Jul 10 2023

A fire season in Canada but not Alaska

*Alaska Midnight Sun crew boards a bus to head for a Canadian fire assignment June 4, 2023 (Photo credit: Beth Ipsen, BLM Alaska Fire Service)*

Why is the Alaska fire season so quiet this year while Canada has major wildfires? Alaska climatologist Rick Thoman attributes the lack of fires in Alaska (only 934 acres burned by the end of June) to a lack of lightning as well as cooler, moister weather this year (Alaska June 2023 Sea Ice and Wildfire). Interesting that this year Alaska retained a lot more sea ice in the Chukchi sea and Arctic Ocean above Barrow: there is some evidence linking regional climate to sea ice concentration (Zou, et al. 2021). Meanwhile, Canada is breaking records with 22.7 million acres burned (9.2 million ha) as of July 9. CiFC (https://ciffc.ca/) reports 3,678 fires spread across the entire country. Canadian and US cities (including Detroit, Pittsburgh, and Chicago) have been suffering poor air quality for much of the mid-summer with little relief in site. Is there an explanation for the unusual pattern? The global temperature anomaly for May (figure) may be one clue. Strong linkages have been found between warm temperatures and wildfire activity, mainly because of accelerated drying of vegetation fuels. In the western US, Abatzoglou and Williams (2016) found that human-caused climate change caused over half of the documented increases in fuel aridity since the 1970s and doubled the cumulative forest fire area since 1984. At any rate, 2023 brought very little snow to eastern Canada, so it melted early and Fire Weather Indices have been unusually high.

*Figure from Scott Duncan (ScottDuncanWX@twitter.com)*

Fire regime is changing in other parts of the world. Rebecca Scholten is finishing up a PhD in Amsterdam studying weather patterns which correlate with fire activity around the north, especially arctic areas. She’s noted that changes in the polar jet stream driven by warming global temperature seem to be correlated with more wildfire in northern tundra ecosystems. A simplified explanation would be that a “wobbly” polar jet stream caused by weaker cold sink over the Arctic can mean calming in mid-latitudes but intense heat domes, dry and windy conditions, and more convection over high northern latitudes. There seems to be a strong link with these conditions and the Siberian megafires in 2019-2021. Her recent paper in Science points to accelerating changes in high latitudes with earlier snowmelt and a tripling in the frequency of this “Arctic front jet pattern.” Curiously, when this pattern sets up, it may moderate conditions–at least with respect to winds–over interior Alaska!

Citations:

Zou, et al 2021. Increasing large wildfires over the western United States linked to diminishing sea ice in the Arctic. Nat Commun 12, 6048. https://doi.org/10.1038/s41467-021-26232-9

Abatzoglou and Williams. 2016. Impact of anthropogenic climate change on wildfire across western US forests. PNAS 113 (42) 11770-11775. https://doi.org/10.1073/pnas.1607171113

Scholten, R.C. et al. 2022. Early snowmelt and polar jet dynamics co-influence recent extreme Siberian fire seasons. Science 378, 1005–1009. https://doi.org/10.1126/science.abn4419

May 28 2022

Fire Management to Reduce Carbon Emissions?

By Randi Jandt, Brendan Rogers, and Carly Phillips

This research brief is available as a standalone PDF

To thwart runaway climate warming, the global community is struggling to find strategies to limit carbon dioxide (CO₂) emissions that are steeply climbing. Increasing boreal wildfires in Alaska and Canada also threaten to increase CO₂ emissions and could contribute potentially 12 gigatons to the world’s carbon headache by mid-century.

Fire Management strategy could make a difference: A research team from The Woodwell Climate Research Center and Union of Concerned Scientists wondered whether fire management offered a realistic way to slow down the release of legacy carbon in boreal forests, giving Nature and humans time to adapt and implement other mitigation strategies. How much would it cost to keep Alaskan wildfires at their historic level, avoiding climate-induced predicted increases? And was it even possible to make a difference? In short, the study found that—yes—more fire suppression could keep nearly 1/3 (4 Gt ) of that carbon in the ground in Alaska and Canada. The study tries to estimate costs associated with carbon savings and compares them to other carbon-sparing strategies being used or planned. Project goals are below are from a presentation given to Alaskan fire managers last fall.

Download our short Research Brief above (and/or you can access the full scientific article, open access, HERE:

Phillips, et al. 2022.

Escalating carbon emissions from North American boreal forest wildfires and the climate mitigation potential of fire management.

Science Advances, Vol. 8(17), https://www.science.org/doi/10.1126/sciadv.abl7161

Jun 15 2016

Adam Young consults the crystal ball on future fire regime across Alaska

A paper just published by the indefatigable Adam Young, a PhD candidate at the University of Idaho, and colleagues pulls together a lot of information about climate, forest, tundra and fire to offer a glimpse of potential future fire regimes in different parts of Alaska. By looking at fire occurrence at a multi-decadal time scale, the researchers drill down into how fire rotations are likely to respond to climate projections at a regional scale.

Exerpt from Fig. 6, Young et al. 2016. Figures in the paper not only show the observed fire rotation for 19 subregions of Alaska (Figure A2 in supplement) with 60 years of fire occurrence data, but also project future rotations under various climate scenarios (in this case a mean of of 5 global climate models).

The use of advanced statistical models to build fire-landscape response models for boreal forest and tundra reaffirms prior findings of the sensitivity of fire regime to summer temperatures and moisture deficit. However, the effect is not uniform among regions: they identify a threshold at about 56⁰ F (30-yr mean temperature of the warmest month) and another threshold for annual precipitation where fire occurrence really seems to jump. This latter finding accounts for results which project large increases in 30-year probability of burning for areas where these thresholds will be crossed in the next several decades. For example, models project the Brooks Range foothills of the North Slope, Noatak tundra and the Y-K Delta may see increases in fire 4-20x greater than historical levels. Some tundra areas are likely to experience fire frequency increase to levels not observed in the paleo record, spanning the past 6,000-35,000 years. Across most of the boreal forest, fire rotation periods are projected to be less than 100 years by end of the 21st century. This is useful information for natural resources management as well as fire protection agencies—a concise, well-researched, well-illustrated paper—put it on your summer reading list.

Young, A. M., Higuera, P. E., Duffy, P. A. and Hu, F. S. (2016), Climatic thresholds shape northern high-latitude fire regimes and imply vulnerability to future climate change. Ecography 39: 1-12. http://dx.doi.org/10.1111/ecog.02205

Mar 29 2016

Do bark beetle outbreaks really affect burning?

It has long been assumed that bark beetle outbreaks on the Kenai lead to increased fire danger, even though beetle disturbance has been shown to have mixed effects on crown fire potential, fuel profiles and burn severity in the Rocky Mountains. Winslow Hansen, doctoral candidate at the University of Wisconsin, recently published an analysis of beetle outbreaks and fire on the Kenai Peninsula between 2001-2014 (Hansen et al. 2016). He looked at effects in pure white spruce stands–where duration of beetle attacks is longer and mortality greater–and in mixed white and black spruce stands common on the northern peninsula, where attacks are less severe. His analysis indicates mixed effects: severely damaged white spruce stands did not demonstrate increased fire occurrence (instead, % canopy cover appeared to drive likelihood of burning) while the mixed white/black spruce stands did show a positive correlation with beetle outbreaks and fire. Winslow explores the reasons for this in his relatively short article: worth reading. You may remember Winslow from his previous work on beetles/fire effects and property values on the Kenai (recorded MS Thesis defense) and climate effects on fire regime (recorded 2015 presentation).

Citation: Hansen, W.D, F.S. Chapin III, H.T. Naughton, T.S. Rupp, and D. Verbyla. 2016. Forest-landscape structure mediates effects of a spruce bark beetle (Dendroctonus rufipennis) outbreak on subsequent likelihood of burning in Alaskan boreal forest. Forest Ecology and Management 369: 38–46.

Feb 12 2016

Fire and Carbon Stores: the Rest of the Story

Estimates of carbon released from combustion of vegetation and organic soil during wildfires have improved dramatically over the past decade. Biomass inventory, fire effects and fire severity studies have contributed more accurate data to improve these models. (See Ottmar 2007, Brendan Rogers webinar 2015) However, figuring out the net effect of all the various effects of fire, the recovery phase and warming climate on the carbon stored in Alaska’s forests and tundra is a lot more challenging! You’d have to consider changes in burn extent and/or severity, increases in plant productivity in recovering burns, changes in species composition and what that means for productivity, changes in permaf CaptureIEM rost distribution and soil C decomposition, methane emissions and carbon fluxes in lake systems and wetlands–etc.! A team lead by Dr. Dave McGuire at UAF has taken on this modeling challenge by applying their Integrated Ecosystem Model (IEM) which includes modules for fire, permafrost, and carbon cycling. Dave recently presented an overview of their findings at an IARPC-WCT/AFSC joint webinar (available HERE). In a nutshell, they found: 1) tundra holds 2x the carbon that boreal forest does in the same area 2) there has been a net C loss from boreal land area of about 8 Tg/yr over the last 60 years, primarily driven by large fires during the 2000’s 3) arctic tundra and SE Alaska still act as C sinks, compensating for these losses so that overall, Alaska sequesters about 3.7 Tg/yr, 4) increases in fire extent predicted with with warming climate will release even more C, but longer growing seasons and increased plant growth (as much as 8-19% increased productivity througho CaptureALF ut the remainder of this century) with warmer climate and higher CO2 concentration in the atmosphere are estimated to offset these losses under most of the climate projection scenarios. Since this nutshell summary glosses over a lot, you should take a look at the presentation and the SNAP projects page with information on scenarios and the individual models used.

Mar 13 2015

Where fire management and carbon studies connect . . .

Screen capture of the WFEIS calculator (http://wfeis.mtri.org)

On the surface Alaska fire management and boreal ecosystem carbon studies have little in common. But a deeper look reveals the connections between them. Carbon scientists in the last decade have become increasingly interested in fire effects on the legacy carbon locked up in permafrost and the deep, slow-to-decompose organic layer of boreal forest floor (Kasischke et al. 2013, Genet et al. 2013). Projections indicating more extensive, frequent and/or severe fires in northern latitudes with a rapidly warming climate, longer fire seasons, and more lightning (Romps, et al. 2014) lend a certain urgency to attempts to quantify the potential impacts of fire-released carbon on greenhouse warming. Fire management agencies are less interested in long-term impacts of fire-released gasses but they are more and more driven to assess impacts of smoke on communities. Work at the boundary between the two sets of interests has started to yield some interesting results. For example, Michigan Tech Research Institute has joined their consumption field data from NASA studies to the USFS Consume Model and FCCS fuels maps and LANDFIRE fire perimeters in a web-based tool that provides users a simple interface for computing wildland fire emissions (1-km spatial resolution). The Wildland Fire Emissions Information System (WFEIS) can calculate tons of CO2 or other gases from large fires across the US and Canada from 1984-2010. Although this tool is for post-facto emissions analysis it is a good example of how large spatial data sets and complex equations can be united in a simple graphical interface allowing one to–say–query the forest fire emissions from the 231,000 acres burned in Alaska in 2010 (10.9 million tons CO2, 95,000 tons PM 2.5). The hope is that weather modeling and research linkages with the common fire danger and risk rating system used in northern latitudes (CFFDRS) will soon bring this kind of application into the real-time and forecast prediction realm.

Feb 17 2015

Does climate warming mean more lightning in Alaska?

Capture-trendgraph-lightning-2012JDisMgmt

Fig. 1. Yearly and monthly number of lightning flashes in Alaska from 1986-2010 (Farukh and Hayasaka, 2012)

A recent article in Science magazine (Romps, et al. 2014) postulated a 12% increase in lightning strikes over the continental US for each degree C of warming. If this model holds true for Alaska, we should have already seen an increase in lightning strikes of roughly 20% in interior Alaska over the last 25 years since summer temperature has warmed by about 2.5 F–up to 3.7 F north of the Brooks Range (data from UAF Geophysical Institute). So, has anyone looked at the trends in Alaska’s Automatic Lightning Detection Data to see what has been observed? AFS has been collecting this data (publicly available at http://fire.ak.blm.gov) since 1986. It turns out the answer is yes! Drs.Farukh and Hayasaka (2012) published an article on how large lightning storms characterized some of our largest recent fire seasons including this figure. I’d like to challenge other investigators to look at the regional significance of this phenomenon in the state, which could be an important fire regime driver in boreal forest/tundra, with the data which is now complete (ALDS went offline in 2013, replaced by a time-of-arrival system)!

Nov 21 2014

Presentations available from the CFFDRS Summit in Fairbanks!

: This presentation and MANY MORE available on fuel moisture sampling, remote sensing validation of FWI, new remote sensing tools for fire detection and growth modeling, using dataloggers on soil moisture probes to track fuel moisture changes, and the seasonality of CFFDRS, to name a few.

Whether you were there or missed it, the presentations and recorded videos from the 2014 Canadian Forest Fire Danger Rating System Summit held in Fairbanks October 28-30th are worth reviewing. 2014. The workshop was a great opportunity to discuss fire risk indices and fire behavior applications in Alaska and to hear how fire managers in Canada, the Great Lakes States and around the world are using the Canadian Forest Fire Weather Index System. There were over 50 managers and scientists in attendance.

Breakout group at the October 2014 CFFDRS Summit in Fairbanks

Jan 19 2014

Research Brief: Fire Severity Filters Regeneration Traits to Shape Community Assembly in Alaska’s Boreal Forest

Fire Severity Filters Regeneration Traits to Shape Community Assembly in Alaska’s Boreal Forest: A recent paper by Hollingsworth et al. (2013) proposes that fire severity and a plant’s intrinsic regeneration strategy are key determinants in post-fire community recovery. The authors identify species that may fare better or worse with predicted changes in Alaska’s fire regime. Hollingsworth–who is based at the University of Alaska-Fairbanks–bases her findings on a large (n = 87) and geographically diverse set of post-fire plots in interior Alaska boreal forest.

Read More >> | Download Research Brief PDF (850 kb)

Jan 5 2014

Research Brief: Is Alaska’s Forest Crossing a Threshold?

Is Alaska’s Boreal Forest Now Crossing a Major Ecological Threshold?: Read up on what Alaskan forest and climate research has found out about the influence of warming climate on boreal forests in the Interior! Here’s a new 2-page Research Brief that digests one of the more significant papers on forest and climate change. The authors– Dan Mann, Scott Rupp, Mark Olson and Paul Duffy– are well-known to Alaska fire managers. This is a good basis to our upcoming focus on multi-faceted influences of dynamic climate on fire regime, forests, and fire management in Alaska in 2014!

AK Fire Science Highlights

Working together to help bridge the gap in boreal fire science delivery, outreach, and application

Tag Archives: Alaska climate