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This article provides an overview of the experimental design, execution, education and public outreach, data collection, and initial scientific results from the Remote Sensing of Electrification, Lightning, and Mesoscale/Microscale Processes with Adaptive Ground Observations (RELAMPAGO) field campaign. RELAMPAGO was a major field campaign conducted in the Córdoba and Mendoza provinces in Argentina and western Rio Grande do Sul State in Brazil in 2018–19 that involved more than 200 scientists and students from the United States, Argentina, and Brazil. This campaign was motivated by the physical processes and societal impacts of deep convection that frequently initiates in this region, often along the complex terrain of the Sierras de Córdoba and Andes, and often grows rapidly upscale into dangerous storms that impact society. Observed storms during the experiment produced copious hail, intense flash flooding, extreme lightning flash rates, and other unusual lightning phenomena, but few tornadoes. The five distinct scientific foci of RELAMPAGO—convection initiation, severe weather, upscale growth, hydrometeorology, and lightning and electrification—are described, as are the deployment strategies to observe physical processes relevant to these foci. The campaign's international cooperation, forecasting efforts, and mission planning strategies enabled a successful data collection effort. In addition, the legacy of RELAMPAGO in South America, including extensive multinational education, public outreach, and social media data gathering associated with the campaign, is summarized. [ABSTRACT FROM AUTHOR]

The Global atmospheric Electric Circuit (GEC) sustains the fair weather (FW) electric field, or potential gradient (PG). In this article, we analyze PG measurements recorded between 2017 and 2021 at the Instituto de Investigaciones Científicas y Técnicas para la Defensa (CITEDEF) in Buenos Aires, Argentina, to calculate the daily PG (FW) curve and examine whether local PG measurements capture the GEC signal. With the aim of supporting future common methodologies that do not rely on meteorological data for FW identification - and hence aid inter-comparisons, we rely on previously developed statistical methodologies to propose a FW selection based on the absolute deviation from the median of the data series. Using this methodology we filtered FW days and showed that the local PG (FW) curve had a significant correlation of 0.83 with the Carnegie curve. In order to test the extent to which the local daily PG (FW) curve captures the global thunderstorm signal, the area of thunderstorms was calculated at both global and regional scales using data from the Thunder Hour Database (http://thunderhours.earthnetworks.com). The PG (FW) curve was shown to have a good correlation with the daily median variation of the global thunderstorm area on both annual and quarterly scales. Additionally, the analysis of coincident aerosol optical thickness (AOD) measurements by the AERONET network and temperature observations helped to conclude that local effects such as pollution from a near highway are not dominating the PG (FW) curve behaviour. Both analyses allowed us to conclude that the GEC signal can be detected in Buenos Aires. [Display omitted] • The daily PG curve (FW) in Buenos Aires has a correlation of 0.83 with the Carnegie curve with 95% confidence. • The daily PG (FW) curve in Buenos Aires has a seasonal variation that accompanies the global changes of thunderstorm areas. • Local effects such as pollution from a near highway are not dominating the PG (FW) curve behaviour. [ABSTRACT FROM AUTHOR]

Satellite observations have revealed that some of the world’s most intense deep convective storms occur near the Sierras de Córdoba, Argentina, South America. A C-band, dual-polarization Doppler weather radar recently installed in the city of Córdoba in 2015 is now providing a high-resolution radar perspective of this intense convection. Radar data from two austral spring and summer seasons (2015–17) are used to document the convective life cycle, while reanalysis data are utilized to construct storm environments across this region. Most of the storms in the region are multicellular and initiate most frequently during the early afternoon and late evening hours near and just east of the Sierras de Córdoba. Annually, the peak occurrence of these storms is during the austral summer months of December, January, and February. These Córdoba radar-based statistics are shown to be comparable to statistics derived from Tropical Rainfall Measuring Mission Precipitation Radar data. While generally similar to storm environments in the United States, storm environments in central Argentina tend to be characterized by larger CAPE and weaker low-level vertical wind shear. One of the more intriguing results is the relatively fast transition from first storms to larger mesoscale convective systems, compared with locations in the central United States. [ABSTRACT FROM AUTHOR]