Study Summary
This study analyzes the variability of the atmospheric electric field (potential gradient, PG) in Ica, Peru, based on continuous measurements conducted between March 2018 and December 2022 by the Research Center for the Study of Solar Activity and its Effects on Earth (CIEASEST) at the San Luis Gonzaga National University (UNICA).
The research focuses on identifying fair weather conditions and characterizing the typical diurnal PG curve for an arid coastal station in the South American Pacific. The study evaluates the PG response to local meteorological variables, including wind speed/direction, precipitation, fog, dust devils, and the regional dust storms known as Paracas.
Results indicate that the PG in Ica is strongly modulated by local processes. A wind speed threshold of 3.5 m/s was identified, beyond which the PG exhibits significant perturbations due to the lifting and transport of dust and aerosols. While sea breeze events generate sustained PG increases, Paracas dust storms cause abrupt decreases, often occurring before any visible reduction in visibility.
Furthermore, marked seasonal variability was observed, with higher PG values during the austral winter (June–August) compared to summer (December–February). This is attributed to seasonal shifts in aerosol concentration, potentially linked to regional biomass burning. Spectral analysis using wavelet transform revealed dominant daily, semi-annual, and annual periodicities, alongside an intra-seasonal signal of approximately 45 days associated with the Madden–Julian Oscillation.
These findings confirm that in arid coastal regions, PG variability is primarily driven by local atmospheric and aerosol effects, demonstrating its utility as a high-sensitivity tool for monitoring regional environmental phenomena.
How to cite this work:
Romero, R., Tacza, J., Arroyo, J., Prieto, F., Macotela, L., Buleje, Y., Loayza, R., Fernandez, U., Raulin, J.-P. (2024). First results of the potential gradient variation in a tropical station in South America (Ica, Peru). Journal of Atmospheric and Solar-Terrestrial Physics, 256, 106198.