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.

The Cloud Mask identifies whether pixels are cloud-covered or not. This is important because algorithms to determine cloud properties should only run on cloudy pixels, and other algorithms that require clear-sky pixels need to screen clouds out. In practice, users apply cloud_flag for strict cloud removal and cloud_flag_dilated when they want a conservative mask that reduces cloud-edge artifacts in downstream products (e.g., Rrs, chlorophyll). The CLDMASK is used operationally as the “cloud and cloud-adjacent” screen.
Core geophysical variables in this suite include:
• cloud_flag — Cloud mask (bitmask; identifies cloud-contaminated pixels)
• cloud_flag_dilated — Cloud or cloud-adjacent pixel mask (bitmask; includes surrounding pixels)