SeaWiFS Ocean Reprocessing 5.1
The K_490 and chlorophyll changes discussed here were put into forward-stream production in May 2005. Reprocessing of the mission archive was completed in July 2005.
Status of Current Operational ProductsThe current SeaWiFS operational products are based on reprocessing 5.
Evaluation of Reprocessing ConfigurationPrior to the ozone update, a complete mission reprocessing was performed on a temporal subset consisting of the first 4 days of each 32-day period to evaluate the K_490 and solar irradiance updates. A generic discussion of the analysis methods is available here. On average, the change from Neckel & Labs to Thuillier solar irradiances has the effect of raising OC3 chlorophyll by 3% in clear water and 5% in coastal waters, but larger changes are possible. No change in nLw was expected or observed. The effect of the solar irradiance change relative to SeaWiFS reprocessing 1.1 on global deep-water nLw and chlorophyll is shown below. The complete analysis is available here.
The ozone update has the effect of generally reducing the normalized water-leaving radiances at 555nm, which also impacts the chlorophyll. The effect of the ozone change to global mean chlorophyll is usually in the opposite direction to that of the solar irradiance change. As a result, the change in global mean chlorophyll (e.g., deep-water average) due to this reprocessing can be negligibly small for some periods, but changes on a regional spatial scale can still be significant. The cumulative effect relative to SeaWiFS reprocessing 1.1 on global deep-water nLw and chlorophyll is shown below.
For further details, see: