Indian Ocean Dipole Gradient Classifier

Explicit west-minus-east same-period/baseline anomaly gradient and independently verified strict phase bounds, equality neutral; no live data/ENSO inference. Caller independently establishes units, regime, calibration and applicability; this does not establish design-code compliance, authenticity, operational safety, treatment efficacy or a validated forecast.

Description

The Indian Ocean Dipole gradient compares western and eastern sea-surface-temperature anomalies on a matched baseline.

The Indian Ocean Dipole gradient compares western and eastern sea-surface-temperature anomalies on a matched baseline.^[1]

The classification depends on supplied bounds and a strict boundary convention.

When to use Indian Ocean Dipole Gradient Classifier

Use this tool to calculate or review the supplied observations under the stated rules. Match the observation interval, units, datum, coordinate signs and model regime.

How to use Indian Ocean Dipole Gradient Classifier and understand its results

Match the observation interval, units, datum, coordinate signs and model regime.
Enter observedWestIndianOceanAnomalyC, observedEastIndianOceanAnomalyC, callerNegativePhaseUpperC, callerPositivePhaseLowerC, using the field meanings and rules below, then run the tool.
Read indianOceanDipoleGradientC, callerDipolePhase. Inspect nested result fields where present, and review unknown records separately from known matches.
Correct any reported input issue and run again. Before using a successful result, check the stated units, signs, reference scope and observation coverage.

Input field	Meaning	Value type	Requirement
observedWestIndianOceanAnomalyC	Observed west indian ocean anomaly c	number	Required
observedEastIndianOceanAnomalyC	Observed east indian ocean anomaly c	number	Required
callerNegativePhaseUpperC	Caller negative phase upper c	number	Required
callerPositivePhaseLowerC	Caller positive phase lower c	number	Required

Compute west minus east anomaly. Require finite lower≤upper bounds; their signs are not constrained. Gradients strictly below the lower bound are negative phase; strictly above the upper bound are positive phase. Values on either boundary are neutral.

D=west−east; phase=negative if D<lower, positive if D>upper, otherwise neutral

Use the matching field units and the exact boundary, ordering and reference rules above.

Output field	Meaning	Value type
indianOceanDipoleGradientC	Indian ocean dipole gradient c	number
callerDipolePhase	Caller dipole phase	string

json

{
  "input": {
    "observedWestIndianOceanAnomalyC": 1,
    "observedEastIndianOceanAnomalyC": 0.2,
    "callerNegativePhaseUpperC": -0.4,
    "callerPositivePhaseLowerC": 0.4
  },
  "output": {
    "indianOceanDipoleGradientC": 0.8,
    "callerDipolePhase": "positive"
  }
}

Limitations and assumptions

The stated observation or model covers only the supplied record and reference regime. It does not fill missing measurements, supply uncertainty estimates or produce a validated forecast.

Missing required fields, unknown fields, wrong types and violated rules return input issues. Numeric values and outputs must be finite.

Alternative or Complementary methods

For a related step, use Pacific Decadal Phase Lookup: A Pacific Decadal Oscillation phase record depends on its index source, baseline and time window. For a complementary comparison, use Atlantic Multidecadal Window Average Calculator: A multidecadal index average depends on the anomaly baseline and the amount of time actually observed.

References

Indian Ocean Dipole Gradient Classifier — tool.io

Similar or alternative tools

Pacific Decadal Phase Lookup
A Pacific Decadal Oscillation phase record depends on its index source, baseline and time window.
Atlantic Multidecadal Window Average Calculator
A multidecadal index average depends on the anomaly baseline and the amount of time actually observed.