). Evaluation of CMORPH V1.0, IMERG V07A and MSWEP V2.8 Satellite Precipitation Products over Peninsular Spain and the Balearic Islands. Remote Sensing, 17(21), 3562. https://doi.org/10.3390/rs17213562 

[2] Miró JJ, Estrela MJ, Caselles V, Gómez I. Spatial and temporal rainfall changes in the Júcar and Segura basins (1955–2016): Fine-scale trends. Int J Climatol. 2018; 38: 4699–4722. https://doi.org/10.1002/joc.5689

[3] Tian, Y., C. D. Peters-Lidard, J. B. Eylander, R. J. Joyce, G. J. Huffman, R. F. Adler, K. Hsu, F. J. Turk, M. Garcia, and J. Zeng (2009), Component analysis of errors in satellite-based precipitation estimates, J. Geophys. Res., 114, D24101, doi:10.1029/2009JD011949.

####### Funding

This research was conducted within the framework of the Spanish national research project Tool4Extreme PID2020-118797RB-I00, supported by MCIN/AEI/10.13039/501100011033, and within the project PROMETEO/2021/016, supported by Generalitat Valenciana. Alejandro García-Ten was hired within the program of research support staff funded by Generalitat Valenciana and the European Social fund (INVEST/2022/52), and later through a FPU grant funded by Ministerio de Universidades (FPU/22/02807).

####### Contact

For any queries, please contact alejandro.garcia-ten@uv.es

For any question related to the project PID2020-118797RB-I00 (Tool4Extreme) or datasets contact the Principal Researcher of the project (PID2020-118797RB-I00 (Tool4Extreme) funded by the Spanish Ministry of Science and Innovation and the Spanish State Research Agency (MCIN/AEI/10.13039/501100011033)): raquel.niclos@uv.es
