Fig. 2

(a) Seasonal distribution of most frequently occurring optical water types derived from GOCI L2 remote sensing reflectance (Rrs) spectra in the study area for 2015; the asterisk indicates the location of I-ORS. Optical water type was classified according to Wei et al.(2016) and Cui et al.(2020). (b) Monthly distribution of optical water types derived from MODIS data over two decades (2003–2022).