In May 2024, auroras were observed at unusually low latitudes across the globe, lighting up skies that rarely see such displays. Inside Earth’s magnetosphere, the region of space surrounding our planet and dominated by its intrinsic magnetic field, something significant was finally being observed. It started with a large sunspot firing a rapid series of powerful solar eruptions. Clouds of magnetized plasma merged as they traveled through space and impacted Earth's magnetosphere. No geomagnetic storm this powerful had ever been measured in the Earth’s ring current region, a belt of charged particles in space near our planet. Two sources of ring current ions are known: solar wind and Earth's ionosphere, the electrically charged upper layer of the atmosphere. For decades, scientists have debated how much each source contributes to the ring current. During most storms, both contribute. However, during a storm driven by a dense solar wind, some scientists expected solar wind ions to continue to play a notable role. Yet the first direct measurements of ring current composition from a super geomagnetic storm revealed that solar wind ion contributions were minimal, and the level of Earth-origin ion dominance had never been observed before. The findings, published in Science Advances, suggest that understanding how much Earth's ionosphere contributes to the ring current may be essential to accurately predict the severity of super geomagnetic storms. The dominance of ionospheric ions, which are far heavier than solar wind particles, may have intensified the magnetic disturbance and concentrated the ring current peak unusually close to Earth. The researchers also make a case for a proposed Japanese multi-satellite mission to understand exactly how ion supply processes work.

Accounting for atmospheric degradation of levoglucosan is essential for accurate identification of biomass burning sources in tropical regions, but as much as 88% of levoglucosan may be lost before measurement. After correcting for this atmospheric loss, the researchers identified urban domestic use of fuels, rather than agricultural burning, as the dominant source of PM_2.5 in Ho Chi Minh City, Vietnam. 

Marine plankton release a gas that helps in forming aerosol particles that can seed clouds over cold ocean regions —far more effectively than previously assumed. An international study led by the University of Helsinki improves our understanding of the atmosphere and the accuracy of climate models.

New cloud radar data from the ESA-JAXA EarthCARE space mission is being assimilated into the European Centre for Medium-Range Weather Forecast (ECMWF)’s global forecasting system for the first time.

In a new perspective paper, Qin Huang, of Arizona State University, and colleagues, propose that the worst damage from extreme weather events could be prevented through Weather Jiu-Jitsu, a  theory-based approach to “nudge” weather systems away from harmful trajectories. The paper publishes June 24 in the open-access journal PLOS Water. 

As India grapples with searing heat and an erratic monsoon, a perspective paper reveals the crisis is worse than thought—and offers a surprising ray of hope.