I am sitting on a hotel terrace in the Thousand Islands area of the St. Lawrence Seaway, Ontario. A rainy day has yielded to golden light and jewel-like sparkles in the water in the early evening, with hours of light still remaining - in these northern climes. The River is sprinkled with small islands, mostly crowned with a cluster of trees, which are ebulliently vivid in their variety of greens above the ochres and greys of the granite rock shorelines. Limpid reflections shimmer on smooth waters. Above, osprey hover and dive, while great blue heron wing purposefully west above the pine tree crowns on the distant shore.

I have been watching this wonderful parade of light and magic because I have my artist's eye turned on. I keep analysing the scene in terms of how to depict what I see. I don't mean literally, in terms of representation, necessarily, because I am always "pruning" and editing the scene I am looking at, trying to select the most relevant details. Nevertheless, at the back of my head, I am aware that the veracity of a painting of drawing is underlined by the references, direct or indirect, to the climate, the light, the prevalent weather ... In the days that I have spent here, the light has been amazingly varied but always wonderful and very northern and cool, compared to the light of coastal Georgia or the Mediterranean.

Artistic fidelity to weather and atmospheric phenomena has proven useful on occasions. I have read that meteorologists have consulted paintings done in previous centuries to confirm weather events, volcanic eruptions, meteor showers and more. We were all recently reminded about the amazing sunsets caused by volcanic ash. I heard Simon Winchester talking on PBS about the insights into wind patterns circling the globe that were obtained from paintings done around the world by artists enthralled by the sunsets drama caused by the eruption of Krakatoa in 1883.

Constable's drawings and paintings of clouds and related weather in 18th/19th century England have also yielded good science, thanks to their accuracy. He spent many an hour studying clouds and drawing them in their fugitive glory. I felt considerable empathy with him when I was Artist in Residence in Brittany in autumn, 2008, because there, too, the weather is never the same for more than half an hour!

Another benefit of artistic fidelity to weather conditions was written about by Dan Falk, an environmental journalist writing on June 6th, 2010, in the Toronto Star. A Canadian artist, Gustav Hahn (1866-1962), depicted a west Toronto neighbourhood in the winter of 1913. Above, the night sky shows the constellation, Orion, and also a bright series of objects streaking across the sky. Hahn, also an amateur astronomer, was recording the famous Canadian Fireball Procession of 1913, a very rare event when meteors graze the earth's atmosphere at a very low angle and break up into glowing fragments. This painting yielded all sorts of insights for Donald Olson, a physicist at Texas State University, who is known as the world's leading "forensic astronomer". He mines classic works of literature and art for references to our universe - the moon, the stars and the sun - and calculates where and when each piece of art was created. For example, Olson has calculated the exact spot and time when Van Gogh painted Moonrise: 9.08 p.m. on July 13th, 1889. Another piece of art that became important in Olson's studies was a painting by Hudson River School artist, Frederic Church, entitled The Meteor of 1860, showing a peaceful late evening river scene, with a brilliant array of meteors streaking across the sky on an almost horizontal trajectory. Olson later deduced that Walt Whitman, in New York, had witnessed and then written of the same event in one of his poems. Both conclusions were buttressed by his having seen a copy of Hahn's painting of a meteor procession. Olson's analysis is appearing in the July issue of Sky and Telescope magazine.

Without the keen watch that artists keep on the skies above, we would all lose a lot of fascinating information.