Study Summary
Extreme dust storms evolving on sub-hourly timescales pose a serious challenge for conventional air-quality monitoring systems. Particulate matter (PM) sensors require enough aerosol to accumulate before they can trigger an alert, which means they often detect a dust storm only after it has already arrived. This study investigates whether the atmospheric electric field, measured as the potential gradient (PG), can serve as a faster early-warning indicator during these extreme events.
The research focuses on an unusually intense dust storm (Paracas) that struck the city of Ica, Peru, on 31 July 2025. In the southern Peruvian coastal desert, dust storms known locally as "Paracas" are the dominant regional dust phenomenon, driven by strong alongshore winds from the Paracas-Pisco coast. The July 2025 event, however, exhibited characteristics of a haboob: a sharply defined, vertically organized dust front that advances like a wall, rather than the gradual inland transport typical of canonical Paracas dust storms. Satellite imagery from the GOES-19 geostationary satellite, ground-based cameras, and two monitoring stations separated by 13.6 km were used to reconstruct the event timeline with minute-scale precision.
The results reveal a clear temporal hierarchy in detection capability. The PG began to deviate significantly from its seasonal baseline more than 100 minutes before any measurable increase in PM₂.₅ concentrations. A conservative rapid-growth electrical onset occurred 24 minutes before particulate arrival at the main station. The event produced an extreme bipolar electrical structure, with a polarity reversal reaching 5.8 kV/m, a value exceeding the 99.9th percentile of all records at this station since 2018.
These findings demonstrate that the electric field responds to boundary-layer electrification processes (charge separation and transport within the advancing dust front) that develop well ahead of the visible dust wall. This physical mechanism justifies PG monitoring as a critical tool to extend early-warning capabilities for dust storms and Paracas events, overcoming the inherent latency of mass-based air-quality sensors and the limited cadence of satellite imagery. Under Paracas-like wind regimes and more extreme haboob-type intrusions, the atmospheric electric field provides physically meaningful and temporally advanced information for real-time tracking of dust fronts in arid coastal regions.
Figure 1: Graphical summary of the electrical lead time and bipolar structure during the 31 July 2025 event. Click to enlarge.
How to cite this work:
Romero, R., Loayza, R., Huaman, G., Calderon, D., Buleje, Y., Arroyo, J., Tasayco, M., Torres, C., Tacza, J. C., Szpigel, S., & Raulin, J.-P., Electrical lead time during an extreme haboob-like dust-front intrusion in Ica, Peru. Available at SSRN: https://ssrn.com/abstract=6511441 or http://dx.doi.org/10.2139/ssrn.6511441