The aurora borealis, with its ribbons of green and pink light, has captivated people for centuries. Yet, beyond its visual splendor, this dazzling phenomenon carries an auditory mystery—strange, crackling “sounds” that many claim to have heard. The science driving these elusive noises is as fascinating as the lights themselves, blending atmospheric physics with emerging theories about our sensory experiences.
For years, the idea of auroral sounds was dismissed as folklore, a product of overactive imaginations or exaggerated storytelling. After all, the lights occur high in the Earth’s atmosphere, sometimes as far as 60 miles above the ground, a distance that seems too vast for audible connections. However, recent studies have not only validated the existence of these sounds but have begun uncovering the mechanisms behind them.
One widely supported theory involves electrophonic noise. High-energy particles from the sun collide with Earth’s magnetosphere during periods of strong solar activity, creating the vibrant displays of the northern lights. These same charged particles can also generate low-frequency electromagnetic waves. As these waves reach the ground, they interact with nearby objects such as metal structures, trees, or even glasses perched on a person’s face, converting electromagnetic energy into audible sound waves. This conversion explains why some claim to hear faint pops, hisses, or crackles during an aurora display, even in otherwise silent landscapes.
Research has even pointed to temperature inversions—a common atmospheric phenomenon in cold regions—as another factor at play. When a layer of warm air traps colder air closer to the Earth’s surface, it can create conditions where sound from miles away seems to materialize suddenly and sharply. While this doesn’t directly explain the creation of auroral sounds, it suggests a way for existing noises to be perceived more prominently in areas where auroras occur.
Still, part of the mystery lies in the fleeting and unpredictable nature of these sounds. Unlike the lights, which can be mapped and forecasted based on solar activity, the auditory phenomena don’t always accompany an aurora event. They can occur sporadically, making them difficult to study in controlled environments. This very unpredictability has kept scientists intrigued, sparking a wave of new research into the intersection between human perception and environmental acoustics.
Conditions that amplify aurora acoustics
The aurora borealis is a visual marvel, but the conditions that allow its mysterious sounds to manifest are complex and heavily dependent on the surrounding environment. The elusive nature of these auditory phenomena can be attributed to a delicate combination of atmospheric, geomagnetic, and terrestrial factors that work together, often in ways that seem almost serendipitous. To truly grasp why these sounds occur, it’s necessary to explore how the interplay of such conditions amplifies or brings them into existence.
One crucial element is the geomagnetic activity—the very force that gives rise to the auroral display itself. When solar storms send charged particles careening toward Earth’s magnetosphere, the energy transfer generates not only the shimmering lights but also the potential for electromagnetic disturbances near the Earth’s surface. These disturbances, when strong enough, can effectively “prime” the environment for sound waves to emerge. The stronger the solar activity, the higher the likelihood of experiencing sharper, more pronounced phenomena like crackles or faint popping noises during an aurora display.
Another important factor lies in the stillness of the surrounding landscape. The areas where the aurora borealis often appears—remote, open spaces far from urban interruptions—create near-perfect conditions for faint sounds to carry and resonate. Imagine standing on an expansive tundra or a frozen lake under a canopy of vibrant northern lights. The absence of background noise in such vast, isolated environments allows subtle auditory phenomena to feel magnified, making faint electromagnetic conversions easier to detect by the human ear.
Temperature inversions also set the stage for these sounds to travel further than usual. In polar and subpolar regions, surface temperatures often plummet far below those of the higher atmosphere, forming layers of air that act almost like an acoustic lens. This inversion not only enhances how sound waves travel but may also contribute to sudden bursts of auditory clarity, as if the sounds have been caught and projected toward listeners by the atmosphere itself. While these conditions don’t produce the sounds, they undeniably shape how they are perceived, amplifying faint noises into something distinct and memorable.
Interestingly, local topography and objects in the environment can also act as triggers or amplifiers. Physical features—such as sparse forests, metal structures, or even icy surfaces—have been theorized to interact with electromagnetic waves, converting them into audible vibrations. The specific materials and surroundings of a location can dictate the intensity, frequency, and even the unique “character” of the sounds individuals might hear during an aurora event. This variability explains why reports of auroral noises range from eerie whispers to sharp crackles, depending on where the listener is stationed.
What makes the aurora borealis an even greater enigma is how unpredictably these factors align. A breathtaking visual display doesn’t guarantee accompanying sounds—it takes a perfect storm of environmental and atmospheric conditions for them to come to life. For those lucky enough to experience the rare convergence of these elements, the auditory aspect of an aurora becomes an unforgettable counterpart to its visual brilliance.