对树木年轮物质的光谱分析表明，碳-14浓度在一年内急剧上升，这与发生在公元前5410年左右的极端太阳高能粒子事件相一致。
Solar cycle variations
Posted inResearch Spotlights
Tree Rings Show Record of Newly Identified Extreme Solar Activity Event
Mass spectroscopy of tree ring material indicates a sharp, single-year rise in carbon-14 concentrations consistent with an extreme solar energetic particle event that occurred around 5410 BCE.
Posted inEditors' Highlights
Solar Properties Rival for Control of Mars’s Bow Shock
While most planetary bow shocks are controlled by the solar wind, at Mars the solar EUV flux is equally important.
Posted inResearch Spotlights
Sun's Magnetic Fields Best at Forecasting Solar Cycle Peaks
Models based on the Sun's polar magnetic fields performed best in simulating the solar cycle and predicting solar behavior.