Development of Daily PAR from GOCI and Comparison with PARs from Other Satellite Sensors

Abstract

Phytoplankton carbon in marine environment is one of the important factors for ecosystem and climate change. Using satellite-based primary production, which is mainly influenced by the sun light energy, especially photosynthetically available radiation (PAR), phytoplankton carbon at the ocean surface can be estimated. Thus estimating PAR at the ocean surface accurately is important to understand the marine ecological environment. Here, daily PAR from Geostationary Ocean Colour Imager (GOCI) was estimated and validated in terms of a comparison with in-situ measurements from ocean research station, Socheong-cho station located in turbid water condition and Ieodo station in clear water condition. GOCI daily PAR had shown a constant value of difference with the in-situ measurements, which was corrected using the in-situ measurements obtained on the days of clear-sky conditions. After the corrections, GOCI daily PAR showed overall good agreements with in-situ measurements. Validations were made with sufficient in-situ data, although they were from only two locations, which indicating a relatively high level of reliabilities. GOCI-derived daily PAR was also compared with the ones from MODIS and Himawari, the Japanese weather satellite system. It seems that around the Korean peninsula GOCI showed good agreements with MODIS or Himawari, but near the edges of the GOCI boundaries there were some disagreements and relatively big differences at some spots. Thus, more in-situ data collected at various locations within GOCI coverage are needed to improve the accuracies and reliabilities of GOCI-derived daily PAR.