Contrail Persistence Temp Humidity Checker
Audit ice-supersaturation/subzero observations against caller contrail persistence policy; supersaturation above 100% is retained, formation requires separate engine/Schmidt–Appleman conditions and persistence is not proven.
Description
Ice-supersaturated air can support contrail persistence, with relative humidity over ice greater than one retained as meaningful.
Ice-supersaturated air can support contrail persistence, with relative humidity over ice greater than one retained as meaningful. Persistence screening differs from determining whether an engine exhaust plume can initially form a contrail.1
Audit ice-supersaturation/subzero observations against caller contrail persistence policy; supersaturation above 100% is retained, formation requires separate engine/Schmidt–Appleman conditions and persistence is not proven.
When to use Contrail Persistence Temp Humidity Checker
Use this tool to audit ice-supersaturation/subzero observations against caller contrail persistence policy; supersaturation above 100% is retained, formation requires separate engine/Schmidt–Appleman conditions and persistence is not proven.
Prepare the observed sounding, cloud records or forecast verification data. Check pressure and height coordinates, wind conventions and the stated units.
How to use Contrail Persistence Temp Humidity Checker 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 observedTemperaturesC, relativeHumidityOverIceFractions, callerMaximumPersistenceTemperatureC, callerMinimumIceHumidityFraction using the field table and calculation rules, then run the tool.
- Read callerPersistenceCriterionFlags, criterionMatchFraction. 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 |
|---|---|---|---|
| observedTemperaturesC | Observed temperatures c | list of number | Required |
| relativeHumidityOverIceFractions | Relative humidity over ice fractions | list of number | Required |
| callerMaximumPersistenceTemperatureC | Caller maximum persistence temperature c | number | Required |
| callerMinimumIceHumidityFraction | Caller minimum ice humidity fraction | number | Required |
Pair observed Celsius temperatures with nonnegative ice-humidity fractions, including values above 1. Require a maximum temperature strictly below zero and a minimum humidity at least 1. Return binary inclusive criterion flags and their mean fraction.
Paired lists must be nonempty and have equal lengths.
flag = temperature ≤ caller subzero maximum and ice-relative humidity ≥ caller minimum Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| callerPersistenceCriterionFlags | Caller persistence criterion flags | list of number |
| criterionMatchFraction | Criterion match fraction | number |
{
"input": {
"observedTemperaturesC": [
-50,
-30
],
"relativeHumidityOverIceFractions": [
1.2,
1.2
],
"callerMaximumPersistenceTemperatureC": -40,
"callerMinimumIceHumidityFraction": 1
},
"output": {
"callerPersistenceCriterionFlags": [
1,
0
],
"criterionMatchFraction": 0.5
}
}Limitations and assumptions
This is a caller-policy screen. Engine conditions, Schmidt–Appleman formation requirements and actual persistence are not resolved.
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 Virtual Temperature Correction: Compute exact ideal moist-air virtual temperature with vapor and suspended-liquid specific mass fractions relative to total mixture; differs from vapor mixing-ratio approximations and excludes ice unless caller independently models it. For a complementary task, use Lifting Condensation Level Height: Compute named Bolton LCL temperature then caller dry-adiabatic pressure/height for a surface parcel; not existing dewpoint-spread fog proxy, inferred environmental cloud base or moist-convective ascent.
References
Similar or alternative tools
- Virtual Temperature Correction
Compute exact ideal moist-air virtual temperature with vapor and suspended-liquid specific mass fractions relative to total mixture; differs from vapor mixing-ratio approximations and excludes ice unless caller independently models it.
- Lifting Condensation Level Height
Compute named Bolton LCL temperature then caller dry-adiabatic pressure/height for a surface parcel; not existing dewpoint-spread fog proxy, inferred environmental cloud base or moist-convective ascent.