NOAA GOES-R Series Advanced Baseline Imager (ABI) Level 2 Cloud Optical Depth (COD)

The GOES-R Advanced Baseline Imager (ABI) Cloud Optical Depth product contains an image with pixel values identifying the measure of the extinction due to condensed water or ice clouds at a wavelength of 0.64 um. Separate algorithms are used for daytime, solar zenith angle to 82 degrees, and nighttime, solar zenith angle greater than 82 degrees, conditions. The product is generated in combination with the Cloud Particle Size product by the same algorithms. The product includes data quality information that identifies whether the daytime or nighttime algorithm generated the pixel, and provides an assessment of the cloud optical depth data values for on-earth pixels. The cloud optical depth value is a dimensionless quantity. The Cloud Optical Depth product image is produced on the ABI fixed grid at 4 km resolution for Full Disk and 2 km resolution for CONUS coverage regions. The product's spatial resolution increased from 4 km to 2 km on 22 March 2023. Product data is produced under the following conditions for the daytime algorithm: Cloudy; Geolocated source data to local zenith angles of 65 degrees and to solar zenith angles of 82 degrees. Product data generated by the nighttime algorithm is produced under the following conditions: Cloudy; Geolocated source data to local zenith angles of 70 degrees and solar zenith angles between 82 and 180 degrees. The cloud optical depth values reported range from 0 to 160. The sensitivity of the product to high optical depths is limited for nighttime conditions to the nighttime maximum threshold, which is an optical depth value of 16. Cloud Optical Depth product data is identified as degraded in the terminator region, which is a solar zenith angle between 65 and 82 degrees for the daytime algorithm, and 82 and 90 degrees for the nighttime algorithm.