Absorption properties of shoal-dominated waters in the Atchafalaya Shelf, Louisiana, USA
Spectral absorption coefficients of coloured dissolved organic matter (a
CDOM(λ)) and particulate matter (a
p(λ)) (phytoplankton (a
PHY(λ)) plus non-algal particles (a
NAP(λ)), measured
on the shoal-dominated region off the Atchafalaya River (AR) Shelf, Louisiana, USA, are analysed, and their effect on chlorophyll-a retrievals from ocean-colour sensors examined. Compared to a
CDOM(λ) and a
NAP(λ), a
PHY(λ)
is relatively constant, with a
CDOM(λ) and a
NAP(λ) varying by approximately 1.2 and 1.8 times as much as a
PHY(λ) at 443 nm, respectively. The specific a
PHY(λ) (a*PHY(λ))
ranges from 0.006 to 0.0612 m−2(mg chla)−1 at 443 nm, which indicates a pigment-packaging effect or a variation in pigment composition. The a
NAP(λ) accounts for approximately 3–93% of a
p(λ) at 443 nm,
with a higher contribution to a
p(λ) during an October 2007 cruise (62–93%) as compared to an August 2007 cruise (31–89%). Our results indicate that a
CDOM(λ) and a
NAP(λ) collectively dominate light absorption,
even at higher wavelengths where their effect is expected to be minimal. In situ and satellite data match-up of chlorophyll-a yield root-mean square errors of 2.17 and 2.62 for the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and the Medium Resolution Imaging Spectrometer (MERIS),
respectively. The non-covarying a
CDOM(λ) and a
NAP(λ), along with variable a*PHY(λ), greatly influenced the remote retrieval of biogeochemical variables using satellite ocean-colour algorithms in this region.
Document Type: Research Article
Affiliations: 1: Department of Oceanography and Coastal Sciences,Coastal Studies Institute, Louisiana State University, Baton RougeLA-70803, USA 2: Department of Biological Sciences,Louisiana State University, Baton RougeLA-70803, USA 3: Department of Oceanography and Coastal Sciences,Coastal Fisheries Institute, Louisiana State University, Baton RougeLA-70803, USA
Publication date: 10 August 2011
- Editorial Board
- Information for Authors
- Subscribe to this Title
- Ingenta Connect is not responsible for the content or availability of external websites
- Access Key
- Free content
- Partial Free content
- New content
- Open access content
- Partial Open access content
- Subscribed content
- Partial Subscribed content
- Free trial content