IMOS - Satellite Remote Sensing - MODIS - 01 day - Picoplankton fraction (OC3 model and Brewin et al 2012 algorithm)

The Aqua satellite platform carries a MODIS sensor that observes sunlight reflected from within the ocean surface layer at multiple wavelengths. These multi-spectral measurements are used to infer the concentration of chlorophyll-a (Chl-a), most typically due to phytoplankton, present in the water. An empirical relationship is then used to compute an estimate of the relative abundance of three phytoplankton size classes (micro, nano and picoplankton). The methods used to decompose chl_oc3 are described by Brewin et al in two papers in 2010 and 2012. The two methods, denoted Brewin2010at and Brewin2012in, used calibration data from the Atlantic and Indian Oceans respectively. Users should note that these are unvalidated experimental products and they should familiarise themselves with the underlying algorithms and methodologies described in the published literature before making use of them.The data are produced from the same data stream as the MODIS Chla_oci data set (https://catalogue-imos.aodn.org.au:443/geonetwork/srv/api/records/d7a14921-8f3f-4522-9a54-e7d1df969c8a). Data are provided as two files per day, one with the percentage of nanoplankton, and one for picoplankton. The percentage of microplankton is computed as the balance to 100%, that is %micro = 100 - %nano - %pico.Production of contemporary MODIS data ceased at 2024/12/26. Users requiring similar Ocean Colour Radiometry data beyond 2024 should consider the VIIRS instruments on the SNPP and NOAA20+ series of satellites, also provided by IMOS.

Aqua卫星平台搭载了中分辨率成像光谱辐射计（MODIS）传感器，可在多个波段下观测海洋表层反射的太阳光。此类多光谱测量数据被用于反演水体中叶绿素-a（Chl-a）的浓度，而该物质主要由浮游植物产生。随后可通过经验关系，估算得到三类浮游植物粒径类群（微型、小型与超微型浮游生物）的相对丰度。用于分解chl_oc3数据的方法由Brewin等人于2010年和2012年发表的两篇论文中详细阐述。两种方法分别记为Brewin2010at与Brewin2012in，其校准数据分别取自大西洋与印度洋。用户需注意，此类产品属于未经过验证的试验性成果，在使用前应仔细研读已发表文献中记载的底层算法与研究方法。本数据集与MODIS Chla_oci数据集采用同源数据流生产，数据来源为：https://catalogue-imos.aodn.org.au:443/geonetwork/srv/api/records/d7a14921-8f3f-4522-9a54-e7d1df969c8a。本数据集每日提供两份数据文件：其一包含小型浮游生物占比数据，其二包含超微型浮游生物占比数据；微型浮游生物占比可通过100%减去前两者占比计算得到，即%微型 = 100 - %小型 - %超微型。现代MODIS数据的生产已于2024年12月26日终止。对于2024年之后需要同类海洋色度辐射测量数据的用户，可考虑使用由IMOS提供的、搭载于SNPP与NOAA20+系列卫星上的VIIRS传感器数据。