Time Series of Bio-Optical Properties in a Subtropical Gyre: Implications for the Evaluation of Interannual Trends of Biogeochemical Properties

Authors

ZhongPing Lee, Mississippi State University
Shaoling Shang, Xiamen University
Chuanmin Hu, University of South FloridaFollow
Marlon Lewis, Dalhousie University
Robert Arnone, John C. Stennis Space Center
Yonghong Li, Xiamen University
Bertrand Lubac, John C. Stennis Space Center

Document Type

Article

Publication Date

9-2010

Keywords

bio‐optical properties, gyre, ocean color remote sensing, time series

Digital Object Identifier (DOI)

https://doi.org/10.1029/2009JC005865

Abstract

With a validated Quasi‐Analytical Algorithm, an 11 year (1998–2008) monthly time series of the primary optical properties of waters in the center of the South Pacific gyre was developed from Sea‐viewing Wide Field‐of‐view Sensor (SeaWiFS) and Moderate Resolution Imaging Spectroradiometer (MODIS). Also derived are chlorophyll a (Chl a) concentrations with the operational empirical algorithms for SeaWiFS and MODIS. The optical properties include the absorption coefficient (at 443 nm) of phytoplankton (a_ph) and that of the combination of detritus and gelbstoff (a_dg). From these time series, we further derived their annual background (summer low) and seasonal intensity (the difference between winter high and summer low). These time series show that (1) the optical properties have different seasonal and interannual variations, indicating different dynamics of these properties in the subtropical gyre; (2) there is a decreasing trend (r² = 0.24) of the background a_ph in the 1998–2008 period and an increasing trend of the a_ph seasonal intensity (r² = 0.11) for this period, and both trends are not statistically significant; (3) the a_ph time series agrees with the Chl a time series at the seasonal scale, but differs with respect to interannual variations; and (4) different interannual trends could be inferred with different time frames. These results emphasize that it is difficult to draw unequivocal conclusions about long‐term trends of biogeochemical properties in the oceans with the current relatively short bio‐optical records. To clarify and predict such trends, it is critical to get a full account of the forces that are responsible for the seasonal and interannual variations of these properties.

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Was this content written or created while at USF?

Yes

Citation / Publisher Attribution

Journal of Geophysical Research - Oceans, v. 115, issue C9, art. C09012

Copyright 2010 by the American Geophysical Union.

Scholar Commons Citation

Lee, ZhongPing; Shang, Shaoling; Hu, Chuanmin; Lewis, Marlon; Arnone, Robert; Li, Yonghong; and Lubac, Bertrand, "Time Series of Bio-Optical Properties in a Subtropical Gyre: Implications for the Evaluation of Interannual Trends of Biogeochemical Properties" (2010). Marine Science Faculty Publications. 41.
https://digitalcommons.usf.edu/msc_facpub/41