Global Analysis - Reprocessing #3

Reprocessing #2 Reprocessing #3 Description
Chlorophyll a comparison - Winter (17 - 24 Jan 1998)
The high chlorophyll can be seen to be reduced in the coastal regions. Also, the low chlorophyll in the gyres is noticably lower. The extent of chlorophyll retrievals goes slightly further north in the reprocessing 3 image.
Chlorophyll a comparison - Summer (13 - 21 Jul 1998)
The reduction of high chlorophyll is even more evident here in the Baltic Sea and other coastal areas. A significant coverage increase can be seen in the Artic Ocean using reprocessing 3. This is due to the use of the wind-dependent Rayleigh radiances.
Summary Plots  
Winter Summer  
These 2 sets of plots show a comparison of the percentage of negative nLw vs solar zenith angle (left column) and mean nLw vs solar zenith angle (right column) for reprocessing 3 (solid lines) with the operational processing also plotted (dotted lines) for the Winter and Summer 8-day periods. The rows from top to bottom are for nLw_412, nLw_443, nLw_490, nLw_510 and nLw_555. The reduction in negative nLw is dramatic at higher solar zenith angles due mainly to the use of the wind-dependent Rayleigh radiances but also due to the use of the Siegel NIR algorithm to get a better aerosol model. For the 412 band, the percentage of negative nLw at around 70 degrees solar zenith reduces from 70% with current processing to 20% with reprocessing 3 in the summer period and smaller reductions in the winter period. The mean nLw, using the current processing, dropped noticably at higher solar zenith angles. This happened so much so that the average nLw_412 went negative and the average nLw_555 went below the cloud shadow threshold of 0.15. With reprocessing 3, these declines are lessened to a great degree.
This plot shows a summary of the scatter diagram comparing the reprocessing 3 chlorophyll (y axis) vs the current reprocessing (x axis) for Winter (top plot) and Summer (bottom plot). The high chlorophyll, above 2 mg / m^3 can be seen to decrease with reprocessing 3 greatly: about 40% in the 5 - 10 range of chlorophyll. This is mainly due to the use of the Siegel NIR algorithm.
This plot compares the chlorophyll distributions from reprocessing 3 (solid line) to the current processing (dotted line) for the Winter (top plot) and Summer (bottom plot) periods. The chlorophyll below about 0.06 mg / m^3 gets reduced. Also, the sharp cutoff at 0.01 in the current processing (peak at 0.01) is replaced by a smooth drop-off with reprocessing 3.