SST4 provides sea surface temperature retrieved from the mid-wave IR bands near 4 µm (∼3.7–4.1 µm). These channels are typically used at night (to avoid solar contamination) and can offer reduced sensitivity to atmospheric water vapor compared with long-wave (11/12 µm) split-window SST, making SST4 a valuable complement in humid or tropical conditions.
Geophysical variables in this suite include:
- qual_sst4 — Quality levels for 4 µm Sea Surface Temperature (integer quality flag) – “qual_sst4” is used to output quality for SST4.
- sst4 — 4 µm Sea Surface Temperature (°C) – skin SST product from short-wave IR bands.