Figure 2

Oceanographic observation. Contour maps of four marine environments at a latitudinal line from 26.6°N to 14.0°N at 131°E (a–d) and at a longitudinal line from 129.0°E to 138.0°E at 14.0°N (e–h): temperature (a, e), salinity (b, f), nitrate concentration (c, g), and chlorophyll-a concentration (d, h).