Seasonal and Inter-Annual Patterns of Chlorophyll and Phytoplankton Community Structure in Monterey Bay, CA Derived from AVIRIS Data During the 2013-2015 HyspIRI Airborne Campaign

Sherry L. Palacios1,2, David R Thompson3, Raphael Martin Kudela4, Kendra Negrey4, Liane S Guild1, Bo-Cai Gao5, Robert O Green6 and Juan Luis Torres-Perez7, (1)NASA Ames Research Center, Moffett Field, CA, United States, (2)Bay Area Environmental Research Institute at NASA/ARC, Moffett Field, CA, United States, (3)NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States, (4)University of California Santa Cruz, Ocean Sciences, Santa Cruz, CA, United States, (5)Naval Research Lab DC, Remote Sensing, Washington, DC, United States, (6)NASA Jet Propulsion Laboratory, Pasadena, CA, United States, (7)NASA Ames Research Center, Earth Science Division, Moffett Field, CA, United States
There is a need in the ocean color community to discriminate among phytoplankton groups within the bulk chlorophyll pool to understand ocean biodiversity, track energy flow through ecosystems, and identify and monitor for harmful algal blooms. Imaging spectrometer measurements enable the use of sophisticated spectroscopic algorithms for applications such as differentiating among coral species and discriminating phytoplankton taxa. These advanced algorithms rely on the fine scale, subtle spectral shape of the atmospherically corrected remote sensing reflectance (Rrs) spectrum of the ocean surface. Consequently, these algorithms are sensitive to inaccuracies in the retrieved Rrs spectrum that may be related to the presence of nearby clouds, inadequate sensor calibration, low sensor signal-to-noise ratio, glint correction, and atmospheric correction. For the HyspIRI Airborne Campaign, flight planning considered optimal weather conditions to avoid flights with significant cloud/fog cover. Although best suited for terrestrial targets, the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) has enough signal for some coastal chlorophyll algorithms and meets sufficient calibration requirements for most channels. The coastal marine environment has special atmospheric correction needs due to error introduced by aerosols and terrestrially sourced atmospheric dust and riverine sediment plumes. For this HyspIRI campaign, careful attention has been given to the correction of AVIRIS imagery of the Monterey Bay to optimize ocean Rrs retrievals to estimate chlorophyll (OC3) and phytoplankton functional type (PHYDOTax) data products. This new correction method has been applied to several image collection dates during two oceanographic seasons in 2013 and 2014. These two periods are dominated by either diatom blooms or red tides. Results to be presented include chlorophyll and phytoplankton community structure and in-water validation data for these dates during the two seasons.