A life ruled by seasons, former Split Rock Lighthouse keeper writes of autumn

Lee Radzak has done a lot and observed a lot as the caretaker of one of Minnesota's most popular and recognizable landmarks: Split Rock Lighthouse on the North Shore. In addition to raising a family, he managed the site's buildings and security and was in charge of the waves of visitors for more than three decades.

"That's what's kept it interesting for 36 years — there's so much variety to it," Radzak told the Star Tribune before he departed in April 2019.

As Radzak's wife, Jane, writes in the foreword of his new memoir about their time at the Minnesota Historical Society site, theirs were lives "ruled by the seasons." Fittingly, he has organized the book, written with Curt Brown, by season — and there are colorful stories to tell.

Below is an excerpt about autumns on Lake Superior from "The View from Split Rock: A Lighthouse Keeper's Life":

"There is never a bad dawn over Lake Superior, but I think the most spectacular sunrises occur in October. For most of the spring and summer, the sun rises far enough north that if you stand along the shoreline in the state park west of the lighthouse and look toward the lighthouse, the sunrise is hidden from view behind the lighthouse cliff. Beginning at the summer solstice in late June, the sun begins to rise and set a little farther south every day. By mid-September, it appears right out of the lake when viewed from this shoreline spot. Each day the sun rises a few degrees farther out over the lake and farther away from the cliff and lighthouse.

The autumn sun rises about two minutes later in the morning each day, around 7 am in late September instead of around 5 am as it does in June.

Since the lake has been warming up all summer, October mornings tend to be mild and comfortable. But, best of all, the autumn dawn skies display fantastic colors. Two factors contribute to the color storm: farm harvesting to the west, which raises more dust into the atmosphere, and smoke from wildfires in Canada and the western United States. Either way, the sky at sunrise is usually lit up with colors ranging from shades of orange and yellow to turquoise and lavender. On many autumn mornings, the lake grows calm, affording wonderful reflections of the sunrise colors.

Early on some autumn mornings, I tried to watch for the green flash at sunrise. I observed this meteorological optical phenomenon just a handful of times and was able to photograph it only once. The green flash, sometimes appearing as a green ray, lasts for a couple of seconds as the top edge of the sun appears over the horizon. It can also occur at sunset, as the top edge of the sun dips below the horizon. The light passes through the earth's atmosphere, which acts like a prism to cause the sun's light to separate into the colors of the spectrum. Atmospheric conditions must be just right for a distinct spot of green to appear for about two seconds.

Other colors are refracted or absorbed. I have heard it is best observed over the oceans of the tropics, but it does happen on Lake Superior. If you are patient, you may be lucky enough to see it.

In late summer and early fall when air above the lake is at its warmest, it's a good time to watch for Lake Superior mirages. Called fata morgana, these mirages occur in the air above an object in the far distance when cool air is trapped beneath a warmer layer of air above. In calm weather, this layer of warmer air, called a temperature or thermal inversion, can act like a refracting lens and produce an inverted image. I have watched ore carriers sailing past the lighthouse, perhaps a dozen miles out on the lake, with a perfect image of the ship inverted directly above the real ship.

At other times, these layers of warmer air caused distant objects to appear much closer by compressing or stretching objects seen at long distances. The light is refracted downward and actually travels around the curvature of the earth. There were times when the South Shore of the lake near Cornucopia, Wisconsin — nearly thirty miles away — appeared so close that barns and fields were easily visible through binoculars. On one perfectly calm day in April, peering with binoculars through the dry, clear air over the lake, I saw the trees on the shoreline of the Keweenaw Peninsula on the Michigan South Shore. I found it hard to believe, so I confirmed the compass bearing and checked the official National Oceanic and Atmospheric Administration (NOAA) Lake Superior navigation chart that hangs in the visitor center. The peninsula is one hundred miles from Split Rock."

Excerpt from The View from Split Rock: A Lighthouse Keeper's Life by Lee Radzak with Curt Brown. Reproduced with permission from the Minnesota Historical Society Press.