Single-celled algae (phytoplankton) make up the base of the marine food web using chlorophyll pigments to absorb sunlight for photosynthesis. The distribution of phytoplankton provides an indication of high productivity areas and the abundance of other marine life. High concentrations of chlorophyll-a are common in areas of upwelling where cold, deep water rises to the surface bringing abundant nutrients needed by phytoplankton. Coastal areas are more challenging to estimate accurately due to a variety of other suspended particles including sediments and organic material but offshore productivity patterns are produced more consistently. Satellite measurements of chlorophyll-a concentrations provide a proxy for the biomass of phytoplankton present near the ocean surface (to ~30 m). This layer is blended from a coastal ChlA estimate (quasi-analytic algorithm, QAA, local aph*(555)) and the default open-ocean ChlA value from MODIS-Aqua (v2018.0) based on processing described in Pinkerton et al. (2018). The QAA algorithm is updated in Lee et al. (2009) and values are shown in mg m-3 with 4 km offshore 500 m coastal resolution.

Reference:

Pinkerton, M.H. (2018). Ocean colour satellite observations of phytoplankton in the New Zealand EEZ, 1997–2018. NIWA report MFE18301-2018180WN, Prepared for Ministry

Lee Z, Lubac B, Werdell J, Arnone R (2009) An update of the quasi-analytical algorithm (QAA_v5). International Ocean Color Group Software Report:1–9.

Single-celled algae (phytoplankton) make up the base of the marine food web using chlorophyll pigments to absorb sunlight for photosynthesis. The distribution of phytoplankton provides an indication of high productivity areas and the abundance of other marine life. High concentrations of chlorophyll-a are common in areas of upwelling where cold, deep water rises to the surface bringing abundant nutrients needed by phytoplankton. Coastal areas are more challenging to estimate accurately due to a variety of other suspended particles including sediments and organic material but offshore productivity patterns are produced more consistently. Satellite measurements of chlorophyll-a concentrations provide a proxy for the biomass of phytoplankton present near the ocean surface (to ~30 m). This layer is blended from a coastal ChlA estimate (quasi-analytic algorithm, QAA, local aph*(555)) and the default open-ocean ChlA value from MODIS-Aqua (v2018.0) based on processing described in Pinkerton et al. (2018). The QAA algorithm is updated in Lee et al. (2009) and values are shown in mg m-3 with 4 km offshore 500 m coastal resolution.

Reference:

Pinkerton, M.H. (2018). Ocean colour satellite observations of phytoplankton in the New Zealand EEZ, 1997–2018. NIWA report MFE18301-2018180WN, Prepared for Ministry

Lee Z, Lubac B, Werdell J, Arnone R (2009) An update of the quasi-analytical algorithm (QAA_v5). International Ocean Color Group Software Report:1–9.