The Ocean Biology DAAC produces near real-time (NRT) products using the best-available combination of ancillary data from meteorological and ozone data. As such, the inputs and the calibration used are less than optimal. Near real-time products provide a snapshot of the data during a short time period within a single orbit.
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:
- bias_sst4 — 4 µm Sea Surface Temperature bias (°C)
- flags_sst4 — Product-specific flags, 4 µm Sea Surface Temperature (integer bitmask)
- l2_flags — Level-2 Processing Flags (integer bitmask; see bit definitions)
- qual_sst4 — Quality levels for 4 µm Sea Surface Temperature (integer quality flag)
- sst4 — 4 µm Sea Surface Temperature (°C)
- sstref — Sea Surface Temperature reference (°C)
- stdv_sst4 — 4 µm Sea Surface Temperature standard deviation (°C)