Standardized Precipitation Index Analyses from Four Global Datasets

SPI analyses were performed on four global precipitation datasets: NASA GPCP V2, NOAA NCEP CPC CAMS_OPI, NOAA NCEP CPC Merged_Analysis (CMAP), and UEA CRU New CRU05. The UEA CRU New dataset is the only one meeting the recommended minimum of 50 years of precipitation data for reliable SPI calculation. The analyses use a Pearson Type III distribution and Fortran 77 source code from Guttman (1999).

Use Cases

• Drought monitoring based on standardized precipitation deviations across climatic regions.
• Water resource assessment based on monthly precipitation accumulations.
• Comparative analysis of precipitation anomalies based on SPI values from multiple global datasets.
• Validation of precipitation data quality based on the recommended 50-year minimum data length.

Strengths

• SPI values can be compared across different climatic and geographic regions.
• Analyses are based on a Pearson Type III distribution as suggested by Guttman (1999).
• The UEA CRU New dataset meets the recommended minimum of 50 years of precipitation data.

Limitations

• Extreme SPI values in three datasets (CAMS OPI, CMAP, GPCP) may be suspect as they are based on roughly half the recommended 50 years of data.
• Column-level documentation is absent; field semantics must be inferred after download.
• Row count and file formats are unknown, which may limit suitability assessment.

Provenance

Source

LDEO/IRI Climate Data Library

Collection Method

SPI analyses performed on climatological datasets using Fortran 77 source code.

Geography

Global