Stockholm University

In this workpackage (WP2 The snowball effect) we address the question of how dramatic annual changes in climate impact on psychology, behaviour and physiology mediated by snow and changes in lighting quality. 

We have invited 1,500 randomly selected residents in the Uppsala Region of Sweden to respond to a questionnaire on the perception and use of local green areas both during the daytime and at night. We also reflect on behaviour during snow cover and periods without snow.

A subgroup of 45 subjects was invited to participate for two weeks in a field study in winter. Subjects wore motion loggers, kept daily logs and measured their saliva melatonin during one morning of a field week when the ground was covered by snow. This week was compared to a similar week when there was no snow. Preliminary data demonstrate snow cover yield more alertness and elevated mood across the day and that morning melatonin levels are suppressed. Light exposure measured with a light sensor in the wrist-worn motion logger showed higher light exposure levels across the day (see Figure below).

The perception of snow seems overall to induce increased subjective health and elevated mood combined by increased outdoor stay. According to climate change prognoses, the Nordic countries are confronted with global warming and have to develop coping strategies to adjust to changes, for example, with very little snow cover in winter. WP2 will also study the effects of increased nighttime snowglow related to illumination at night in local green areas.