polar-easterlies index

polar-easterlies index

[′pō·lər ′ēs·tər‚lēz ′in‚deks]
(meteorology)
A measure of the strength of the easterly wind between the latitudes of 55° and 70°N; the index is computed from the average sea-level pressure difference between these latitudes and is expressed as the east to west component of geostrophic wind in meters and tenths of meters per second.