Biologically Effective Degree Days
Evaluate caller explicit BEDD thermal-cap, diurnal-range adjustment and daylight convention, exposing all calibration rather than prescribing a universal viticultural formula or maturity date.
Description
Biologically effective degree days combine thermal accumulation with supplied caps, diurnal adjustments and daylight weighting.
Biologically effective degree days combine thermal accumulation with supplied caps, diurnal adjustments and daylight weighting. Exposing those parameters allows a stated regional convention to be applied consistently.1
Evaluate caller explicit BEDD thermal-cap, diurnal-range adjustment and daylight convention, exposing all calibration rather than prescribing a universal viticultural formula or maturity date.
When to use Biologically Effective Degree Days
Use this tool to evaluate caller explicit BEDD thermal-cap, diurnal-range adjustment and daylight convention, exposing all calibration rather than prescribing a universal viticultural formula or maturity date.
Prepare the climate observations and independently chosen model parameters. Confirm units, daily coverage, chronological order and the intended seasonal window.
How to use Biologically Effective Degree Days and understand its results
- Prepare the climate observations and independently chosen model parameters. Confirm units, daily coverage, chronological order and the intended seasonal window.
- Enter dailyMeanTemperaturesC, dailyDiurnalRangesC, callerBaseTemperatureC, callerMaximumDailyThermalContribution, callerDiurnalAdjustmentPerDegree, callerDiurnalReferenceC, callerDayLengthMultiplier using the field table and calculation rules, then run the tool.
- Read biologicallyEffectiveDailyDegreeDays, biologicallyEffectiveDegreeDayTotal. 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 |
|---|---|---|---|
| dailyMeanTemperaturesC | Daily mean temperatures c | list of number | Required |
| dailyDiurnalRangesC | Daily diurnal ranges c | list of number | Required |
| callerBaseTemperatureC | Caller base temperature c | number | Required |
| callerMaximumDailyThermalContribution | Caller maximum daily thermal contribution | number | Required |
| callerDiurnalAdjustmentPerDegree | Caller diurnal adjustment per degree | number | Required |
| callerDiurnalReferenceC | Caller diurnal reference c | number | Required |
| callerDayLengthMultiplier | Caller day length multiplier | number | Required |
Pair daily mean temperatures and nonnegative diurnal ranges in °C. Supply a finite base, reference range and signed adjustment coefficient, plus nonnegative thermal cap and daylight multiplier. The tool caps the basic positive thermal excess before adding the range adjustment, clips the adjusted result at zero, then applies the multiplier. It returns daily contributions and their total.
Paired lists must be nonempty and have equal lengths.
BEDD_i = max[0, min(cap,max(0,Tmean_i−base)) + adjustment(range_i−referenceRange)] × daylightMultiplier Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| biologicallyEffectiveDailyDegreeDays | Biologically effective daily degree days | list of number |
| biologicallyEffectiveDegreeDayTotal | Biologically effective degree day total | number |
{
"input": {
"dailyMeanTemperaturesC": [
10,
20
],
"dailyDiurnalRangesC": [
5,
15
],
"callerBaseTemperatureC": 10,
"callerMaximumDailyThermalContribution": 9,
"callerDiurnalAdjustmentPerDegree": 0.1,
"callerDiurnalReferenceC": 10,
"callerDayLengthMultiplier": 1
},
"output": {
"biologicallyEffectiveDailyDegreeDays": [
0,
9.5
],
"biologicallyEffectiveDegreeDayTotal": 9.5
}
}Limitations and assumptions
The adjustment can raise contributions beyond the initial thermal cap because clipping occurs before it. No universal calibration or growing-season dates are built in. This heat index does not predict maturity or development events by itself.
Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. 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 Growing Degree Days Single Sinusoid Method: Integrate ideal single-sinusoid daily temperature excess between caller lower and horizontal upper cutoffs analytically; differs from arithmetic daily-mean GDD and is not a development-event forecast. For a complementary task, use Huglin Heliothermal Index: Calculate Huglin mean/maximum heliothermal contributions over caller supplied season with caller latitude/daylength coefficient and base; no implicit hemisphere calendar or grape suitability classification.
References
-
Biologically Effective Degree Days — tool.io
Similar or alternative tools
- Growing Degree Days Single Sinusoid Method
Integrate ideal single-sinusoid daily temperature excess between caller lower and horizontal upper cutoffs analytically; differs from arithmetic daily-mean GDD and is not a development-event forecast.
- Huglin Heliothermal Index
Calculate Huglin mean/maximum heliothermal contributions over caller supplied season with caller latitude/daylength coefficient and base; no implicit hemisphere calendar or grape suitability classification.