MERIS Ocean Color Reprocessing 2022.0
Introduction
Reprocessing 2022.0 is a multi-mission reprocessing to incorporate updates in instrument calibration, vicarious calibration, new ancillary sources and algorithm improvements. The affected missions are CZCS, SeaWiFS, OCTS, MERIS, MODIS on Aqua and Terra, VIIRS on SNPP and NOAA-20, OLCI on Sentinel-3A and Sentinel-3B, GOCI, and HICO. Here we describe the changes and results specific to MERIS.
Instrument Calibration
The MERIS data are now based on ESA's 4th reprocessing .
Product Formats
As this is the first reprocessing of MERIS since R2012.0, the file formats and
product suites for MERIS will now be brought into alignment with those employed
in the R2014.0 multi-mission reprocessing.
This brings the MERIS L2 and L3 data formats consistent with the other supported
missions.
Results
Time Series Comparison
The comparison of the MERIS time series for global deep water (>1000m) generated for the R2022 configuration to the corresponding SeaWiFS time series is shown below (left panels). The ratio of MERIS to SeaWiFS is also shown for both R2022 and R2012 (right panels). Overall, the comparison to SeaWiFS is good and the differences in the ratios between R2012 and R2022 are small.

Comparison with In Situ Measurements
Validation of the apparent optical properties (Rrs, Kd490), inherent optical properties (a_giop, aph_giop, adg_giop, bbp_giop), chlorophyll, PAR, PIC, and POC retrievals was performed relative to all available match-ups from SeaBASS and the Aerosol Robotic Network - Ocean Color (AERONET-OC). Statistical analysis, scatter plots and frequency distribution comparisons of the satellite to in situ match-ups are provided below.
Apparent Optical Properties
Remote Sensing Reflectance (Rrs)
Product Name | # | Mean Bias | Mean Absolute Error (MAE) | MERIS Range | In situ Range |
---|---|---|---|---|---|
Rrs413 | 1222 | 0.00026 | 0.00128 | -0.00217, 0.01551 | -0.00000, 0.01555 |
Rrs443 | 1349 | 0.00001 | 0.00108 | -0.00059, 0.03309 | 0.00026, 0.01557 |
Rrs490 | 1165 | -0.00040 | 0.00107 | 0.00032, 0.03268 | 0.00078, 0.02442 |
Rrs510 | 328 | -0.00029 | 0.00072 | 0.00084, 0.02594 | 0.00119, 0.02538 |
Rrs560 | 235 | -0.00018 | 0.00067 | 0.00096, 0.02829 | 0.00095, 0.02862 |
Rrs665 | 1045 | -0.00010 | 0.00034 | -0.00025, 0.01179 | 0.00003, 0.01078 |
Rrs681 | 260 | -0.00013 | 0.00035 | -0.00045, 0.01084 | 0.00005, 0.01075 |














Diffuse Attenuation Coefficients (kd490)
Product Name | # | Mean Bias | Mean Absolute Error (MAE) | MERIS Range | In situ Range |
---|---|---|---|---|---|
kd490 | 229 | 1.03730* | 1.33034* | 0.02204, 0.82807 | 0.01190, 3.88735 |


Inherent Optical Properties
Total Absorption Coefficients (a_giop)
Product Name | # | Mean Bias | Mean Absolute Error (MAE) | MERIS Range | In situ Range |
---|---|---|---|---|---|
a_giop413 | 25 | 0.72762* | 1.73617* | 0.01599, 0.62617 | 0.02474, 0.95427 |
a_giop443 | 25 | 0.76703* | 1.48313* | 0.01644, 0.39944 | 0.02039, 0.68512 |
a_giop490 | 25 | 0.74939* | 1.38455* | 0.02033, 0.25764 | 0.02148, 0.38107 |
a_giop510 | 25 | 0.79854* | 1.29349* | 0.03550, 0.21361 | 0.03721, 0.30252 |
a_giop560 | 25 | 0.88565* | 1.15405* | 0.06290, 0.14715 | 0.06415, 0.19487 |
a_giop665 | 25 | 0.99364* | 1.04291* | 0.34893, 0.58468 | 0.43053, 0.51604 |












Phytoplankton Absorption Coefficients (aph_giop)
Product Name | # | Mean Bias | Mean Absolute Error (MAE) | MERIS Range | In situ Range |
---|---|---|---|---|---|
aph_giop413 | 30 | 1.11421* | 1.64520* | 0.00264, 0.26804 | 0.00141, 0.17281 |
aph_giop443 | 30 | 1.14503* | 1.64879* | 0.00394, 0.30013 | 0.00193, 0.18974 |
aph_giop490 | 30 | 1.19887* | 1.63031* | 0.00277, 0.20280 | 0.00102, 0.11532 |
aph_giop510 | 30 | 1.18637* | 1.65676* | 0.00128, 0.15343 | 0.00055, 0.08476 |
aph_giop560 | 30 | 1.62950* | 2.23103* | 0.00020, 0.07756 | 0.00002, 0.04263 |
aph_giop665 | 30 | 1.35185* | 1.75562* | 0.00080, 0.15785 | 0.00038, 0.07247 |












Absorption Coefficient of Non-algal Material plus CDOM (adg_giop)
Product Name | # | Mean Bias | Mean Absolute Error (MAE) | MERIS Range | In situ Range |
---|---|---|---|---|---|
adg_giop413 | 24 | 0.50934* | 2.77703* | 0.00160, 0.79563 | 0.01868, 0.77681 |
adg_giop443 | 24 | 0.46445* | 3.01686* | 0.00093, 0.46364 | 0.01140, 0.48832 |
adg_giop490 | 24 | 0.37496* | 3.60127* | 0.00040, 0.19897 | 0.00507, 0.25096 |
adg_giop510 | 24 | 0.34850* | 3.82019* | 0.00029, 0.13881 | 0.00334, 0.18523 |
adg_giop560 | 24 | 0.27528* | 4.58815* | 0.00007, 0.05644 | 0.00138, 0.09013 |
adg_giop665 | 24 | 0.19952* | 5.51382* | 0.00010, 0.00853 | 0.00033, 0.02001 |












backscattering coefficient of particles (bbp_giop)
Product Name | # | Mean Bias | Mean Absolute Error (MAE) | MERIS Range | In situ Range |
---|---|---|---|---|---|
bbp_giop413 | 43 | 0.93414* | 1.36488* | 0.00038, 0.01075 | 0.00067, 0.01028 |
bbp_giop443 | 43 | 0.92384* | 1.35468* | 0.00036, 0.01025 | 0.00058, 0.00990 |
bbp_giop490 | 43 | 0.89977* | 1.34889* | 0.00034, 0.00956 | 0.00047, 0.00942 |
bbp_giop510 | 43 | 0.89324* | 1.34904* | 0.00032, 0.00930 | 0.00044, 0.00922 |
bbp_giop560 | 43 | 0.87145* | 1.35363* | 0.00027, 0.00868 | 0.00036, 0.00880 |
bbp_giop665 | 43 | 0.83531* | 1.40285* | 0.00020, 0.00771 | 0.00026, 0.00807 |
bbp_giop681 | 2 | 0.71190* | 1.40469* | 0.00133, 0.00137 | 0.00186, 0.00194 |












Chlorophyll a (chlor_a)
Product Name | MERIS Range | In situ Range | # | Mean Bias | Mean Absolute Error (MAE) |
---|---|---|---|---|---|
chlor_a | 717 | 1.48986* | 1.89465* | 0.01300, 858.28147 | 0.01700, 46.64000 |


Photosynthetically Available Radiation (par)
Product Name | # | Mean Bias | Mean Absolute Error (MAE) | MERIS Range | In situ Range |
---|---|---|---|---|---|
par | 139 | 4.55108 | 4.55382 | 21.53575, 63.84155 | 11.52175, 60.62418 |


Particulate Inorganic Carbon (pic)
Product Name | # | Mean Bias | Mean Absolute Error (MAE) | MERIS Range | In situ Range |
---|---|---|---|---|---|
pic | 29 | 0.17620* | 7.36911* | 0.00001, 0.00034 | 0.00003, 0.00104 |


Particulate Organic Carbon (poc)
Product Name | # | Mean Bias | Mean Absolute Error (MAE) | MERIS Range | In situ Range |
---|---|---|---|---|---|
poc | 78 | 0.94232* | 1.47399* | 19.59990, 564.76513 | 11.31300, 796.91229 |

