Dryline Mixing Ratio Gradient Checker

Screen observed signed moisture gradients on caller measured planar transect distances; no coordinate distance computation or dryline identification from humidity gradient alone.

Description

A dryline separates air masses with contrasting moisture.

A dryline separates air masses with contrasting moisture. A measured transect can quantify that contrast, though gradient size alone does not identify a dryline.^[1]

Screen observed signed moisture gradients on caller measured planar transect distances; no coordinate distance computation or dryline identification from humidity gradient alone.

When to use Dryline Mixing Ratio Gradient Checker

Use this tool to screen observed signed moisture gradients on caller measured planar transect distances; no coordinate distance computation or dryline identification from humidity gradient alone.

Prepare the observed sounding, cloud records or forecast verification data. Check pressure and height coordinates, wind conventions and the stated units.

How to use Dryline Mixing Ratio Gradient 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 signedTransectPositionsKm, vaporMixingRatiosGramsPerKg, callerAbsoluteGradientThresholdGramsPerKgKm using the field table and calculation rules, then run the tool.
Read intervalSignedMixingRatioGradients, aboveCallerAbsoluteGradientFlags. 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
signedTransectPositionsKm	Signed transect positions km	list of number	Required
vaporMixingRatiosGramsPerKg	Vapor mixing ratios grams per kg	list of number	Required
callerAbsoluteGradientThresholdGramsPerKgKm	Caller absolute gradient threshold grams per kg km	number	Required

Pair nonnegative vapor mixing ratios in g/kg with strictly increasing planar transect positions in km. Compute signed adjacent gradients and binary flags for absolute gradient strictly greater than the nonnegative caller threshold. Equality does not flag.

Paired lists must be nonempty and have equal lengths. Each sequence checked for increasing order must contain at least two strictly increasing values.

interval gradient = change in vapor mixing ratio/change in signed position km

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
intervalSignedMixingRatioGradients	Interval signed mixing ratio gradients	list of number
aboveCallerAbsoluteGradientFlags	Above caller absolute gradient flags	list of number

json

{
  "input": {
    "signedTransectPositionsKm": [
      0,
      10,
      20
    ],
    "vaporMixingRatiosGramsPerKg": [
      5,
      15,
      10
    ],
    "callerAbsoluteGradientThresholdGramsPerKgKm": 0.8
  },
  "output": {
    "intervalSignedMixingRatioGradients": [
      1,
      -0.5
    ],
    "aboveCallerAbsoluteGradientFlags": [
      1,
      0
    ]
  }
}

Limitations and assumptions

Positions and orientation are supplied. Geographic distance, front classification and forecasts are not computed.

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 Frontogenesis Function 2D: Compute 2D adiabatic kinematic material growth of temperature-gradient magnitude from caller local velocity-gradient tensor; no vertical tilting/diabatic term, coordinates or front forecast. For a complementary task, use Cold Front Passing Temp Drop Rate: Audit observed interval cooling rates over irregular hours while preserving warming sign; temperature change alone does not establish a cold-front passage or weather hazard.

References

Dryline Mixing Ratio Gradient Checker — tool.io

Similar or alternative tools

Frontogenesis Function 2D
Compute 2D adiabatic kinematic material growth of temperature-gradient magnitude from caller local velocity-gradient tensor; no vertical tilting/diabatic term, coordinates or front forecast.
Cold Front Passing Temp Drop Rate
Audit observed interval cooling rates over irregular hours while preserving warming sign; temperature change alone does not establish a cold-front passage or weather hazard.