Zonal index

Term · Meteorology and atmospheric science · MLC-T-MET-010330

A measure of the strength of the zonal flow in the mid-latitudes, typically calculated as the difference in mean sea-level pressure or geopotential height between two latitude circles. A high zonal index indicates strong westerly winds, while a low index suggests a more meridional flow pattern. It is used to characterize atmospheric circulation regimes.

Table 1. Record
Identifier	MLC-T-MET-010330
Field	Meteorology and atmospheric science
See also	Circulation index; High index; Low index; Polar-easterlies index; Subtropical easterlies index; Temperate-westerlies index

Record as JSON

{
  "id": "MLC-T-MET-010330",
  "term": "Zonal index",
  "field": "Meteorology and atmospheric science",
  "definition": "A measure of the strength of the zonal flow in the mid-latitudes, typically calculated as the difference in mean sea-level pressure or geopotential height between two latitude circles. A high zonal index indicates strong westerly winds, while a low index suggests a more meridional flow pattern. It is used to characterize atmospheric circulation regimes.",
  "see_also": [
    "circulation index",
    "high index",
    "low index",
    "polar-easterlies index",
    "subtropical easterlies index",
    "temperate-westerlies index"
  ],
  "url": "https://mlchart.com/terminology/meteorology/zonal-index/"
}

Record 10,797 of 10,816 in Meteorology and atmospheric science terminology (MLC-0110). Request the full dataset.