Salinity Front Edges
ProThin lines where the detector found a salinity 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; forecast in 3-hour steps
More detail
What you see. A scatter of thin lines over mostly empty water. Each line marks the middle of a zone where the salinity changes sharply over a short distance. The layer cannot say how strong a change is.
How to use it. Switch to Sea Surface Salinity 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. Salinity Front Intensity comes from the same calculation. It shades every spot by how sharp the change is and always paints something. Use Salinity Front Edges to see only where the lines are, and Salinity 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 forecast surface salinity of HYCOM (U.S. Navy model), the Sea Surface Salinity 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. The forecast behind it has about 5 nautical miles of real detail, so read it as a broad zone. There are eight frames a day, three hours apart. The newest frame is from a run started between one and four days ago, and the time slider reaches up to 7 days ahead as a forecast.
When it looks blank. When this map is empty, check Salinity Front Intensity for the same frame to see whether the change has weakened.
The numbers
| How often it updates | 8 frames a day, three hours apart |
| How fresh it usually is | The newest frame is from a run started between one and four days ago |
| How detailed it is | The forecast behind it has about 5 nautical miles of real detail |
| 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 |
| How far forward you can look | Up to 7 days ahead, as a forecast |
| Goes blank under cloud? | Never |
| Observed or modeled | Calculated by RipIQ from HYCOM (U.S. Navy model) |
| What you see on screen | Lines only |
Source: computed by RipIQ from Sea Surface Salinity (HYCOM model).