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Putting the puzzle together: Connecting the HyperSAS with BreveBuster absorbance spectra, fluorometer, extracted chlorophyll and MODIS data.

Blake Schaeffer, North Carolina State University, baschaef@ncsu.edu (Presenting)
Daniel Kamykowski, North Carolina State University, dan_kamykowski@ncsu.edu
John Morrison, University of North Carolina at Wilmington, morrisonj@uncw.edu
Stuart Banks, Charles Darwin Research Station, sbanks@fcdarwin.org.ec
Anita McCulloch, North Carolina State University, aamccull@unity.ncsu.edu
William Sweet, North Carolina State University, wvsweet@ncsu.edu

The absorbance characteristics of different phytoplankton classes vary due to specific photosynthetic accessory pigments. This phytoplankton class specificity has been used with HPLC and Chemtax for taxonomic purposes. Since hyperspectral sea surface reflectance is strongly affected by phytoplankton spectral absorbance, the extension of phytoplankton taxonomic discrimination to remote sensing applications appears feasible. Hyperspectral data was recorded with a Satlantic HyperSAS configured with 166-channel MiniSpec radiance and irradiance sensors during daylight travel. HyperSAS remote sensing reflectance was used to calculate chlorophyll a, which was compared to in situ fluorometric, extracted, and MODIS chlorophyll determinations. HyperSAS chlorophyll a calibrations against other methods gave a sigmodial response. Discrete phytoplankton absorption spectra were calculated from the HyperSAS data, Kishino filter method, and a BreveBuster using a liquid-waveguide capillary cell during day and night travel to measure absorbance spectra. The HyperSAS calculated absorption was in reasonable agreement with the other methods. The influence by several different water masses including the Equatorial Undercurrent, the Panama Current from the north, the Humboldt Current from the south, as well as the temporal variability seasonally contributed to changing phytoplankton absorption spectra over short distances based on temperature and salinity.

Presentation Type:  Poster

Abstract ID: 54

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