Editorial: Solar Energy is Good for the Soul

This is an expanded version of the Editorial that appeared in the print version of Chemical Engineering Progress, December 2016.

The December solstice is right around the corner — marking the beginning of winter in the Northern Hemisphere and ushering in colder temperatures and the prospects of snow and ice (at least here at this latitude). For some of us, it also ushers in the winter blues.

Weather can influence how we feel at any given time. Think about your mood on a chilly, damp, cloudy day, versus your mood on a warm, sunny day. Have you thought about what specifically makes you feel that way — temperature, cloud cover, rain, barometric pressure, or some other factor?

Psychologist Mark Beecher, physicist Lawrence Rees, statistician Dennis Eggett, and their colleagues at Brigham Young Univ. (BYU) recently pinpointed the weather variable that matters most to mental and emotional health — sun time, i.e., the amount of time between sunrise and sunset. They reported that no other weather or pollution variables (including temperature, barometric pressure, wind speed, wind chill, rainfall, dew point, solar irradiance, lunar day, particulate matter, ozone, and nitrogen oxide) were significant predictors of mental well-being after accounting for sun time.

Although the terms seasonal affective disorder (SAD) and winter blues are often used synonymously, they are not the same thing — the former is a subtype of clinical depression that occurs during the winter months, while the latter is a milder, subclinical form of SAD. According to Norman Rosenthal, MD, 6% of the U.S. adult population is affected by SAD, and another 14% suffers from the lesser form of seasonal mood changes. Symptoms include moodiness, apathy, irritability, anxiety, fatigue, boredom, weight gain (due to giving into cravings for carbohydrates), sleep problems, difficulty staying awake, diminished interest in activities, and a desire to avoid social contact.

Fortunately, exposure to light can help alleviate those symptoms. Natural sunlight is best — so let the sun shine in, and get outside as much as you can. Or consider phototherapy, which involves sitting near a special lamp, called a light box, for 30–90 minutes each day. Other suggestions for warding off the winter blues include: take vitamin D supplements, eat a healthy diet (including more complex carbohydrates), limit your caffeine intake, avoid binge drinking, exercise (at an indoor gym or outside dressed warmly), wear bright colors, stick to a regular sleep schedule seven days a week, make your bed every day (which apparently gives you a sense of accomplishment, and prevents you from getting back into bed), try something new, catch up on the books and movies you’ve been meaning to read and watch, surround yourself with positive people, and, if your symptoms persist, see your doctor and/or a therapist.

Therese Borchard, an author of several books on depression, wrote online that one of her favorite techniques is “behave like you’re from Minnesota.” She says: “I learned an important lesson the year I lived in Minneapolis during the blizzard of 1996, when snow hit the ground in October and didn’t leave until the end of May: These people adapt! They love it. They make a trip to L.L. Bean in the fall, get all the necessary gear, and go ice-fishing, ice-skating, snowshoeing, and do everything in their power to appreciate the very elements that I cursed. By February, I couldn’t take being inside anymore, so I followed suit. I started running in the snow, having fun with the icicles that would form inside our car, and throwing up a pail of water and watching it come down as snow from our apartment balcony. Once I tried to act like a Minnesotan and stopped resisting the cold temperature, the better I tolerated it.”

Kari Leibowitz, a PhD candidate in psychology at Stanford Univ., is studying this approach, which she refers to as our winter mindset. Leibowitz spent ten months in Tromsø, Norway, an island of 70,000 people located more than 200 miles north of the Arctic Circle, where the polar night — when the sun does not rise above the horizon — lasts two months. Studies have shown that residents of Tromsø do not experience as much seasonal depression and wintertime mental distress as one might expect. “Most people I spoke to in Tromsø were actually looking forward to the winter. They spoke enthusiastically about the ski season. They loved the opportunities for coziness provided by the winter months,” she said.

Leibowitz’s advisor at Stanford, Alia Crum, introduced her to the concept of mindsets, which Crum defines as “lenses through which information is perceived, organized, and interpreted.” Mindsets serve as an overarching framework for our everyday experiences, and they can profoundly influence how we react in a variety of situations. So Leibowitz and Joar Vittersø, her research advisor while she was at the Univ. of Tromsø, developed a wintertime mindset scale to measure how residents of Tromsø view the winter. They found that “having a positive wintertime mindset was associated with greater life satisfaction, willingness to pursue the challenges that lead to personal growth, and positive emotions.”

Perhaps the best way to get through the next few months is to do what Leibowitz says the Norwegians do: “embrace the idea of koselig, or ‘coziness’ — that making the conscious effort to light candles and fires, drink warm beverages, and snuggle under blankets can be enjoyable and relaxing.” Use this time to catch up on reading your back issues of CEP. And, of course, remember that December 21 is not just the shortest day of the year, but the point at which the days begin to get longer — only six more months till summer.