The Stuart Creek wildfire plume as seen from Scott Rupp’s yard on a midsummer day.

Photo by Scott Rupp.

While pounding nails on a roof extension for his shed this summer, Scott Rupp heard a roar that almost scared him off the roof. Three planes with bellies full of fire retardant swooped low, then banked over the mountain behind his home.

“I looked up and saw this big smoke cloud,” said the part-time farmer and leader of an organization devoted to studying climate change. “That was my first sense that this was something that was going to personally affect me.”

A water pipeline near U.S. Creek that makes up part of the Davidson Ditch, a 90-mile aqueduct from the upper Chatanika River to near Fairbanks. Workers finished the project in the late 1920s. It lasted until the late 1960s, when a flood damaged the containment dam.

Photo by Craig McCaa, Bureau of Land Management.

Like a bright yellow contour line painted above the Steese Highway, the Davidson Ditch now reveals itself by the flagging autumn birches and poplars that clog its path.

The 90-mile system of canal, pipeline and tunnel becomes harder to see with each passing day, but the engineering triumph once helped prevent Fairbanks from ghosting out. The 1920s-era aqueduct provided the water needed to float dredges the size of apartment complexes and power hydraulic giants that firehosed water at Tanana River valley hillsides, stripping them to bedrock.

Northwest Passage rowers Denis Barnett and Paul Gleeson row their ocean-going craft into their stopping point of Cambridge Bay, Nunavut.

Photo courtesy MainStream Last First.

Beavers and jet skis surprised four adventurers on their recent attempt to row through the Northwest Passage. Vancouver, British Columbia residents Kevin Vallely, Paul Gleeson, Frank Wolf and Denis Barnett are now back home after the team stopped short of its goal of gliding through the northern waterway on muscle power.

The SS Manhattan on its 1969 journey from Pennsylvania through the Northwest Passage to Alaska and then back to New York.

Merritt Helfferich photo.

Forty-six years ago, a ship long as the Empire State Building sailed with intention toward obstacles that captains usually avoid. The icebreaking tanker SS Manhattan was an oil company’s attempt to see if it might be profitable to move new Alaska oil to the East Coast by plowing through the ice-clogged Northwest Passage.

For 50 years, scientists at UAF’s Institute of Arctic Biology have been studying creatures great and small, including the wood frog.

Photo by Ned Rozell.

While waiting for the talking to begin in darkened auditoriums, I sometimes scan the room, counting heads. “I’ve interviewed him, and her, and him. And her.”

At last week’s dedication of the Institute of Arctic Biology’s lovely new building on the University of Alaska Fairbanks campus, I saw more than a dozen people who have appeared in this space since fall 1994 (when I took over this column from Carla Helfferich).

Jack Hébert, president and founder of the Cold Climate Housing Research Center, walks into a headwind toward a café in Bethel where he will wait out a flight to a neighboring village.

Photo by Ned Rozell.

BETHEL — Outside the Fly By Café, the ravens are flying backwards. At least they appear to be, as a powerful wind suspends them in time and space.

A rocket part recovery in summer 2012 from the Marsh Fork of the Canning River in northern Alaska.

Courtesy Poker Flat Research Range.

Following up on a NASA promise to recover spent rocket parts scattered for decades across northern Alaska, workers for Poker Flat Research Range recovered more than 7,000 pounds of debris from 17 different sites in 2012.

Craig George at work watching for bowhead whales on a sea-ice platform north of Barrow.

Photo by Ned Rozell.

From my notebook, here’s more northern news presented at the Fall Meeting of the American Geophysical Union, a five-day gathering of more than 20,000 scientists held in early December 2012 at the Moscone Center in San Francisco:

Aspen trees in Fairbanks, part of the Alaska boreal forest in decline.

Photo by Ned Rozell.

In almost every patch of boreal forest in Interior Alaska that Glenn Juday has studied since the 1980s, at least one quarter (and as many as one-half) of the aspen, white spruce and birch trees are dead.

“These are mature forest stands that were established 120 to 200 years ago,” said Juday, a professor of forest ecology at the University of Alaska Fairbanks’ School of Natural Resources and Agricultural Sciences. “Big holes have appeared in the stands.”

Hall Island in the Bering Sea.

Photo by Ned Rozell.

HALL ISLAND — On this windy, misty August day, there are perhaps one million birds clinging to the cliffs that buttress this Bering Sea island. These seabirds, crazy-eyed and with bodies both sleek and clumsy, need solid ground for just a few months to hold their eggs. When their summer mission is complete, the birds scatter to the vastness of the sea.