Inertial Period F Latitude Calculator
Ideal f-plane inertial period in seconds; signed hemisphere does not change period, equator rejected.
Description
Calculate an ideal local inertial period at a nonzero latitude.
A local inertial period is the rotation timescale associated with the Coriolis parameter. The simple latitude model becomes singular as the equator is approached.
When to use this tool
Calculate an ideal local inertial period at a nonzero latitude. Use it when the input measurements and conventions below match the operation you need.
- Prepare latitudeDegrees, respecting the measurement basis and boundaries below.
- Compare the worked example with your intended operation before reusing its result.
How to use the tool and how it works
- Enter every field in the input table using the stated units and exact supported selector spelling where applicable.
- Run the tool. Correct input errors before interpreting an output.
- Read the result fields below; use accompanying flags and the stated sign, boundary or model convention when interpreting a number.
For a nonzero latitude from -90 to 90 degrees, the tool calculates f = 2 times 7.292115e-5 times sin(latitude), then returns 2 pi divided by the absolute value of f.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| latitudeDegrees | Latitude degrees. Degrees. | Finite number; from -90 to 90 inclusive |
| Output field | Interpretation |
|---|---|
| result | Object containing the following named result fields. |
| result.periodSeconds | Period seconds; use the stated units and sign convention. |
{
"input": {
"latitudeDegrees": 30
},
"output": {
"result": {
"periodSeconds": 86164.10063718943
}
}
}Limitations and assumptions
- The equator is rejected rather than assigned a finite period. This ideal local timescale is not a forecast of an observed drifter's motion.
- Every declared field is required and unexpected fields are rejected. Numeric inputs must be finite; input errors are distinct from a valid false result or an explicitly qualified output.
- Extremely large inputs and nonfinite or excessively large outputs are rejected. List positions reported by the tool use zero-based indices unless stated otherwise.
Alternative or Complementary methods
Compare the result with independently checked observations or a model that covers the omitted dynamics. Use compatible frames, units and sampling conventions when carrying the value into another calculation. Compare the scope of the nearby tools below before substituting one.
References
Similar or alternative tools
- Coriolis Parameter F Latitude Calculator
Signed spherical-Earth Coriolis parameter using fixed rotation rate; zero at equator retained.
- Inertial Circle Radius Latitude Calculator
Ideal f-plane inertial circle radius; equatorial f=0 rejected, not actual drifter prediction.