Description
Return friction velocity from stress magnitude and density.
Atmospheric dynamics uses signed coordinates, rotating-flow approximations, fluctuation definitions and stability conventions. One advection, shear, vorticity or wave term omits parts of the full equations and need not establish the state or stability of an observed atmosphere.
Return friction velocity from stress magnitude and density.
When to use this tool
Use Friction Velocity Stress Density Factor when evaluating the stated local atmospheric dynamic, turbulence, stability or wave term.
How to use the tool and how it works
- Enter stressMagnitude, density. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read frictionVelocity. Use the output convention below.
Return friction velocity from stress magnitude and density. Require stressMagnitude >= 0 and density > 0; frictionVelocity = sqrt(stressMagnitude/density).1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| stressMagnitude | Stress Magnitude | Required. Finite number; minimum 0. |
| density | Supplied physical density with compatible mass/volume units under the stated model. | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| frictionVelocity | Friction Velocity | Required. Finite number. |
{
"input": {
"stressMagnitude": 4,
"density": 1
},
"output": {
"frictionVelocity": 2
}
}Limitations and assumptions
- Stress magnitude and density must match the intended surface-layer convention; no actual stress direction, flux or similarity validity is established.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use complete verified fields and an appropriate dynamical model, including coordinate directions, omitted terms and approximation validity, for physical or forecast interpretation.
References
Similar or alternative tools
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