Measurements of the Atmospheric Electric Field through a Triangular Array and the Long-range Saharan Dust Electrification in Southern Portugal

TL;DR

This study measures atmospheric electric fields in Southern Portugal during Saharan dust events, revealing long-range dust electrification effects and changes in electric field strength associated with dust outbreaks.

Contribution

It provides new measurements of atmospheric electric fields during Saharan dust events using a triangular array, highlighting long-range dust electrification phenomena.

Findings

AEF increased by ~23 V/m during dust event

Detected positive space-charge inside dust layer (~20-2 pCm-3)

AEF decreased after the dust event

Abstract

Atmospheric electric field (AEF) measurements were carried out in three different sites forming a triangular array in Southern Portugal. The campaign was performed during the summer characterized by Saharan dust outbreaks; the 16th-17th July 2014 desert dust event is considered here. Evidence of long-range dust electrification is attributed to the air-Earth electrical current creating a positive space-charge inside of the dust layer. An increase of ~23 V/m is observed in AEF on the day of the dust event corresponding to space-charges of ~20-2 pCm-3 (charge layer thicknesses ~10-100 m). A reduction of AEF is observed after the dust event.