Two simple equations with sea surface temperature and total primary production as independent variables were used to estimate ratios of new or export production to total primary production (ef-ratios) in the ocean. Both equations assume that ef-ratios are negatively correlated with temperature in a linear manner and positively correlated with total primary production in a curvilinear manner characteristic of a Holling type II function. The two equations were parameterized based on different sets of field data: in one case entirely from estimates of new production based on nitrate uptake, and in the other case based on a comprehensive summary of new and export production estimates derived from a combination of techniques. Estimates of global export production based on satellite observations and use of the two equations were 9-13 Gt C per year. The form of both equations likely captures the principal effects of temperature and total production on ef-ratios, and their mathematical simplicity should facilitate their prognostic application in climate change research and studies of the ocean's carbon cycle.

During the passage of a cold front in March 2002, bio-optical properties examined in coastal waters impacted by the Mississippi River indicated that westward advective flows and increasing river discharge containing high concentrations of nonalgal particles contributed significantly to surface optical variability. A comparison of seasonal data from three cruises indicated spectral models of absorption and scattering to be generally consistent with other coastal environments, while their parameterization in terms of chlorophyll (Chl) alpha concentration showed seasonal variability. The exponential slope of the colored dissolved organic matter (CDOM) averaged 0.0161+/-0.00054 nm(-1) and nonalgal absorption averaged 0.011 nm(-1) with deviations from general trends observed due to anomalous water properties. Although the phytoplankton specific absorption coefficients varied over a wide range [0.02 to 0.1 m2 (mg Chl)(-1) at 443 nm] being higher in offshore surface waters, values of phytoplankton absorption spectra at the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) wave bands were highly correlated to modeled values. Particulate scattering characteristics were similar to observations for other coastal waters, while backscattering ratios were on average lower in phytoplankton-dominated surface waters (0.011+/-0.003) and higher in low Chl near-bottom waters (0.0191+/-0.0045). Average percent differences in remote sensing reflectance Rrs derived from modeled and in-water radiometric measurements were highest in the blue wave bands (52%) and at locations with more stratified water columns. SeaWiFS estimates of Chl and CDOM absorption derived using regional empirical algorithms were highly correlated to in situ data.

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[1] Suspended particulate matter (SPM) plays an important role in primary production, pollutant transport, and other biogeochemical processes in coastal marine environments. We present an empirical two-band ocean color remote sensing reflectance algorithm (R rs 670/R rs 555) for SPM concentrations developed using field measurements obtained in coastal waters influenced by the Mississippi River in 2000, 2002, and 2004. The ratio algorithm was also found to be highly correlated to backscattering coefficient (b bp (555), r 2 = 0.96), the backscattering ratio (b bp (555)/ b p (555), r 2 = 0.82) and the spectral backscattering slope (g, r 2 = 0.72) in March 2002, a period with large hydrographic variability in the study area. Strong correlations between water column b bp (555), SPM and nonalgal absorption a nap (443) suggest the dominant influence of nonalgal particles on b bp . SeaWiFS derived SPM and g distributions indicated event-based variability linked to energetic disturbances such as frontal passages, resuspension, and river discharge that with b bp /b p could reveal refractive index and particle size characteristics in the coastal environment.

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