Types of Graphs
1. Climatological: The graph shows the mean weekly data obtained during the current year, the climatological mean, and the ±1 standard deviation from the mean between 2002 and the present. Large deviations from the climatology represent anomalous events.
2. Historical: The graph shows all available data in one continuous time series.
Parameter Definitions
Sea Surface Temperature (SST)
SST data were extracted from MODIS/Aqua measurements for a 2 kmˆ2 region centered at the station location, and updated on the 5th day of each ordinal week. SST is derived from MODIS/Aqua multi-band measurements using the software package SeaDAS and a non-linear SST (NLSST) algorithm (Walton et al., 1998, JGR). Although the satellite instrument measures the temperature of the ocean “skin” (micrometer on the surface), most validation work has used in situ temperature measured in the top meters of the water column.
Chlorophyll-a (Chl-a)
Chl-a is a measure of the photosynthetic pigment of phytoplankton, with units of mg mˆ-3. It can also be used as a relative index of algae biomass. Chl-a is derived from MODIS/Aqua multi-band measurements using the software package SeaDAS and a band-ratio OC3 algorithm (O’Reilly et al., 2000). It represents the chlorophyll-a concentration in the surface layer of the water column where the depth of this layer varies with water clarity (can be a few meters in turbid water and tens of meters in offshore clear water). The validity may be degraded due to algorithm contamination by suspended sediments, colored dissolved organic matter, and/or shallow bottom (Cannizzaro et al., accepted in JCR).
Turbidity
Water turbidity is a measure of the amount of particles in the water, often expressed in units of NTU. Here water turbidity is derived from MODIS/Aqua multi-band measurements using the software package SeaDAS and a regressional relationship derived from water turbidity measured in Tampa Bay and MODIS-derived remote sensing reflectance at 645-nm (Chen et al., 2007, RSE). It represents the water turbidity in the surface layer (several meters) of the water column. The data have been only validated in Tampa Bay for turbidity < 10 NTU, with RMS uncertainties of ~30% and no significant bias. Elsewhere, interpretation requires more caution.
ADG433
adg(443) is a measure of the absorption of light by detritus and colored dissolved organic matter (CDOM) within the water column, with units of mˆ-1. CDOM is a product of plant decay, either from terrigenous (e.g., land plants and mangroves) or oceanic (seagrasses and phytoplankton) sources. CDOM strongly absorbs blue and ultraviolet light, the intensity of which can impact the health and photosynthetic capabilities of many benthic organisms (e.g., corals, sponges, and seagrasses). Detritus is particulate matter (excluding chloropyhll) in the water column. Here adg(443) is derived from MODIS/Aqua multi-band measurements of reflectance using the software package SeaDAS and a semi-analytical inversion algorithm by Lee et al. (2005, JGR). The derived adg(443) value represents the CDOM and detrital absorption at 443 nm in the surface layer of the water column. The depth of this layer varies with water clarity (can be a few meters in turbid water and tens of meters in offshore clear water).
PAR
PAR is a measure of the visible light reaching the water surface, with units of Einstein mˆ-2 dayˆ-1. Here PAR is derived from MODIS/Aqua multi-band measurements using the software package SeaDAS and an algorithm developed by Carder et al. (2003). Neglecting atmospheric effects, PAR can be calculated based on solar geometry. However, light passing through Earth's atmosphere is attenuated by a variety of factors (e.g., clouds, ozone, aerosols). PAR is essential for photosynthesis, thus its intensity can have large effects on many marine and terrestrial organisms.
KD488
Kd(488) is a parameter to describe how fast the downwelling diffuse light at 488 nm (blue light) is attenuated through the water column, with units of mˆ-1. It is derived from MODIS/Aqua multi-band measurements using the software package SeaDAS and a semi-analytical inversion algorithm by Lee et al. (2005, JGR). One way to interpret Kd(488) is the estimation of light availability at a certain depth. The Kd(488) data product has been validated for optically deep waters where the bottom contribution to the satellite measurement is negligible (Chen et al., 2007; Zhao et al., submitted, RSE). For optically shallow waters where the bottom can be seen clearly by a human eye, Kd(488) is overestimated and interpretation requires more caution.
Radar
