Surge Front Advance Rate Calculator
Track actual caller-defined surge activation threshold front between observations in m/day; not ice particle velocity, calving-minus-flow integration or a surge onset forecast.
Description
A surge-activation front is a tracked threshold location.
A surge-activation front is a tracked threshold location. Its motion differs from the velocity of individual ice particles.1
Enter aligned finite positions and at least two strictly increasing observation days. Return signed interval/net m/day.
When to use Surge Front Advance Rate Calculator
Use Surge Front Advance Rate Calculator when you need to evaluate the supplied records under the calculation and evidence rules below. No surge onset, particle velocity or calving-minus-flow integration is inferred.
Prepare the observed ice, snow, water or geometry measurements and explicit calibration parameters requested. Keep coordinates, datum, density and time units consistent.
How to use Surge Front Advance Rate Calculator and understand its results
- Prepare the observed ice, snow, water or geometry measurements and explicit calibration parameters requested. Keep coordinates, datum, density and time units consistent.
- Enter observationDays, observedSurgeThresholdFrontPositionsM using the field table and calculation rules, then run the tool.
- Read intervalSurgeFrontRatesMDay, netThresholdFrontRateMDay. 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 |
|---|---|---|---|
| observationDays | Observation days | list of number | Required |
| observedSurgeThresholdFrontPositionsM | Observed surge threshold front positions m | list of number | Required |
Enter aligned finite positions and at least two strictly increasing observation days. Return signed interval/net m/day.
rate[i]=Δposition/Δday; netRate=(last−first)/(lastDay−firstDay) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| intervalSurgeFrontRatesMDay | Interval surge front rates m day | list of number |
| netThresholdFrontRateMDay | Net threshold front rate m day | number |
{
"input": {
"observationDays": [
0,
2,
5
],
"observedSurgeThresholdFrontPositionsM": [
0,
20,
50
]
},
"output": {
"intervalSurgeFrontRatesMDay": [
10,
10
],
"netThresholdFrontRateMDay": 10
}
}Limitations and assumptions
No surge onset, particle velocity or calving-minus-flow integration is inferred.
Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Numeric lists are limited to 10,000 entries; string lists to 128 strings of at most 128 characters each. The rules above may impose smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Snout Recession Length Per Decade Calculator: An observed decade recession uses positions at both ends of a complete ten-year window. Short-term rates are not rescaled beyond coverage. For a complementary task, use Retreat Acceleration Percent Change Calculator: Retreat-rate change can be expressed relative to an earlier rate and per actual epoch separation. A later advance remains a signed reversal.
References
-
Surge Front Advance Rate Calculator — tool.io
Similar or alternative tools
- Snout Recession Length Per Decade Calculator
An observed decade recession uses positions at both ends of a complete ten-year window. Short-term rates are not rescaled beyond coverage.
- Retreat Acceleration Percent Change Calculator
Retreat-rate change can be expressed relative to an earlier rate and per actual epoch separation. A later advance remains a signed reversal.