| Collection | Format | Approx. files | Approx. size | Last refresh |
|---|---|---|---|---|
| CO2 surface-flask network | NOAA CCGG text (.txt) | ~20 | ~9 MB | 2026-05 (one-shot) |
| Tree-ring measurements | Tucson (.rwl) | ~10 | ~3 MB | 2026-05 (one-shot) |
| MODIS NDVI metadata | tile index (HTML/JSON) | — | <1 MB | 2026-05 (manual) |
| Forest biomass density (reference table) | HTML reference table | — | <1 MB | 2026-05 (manual) |
Subdirectories beneath collection pages use directory auto-listings with upstream Last-Modified timestamps preserved (per methods page).