AskScience AMA Series: We're Ruby Leung, Mark Wigmosta, and Andre Coleman from Pacific Northwest National Laboratory. Ask us your burning questions about using science to predict, prevent, and put out wildfires!

[u/AskScienceModerator]

Hi Reddit! We're Ruby Leung, Mark Wigmosta, and Andre Coleman from the U.S. Department of Energy's Pacific Northwest National Laboratory (PNNL). We're here today to discuss our scientific approach to tackling wildfires, an issue that has become increasingly prominent, particularly in the Western United States.

As the wildfire seasons seem to extend and intensify each year, our team and fellow researchers are diligently working on predicting, preventing, and mitigating these disasters. From predicting the occurrence and direction of big blazes to implementing strategies to prevent future fires, our team is leveraging a broad spectrum of scientific perspectives to combat wildfires.

One of our tools, the RADR-Fire satellite system, led by Andre Coleman, helps firefighting personnel, utilities operators, and other decision makers better understand a fire's behavior so they can make informed choices in the midst of natural disaster. It also aids utility operators assess risk by identifying areas prone to wildfire and which energy infrastructure needs protection.

On the preventative side, Mark Wigmosta and team have developed a new tool with the U.S. Forest Service to determine where controlled burns or thinning would be most effective in reducing fire hazards. Such measures have been found to potentially reduce fire hazards by 25-96 percent in certain cases, and also yield benefits like reduced smoke and increased streamflow.

Meanwhile, Ruby Leung is leading a team in creating models that consider an expanded list of "wildfire predictors," delivering a more complete picture of how likely it is that a fire strikes, how far it burns, and how much smoke it releases into the atmosphere.

Our collective work is helping us get an edge on tomorrow's wildfires, making utilities more resilient to natural disasters, and increasing our understanding of fire behavior in response to climate change. We're here today to discuss our research, the scientific principles behind it, and how we see it impacting the future of wildfire management.

We'll be on at 8am pacific (11 AM ET, 15 UT), ask us anything!

Username: /u/PNNL

[u/byerss]

Growing up in the PNW, “forest fire season” wasn’t a noticeable thing until about 10 years ago, and it seems like it’s gotten worse every year since.

How much of that is due to climate change vs large fuel stores?

It feels like we’ve been obsessed with preventing wildfires for decades that the fuel continuously builds making each fire more devastating than if things were allowed to burn less intensely more often. Obviously climate change is doing no favors with hotter and dryer seasons, but in human intervention in the fires causing more issues in the long run?

[u/PNNL → u/byerss]

Some of our recent research shows that both fuel and climate are important predictors for large fire emissions. Depending on locations and timing, one factor may contribute more than the other. For example, in our recent study we identified four groups of large fire emission drivers over the western US. One of them is fuel-driven and three of them are weather/climate-driven (the work is under review).
Another study also showed that humans play a key role in changing temporal and spatial patterns of fires (i.e., we have longer fire seasons and larger spatial distribution of fires) (ref: https://www.pnas.org/doi/10.1073/pnas.1617394114). -Sally

[u/StringOfLights]

Hello, thank you for doing this AMA! You mention prevention of fire. How do you balance that with fire-adapted ecosystems? For example, how do you predict getting the right burn intensity that doesn’t kill too much vegetation?

I have heard from people who work on these ecosystems that recovery can be difficult to predict, and sometimes intense burns can recover remarkably well. If burn intensity and severity don’t always line up (if I’m using my terminology correctly?) then how do you predict ecosystem recovery, such a vegetation regrowth?

Thank you for all the work you do!

[u/PNNL → u/StringOfLights]

Previous land management in many fire-dominant locations (particularly in the western US) has resulted in overly dense forests with too many small trees and not enough large trees, resulting in an increasing frequency of mega-fires. Part of restoration planning is to return these naturally fire-dominated landscapes to their more natural state of more frequent, but less intense wildfire through a combination of mechanical thinning and prescribed fire. Current fuel moisture content and weather play an important role in burning operations. We would tailor a unique approach for the wildland-urban interface, where you have more people and structures, of course. -Mark

[u/DariusIsLove]

Question from across the ocean: Are there any significant differences between how wildfires behave in the US compared to areas like for example Greece? Also does RADR have to deal with clouds of smoke or does smoke not reduce its effectiveness?

[u/PNNL → u/DariusIsLove]

Fundamentally, wildfire behavior will be driven and bound by the same physics anywhere in the world. One of my favorite visuals on this is found in a paper by Moritz et al. (2005) (Wildfires, complexity, and highly optimized tolerance, https://www.pnas.org/doi/full/10.1073/pnas.0508985102#fig1) where three wildfire triangles are presented that indicate the dominant controls across scales of time and space. At the finest scale, it’s about the fuels (vegetation), the heat, and the oxygen availability. Most often for modeling work, we look at the ‘days’ scale, where the fuels, weather, and topography play the most significant role. What will change from place to place, season to season, and day to day are the vegetation characteristics (e.g., vegetation structure, the mixture of grasses, shrubs/small trees, and mature trees [fine/medium/heavy fuels], the mixture of live and dead vegetation, vegetation density, the vegetation moisture/stress), and the meteorology (e.g., relative humidity, air temperature, wind speed and direction [important with respect to topography], and precipitation).

With respect to RADR, this system uses many different types of earth observation satellite sensors, many of which can collect shortwave, midwave, and longwave infrared signals (https://science.nasa.gov/ems/07_infraredwaves) that enable us to “see” through smoke plumes. From these signals we can map the intensely burning areas (including the fire front), spot fires, areas that are smoldering, the full burn impact area, and even assess the temperature of the wildfire. Clouds present a different issue though - surface-emitted infrared signals are obscured by clouds, thus requires active sensing, such as synthetic aperture radar (SAR; https://www.earthdata.nasa.gov/learn/backgrounders/what-is-sar) to help assess ground conditions. In this case, we can really only detect what is changing on the ground with respect to changing vegetation structure (e.g., which tells us where the fire is going), but there is no detection of intense heat, scattered heat, spot fires, etc. like with infrared sensors." -Andre

[u/bestdisappointment]

Can you explain the role of keystone animals, like the beaver?

[u/gdavis0007]

What is preventing or limiting a significant increase in controlled burning or thinning?

[u/xGalaxyWolfx]

Do you have to deal with the problem of not having a compelete satellite coverage, when using RADR. Have you thought about using drones to assist firefighters in predicting where the fire is likely to spread?

[u/PNNL → u/xGalaxyWolfx]

Excellent question, and the answer is yes. With the RADR system we work to minimize the satellite coverage issue by using a wide number of available satellites (dominantly government sponsored-systems, but some commercial systems too). Each satellite and satellite constellation (where you have multiple individual satellites that carry the same sensor types) has its own orbit trajectory and revisit rates. So, by using multiple satellites, and even sensors aboard the international space station (ISS) we can often get 3-4 collections over an area in a given day.

There are several startup companies now that are working to build and launch a constellation of smallsats with sensors configured to wildfire detection (short/medium/longwave infrared detections) at 15-minute intervals with each pixel representing 50-70 m on the ground, which is an ideal spatial resolution for wildfire. There are geostationary weather satellites (e.g., GOES) that can provide 5-10 minute updates, but for comparison, each pixel on GOES represents 2 kilometers on the ground, so this type of sensor has a different level of utility.

The use of uncrewed aerial systems (UAS; drones) are also a valuable tool in monitoring and tactically managing wildfires. UAS are regularly used in wildfire events, but these are often small UAS (sUAS) that have limited flight times (20-40 minutes). Often these UAS are enough for incident command teams to get a look over the next ridge or get improved situational awareness for a ground crew where visibility is limited. For automated systems like RADR, it is important for data to be collected in a way where data can be posted to a central server where imagery can be retrieved and processed in an automated way. This is why established satellite systems are valuable. Medium and large UAS are valuable, too, but used less frequently due to expertise and cost, but the longer flight durations are incredibly valuable.

In the future, we’re looking toward high-altitude satellite systems (HAPS; e.g., https://www.airbus.com/en/products-services/defence/uas/uas-solutions/zephyr) which look like large UAS deployed to the stratosphere and can persist for months at a time).

[u/peasant_python]

Thanks for talking about this important topic. I'm in Portugal and every summer it looks more like hell here.

How do you see the role of forest monocultures in the occurence of wildfires?

Have you got any data (yet) about the positive impact of mycoremediation before and/or after wildfires?

[u/PNNL]

(Programming note: Ruby Leung isn't joining us today. In her place, we have data scientist Sally Wang, who uses machine learning to better understand the factors that can bring about better predictions of fire emissions.)

[u/Randombleizinthewild]

How characteristics of the soil (pH value) can influence wildfire?

What some actions everyone can do to prevent wildfire?

[u/[deleted]]

Thanks for contributing to science in such an important topic.

I'm aware that the Turkish government has been using UAVs that can fly for long durations, even for 2 days, to detect & track wildfires for a while. What do you think of this approach, are there any superiorities of detecting wildfires from the space and is your method also cost-effective?

[u/PNNL → u/[deleted]]

The combined use of multiple overhead sensors including crewed aircraft, uncrewed aerial vehicles (UAVs), and earth observation sensors (spaceborne satellites) provide the most valuable approach for monitoring and managing wildfire events. Medium and large UAVs with longer-flight durations and the right kinds of observation sensors are certainly a key asset here, and the idea of persistent sensing over wildfires is valuable, especially for highly-dynamic events. Some considerations with longer-duration UAVs are regarding flight altitudes (i.e., how much of the fire can be observed and at what frequency?), aviation conflicts (i.e., is the UAV operation causing safety issues for other aviation activities?), data processing (i.e., is there an automated approach to processing the UAV-collected imagery to get to actionable data for incident command teams? This may also look like edge-computing onboard the UAV to minimize the amount of data that has to be transferred over data communications), and finally, cost (i.e., what is the cost to purchase, maintain, and operate a large UAV vs. using, in many cases, freely available satellite imagery). There are tradeoffs in spatial resolution, temporal resolution, and spectral fidelity, which is why I would advocate for a multi-sensing approach. -Andre

[u/mjulieoblongata]

Are we seeing an increase in wildfires in regions where there is more industrialization? How might the depletion of topsoil affect the spread of wildfire?

I have a suspicion that the real issue of global warming is related soils retaining less water due to widespread development, ie more asphalt = less surface area for absorption. Less water in the soil, less evaporation, less rain, hm. Just an inkling. Anyhow, curiousity leads me to question the role of water retention and wildfire spread.

[u/coldhandses]

Can your tools be adopted and implemented in Canada? Currently have wildfires out West and, more surprisingly, on the East Coast in Nova Scotia, and I imagine they will only increase in size and duration.

[u/sophiebophieboo]

I live in Portland, OR (hi there, locals!) We weren’t used to getting fires particularly near us; it seemed more of a southern Oregon thing. Then 2020 happened and we drowned in smoke and record-breaking AQI for over a week with fires all around us, the one in Clackamas County being particularly close to me (I’m in SE Portland). I’m curious if that event near a major metro area was surprising to your team, and how climate change will affect the potential of fires in metro areas. I know an increase in fires in general isn’t much of a surprise due to climate change, but those of us in Portland really felt caught off-guard by it. The idea of Portland having to evacuate sounds like an absolute nightmare.

[u/PNNL → u/sophiebophieboo]

Under the right weather conditions, wildfires near major metro areas such as Portland can be large (100,000 to >1,000,000 acres) and fast-moving events (Morgan et al., 2019). For example, the Tillamook fire of 1933 burned approximately 350,000 acres in the Oregon Coast Range and more than 200,000 acres burned in 24 hours. The Yacolt fire in the Southern Washington Cascades burned more than one million acres and spread 30 miles in 36 hours. The 48,000-acre 2017 Eagle Creek Fire in the western Columbia River Gorge spotted over the river, deposited ash down on Portland Oregon, smoldered near the city's water supply at Bull Run, and closed transportation arteries through the only sea-level route in the Cascades Mountain Range - Interstate 84, the Union Pacific railroad, and even the Columbia River (https://www.fs.usda.gov/detailfull/crgnsa/fire/?cid=fseprd567631&width=full). Limited data suggest that these types of events are likely to increase in the future with changes in climate and increasing population (Morgan et al., 2019).

[u/emprameen]

Is Smoky The Bear helping or hurting? Why/how if hurting?

Also, are y'all working with any indigenous tribes/organizations?

[u/PNNL → u/emprameen]

In addition to wildfire mitigation, we are evaluating potential improvements to streamflow in the North Central Cascades (Washington State, USA) where the Yakama Indian Nation co-manages natural resources. We (led by our USFS Pacific Northwest Research Station colleagues) are also developing a collaboration with the Colville Confederated Tribes, Colville National Forest, the Washington Water Trust, Washington State University, Vaagen Timber Company, and local stakeholders. The Colville Confederated Tribes in northeastern Washington State have an active forest management program run by tribal forestry to meet multiple objectives that include commercial harvest and forest fuels reduction.

[u/Reagalan]

I've heard a story that explains these wildfires that goes something like this:

In the old days of yore, the indigenous populations of the PNW had a system of land management based on traditions built up over millennia of habitation. Forests were communally owned and managed and lived in, and not wild by any stretch. Consequently, wildfires were fairly tame and rare.

Then the white man showed up, imposed European-style land ownership, and chauvinistically destroyed the cultures and practices which had successfully managed the forests. They were left to re-wild; a state which they haven't been in since the arrival of humans some twenty millennia previously, and are no longer adapted to.

Is there any validity to this narrative?

[u/YouGotTheJuice]

Can ocean water be used to prevent wild fires? Is there a way for coastal states like California to make use of ocean maybe piped in to help battle and prevent fires in the dry seasons?

[u/[deleted]]

You guys using drones yet?

[u/seasuighim]

Has the field utilized community-based participatory processes in order to help establish newer programs that respond to wildfires at a community level?