Mirages Of Early Summer

May and June are a good time while sailing to keep an eye out for an interesting embellishment of the horizon, a Lake Ontario generated mirage- the following is excerpted from Lake Legends And Lore, a book length manuscript on Lake Ontario folklore and history in preparation for publication possibly next year by yours truly, Susan P. Gateley of Silver Waters Sailing

Perhaps less scary and mysterious than a UFO but still wonderous to see is one of the lake’s spectacular mirages. They occur most often in May and June when the chill of winter lingers within Lake Ontario’s dark depths and long hours of strengthening sun warm the air. They aren’t common, but when you are lucky enough to see a mirage while at the lake shore, they can be spectacular. An old neighbor of mine told once of seeing many years ago on a bitter cold winter morning, a mirage of the Canadian shore. The landscape was greatly magnified and so sharply detailed that she could even see cars moving about on the streets. And the whole landscape appeared to be upside down. Another winter mirage of Canada made the Rochester newspaper in the 1880s it was so vivid and widely seen by hundreds of people.

Last spring I saw several striking mirages while out sailing. The first of these occurred on a bright sunny afternoon of light wind and cold water. Upon coming about and heading towards homeport, the shore before us seemed suddenly transformed. Distant gigantic flat topped mesas and huge buttes of tawny brown and dark green now appeared to loom hundreds of feet into the air. A few isolated spires and columns also appeared and the more distant headlands showed a distinct horizontal dark line like a layer of smoke trailing off over the water from the top of the mountainous horizon. Occasionally as I studied this improbable stretch of shore a little piece of a mesa top would detach itself and float up and dwindle away. The whole thing kept changing but so slow and subtle were the shifts it was almost impossible to track them. It was as if the front range of the Rockies had suddenly erupted before us.

Closer along shore a band of luminous aqua colored mist obscured the mirage shore where It changed into the prosaic trees and hills and familiar clay bluff faces. This “phantom mist” seemed to shield the transition between normal looking land before us and the fantastically craggy jagged changing mirage land a little ways down the shore. Try as I might I was unable to penetrate this mist with binoculars or close scrutiny, though it seemed to the key to understanding the baffling shifting beautiful land to the west. I saw no fairy castles of the fata morgana that day, but I did see a landscape that would have been a credit to New Mexico’s land of enchantment or Utah's arches landscape.

A few days later another striking mirage appeared again on a sunny spring day of light wind and still cold water. I looked off to the northeast and spotted Oswego’s regular weekly cement boat leaving port. Only today he had a consort, a second grey hulled cement boat suspended directly above him and upside down. Both boats also seemed somewhat magnified, but neither seemed distorted unlike the shoreline we’d seen a few days before. Quite the contrary, the boats appeared very sharply detailed and distinct on this bright but chilly afternoon.

There are of course, well understood explanations for these phenomena, superior and inferior mirages, changing refractive indexes and all that. And to my mind understanding the optics renders these things not one jot less wonderous. In fact, if you recognize a little bit of what’s going on you can even experiment a bit with the mirage such as by changing your height above the water to see how it alters the images before you. I am certainly no optics expert but with the help of Marcel Minnaert, author of Light And Color in the Outdoors I’l l dip a toe very briefly into the science of the miraculous and enchanting phenomena of the mirage.

Minnart’s book actually contains a photo, a good one, of a mirage very much like those I’ve seen over the lake. It shows an island with not one but several inverted and compressed images hanging above it. Minnaert explains that if more than one layer of air of different temperature lies over the water you may get these multiple images and he says they are also sensitive to the height of the observer. I can attest to this. A couple years ago one April afternoon we observed a distinct layer like a dark narrow cloud bank lying over the water as we stood about 80 feet above its surface on a bluff. We debated as to whether it was a mirage perhaps of Canada, or a patch of fog out over the cold water. We then hiked down to the beach and upon looking out at the horizon again, it appeared completely normal.

Lake Ontario mirages are usually the “superior” type where something below the horizon appears to float above it inverted. The “inferior” mirage is seen where cold air lies over a sharply warmer surface such as a concrete road or a large area of desert basin. Minnaert says you need a temperature difference of 10 to 20 degrees F to see a really strong mirage. The silvery puddle on the road effect is actually the distant sky being reflected by this sharply different air layer acting as a lens to bend the light.

The best conditions for seeing a mirage on the lake are calm days when there isn’t a lot of wind to stir up and mix the atmosphere near the lake surface. You might see a mirage in winter but most of the ones I’ve observed have been early in the sailing season when we can easily get that 20 degree difference between the air right over the cold lake and the air a foot or so above.