Light Pollution's Impact On The Northern Lights

Light pollution refers to the brightening of the night sky due to artificial light sources such as street lamps, buildings, cars, and digital billboards. It is a significant issue for stargazers and those who want to observe the night sky, including the Northern Lights or the aurora borealis. Light pollution can make it difficult to see the Northern Lights, and in some cases, can even break up the lights entirely. The excess artificial light causes atmospheric light to scatter, and the Northern Lights, being a natural phenomenon, cannot compete with the brightness of light pollution. As a result, the Northern Lights are best viewed in rural, secluded areas, far away from cities and light pollution.

Light pollution washes out the Northern Lights

The Northern Lights, or Aurora Borealis, is a spectacular light show that has captivated people for generations. The lights are caused by charged particles given off by the sun during solar storms interacting with the gases in the Earth's atmosphere. The lowest part of an aurora is typically around 80 miles above the Earth's surface, but the top of a display may extend several thousand miles above the Earth. The lights can occur anywhere between 40 and 600 miles above the Earth's surface.

The Northern Lights are usually most active after midnight, and the best viewing conditions are clear, dark skies with very few clouds. The darker the sky, the better. The further away from light pollution, the better the experience of viewing the aurora will be. The best places to see the Northern Lights are in secluded, rural areas with little human habitation, minimising both light and air pollution.

Light pollution is caused by excess light from buildings, cars, streetlamps, high-rise blocks, and gas flaring from petrochemical plants. In clear and moonless nights, the night sky in urban settings is typically 14–23 times brighter than expected from a nominal natural dark sky. This has big side effects. It is estimated that 60% of Europeans are now unable to see the Milky Way. Light pollution also affects your chances of seeing the Northern Lights.

Light pollution can be combated by turning off unnecessary lights, and by encouraging companies to take action.

Light pollution scatters the atmospheric light

Light pollution is the brightening of the night sky due to man-made light sources, such as street lamps, high-rise buildings, and gas flaring from petrochemical plants. It is a significant issue for those wanting to view the Northern Lights, as it makes the lights more difficult to see and can even break them up entirely.

The Northern Lights, or the aurora, is a spectacular natural light show that has captivated humans for generations. The lights are caused by charged particles from solar storms interacting with gases in the Earth's atmosphere. The varying colours of the lights are due to the types of gases that the sun particles collide with and the altitude at which this occurs. The more common green colour is caused by oxygen at lower altitudes, while red is caused by oxygen at higher altitudes. Nitrogen produces blue, purple, and pink hues.

Light pollution affects the visibility of the Northern Lights by scattering atmospheric light. The artificial light from cities causes light from stars, planets, the moon, and the aurora to break up and disperse. This is similar to the effect of the sun's powerful rays during the day, which prevent auroras from forming. The brighter the night sky is due to light pollution, the harder it is to see the Northern Lights. In fact, light pollution is often brighter than the aurora, washing out the display.

The impact of light pollution on the visibility of the Northern Lights is influenced by several factors. Firstly, the strength of the aurora itself plays a role. In certain locations within or near the Arctic Circle, such as Fairbanks, Alaska, and Tromsø, Norway, light pollution weakens the display of the lights but does not completely obscure them. However, weaker auroras can be entirely drowned out by light pollution. Additionally, cloud cover can amplify the effects of light pollution, as clouds reflect artificial light, further reducing the visibility of the Northern Lights.

To optimise the viewing experience of the Northern Lights, it is essential to minimise light pollution. This can be achieved by reducing the number of light sources, such as streetlights, and adjusting the direction of lighting to point downwards rather than upward or outward. By mitigating light pollution, the atmospheric light from the aurora can remain intact, providing a more vivid and detailed viewing experience.

Light pollution is brighter than the Northern Lights

Light pollution is a significant hindrance to viewing the Northern Lights, and it is often brighter than the aurora itself. This is because light pollution refers to the excess artificial light generated by buildings, cars, billboards, and street lamps, which drowns out the night sky, making it difficult to observe celestial bodies and phenomena. On clear, moonless nights, light pollution can make the urban sky up to 23 times brighter than the natural level of darkness, severely impacting the visibility of the Northern Lights.

The effects of light pollution on the visibility of the Northern Lights are twofold. Firstly, the excess artificial light scatters the atmospheric light, including that of the aurora, making it weaker or even breaking it up entirely. Secondly, light pollution raises the baseline brightness of the night sky, often outshining the Northern Lights. This means that even if the aurora is not completely obscured by light pollution, it may still be too faint to be seen by the naked eye.

The impact of light pollution on the visibility of the Northern Lights is so significant that even in locations within or near the Arctic Circle, such as Fairbanks, Alaska, and Tromsø, Norway, light pollution can diminish the aurora displays. In these places, the Northern Lights may appear weaker or may not be visible at all due to the interference of artificial light. Therefore, to maximise the chances of witnessing the Northern Lights in their full splendour, it is advisable to seek out secluded areas with minimal human habitation, thereby reducing both light and air pollution.

While light pollution can be a challenge for aurora hunters, there are ways to mitigate its effects. On an individual level, simple actions such as turning off unnecessary lights at home or adjusting outdoor lights to point downwards can help reduce light pollution. Additionally, supporting initiatives like the UK government's 'Artificial Light in the Environment' policy update demonstrates a commitment to addressing this issue. By working together, we can help preserve the darkness of the night sky and ensure that the dazzling display of the Northern Lights remains accessible for future generations to enjoy.

Light pollution affects human health

Light pollution refers to excess light generated by buildings, cars, and streetlamps. While it does not have a direct effect on human health, it can ruin the view of the night sky and the Northern Lights. The larger a city, the more light pollution it gives off.

However, light pollution can have an impact on human health in several indirect ways. Firstly, it can affect sleep patterns and quality. The proliferation of artificial light at night means that most people no longer experience truly dark nights, which can disrupt the natural day/night cycle that humans have evolved to follow. This, in turn, can lead to sleep disorders and a higher risk of obesity, depression, diabetes, and even breast cancer.

Secondly, light pollution can have ecological effects, which then have a knock-on effect on human health. For example, prolonged exposure to artificial light can prevent trees from adjusting to seasonal variations, which has implications for the wildlife that depends on them. It can also alter the behaviours and breeding cycles of insects, turtles, birds, fish, and other wildlife species.

Thirdly, light pollution can be a contributing factor to energy waste and climate change. By reducing our use of artificial lighting at night, we can not only improve our health but also reduce our energy consumption and carbon footprint.

To combat light pollution, individuals can take simple steps such as turning off unnecessary lights and using dimmers or lower-temperature light bulbs. Governments and companies also have a role to play in reducing light pollution by implementing policies and practices that minimise the use of artificial lighting and prevent light trespass.

Light pollution affects wildlife

Light pollution, the brightening of the night sky due to the presence of man-made light sources, has a detrimental impact on wildlife. It disrupts the biological rhythms and behaviours of nocturnal animals, which make up 80% of the world's population.

Impact on Nocturnal Animals

Nocturnal animals, which are active at night and sleep during the day, are particularly vulnerable to light pollution. Their natural environment is drastically altered, as the night sky is brightened by artificial light sources. This disruption can impact their ability to hunt, feed, and reproduce, with potential deadly consequences.

Impact on Birds

Light pollution has a significant impact on bird populations, especially nocturnal birds that migrate at night. These birds rely on the moon and stars for navigation during their journeys. When they encounter brightly lit areas, they become disoriented and may crash into buildings or towers. They may also circle these structures until they drop from exhaustion. Over 450 bird species in North America are susceptible to such collisions, including endangered species. In some cases, entire flocks have collided with over-lit structures, resulting in thousands of bird deaths.

Impact on Sea Turtles

Light pollution also poses a threat to sea turtles. Female sea turtles are discouraged from coming ashore to nest on beaches near bright lights. Newly hatched turtles, which orient themselves towards the sea by the light of the moon, are lured away from the ocean by artificial lights. This can lead to their demise as they crawl inland or crawl aimlessly down the beach, becoming easy prey for predators.

Impact on Other Species

Light pollution affects a wide range of species, including amphibians, insects, and mammals. For example, artificial lights can disrupt the breeding rituals of frogs and toads, interfering with their reproduction and reducing their populations. Bats, which are slow fliers, avoid feeding in illuminated areas as it exposes them to predators. Even large predators, such as cougars, may be deterred from crossing brightly lit areas, leading to habitat fragmentation.

Solutions and Conservation Efforts

Conservationists and researchers have proposed various solutions to mitigate the impact of light pollution on wildlife. These include dimming or turning off unnecessary lights, using shields or shades to reduce light spill, and adopting more focused lighting technologies like LED microarray lamps. Some communities have implemented ordinances to turn off lights during certain seasons, such as turtle nesting season, to protect vulnerable species. Additionally, organizations like DarkSky International and the Fatal Light Awareness Program are working to raise awareness and promote the preservation of dark skies.

Frequently asked questions