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Chlorophyll Front Edges

Pro

Thin lines where the detector found a chlorophyll change sharp enough to call a front. A pixel is either on a line or not, so on a flat day the map is meant to come up empty.

Updates daily

More detail

What you see. A scatter of thin lines over mostly empty water. Each line marks the middle of a zone where the chlorophyll changes sharply over a short distance. The layer cannot say how strong a change is.

How to use it. Switch to Chlorophyll Concentration to see the values on each side of a line, and fish it if it fits the rest of the picture. A line that holds its place across several frames counts for more. In Layer Settings you can change the line color and the Opacity.

How it relates to the other front layers. Chlorophyll Front Intensity comes from the same calculation. It shades every spot by how sharp the change is and always paints something. Use Chlorophyll Front Edges to see only where the lines are, and Chlorophyll Front Intensity to see how strong and how wide a change is. There is a pair like this for four things: SST Front Intensity and SST Front Edges for temperature, Salinity Front Intensity and Salinity Front Edges for salinity, Chlorophyll Front Intensity and Chlorophyll Front Edges for chlorophyll, and Phytoplankton Front Intensity and Phytoplankton Front Edges for plant plankton. All eight are worked out from a forecast or a model, so none of them has cloud gaps. The only front layers made from satellite pictures are SST (ACSPO) Fronts and SST (GOES-19) Fronts, and both are for temperature.

Who makes it. RipIQ makes this layer itself from the Copernicus Marine model's chlorophyll, the Chlorophyll Concentration layer. The layer covers the Gulf of America, the East Coast and Baja.

Its limits. It is blank within about 2.5 nautical miles of land. There is one frame a day, about a day behind today's date. Values are revised for up to two weeks afterward.

When it looks blank. When this map is empty, check Chlorophyll Front Intensity for the same frame to see whether the change has weakened.

The numbers

How often it updates Once a day
How fresh it usually is About one day behind today's date, and revised for up to two weeks afterward
How detailed it is About 15 nautical miles (the Copernicus Marine model's grid)
Where it covers Gulf of America, East Coast and Baja, minus a band of about 2.5 nautical miles along every coast
How far back you can look 8 days back
Goes blank under cloud? Never
Observed or modeled Calculated by RipIQ from a Copernicus model field
What you see on screen Lines only

Source: computed by RipIQ from Chlorophyll Concentration (Copernicus model).

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