Electric Field Measurements in the Antarctic Reveal Patterns Related to the El Niño—Southern Oscillation

• Published in: Geophysical research letters 2021-11, Vol.48 (21), p.n/a
• Main Authors: Slyunyaev, Nikolay N., Frank‐Kamenetsky, Alexander V., Ilin, Nikolay V., Sarafanov, Fedor G., Shatalina, Maria V., Mareev, Evgeny A., Price, Colin G.
• Format: Article
• Language: English
• Subjects: ENSO; global electric circuit; ionospheric potential; measurements; modeling; potential gradient
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2021GL095389

Electric field measurements at Vostok station in Antarctica reveal that the El Niño—Southern Oscillation (ENSO) has a statistically significant effect on the global electric circuit, as earlier predicted by simulations. Analysis of 10 October‐February periods during 2006–2016 indicates that the shape of the diurnal variation of the surface electric field is significantly different for El Niño and La Niña years, with an especially pronounced deviation during the super El Niño of 2015/16. During strong El Niños the potential gradient relative to the diurnal mean is generally higher than usual around 8:00–14:00  UTC and lower than usual around 16:00–0:00 UTC; La Niñas are characterized by the opposite behavior. Simulations with the Weather Research and Forecasting model imply that the observed patterns are the result of changes in the global distribution of electrified clouds over the Pacific Ocean, Maritime Continent, and South America during ENSO events. Plain Language Summary The El Niño—Southern Oscillation (ENSO) is one of the most remarkable modes of climate variability on Earth. Being made up of irregularly alternating warm (El Niño) and cold (La Niña) phases, the ENSO affects atmospheric circulation, global temperature and rainfall patterns, agriculture, and economic output. Recent simulations have suggested that changes in global convection patterns due to ENSO should also affect surface atmospheric electric fields and currents in remote regions of the planet. Here, we present electric field measurements performed during 2006–2016 at Vostok station in the Antarctic that reveal clear patterns related to ENSO as earlier predicted by simulations. Measurements show that the shape of the diurnal variation of the surface electric field is significantly different for El Niño and La Niña years (with an especially pronounced effect during the super El Niño of 2015/16), which, according to simulations, is the result of changes in the global distribution of electrified clouds over the Pacific Ocean, Maritime Continent, and South America during ENSO events. This provides further evidence of the influence of climate fluctuations on the Earth's global electromagnetic environment. Key Points Electric field measurements in Antarctica show that strong El Niños and La Niñas consistently impact the atmospheric global circuit For the super El Niño event of 2015/16, the anomalies in the global electric circuit are especially pronounced Simulations show that the observed