Description
Calculate a supplied first-order residence-time decay fraction.
Gas and aerosol records need explicit species, charge, reference state, concentration and wet/dry bases. A pressure correction to mass concentration differs from a change in mole fraction, and absolute uncertainty differs from a relative percentage. Blank-corrected negative values can expose discrepancies without proving physical concentrations.
Calculate a supplied first-order residence-time decay fraction.
When to use this tool
Use Trace Gas Residence Decay Factor when you already have elapsedTime, residenceTime and need to calculate a supplied first-order residence-time decay fraction.
How to use the tool and how it works
- Enter elapsedTime, residenceTime. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read remainingFraction. Use the output convention below.
Require elapsedTime>=0 and residenceTime>0; return exp(-elapsed/residence).1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| elapsedTime | Elapsed Time | Required. Finite number; minimum 0. |
| residenceTime | Positive supplied e-folding time, in the same unit as elapsedTime; not half-life. | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| remainingFraction | Remaining Fraction | Required. Finite number. |
{
"input": {
"elapsedTime": 10,
"residenceTime": 10
},
"output": {
"remainingFraction": 0.36787944117144233
}
}Limitations and assumptions
- Residence time is the e-folding time under a constant first-order removal model, not half-life. No emissions, transport, variable removal or actual lifetime is inferred; extreme ratios can yield zero.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Review the complete sampling, calibration and chemical analysis with verified reference conditions. Check dilution, background, charge and uncertainty definitions before using local terms in an emissions, composition or compliance assessment.
References
Similar or alternative tools
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