North American Drought History from Tree-Ring Chronologies

The North American Drought Atlas provides 286 annual drought reconstructions based on the Palmer Drought Severity Index (PDSI). Reconstructions are derived from 835 tree-ring chronologies and extend up to 1,992 years into the past. It was developed by researchers at the Lamont-Doherty Earth Observatory of Columbia University with support from the National Science Foundation.

Use Cases

• Analyze long-term PDSI trends and drought frequency across 286 grid points in North America.
• Validate climate model simulations of hydroclimate using the 1,992-year reconstructed PDSI record.
• Correlate tree-ring chronology data from 835 sites with instrumental drought indices for calibration.
• Map spatial patterns of severe drought events over centuries using the 2.5-degree resolution gridded data.

Strengths

• Long temporal coverage spanning up to 1,992 years.
• Spatial reconstruction across 286 grid points covering most of North America.
• Derived from a large network of 835 exactly dated, annual tree-ring chronologies.

Limitations

• Spatial resolution is coarse at 2.5 degrees latitude by 2.5 degrees longitude.
• Reconstruction relies on proxy data (tree rings) with inherent uncertainties versus direct measurements.
• Geographic coverage is limited to North America.

Provenance

Source

Tree-Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University.

Collection Method

Drought reconstructions derived from 835 tree-ring chronologies to calculate the Palmer Drought Severity Index (PDSI).

Time Range

Reconstructions extend up to 1,992 years into the past.

Geography

286 grid points covering most of North America.