Impact of Solar Proton Events on the Stratospheric Polar Vortex in the Northern Hemisphere: A Quantitative Analysis.

The stratospheric polar vortex (SPV) profoundly affects northern hemisphere weather and climate, with its dynamics influenced by terrestrial and solar factors. Despite established terrestrial influences, the quantitative effects of solar energetic particles have not yet been fully understood. This study presents a quantitative analysis of 27 intense solar proton events (SPEs) from 1986 to 2020, revealing a significant correlation between the integrated flux of SPEs and enhanced SPV wind speeds across altitudes. Notably, the wind speed enhancements, ranging from 1.8 m/s (15.1%) at 100 hPa to 3.0 m/s (7.3%) at 1 hPa, demonstrate an altitude‐dependent pattern, with the greatest impacts of 5.8 m/s (19.1%) at 5 hPa. A partial correlation analysis identifies SPEs as the dominant driver of SPV enhancement in the middle and lower stratosphere, while ultraviolet radiation dominates at the stratopause. We propose a mechanism involving the amplification of the meridional temperature gradient due to differential ozone responses, thereby linking solar activity to the modulation of the SPV. These findings enhance our understanding of solar‐terrestrial interactions and their implications for climate modeling. Plain Language Summary: How does the solar activity affect our weather and climate? This question is at the forefront of space physics research. We have discovered that powerful bursts of solar energy, known as solar proton events (SPEs), can significantly impact Earth's atmosphere, especially during intense solar flares. Our study explores how solar particles and electromagnetic radiation alter stratospheric ozone levels. This change in ozone increases the stratospheric temperature gradient from the equator to the poles, driving the stratospheric polar vortex (SPV). While the Sun's ultraviolet rays kick‐start the SPV's growth, the SPEs have a more notable and lasting effect. Understanding these solar‐terrestrial interactions is key to predicting how space weather can influence our daily lives, from short‐term weather changes to long‐term climate patterns. Key Points: We demonstrate a quantitative altitude‐dependent pattern of stratospheric polar vortex (SPV) enhancements during intense solar proton events (SPEs)SPE is the dominant driver of SPV enhancement in the mid‐low stratosphere, while ultraviolet radiation dominates at the stratopauseWe propose a mechanism involving the amplification of the meridional temperature gradient due to differential ozone responses [ABSTRACT FROM AUTHOR]