Monthly Chlorophyll-a Climatology for Canadian Pacific EEZ (2003-2020)

Fisheries and Oceans Canada provides monthly climatological composites of satellite-derived Chlorophyll-a concentration, a proxy for phytoplankton biomass, for the Canadian Pacific Exclusive Economic Zone. The dataset spans 2003 to 2020, excluding January and December, and includes geometric mean, geometric standard deviation factor, and data occurrence counts per pixel at two spatial resolutions.

Use Cases

• Analyze seasonal phytoplankton bloom patterns using the monthly geometric mean Chlorophyll-a values across the EEZ.
• Assess data reliability for specific ocean regions by examining the number of valid data occurrences per pixel over the 18-year period.
• Model environmental variability by incorporating the geometric standard deviation factor as a measure of Chlorophyll-a concentration dispersion.
• Compare coastal versus open-ocean productivity by mapping the geometric mean values at the provided 1 km and 4 km pixel resolutions.

Strengths

• Long-term temporal coverage from 2003 to 2020, providing an 18-year climatology.
• Includes three key data layers per month: geometric mean, geometric standard deviation factor, and count of valid data occurrences.
• Data is processed specifically for the Canadian Pacific Exclusive Economic Zone and provided in a standard geographic coordinate system (NAD83).
• Offers data at two spatial resolutions (approximately 1 km and 4 km) for consistency with other satellite products.

Limitations

• Winter months (January and December) are excluded due to insufficient satellite data at high latitudes.
• Pixels with fewer than two valid observations over the entire period were removed, potentially creating data gaps in some areas.
• The averaging process for creating climatological composites can miss short-lived or spatially limited phytoplankton events.

Provenance

Source

NASA Ocean Biology Processing Group (MODIS-Aqua Level 2 Ocean Color Data Version R2018.0).

Collection Method

Chlorophyll-a concentration was retrieved from MODIS-Aqua, processed using the OC3/OCI algorithm, and averaged into monthly geometric mean climatologies, excluding winter months.

Time Range

2003 to 2020.

Freshness

Data covers up to 2020; the record itself was last updated in March 2026.

Geography

Canadian Pacific Exclusive Economic Zone.