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A proxy for the biomass of phytoplankton present in the surface ocean (to ~30 m). Blended from a coastal Chl-a estimate (quasi-analytic algorithm (QAA), local aph*(555)) and the default open-ocean chl-a value from MODIS-Aqua (v2018.0). |
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A proxy for the biomass of phytoplankton present in the surface ocean (to ~30 m). Blended from a coastal Chl-a estimate (quasi-analytic algorithm (QAA), local aph*(555)) and the default open-ocean chl-a value from MODIS-Aqua (v2018.0). |
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National Institute of Water and Atmospheric Research Ltd. (NIWA) |
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<DIV STYLE="text-align:Left;font-size:12pt"><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>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 </SPAN></SPAN><SPAN><SPAN>offshore productivity patterns are produced</SPAN></SPAN><SPAN><SPAN> 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</SPAN></SPAN><SPAN><SPAN>-3</SPAN></SPAN><SPAN> with 4 km offshore 500 m coastal resolution.</SPAN></P><P STYLE="margin:0 0 11 0;"><SPAN STYLE="font-weight:bold;">Reference:</SPAN></P><P STYLE="margin:0 0 11 0;"><SPAN>Pinkerton, M.H. (2018). Ocean colour satellite observations of phytoplankton in the New Zealand EEZ, 1997–2018. NIWA report MFE18301-2018180WN, Prepared for Ministry </SPAN></P><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>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.</SPAN></SPAN></P><P STYLE="margin:0 0 11 0;"><SPAN><SPAN /></SPAN></P></DIV> |
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<DIV STYLE="text-align:Left;font-size:12pt"><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>Difficulty in distinguishing between different coloured materials near coasts results in errors in the estimates of ChlA, and though efforts have been made to correct for this, it remains complex and data are considered less accurate near shore. In addition, areas with large tidal differences, such as estuaries, can change quickly and dramatically, and variation in atmospheric corrections or surface wave effects can add uncertainties to remote sensing data. Offshore ChlA concentration is more accurate and representative of expected patterns of offshore productivity. </SPAN></SPAN></P></DIV> |
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Chlorophyll-a concentration |
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["Chlorophyll-a concentration","ChlA"] |
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en-NZ |
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0 |
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