Archived Posts from this Category
Archived Posts from this Category
Globally, temperature has been rising as the CO2 from burning of fossil fuels insulates the earth. The most pronounced warming has occurred in the last several decades, especially in the arctic.
But that’s a global average. I also really want to know what’s happening right here. So, I had some fun staring at the more-local temperature graphs. Looking at Alaska specifically, temperature records only go back to 1949, and basically consist of a cold half (1949-1976) and a warm half (1977-today). So even Hig, who grew up here, never experienced that cold. During the cold half, the Pacific Decadal Oscillation (a natural cycle of ocean temperatures with a time frame of 20-30 years) brought cold waters to the eastern North Pacific, and warm waters to the western North Pacific – making Alaska cooler. In the late 1970s, the Pacific Decadal Oscillation switched, and Alaska got warm.
What next? Well, the Pacific Decadal Oscillation appears to be dropping back into a persistently cold phase, and if that was the only big factor here, I’d expect to see Alaska dipping back down into those 1949-1976 temperatures along with it. Actually, I’d expect that to have happened already, given the PDO in the last few years has been as low as it was in the early 70s. But human-caused climate change introduces a consistent and increasing warming trend, which coexists with natural variation.
So, cool periods get less cool, and warm periods get even warmer. Average temperatures will continue to climb, more rapidly during natural warm cycles, and more rapidly as the carbon dioxide levels in the atmosphere continue to increase. We might never see temperatures as cold as the 1949-1979 average again – certainly not over any extended time frame. And next time the Pacific Decadal Oscillation shifts into a warm phase, we’ll probably see temperatures shoot well above the exceptionally warm years seen in the early 2000s. The latest report by the USGS shows predicted temperature increases across the state for the 21st century, against a reference frame of 1971 to 2000 temperatures (a period already dominated by warm). The degree of future change is predicted to be greatest in the northwestern regions of the state, and greatest during winter months, as has been true of the warming Alaska has already experienced.
From this USGS report: left shows a higher emissions (A2) and right a lower emissions (B2) scenario for the years 2070-2099.
The narrow time frame of recorded temperatures and the high natural variability of Alaska climate makes local temperature trends difficult to pick out from measurements alone. Global data is much more robust, and shows warming trends more clearly. But temperature measurements aren’t our only signal. Alaska’s overall warming trend is clearly visible in its natural systems, including melting permafrost, shrinking glaciers, advancing trees and shrubs, disappearing sea ice, dramatic coastal erosion, and changing species distributions.
This is the first of a series of posts from our adventure within 1/4 mile of home.
This is the first of a series of posts from our adventure within 1/4 mile of home.
The transformation was nearly instant. From whining over the exact proper amount of jam and milk in his oatmeal, to slipping bare feet into rubber boots (one bumblebee striped, one black, both on the wrong feet), racing out the door at dad’s promise to measure something with the measuring tape. Hig followed, while I pulled a squawking and barefoot Lituya from where she balanced on the doorframe, stuffing her in the duct-taped yellow rain suit that had borne all the abuse of Malaspina Glacier and a pair of black neoprene booties that had suffered the same. I was still in my nightgown. Soon we were all outside, and Katmai squeaking in high-pitched excitement each time he found a currant bush, Hig noting down leaf sizes on a clipboard, Lituya struggling to catch up as they flitted from bush to bush. It was just what we envisioned. For about 15 minutes.
The currants are one of the first plants to leaf out in the spring, and of course the largest leaves are right where we know the snow always melts out first. But before we could notice anything more profound, the kids were onto another idea.
How to stay near home but not AT home? Learn something new about a place we see all the time, rather than falling into regular patterns of work and chores? And do it at a level that can interest people from age 1 to 35? Backyard adventures allow us to slide into a relaxation impossible to achieve with the logistics, gear weight, and distances of an expedition. But juggling the desires of four, and hanging onto visions of learning and adventure while surrounded by all of your toys (adults and kids) requires a complicated balance.
Hig dumps a bucket of muddy water from a quickly-filling hole in the marsh, as he digs down to learn more about its geologic history.
A stone’s throw away and ten thousand years ago, a small patch of sloping ground stood clean and barren in the wake of retreating glaciers. Water streamed over the relatively impermeable surface of silty mud ground fine by the ice of the Kachemak Glacier. A few straggling plants popped up, adding their meager nutrients to the barren ground. When these plants died, they lay on ground so wet that no oxygen could seep in to speed their decay. More plants grew, and died, and grew and died again, layering the barren ground in first inches, then foot after foot of rich chocolate-colored peat. Once in a millenia, an ominous boom from the volcanoes across the bay turned the sky to black, smothering the plants in a layer of abrasive ash so thick it laid a bold stripe in the layers of mud and peat, still visible thousands of years later. All the smaller ashfalls have been spread out into nothingness, mere smears in the dirt.
Sweaty, with mud in his hair, shoulder deep in a giant hole, Hig told us this story, talking animatedly about all he was discovering in the layers of ash and mud, while Katmai perched curiously on the pile of overturned peat. I stood with my visiting parents, our rubber boots squelching on the surface of this cranberry-lined meadow, watching birds and chatting as Hig’s shovel uncovered the history (the hole was carefully filled in afterwards, and plants replaced). He’d been itching to do this for years – to dig down into the geologic history of this unusual meadow. Hig has loved digging holes since childhood, and is about as close as you can get to a PhD ditch digger.
He’s a sedimentary geologist. While we are both science geeks at a level I cannot deny, Hig is far more of a scientist than I ever was, yearning for graphs and measurements and careful data analysis while I am mostly content to learn more loosely, embracing numberless observations and telling stories. Sometimes, his science folds perfectly into our adventures, with Katmai peering into the hole in great excitement, as if every rock Hig unearthed was made of chocolate. Other times, it tumbles into conflict between careful measurement, detailed thought, and the chaos of children scribbling on notebooks and running off with crucial pieces of data. Toddlers and preschoolers make fickle field assistants.
This small dead pine was carefully sliced and measured, to figure out its rate of growth, and how much carbon it stored in its brief life.
Six or so years ago, a young pine seedling was planted in the clearcut below our house. Two winters ago, the upper five feet of its trunk was busted off by heavy snow. (It’s been sitting in our yard ever since). In the four years of growth recorded by this broken top, the tree stretched over a foot higher each year – nearly fifteen and a half inches on its best year. As it added rings of wood, it sucked carbon dioxide from the air, turning the intangible gas into lengthening branches and long fingery needles. Hig laid out the tree on a stretch of white cloth in a careful dissection, each segment cut and measured, each section of trunk polished to count the few wide rings. I shooed the kids (and their muddy boots) away from the edge, as he marked down columns of numbers. Each year the trunk captured more CO2 than the last… just a third of an ounce in 2007, then nearly an ounce, then three ounces, then nearly eight ounces.
Hig measures rings cut from a tiny pine tree, estimating its rate of growth and carbon sequestration
Climate change is shifting all the ecosystems around us. But what are the ecosystems doing to climate change? We watch the clearcut all the time, watching the non-native larch and pine seedlings shoot up beyond the native spruce, the alder cover old road beds, the berries and brambles spilling in profusion over the remain of old stumps, wondering what it will become. Hig’s measurements began to ask the less visible questions. How much carbon is going into the clearcut? Is it more, or less, than what went into the older forests around? How do the non-native pines compare to native spruce and alder for carbon uptake? If the forests were managed for carbon storage (rather than habitat or timber) what would the optimal management strategy be? When we burn firewood, what impact do we have on the carbon cycle? How many trees does it take to capture the carbon burned in our weekly van trips to town for lunch?
Inspired, Hig began a similar dissection of an alder, as Katmai borrowed the nippers to “help”, and Lituya began to investigate all the interesting little pieces of wood. Real science may have to come later.
“Whatever you do, don’t put wood ash on the garden. Then it’ll definitely snow.”
I should have listened to my friend’s warning. On the morning of April 6, a light dusting of snowflakes drifted down to the ground, landing on top of the 56.5 inches of snow already sitting on the ground, and covering the wood ash I had put on top of the garden the day before in the hopes it would melt faster.
A few days later, Anchorage busted its all time snowfall record with 134.5 inches for the winter.
The news from the lower 48 this winter was all about the lack of winter. Friends in Minnesota saw summer in March. The entire eastern half of the U.S. pretty much skipped winter altogether. This winter was the 4th warmest on record in the U.S. (excluding Alaska and Hawaii), and the warmest March ever recorded.
Here in Seldovia, people chuckled at that news, while walking up to the top of their roofs, snow shovels in hand. Or cursed the news while running their plow trucks in a losing battle against drifted-in parking lots. Or they didn’t hear the news at all, busy skiing through an endless supply of powder up in the mountains, or zooming their snowmachines along the trail through our yard.
Seldovia doesn’t keep snowfall records. But we’ve been recording snow depth through the winter on a measuring pole in our yard, which usually shows numbers around twice the depth in Anchorage. And we’re nowhere near the snowiest. Other places in the state, such as Valdez, Cordova, Yakutat, and Haines, always have snowfall stats that make Seldovia and Anchorage seem positively desert-like by comparison.
Graph of snow depth in our yard. Click for details.
With snow, it seems that every winter is an entirely different beast. In my childhood in Seattle, I don’t remember that being true. All winters were grey, rainy, and if we were lucky, had maybe one or two small snowstorms that might cancel a day of school.
I’ve only been in Seldovia for 4 winters. There was the winter of the eruption – where the little snow that fell was covered by an ash fall in April, and melted away seemingly instantly. There was so little snow that the berry bushes froze, and took several years to recover the blueberry harvest. Then there was the winter of the March blizzards, burying my mother-in-law’s van to the roof where it sat at the bottom of the driveway. Twice. Then there was the winter of the broken trees, where an enormous November dump of wet snow weighted down the tree tops so much that dozens snapped in half, and the alders were bent down so far that some of them hadn’t popped up fully the next June.
2011-2012 was the winter of the infinite and endless snow. Cold, and relentless, with fluffy snowfall after fluffy snowfall, piling on top of eachother with not much of a melt in between. This year had the coldest January ever recorded in Alaska, with temperatures here hovering in the single digits for pretty much the entire month. No one’s firewood lasted the season. The alders never laid down, and were simply buried standing up.
The lower 48 was warm mostly because the jet stream was farther north than usual this year, leaving much of the country in the warmer air south of the jet stream (particularly the eastern half of the country). Apparently, much of the blame lies with a pair of weather phenomena known as the Arctic Oscillation and the North Atlantic Oscillation. The Arctic Oscillation spent most of the winter in the “positive” phase, which drives winter storms to the north. The North Atlantic Oscillation does a similar thing, and was positive throughout the winter.
So we got everyone’s snow this year, as well as an unusually cold midwinter (particularly in January). Supposedly spring here will be cool and dry. I’m hoping they’re wrong (at least on the cool part), since I would like to see the garden before July. Given how ridiculously off some of the winter predictions were, I’m not too worried.
Weather is complicated. Next year, the pattern may switch entirely, and bury the lower 48 in all of Alaska’s snow. But climate trends are clear. Increasing global temperatures increases the chances of extreme events in any location, particularly on the warm end of the scale. Looking beyond regional weather patterns, February 2012 (the latest month with available data), was the 324th consecutive month where global temperatures beat the 20th century average. That means there hasn’t been a colder-than-average month on a worldwide scale since I was 5 years old (February 1985).
For now, anyone with a shovel is more than welcome to all the snow in my yard. Over 4 feet still available!
(Journal date 10-30-11)
It was a small and gentle stream, flowing out between mossy green boulders on a sunny afternoon, almost shallow enough to wade. Then it was a place of driving rain that stung our faces, driving sea foam that plastered the tents, gusts that lifted boulders from the tent stakes, thunder, lightning, and the deafening clatter of hail.
After the storm, high tide sent surges of water over our hastily abandoned camp. And the mouth of the lagoon had transformed–from a small and gentle stream to a roiling swatch of roiling white several hundred yards wide. Water poured out of the lagoon between giant breaks of surf that sent ocean waves crashing back in. A raft of logs was caught in the tug of war, battered and broken on the rocks until they were finally tossed all the way into the sea, streaming east down the coast with the waves. Salt spray filled the air, and waves splashed the rocks all the way to the top of the beach, where we stood to watch in the forest above. Evening brought a low tide, a flash of sun, and a retreat of the angry ocean. We walked between freshly-broken logs and clear blue icebergs, by the mouth of a small-again stream.
Malaspina is North America’s largest tidewater glacier. Four years ago, when we were first here, it squeaked by on a technicality. A few pieces of kelp, a stripe of sea foam at high tide, coming in through a narrow channel. Now it is unquestionable. The lagoon rises and falls with every tide, and tastes brackish even at the far end. Barnacles grow at the saltier depths. And the surf crashes in and out, sending icy blue chunks of Malaspina scattered along the coast. Sitkagi Lagoon is a place that doesn’t even exist on the USGS maps. A place that is still out of date on most recent satellite photos, and far longer then when we were here 4 years ago. Forest topped ice bluffs calve into the lagoon, and the mouse bite out of the massive Malaspina glacier grows larger and larger.
The children have slowed our pace and redefined our traveling style. Enough that people can communicate with us, airplanes can meet us, and instead of driving forward at a 15-20 miles per day pace, we’re the ones slowing folks down.
For the past week, we’ve been a party of 7. The four of us, plus Carl, a photographer and guide from Anchorage (who’s been with us for a couple weeks), Michael, a weather forecaster from Anchorage, and Sam, our programmer from Wisconsin. Sometimes, more people add more complications, driving us to camp in a terribly exposed spot none of us would have chosen on our own. But they lend helping hands holding a tent up in the storm, and adult conversation around our stove in the evening. They’re all headed out today after high tide, bringing this blog post with them. We were alone for nearly a month before Carl arrived. It will be odd to be alone again.
P.S. Thanks for all the questions. We’re happy to keep answering them. Sorry if any get lost in Sat Phone quirkiness.