ENSOFORECAST: Zebiak and Cane model forecasts of equatorial Pacific sea-surface temperature anomalies, target months 1972 to 2001 (preservation copy of the IRI Data Library directory)

A byte-identical preservation copy of ENSOFORECAST, a directory of monthly tropical-Pacific sea-surface temperature anomaly fields made at the Lamont-Doherty Earth Observatory of Columbia University with the coupled ocean-atmosphere model described by Zebiak and Cane in 1987, and held for years in the IRI Data Library of Columbia's International Research Institute for Climate and Society. The directory holds 49 files, 118.2 MB in all: forecast fields at leads of 3, 6, 9 and 12 months for two model versions (LDEO1 and LDEO2), fifteen further LDEO2 lead files at 0 to 18 months, an observed-anomaly file, five ERBE radiation files and twenty model input files. Target months run from January 1972 to February 2001. The files record no issue dates, and the early years are hindcasts made after the fact; the record documents this limit and makes no claim about when any forecast was issued.

How it came here: as the IRI Data Library wound down in October 2026, Aaron Kaplan of IRI assembled the directory and sent one tar archive with its MD5 on 21 October 2026. The archive was downloaded on 22 October 2026, the MD5 matched, and the 49 files were extracted and hashed. This record holds that archive as received (ENSOFORECAST.tgz, MD5 1e8b1b29f8e77697fbdbc90d3ca168ac, SHA-256 ee0e93452bafaa08e64ade880c5b548d389d0653099be6e8b19de79e112037c7) together with the integrity and documentation files prepared by Vultax Research: README.md, MANIFEST.json (per-file hashes, netCDF metadata and decoded time axes), SHA256SUMS, MD5SUMS, NETCDF-HEADERS.txt, datapackage.json, CITATION.cff, citation.bib, CHANGELOG.md and iri-documentation.zip (the IRI catalogue entry, description page, alternate-sources sheet row and transfer records).

Rights: IRI's alternate-sources sheet lists ENSOFORECAST as unrestricted, and IRI transferred the directory for public hosting. No written licence accompanies the files. Please cite the archive and the model, and name IRI and the Lamont-Doherty Earth Observatory as the source. If IRI states reuse terms, a new version of this record will carry them. The record page at https://vultax.com/archive/ensoforecast lists every file with its checksum, and the reading edition is at https://vultax.com/research/ensoforecast-historical-archive.