Idle Lab
Idle Lab / Experiments

Ocean Temperature Investigator

How has sea-surface temperature off Australia's east coast (25°S–40°S, 148°E–158°E) changed since 1982, relative to the 1991–2020 climatological baseline, and do independent SST products agree?

in progress First full run pending; source data is being assembled and checked.

Published findings

FINDING 001

Sea-surface warming off eastern Australia since 1982

Awaiting independent review

Method

  1. Download daily NOAA OISST v2.1 (0.25°, final) for the region via CoastWatch ERDDAP in quarterly chunks. Days missing from that aggregation (about half of late 1992–1998, plus scattered days) are fetched as original daily files from NCEI's archive. Every file's URL, SHA-256 and retrieval time is recorded.
  2. Keep only grid cells that are valid on every day (a fixed ocean mask); area-weight cells by cos(latitude).
  3. Average to a daily regional mean, then to calendar-month means; only months with complete daily coverage are used.
  4. Compute a 12-month climatology over 1991-01 to 2020-12 and subtract it to obtain monthly anomalies.
  5. Estimate linear trends by ordinary least squares on monthly anomalies, with standard errors inflated for lag-1 autocorrelation (effective sample size, Santer et al. 2000).
  6. Repeat for three latitude bands (25–30°S, 30–35°S, 35–40°S).
  7. Repeat the regional analysis independently with NOAA ERSST v6 (2°, in situ only; the current ERSST release) as a cross-check.
  8. Candidate findings are produced from the measurements; a finding is marked as passing validation only if every sanity check passes and ERSST v6 independently agrees. Human review remains pending in every case.

Region: East Australian coast & western Tasman Sea, 25–40°S, 148–158°E. Baseline: 1991-01 to 2020-12.

Data sources

NOAA OISST v2.1 (AVHRR-only, final), daily 0.25° — primary
NOAA NCEI; regional subsets via NOAA CoastWatch ERDDAP, gaps filled from the NCEI daily archive. Huang, B. et al. (2021) Improvements of the Daily Optimum Interpolation Sea Surface Temperature (DOISST) Version 2.1. J. Climate 34, 2923–2939. doi:10.1175/JCLI-D-20-0166.1 (Public domain (US Government work))
NOAA ERSST v6, monthly 2° (in situ only) — independent cross-check
NOAA NCEI. Huang, B. et al. (2025) Extended Reconstructed Sea Surface Temperature Version 6 (ERSSTv6): Part I. J. Climate 38, 1105–1121. doi:10.1175/JCLI-D-23-0707.1; Part II. J. Climate 38, 1123–1136. doi:10.1175/JCLI-D-24-0185.1 (Public domain (US Government work))

Who we'd tell

Nothing is submitted externally without human approval. Findings that turn out to be wrong are recorded, not removed.

IMOS / Australian Ocean Data Network (AODN) — Unusual temperature patterns, reproducible analyses or suspected data errors; AODN can route dataset feedback to researchers. (status: not contacted)