Using MERIS data to retrieve water components in the Pearl River Estuary, China
Hong-Yan XI(1) and Yuan-Zhi ZHANG(1)
(1) The Chinese University of Hong Kong, Sha Tin, Hong Kong, Hong Kong
Satellite remote sensing is a valuable tool in obtaining information on the processes taking place in the surface of sea and coastal waters. With currently advanced satellite-based data like MERIS and many other optical sensors, a large number of variables concerning water quality conditions such as chlorophyll-a (Chl-a), total suspended matter (TSM), yellow substance, turbidity, salinity and sea surface temperature (SST) could be observed on a regular basis, which are also the primary steps to monitor harmful algal blooms (HABs).
Based on MERIS reduced resolution L_1B product, atmospheric correction and water components are implemented via neural network in Case2Regional processor that ESA provides. Water leaving reflectances are calculated and show reasonable distribution compared with that directly from L_2 data. Chl and TSM concentrations are also retrieved and compared with L_2 data products, which show that low Chl concentrations (<10mg/m3) retrieval is very close to that of L_2 data while TSM concentration are a little higher than that from L_2 data. However, the distribution and values range of Chl and TSM concentrations are accordant with the water quality in the study area. This paper is a preliminary work, still more work and study need to be done; more in-situ data are necessary to verify the accuracy of water components concentrations derived from MERIS data, more parameters should be reconfirmed to fit the study area as well.
Keywords: ESA European
Space Agency - Agence spatiale europeenne,
observation de la terre, earth observation,
satellite remote sensing,
teledetection, geophysique, altimetrie, radar,
chimique atmospherique, geophysics, altimetry, radar,