Image of a large wildfire and image of a scientist testing a controlled fire in a lab
MARK RALSTON/AFP VIA GETTY IMAGES (WILDFIRE); © BRIAN CAHN/ZUMA PRESS WIRE (SARA MCALLISTER)

I Study How Wildfires Burn!

By setting fires in a lab, Sara McAllister learns how to protect people from deadly blazes

By Dani Leviss
From the October/November 2023 Issue

Learning Objective: Students will use evidence from a text to summarize the skills and knowledge needed for a STEM career in wildfire research. 

Lexile: 790L; 560L
Other Focus Areas: Cool STEM Jobs; Chemical Reactions; Measurement & Data
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ANASTASIA WILDE

Sara McAllister

This past August, wildfires devastated towns on two islands in Hawaii. People had little warning of the danger. Flames burned down homes and landmarks. Sadly, as of press time, 99 people had been confirmed dead. The historic town of Lahaina was reduced to smoldering ruins.   

In May, thick, black smoke from Canadian wildfires blew into parts of the United States. The smoke spread, filling the skies across the country. Scientists warned about the risks of breathing dirty, smoke-filled air.

Sara McAllister works to keep people safe from events like these. She’s a wildfire researcher at the Missoula Fire Sciences Laboratory in Montana. There she studies how fires burn and spread. The data is used to help protect people from wildfires. McAllister spoke with SuperSTEM about her work.

This past August, wildfires devastated parts of Hawaii. They destroyed towns on two islands. People had little warning of the danger. Flames burned down homes. They also burned landmarks. Sadly, as of press time, 99 people had been confirmed dead. The historic town of Lahaina was reduced to ashes.  

In May, thick smoke blew into parts of the United States. It came from wildfires in Canada. The smoke spread. It filled the skies across the country. Scientists issued warnings: Don’t breathe the air.

Sara McAllister works to keep people safe from events like these. She’s a wildfire researcher. She works at the Missoula Fire Sciences Laboratory. It’s located in Montana. There she studies how fires burn and spread. The data is used to help protect people. McAllister spoke with SuperSTEM about her work.

How do fires start?

Fires need three things to start burning: heat, fuel, and oxygen (see What Starts a Fire?). Any material that can burn is a fuel. This includes plants, plastic, fabric, and oil. Intense heat causes the fuel and oxygen in the air to combine and go through combustion, the process of burning. We’re surrounded by fuel and oxygen. Intense heat can come from a lightning strike, a match, a spark from a campfire, or other sources. As more fuel gets hot and burns, the fire can spread.

Fires need three things to burn. They’re heat, fuel, and oxygen (see What Starts a Fire?). Anything that can burn is a fuel. This includes plants, plastic, fabric, and oil. High heat causes the fuel and oxygen in the air to combine. They go through combustion. This is the process of burning. Fuel and oxygen are all around. High heat can come from a lightning strike. It can come from a match. Or it can spark from a campfire or other sources. The fire can spread as more fuel gets hot and burns.

How do you study wildfires in your lab?

We do experiments with fire in a metal warehouse called a burn chamber. The chamber has tools to adjust the conditions inside. It’s like controlling the weather! We can set the temperature and how much moisture is in the air. We can make it hot, cold, dry, or windy. I use these tools to investigate how things catch fire and how they burn in different conditions. To stay safe, I wear gloves, masks, and cotton clothing that won’t melt onto my skin the way other materials would.

Many types of experiments happen at the lab. Some scientists study how trees respond to fire. Others study the smoke. A team puts together all the research.

We study fire in a metal warehouse. It’s called a burn chamber. The chamber has tools. They change the conditions inside. It’s like controlling the weather! We can set the temperature. We can change how much moisture is in the air. We can make it hot, cold, dry, or windy. This allows me to study how things burn in different conditions. I wear gloves to stay safe. I also wear masks and cotton clothing. It won’t melt onto my skin like other materials would.

Many studies happen at the lab. Some scientists study how trees react to fire. Others study the smoke. A team puts together all the research.

ANASTASIA WILDE

McAllister measures out dry pine needles for her experiments.

What’s the focus of your research?

One area I’m interested in is how fire spreads through piles of pine needles. I want to understand how a pile’s shape affects how air flows around it. This affects how fast a fire burns.

For my experiments, I often use wooden sticks instead of real pine needles. They’re easier to measure and observe. I glue the sticks into different shapes and set them on fire. Then I observe how long they burn and how high the flames reach. I repeat each experiment up to five times to make sure I get similar results.

I’m interested in how fire spreads through piles of pine needles. I want to learn how a pile’s shape affects air that flows around it. This affects how fast a fire burns.

I often use wooden sticks instead of pine needles. They’re easier to measure and observe. I glue the sticks into different shapes. I set them on fire. Then I watch how long they burn. I see how high the flames reach. I repeat each test up to five times. That way I make sure I get similar results.

What do you do with this information?

Scientists use data like ours to create digital models. These computer programs predict how fires will burn. During a fire, officials enter information into a model. This includes the material that’s burning, weather, and wind conditions. The model calculates how fast the fire is spreading and plots where it may spread on a map. This lets officials know when and where people need help getting to safety.

But many governments still use models from the 1970s. They aren’t very accurate. Our work will help update and improve these models. We’ll be able to make more accurate predictions about the huge fires we see today.

Scientists use data like ours to create digital models. They’re computer programs. They predict how fires will burn. Officials enter information into a model during a fire. This includes the material that’s burning. It also includes the weather and wind conditions. The model calculates how fast the fire is spreading. It plots where it may spread on a map. This lets officials know when and where people need help. Then they can get to safety.

But many governments still use models from the 1970s. They aren’t as exact. Our work will help make these models better. We’ll be able to better monitor the huge fires we see today.

What concerns you the most about wildfires?

What worries me most is that wildfires are impacting people more and more. We saw this happen in the U.S. and Canada last summer. As Earth’s climate warms, the summers in some places get hotter and drier. This can lead to intense fires that cover vast areas.

Today more people are living in places where wildfires are a threat. That’s why it’s so important to make better models, so we can help keep people healthy and safe from future wildfires.

Wildfires are affecting people more and more. We saw this happen in the U.S. and Canada last summer. Earth’s climate is warming. Summers in some places are getting hotter. They’re also getting drier. This can lead to fires that cover large areas.

Today more people are living where wildfires are a threat. That’s why we need to make better models. We can help keep people healthy and safe from future wildfires.

ANASTASIA WILDE

McAllister carefully lights small fires to clear out dry plants that could fuel a wildfire.

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Games (1)
Activities (4) Download Answer Key
Step-by-Step Lesson Plan

Note: Be sensitive to students' experiences and consider how students may need support processing experiences with natural disasters like wildfires. Discuss safety: In the event of a wildfire, experts say it's best to evacuate early. If you can't evacuate, go upwind to get away from smoke. For more safety tips, visit www.ready.gov/wildfires.

1. PREPARE TO READ (10 minutes)
Watch a video about wildfires and identify ingredients for a fire.

  • Draw an equilateral triangle on the board in red and label it “Fire Triangle.” Explain that each side represents an ingredient needed to start a fire. Ask students to listen for the ingredients as they watch the videoWildfires Around the World.” Together, fill in the three sides of the triangle. (fuel, oxygen, heat) For each ingredient, using a blue marker, list a firefighting method that could contain or extinguish the wildfire. (e.g., fuel: clearing some vegetation; oxygen: chemicals in a fire extinguisher; heat: water)

2. READ AND analyze (20 minutes)
Read the article and synthesize information about a career in wildfire research.

  • Preview the article. Read the “What Starts a Fire?” sidebar (p. 30). Relate it back to your fire triangle on the board. Discuss the terms in the Look for These STEM Words! section (p. 28).
  • Read the article aloud, discussing vocabulary terms. Ask: What might wildfire researchers study? (e.g., how fires burn in different weather conditions) How can this research help people? (It is used to improve the computer models that predict how fires will burn, which can help determine when people should evacuate to safety.)

3. RESPOND TO READING (15 minutes)
Summarize the skills and knowledge needed for Sara McAllister’s job.

  • Have student pairs refer to the text to answer the Think Like a Scientist questions (p. 31) OR have students independently complete the Cool STEM Jobs Spotlight activity. Then discuss their responses as a class. Ask: Would you be interested in a career as a wildfire researcher? Why or why not?

Text-to-Speech