Imagery & data. We acknowledge the use of imagery provided by services from NASA's Global Imagery Browse Services (GIBS), part of NASA's Earth Science Data and Information System (ESDIS). Chlorophyll-a from MODIS-Aqua, VIIRS (NOAA-20 / SNPP) and PACE OCI ocean-color products, processed by the NASA Ocean Biology Processing Group (OB.DAAC). Basemap, coastlines and place labels: NASA GIBS.

How averaging works. Weekly and monthly views are composited in your browser: for each pixel, the cloud-free days in the window are decoded from NASA's fixed color scale and combined as a geometric mean (average in log space), then recolored on the same scale. Gaps remain where no day had valid data.

Limitations. Averages are derived from NASA's color-coded image tiles (quantized to 254 log steps), not from source data values, and are intended for visualization and education — not quantitative or navigational use. For research-grade values use NASA Giovanni or the NASA Ocean Color Level-3 archive.

Map library: Leaflet. This site is not affiliated with or endorsed by NASA.