Australian Weather Calendar: October 2020

October photograph by Lyndal Curtis

The icing on the cake

An award-winning political journalist for over 30 years, Lyndal Curtis knows what it's like to be at the top of her game. These days however, Lyndal prefers a less hectic pace of life—choosing to swap her notebook for a camera, and taking the time to capture the beauty of the world around her. 'Photography is my passion, it's what feeds my soul,' Lyndal says. 'When I was at school I applied for both photography and journalism. Journalism won out and I put my camera down for a long time, but when I was on long-service leave I picked it up again, and haven't looked back.' Now running her own photography business, this high achiever makes the most of every day, squeezing in a quick photography session while juggling the demands of work and family life. 'I'm a five-minute photographer, in between work and looking after children. On this particular morning I'd dropped the kids at school, and then headed out to the Jerrabomberra Wetlands. It was winter and freezing cold, but sunny and clear, and there was frost everywhere. There were a couple of crazy joggers and cyclists, and me in a big coat with my camera in hand.' Lyndal said she'd never seen the frost there before, but now looks forward to frosty mornings because 'the ice makes such interesting patterns'. She says she finds winter in Canberra beautiful, and is also 'a sucker for sunrises and sunsets' in the capital. While Lyndal's journalism career is currently on ice, she's found another calling behind the lens—with this picture in the 2020 Australian Weather Calendar the icing on the cake.

The science

Frost is a deposit of soft white ice crystals or frozen dewdrops, formed when the surface temperature falls below freezing point. Frost formation is affected by factors including cloud coverage, humidity, surface winds, topography and location. In Australia, frost is more likely to form under a clear sky, with low humidity and light surface winds. Clouds act as a ‘blanket’ that helps prevent daytime warmth from escaping into space during the night, whereas clear skies mean the heat is free to escape, allowing for lower overnight temperatures. Windy conditions stir up cooler air near the ground, mixing it with the warmer air just above it, slowing cooling at the ground. When it's humid, meaning there's moisture in the air, and water changes from vapour to liquid, small amounts of (latent) heat are released, which also slows the rate of cooling.