|Title||Evaluation of satellite retrievals of ocean chlorophyll-a in the California Current|
|Publication Type||Journal Article|
|Year of Publication||2014|
|Authors||Kahru M, Kudela R.M, Anderson C.R, Manzano-Sarabia M., Mitchell B.G|
|Type of Article||Article|
|Keywords||algorithms; california current; chlorophyll; coastal; estuary; ocean color; phytoplankton; Remote; seawifs; sensing; surface chlorophyll; trends; validation|
Retrievals of ocean surface chlorophyll-a concentration (Chla) by multiple ocean color satellite sensors (SeaWiFS, MODIS-Terra, MODIS-Aqua, MERIS, VIIRS) using standard algorithms were evaluated in the California Current using a large archive of in situ measurements. Over the full range of in situ Chla, all sensors produced a coefficient of determination (R-2) between 0.79 and 0.88 and a median absolute percent error (MdAPE) between 21% and 27%. However, at in situ Chla > 1 mg m(-3), only products from MERIS (both the ESA produced algal_1 and NASA produced chlor_a) maintained reasonable accuracy (R-2 from 0.74 to 0.52 and MdAPE from 23% to 31%, respectively), while the other sensors had R-2 below 0.5 and MdAPE higher than 36%. We show that the low accuracy at medium and high Chla is caused by the poor retrieval of remote sensing reflectance.