Rhythm of light

Too much light or the wrong type can make us less productive and leave us stressed. Lighting designer Anna Rooney looks to Halley VI Research Station in Antarctica, where darkness falls for more than three months of the year, to explore how lighting can be designed for health — even in the harshest of environments.

The body’s natural internal clock regulates many of our bodily functions, also our known as circadian rhythms, which include our sleep patterns, temperature, mood and even our digestion.

Light — especially natural sunlight — has the greatest influence on our circadian rhythms: the wrong type, wavelength and brightness can throw our body clock and hormones out of whack and disrupt not only our sleep patterns but metabolism, mental alertness, emotional wellbeing and overall resilience. In fact, research increasingly shows strong links between disrupted circadian rhythms and the development of health conditions including diabetes, obesity, heart disease and depression.

Making lighting work

Within the workplace, lighting plays a big part in building design, especially considering that most people in office environments receive little natural sunlight each day. Glare, brightness, light direction and colour all impact on how well we feel and how much work we get done.

So, what happens when you live and work in one of highest, windiest and driest places on Earth, with 24-hour darkness in winter, 24-hour sunlight in summer and where temperatures reach minus 56 degrees Celsius?

Lighting extremes

Located on the Brunt Ice Shelf — a 150‑metre‑thick floating ice block in Antarctica, British Antarctic Survey’s (BAS) Halley VI Research Station is the world’s first fully relocatable, permanently-manned Antarctic research station.

Up to 70 people live and work at the station throughout the year, where scientists conduct pioneering research into the Earth’s atmosphere, from climate change to sea level rise, often working in shift patterns for up to 18 months at a time.

All about survival

Designed by AECOM and Hugh Broughton Architects, Halley VI provides life support to its occupants much like a space station supports its astronauts when in orbit — the station must be totally self-sufficient to ensure occupants’ health, wellbeing and survival, with lighting playing a crucial part.

We looked closely at Halley VI’s lighting design to show how light sources can be used to regulate circadian rhythms so people stay happy, healthy and motivated.

Setting the mood

Light sources have a particular colour temperature measured in Kelvin (K). Colour temperatures can be compared to different types of natural light, from coolwhite to warm-blue, each one creating a certain mood or effect, playing an important role in simulating the different strengths and benefits of natural daylight needed to regulate the natural body clock.

Light sources of varying colour temperatures have been used throughout Halley VI to differentiate between work and social and sleeping areas: cool 4000 K lights, which encourage concentration and alertness, illuminate work spaces, while warm 3000 K lights, which create feelings of relaxation and calm, are used in the bedrooms, corridors, lounges and throughout Halley VI’s main module, where occupants relax and socialise.

Combating SAD

Because winter falls for nine months of the year at Halley VI, occupants are at particular risk of developing Seasonal Affective Disorder (SAD). Symptoms are generally worse during winter and include persistent feelings of low mood, irritability and lethargy, and weight gain.

To reduce the chances of occupants developing SAD, we worked with the University of Surrey’s Endocrinology Department, who have been conducting research on lighting in Antarctica for over 20 years. Its research concludes that for Antarctic station workers, a single significant exposure to blue-rich light is more beneficial in suppressing melatonin and maintaining serotonin levels, both vital in regulating the body’s circadian rhythms, than trying to control exposure throughout the day.

To provide occupants with a single powerful burst of vital blue-rich light, each bed has a custom, built-in lighting panel, which can be set and turned on gradually with the occupants’ morning alarm, providing controlled levels of ultra- blue 17000 K daylight-coloured light that mimics the rising of the sun and, in turn, helps regulate their body clocks during periods of darkness, continual daylight and shift work.

Letting in the light

Nearly every workspace, social area and bedroom has a large window, enabling natural light to filter in throughout the station. Interior spaces also have skylights of various shapes and sizes, with a vast glazed wall in Halley VI’s main module to maximise daylight.

In control

Manual black-out window blinds help occupants regulate their circadian rhythms between shifts and at night during the summer months when they seal the station to conduct atmospheric optical experiments. Halley VI staff can also manually dim the lights in every room, giving them control over brightness and mood.

Built to last

Halley VI has been designed and built to endure 20 years of Antarctica’s extreme weather, with at least one relocation expected due to the shrinking of the Brunt Ice Shelf. Most of Halley VI’s lighting has been designed to last for at least 10 years, minimising maintenance and the number and variety of lamp spares that need to be transported and stored on site. All lamps are 600 millimetres or shorter for safety, storage and transport.

Halley VI redefines polar architecture and engineering. Its eight interconnected, elevated modules rest on extendable legs, fitted with giant steel skis that allow the modules to adjust to changing ice and snow levels beneath them. The central module is a large, open space with a dining room, bar, library, gym, living and meeting areas, all accessible by a spiral staircase. The other seven modules contain science facilities, work spaces, bedrooms and energy generation rooms.