Ageostrophic Component Magnitude
Difference measured and independently supplied geostrophic wind vectors, not scalar speed subtraction or computed pressure-gradient wind.
Description
Ageostrophic wind is the vector difference between observed wind and a separately estimated geostrophic wind.
Ageostrophic wind is the vector difference between observed wind and a separately estimated geostrophic wind. Subtracting scalar speeds would lose directional information.1
Difference measured and independently supplied geostrophic wind vectors, not scalar speed subtraction or computed pressure-gradient wind.
When to use Ageostrophic Component Magnitude
Use this tool to difference measured and independently supplied geostrophic wind vectors, not scalar speed subtraction or computed pressure-gradient wind.
Prepare the observed sounding, cloud records or forecast verification data. Check pressure and height coordinates, wind conventions and the stated units.
How to use Ageostrophic Component Magnitude and understand its results
- Prepare the observed sounding, cloud records or forecast verification data. Check pressure and height coordinates, wind conventions and the stated units.
- Enter observedWindComponentsMPerSecond, suppliedGeostrophicWindComponentsMPerSecond using the field table and calculation rules, then run the tool.
- Read ageostrophicWindComponentsMPerSecond, ageostrophicWindMagnitudeMPerSecond. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| observedWindComponentsMPerSecond | Observed wind components m per second | list of number | Required |
| suppliedGeostrophicWindComponentsMPerSecond | Supplied geostrophic wind components m per second | list of number | Required |
Enter exactly two east,north components for each wind in m/s. Subtract corresponding components and return the signed residual vector and Euclidean magnitude.
ageostrophic vector = observed east/north vector − geostrophic east/north vector Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| ageostrophicWindComponentsMPerSecond | Ageostrophic wind components m per second | list of number |
| ageostrophicWindMagnitudeMPerSecond | Ageostrophic wind magnitude m per second | number |
{
"input": {
"observedWindComponentsMPerSecond": [
10,
10
],
"suppliedGeostrophicWindComponentsMPerSecond": [
5,
15
]
},
"output": {
"ageostrophicWindComponentsMPerSecond": [
5,
-5
],
"ageostrophicWindMagnitudeMPerSecond": 7.0710678118654755
}
}Limitations and assumptions
The geostrophic estimate must be supplied. No pressure-gradient inference or coordinate rotation is performed.
Numeric inputs and returned numeric values must be finite; an unrepresentable returned value produces an error. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Bulk Shear 0 To 6KM: Interpolate observed 0/6000 m AGL wind endpoints before signed bulk shear difference; full layer coverage required, not average shear rate, surface-speed difference or a storm warning. For a complementary task, use Geostrophic Wind Speed: Compute signed east/north geostrophic vector under caller horizontal pressure gradients, density and Coriolis, not true terrain wind or a pressure-force magnitude alias.
References
-
Ageostrophic Component Magnitude — tool.io
Similar or alternative tools
- Bulk Shear 0 To 6KM
Interpolate observed 0/6000 m AGL wind endpoints before signed bulk shear difference; full layer coverage required, not average shear rate, surface-speed difference or a storm warning.
- Geostrophic Wind Speed
Compute signed east/north geostrophic vector under caller horizontal pressure gradients, density and Coriolis, not true terrain wind or a pressure-force magnitude alias.