Happy Spring! Usually at this time, here in Interior Alaska, we are enjoying our last bit of winter weather, and a good snowpack, to fulfill our final throes of close-at-hand nordic skiing. But not this year. Interior Alaska remains locked in a drought pattern. The Fairbanks airport has only received 63 cm (24.8 in.) of snow this year, only 38 percent of the average 168 cm (66 in.), up to 01 APR. In addition, since 01 July, Fairbanks has only received 11.2 cm of liquid-equivalent (4.48 in.), only 54 percent of the average of 21.2 cm (8.33in.). 
This satellite image shows the basic pattern that has been responsible for the drought. High pressure ridging, sometimes weak, other times stronger, has been remaining in place over central and eastern Alaska, extending north and west from western Canada, over the past year.
High temperatures over the past few weeks have been around 3-9C (37-48F), which are 3-7C above average. This, combined with the stronger spring sun, has jump started our spring melt, about THREE WEEKS EARLY. The willow trees also began budding, about THREE WEEKS EARLY.
The effects are striking. Here are a few pictures from around town yesterday, showing our almost-gone snowpack, which only contained 3.8 cm (1.47 in.) liquid-equivalent in it.
Driving around the Univ. of Alaska campus (UAF), this shows the flat grassy areas to be almost entirely snow-free. Your lead author has never seen such bare conditions this early, in his nine winters here.
This satellite image shows the basic pattern that has been responsible for the drought. High pressure ridging, sometimes weak, other times stronger, has been remaining in place over central and eastern Alaska, extending north and west from western Canada, over the past year.
This pattern over Alaska is thought to be the result of "El Nino" conditions over the Pacific Ocean. And in fact, there has been a moderate ENSO event over the past year.
http://www.cpc.noaa.gov/products/precip/CWlink/MJO/enso.shtml#discussionHigh temperatures over the past few weeks have been around 3-9C (37-48F), which are 3-7C above average. This, combined with the stronger spring sun, has jump started our spring melt, about THREE WEEKS EARLY. The willow trees also began budding, about THREE WEEKS EARLY.
The effects are striking. Here are a few pictures from around town yesterday, showing our almost-gone snowpack, which only contained 3.8 cm (1.47 in.) liquid-equivalent in it.
Driving around the Univ. of Alaska campus (UAF), this shows the flat grassy areas to be almost entirely snow-free. Your lead author has never seen such bare conditions this early, in his nine winters here.
Then, in the shadier forested areas, only patchy, dirty snow remains. Quite dispiriting for those of us who like to ski on our wonderful trail systems around town.
UAF pays artists to create ice sculptures every winter, around campus. There are a few Nanooks (polar bears, the UAF mascot) in strategic locations. Unfortunately, the unusually warm conditions the last several weeks have managed to put this one on a diet, and it may disappear entirely soon. People have been asking me alot lately, does this drought pattern we've been in, and the rapidly disappearing snowpack, mean that interior Alaska will be in for another bad fire season?
It's very difficult to predict in advance what our fire seasons here will be like. A research study prepared at Alaska Fire Service in 2005 found no significant correlation between low snowpacks the previous winter, and the severity of the ensuing fire season. That is because our fire seasons are driven by short-term weather processes here. Namely, the duration and frequency of high-pressure systems during the summer. Stronger, more frequent, and persistent high pressure ridging and the resultant warm, dry weather they bring, if preceded by patterns producing thunderstorms, igniting wildfires, are responsible for our worst fire seasons.
As you can see from our graph of Alaska fire season acreages, plotted with may-august average temperatures, there is a direct link with the warmer summers, and high acreage years, as well as an increasing trend. It's hard not to think that the loss of our skimpy snowpacks so early, combined with the overall drought conditions that have been in place since last summer, will have some effect on this year's fire season. If this drought pattern persists over interior Alaska through May and June, it could be quite a bad season. Only time will tell... We hope not, as these increasingly large fire seasons, not just in Alaska, but throughout North America, Australia, Europe, and Siberia, are a positive feedback mechanism to global warming. More CO2 is emitted from these larger fire systems, which leads to more warming, and increased fire activity, etc... This warming also leads to more permafrost melting, which also releases vast amounts of CO2 and methane (which is 22X more efficient of a greenhouse gas than CO2). It is unknown, what can, or will stop these vicious positive feedback mechanisms which could raise global average temperatures 5-7C within 50-60 years, as well as lead to the loss of large amounts of ice from Greenland and the periphery of Antarctica. Which could bring rapid sea level rises of 5-15 metres in a few decades.
As an example, the average high and low temperature for the month of July in Missoula, Montana is 29C/9C (84F/48F). If average temperatures rise 6C, then their July temperatures would average 35C/15C 50 years from now. Think about what that would do to the forests and ecosystems, in the Rocky Mountains, or wherever you are living. Fairbanks average high and low July temperatures are 22C/11C (72F/52F). A rise of these to 28C/17C would be catastrophic to our boreal forest ecosystem, and would prove fatal to most of the spruce and birch.
As an example, the average high and low temperature for the month of July in Missoula, Montana is 29C/9C (84F/48F). If average temperatures rise 6C, then their July temperatures would average 35C/15C 50 years from now. Think about what that would do to the forests and ecosystems, in the Rocky Mountains, or wherever you are living. Fairbanks average high and low July temperatures are 22C/11C (72F/52F). A rise of these to 28C/17C would be catastrophic to our boreal forest ecosystem, and would prove fatal to most of the spruce and birch.
Climate change modelling for the Arctic Regions have also been showing that snowpacks will melt earlier overall in spring, and start later in fall, in the coming decades. Since these models were a few decades off, not showing the rapid melting of the summer Arctic Ocean icepack observed currently until 2030 or so, perhaps these models are also off by a few decades with the earlier springs. Food for thought. Cheers.
