South African Precipitation and Southern Hemisphere Pressure Model Ensembles

Monthly model outputs from four large ensemble systems (SPEAR_MED, SPEAR_LO, FLOR, FLOR_FA) simulate precipitation over South Africa and sea level pressure across the Southern Hemisphere. Data spans from 1921-01-01 to 2100-12-31, generated by NOAA NCEI for research on future drought risks like Cape Town's 'Day Zero'. The dataset includes control simulations lasting thousands of years and forced experiments under different CMIP6 and RCP scenarios.

Use Cases

• Analyze precipitation (kg/m2/s) trends over South Africa under SSP2-4.5 and SSP5-8.5 scenarios to project future drought frequency.
• Compare sea level pressure patterns across the Southern Hemisphere between NATURAL-only and anthropogenic forcing ensembles to isolate human climate influence.
• Use the 3,000-year SPEAR_MED CTRL simulation to benchmark the magnitude of natural variability in precipitation against 20th-21st century forced changes.
• Validate model performance by correlating FLOR_FA RCP4.5 ensemble precipitation outputs with historical observational records for South Africa.
• Study teleconnections by examining relationships between Southern Hemisphere sea level pressure fields and regional precipitation anomalies in the model ensembles.

Strengths

• Includes long control simulations, such as a 5,000-year run from SPEAR_LO, for robust natural variability assessment.
• Provides multiple forcing scenarios (NATURAL, SSP2-4.5, SSP5-8.5, RCP4.5, RCP8.5) across four different model ensembles for comparative analysis.
• Covers a 180-year time range from 1921 to 2100, enabling study of past variability and future projections.

Limitations

• Data is model output, not observational, and contains inherent structural and parametric uncertainties from the source climate models.
• Spatial resolution differs between variables, with a dense grid for Southern Hemisphere pressure but a domain-centered grid for South African precipitation.
• The future projection period (up to 2100) relies on specific socioeconomic and radiative pathways which may not fully capture real-world trajectories.

Provenance

Source

NOAA National Centers for Environmental Information (NCEI), Accession 0220095.

Collection Method

Model output from SPEAR_MED, SPEAR_LO, FLOR, and FLOR_FA large ensemble numerical experiments.

Time Range

1921-01-01 to 2100-12-31

Freshness

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Geography

Precipitation centered over South Africa; sea level pressure covers the Southern Hemisphere.