The Ocean Biology Processing Group (OBPG) MODIS-Terra data is cross-calibrated with MODIS-Aqua. Since Aqua has experienced a significant decline in the scientific accuracy of its Ocean Color data products starting in 2023, OBPG has updated the calibration to address these issues (details available in Aqua R2022.0.1). As a result, the Terra/Aqua cross-calibration has been revised to reflect the changes made in Aqua's calibration, which have been applied to data collected since July 1, 2021.
The impact to large-scale regional means in the ocean color time-series is shown below. The plot shows the averages of the MODIS Terra Rrs in global deep water as a function of time both for R2022.0 (blue lines) and R2022.0.1 (red lines).
