EL Equilibrium Level
Locate first upper zero crossing terminating observed positive-buoyancy layer after caller LFC search boundary; retain unobserved EL/right-censored positive layer rather than extrapolating sounding top.
Description
The equilibrium level terminates a positive-buoyancy layer when buoyancy returns to zero or below.
The equilibrium level terminates a positive-buoyancy layer when buoyancy returns to zero or below. A sounding ending inside positive buoyancy leaves that layer's top unobserved.1
Locate first upper zero crossing terminating observed positive-buoyancy layer after caller LFC search boundary; retain unobserved EL/right-censored positive layer rather than extrapolating sounding top.
When to use EL Equilibrium Level
Use this tool to locate first upper zero crossing terminating observed positive-buoyancy layer after caller LFC search boundary; retain unobserved EL/right-censored positive layer rather than extrapolating sounding top.
Prepare the observed sounding, cloud records or forecast verification data. Check pressure and height coordinates, wind conventions and the stated units.
How to use EL Equilibrium Level 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 heightsM, suppliedBuoyancyMPerSecond2, searchAboveLfcHeightM using the field table and calculation rules, then run the tool.
- Read observedEquilibriumLevelFound, observedEquilibriumLevelHeightM, positiveLayerRightCensored. 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 |
|---|---|---|---|
| heightsM | Heights m | list of number | Required |
| suppliedBuoyancyMPerSecond2 | Supplied buoyancy m per second2 | list of number | Required |
| searchAboveLfcHeightM | Search above lfc height m | number | Required |
Use increasing heights, aligned buoyancies and an in-coverage search boundary below the sounding top. Interpolate the boundary and find the first upper crossing after positive buoyancy is seen. If absent, return height −1 and found false; right-censoring is true only when a positive layer was observed.
EL = first interpolated positive-to-nonpositive buoyancy crossing after search boundary Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| observedEquilibriumLevelFound | Observed equilibrium level found | boolean |
| observedEquilibriumLevelHeightM | Observed equilibrium level height m | number |
| positiveLayerRightCensored | Positive layer right censored | boolean |
{
"input": {
"heightsM": [
0,
1000,
2000
],
"suppliedBuoyancyMPerSecond2": [
0,
1,
-1
],
"searchAboveLfcHeightM": 0
},
"output": {
"observedEquilibriumLevelFound": true,
"observedEquilibriumLevelHeightM": 1500,
"positiveLayerRightCensored": false
}
}Limitations and assumptions
No upper sounding extrapolation or parcel calculation 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. A successfully returned false flag is an evaluated outcome; its meaning is explained above.
Alternative or Complementary methods
Use LFC Level Free Convection: Find first strict-positive buoyancy transition at/above caller LCL in supplied linear sounding, with left-censoring or explicit no-observed-LFC sentinel; touches without positive buoyancy are not free convection. For a complementary task, use CAPE Convective Available Potential Energy: Integrate positive portions of caller precomputed virtual parcel/environment buoyancy in observed height window, resolving each linear zero crossing; no hidden parcel lift, full sounding CAPE outside coverage or storm safety.
References
-
EL Equilibrium Level — tool.io
Similar or alternative tools
- LFC Level Free Convection
Find first strict-positive buoyancy transition at/above caller LCL in supplied linear sounding, with left-censoring or explicit no-observed-LFC sentinel; touches without positive buoyancy are not free convection.
- CAPE Convective Available Potential Energy
Integrate positive portions of caller precomputed virtual parcel/environment buoyancy in observed height window, resolving each linear zero crossing; no hidden parcel lift, full sounding CAPE outside coverage or storm safety.