Description
Require nonnegative mixingRatioKgPerKg and return r/(1+r) as specificHumidityKgPerKg.
Atmospheric quantities distinguish temperature coordinates, pressure references, and moisture mass ratios. Specific humidity uses total moist-air mass, while a mixing ratio uses dry-air mass; those denominators must be explicit.
Require nonnegative mixingRatioKgPerKg and return r/(1+r) as specificHumidityKgPerKg.
When to use this tool
Use Water Vapor Mixing Ratio Specific Humidity Crosswalk when you need one atmospheric data component under a specified reference and unit convention.
How to use the tool and how it works
- Enter mixingRatioKgPerKg. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read specificHumidityKgPerKg. Use the output convention below.
Require nonnegative mixingRatioKgPerKg and return r/(1+r) as specificHumidityKgPerKg.1
Specific humidity divides water-vapor mass by total moist-air mass, while mixing ratio divides it by dry-air mass. Keeping these denominators distinct explains the conversion q = r / (1 + r) when both are expressed in kg/kg.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| mixingRatioKgPerKg | Nonnegative vapor mass per dry-air mass, in kg/kg; 0.01 means 10 g per kg of dry air. | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| specificHumidityKgPerKg | Vapor mass per total moist-air mass, in kg/kg, computed as r / (1 + r). | Required. Finite number. |
{
"input": {
"mixingRatioKgPerKg": 0.01
},
"output": {
"specificHumidityKgPerKg": 0.009900990099009901
}
}Limitations and assumptions
- Mixing ratio uses vapor mass per dry-air mass, while specific humidity uses vapor per moist-air mass; no temperature, saturation, or observed atmospheric condition is inferred.
- 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
Verify the complete meteorological definition and input measurements before combining the result with a model or observation series.
References
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