SO2 Flux Trend Escalation Checker
Monitor observed SO2 multiplicative growth and extrapolated caller flux timing; model assumes unchanged trend and is not an eruption escalation/alert forecast.
Description
Multiplicative gas-flux growth appears linear after taking logarithms.
Multiplicative gas-flux growth appears linear after taking logarithms. Extending that line gives a comparison-time scenario.
Monitor observed SO2 multiplicative growth and extrapolated caller flux timing; model assumes unchanged trend and is not an eruption escalation/alert forecast.
When to use SO2 Flux Trend Escalation Checker
Use this tool to monitor observed SO2 multiplicative growth and extrapolated caller flux timing; model assumes unchanged trend and is not an eruption escalation/alert forecast.
Gather the relevant observations and fitted model parameters. Use the stated units and time basis; keep paired observations aligned.
How to use SO2 Flux Trend Escalation Checker and understand its results
- Gather the relevant observations and fitted model parameters. Use the stated units and time basis; keep paired observations aligned.
- Enter timesDays, measuredSo2TonnesPerDay, callerEscalationLogRatePerDay, callerComparisonFluxTonnesPerDay using the field table and calculation rules, then run the tool.
- Read fittedLogGrowthRatePerDay, modelComparisonFluxDay, aboveCallerEscalationRate, fitRSquared. 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 |
|---|---|---|---|
| timesDays | Times days | list of number | Required |
| measuredSo2TonnesPerDay | Measured so2 tonnes per day | list of number | Required |
| callerEscalationLogRatePerDay | Caller escalation log rate per day | number | Required |
| callerComparisonFluxTonnesPerDay | Caller comparison flux tonnes per day | number | Required |
Enter positive fluxes, an increasing time axis and a positive comparison flux. Regress log flux against days, require positive growth and a crossing at or after the last observation, then compare slope strictly above the supplied escalation rate.1
Each sequence checked for increasing order must contain at least two strictly increasing values. The least-squares fit needs at least two aligned observations and a varying independent variable; a constant dependent variable has reported R² of 1.
comparison day = (ln(comparison flux) − intercept)/log-growth slope Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| fittedLogGrowthRatePerDay | Fitted log growth rate per day | number |
| modelComparisonFluxDay | Model comparison flux day | number |
| aboveCallerEscalationRate | Above caller escalation rate | boolean |
| fitRSquared | Fit r squared | number |
{
"input": {
"timesDays": [
0,
1,
2
],
"measuredSo2TonnesPerDay": [
10,
20,
40
],
"callerEscalationLogRatePerDay": 0.5,
"callerComparisonFluxTonnesPerDay": 80
},
"output": {
"fittedLogGrowthRatePerDay": 0.6931471805599452,
"modelComparisonFluxDay": 2.9999999999999996,
"aboveCallerEscalationRate": true,
"fitRSquared": 1
}
}Limitations and assumptions
Unchanged exponential growth is assumed; the timing is not an eruption forecast.
Numbers and computed results must be finite; overflow 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 SO2 Mass Flux Tonnes Day: Integrate blank-corrected SO2 cross-plume column mass and multiply by signed normal plume speed; negative nondetections/transport remain signed, with no eruption-alert threshold or wind-direction inference. For a complementary task, use Fumarole Temperature Trend Monitoring Tool: Monitor thermometer-calibration-corrected fumarole temperature trend with explicitly linear comparison-time extrapolation; signed slopes/past crossing are retained, and gas-source/eruption attribution is not made.
References
-
SO2 Flux Trend Escalation Checker — tool.io
Similar or alternative tools
- SO2 Mass Flux Tonnes Day
Integrate blank-corrected SO2 cross-plume column mass and multiply by signed normal plume speed; negative nondetections/transport remain signed, with no eruption-alert threshold or wind-direction inference.
- Fumarole Temperature Trend Monitoring Tool
Monitor thermometer-calibration-corrected fumarole temperature trend with explicitly linear comparison-time extrapolation; signed slopes/past crossing are retained, and gas-source/eruption attribution is not made.