Breathing Easy: Meteorologists Help Us Understand Ozone Season

You may have heard of Action Day Advisories before, or perhaps your local meteorologist has mentioned ozone when talking about air quality. Though most have heard this term used, they may not understand why it is relevant to the safety and health of all human, animal, and plant life and our environment. Understanding ozone, how it forms, and its consequences can help us take proactive steps to mitigate its effects, so we went to the experts: State of Michigan Senior Meteorologist Jim Haywood and West Michigan’s WOOD TV8 Chief Meteorologist Ellen Bacca, to give us the information we need to make a difference during the ozone season.

What is Ozone Season & What Causes It?

Typically spanning between March and October, ozone season refers to the period when concentrations of ground-level ozone, also known as Tropospheric ozone, are at their highest. You may be familiar with what “smog” is. Well, ozone is the main ingredient. Ground-level ozone is caused by naturally occurring chemicals like nitrogen and hydrocarbons that get hot in the atmosphere. As they get hot, they undergo a chemical reaction. Jim Haywood expands on this: “It’s not something that is directly emitted from industrial processes or vehicles; it forms in the outside air from the chemicals that are directly emitted into the atmosphere. It comes together in what we call a photochemical process, and it needs sun and solar radiation to do that. And, of course, the energy from the sun is at its highest peak during the warmer months, the summer, spring, summer and fall seasons. So, it really is a summertime phenomenon.”

Ellen Bacca gave further insight, adding: “We typically must have temperatures of at least 80 degrees or around that threshold, especially in Michigan and West Michigan, to see the release of ozone. Typically, there is a lot of sunshine, too. Especially in West Michigan, Lake Michigan acts as this double-bake oven. So, any pollutants that come in from Chicago get heated up from the sunshine from above and then also from below as the sunshine reflects back and double-heats some of those pollutants.”

When it comes to the cause of ground-level ozone, pollutants are the majority. “You won’t get ozone if you don’t have pollutants. So, typically, city centers are the biggest pollutant producers because it’s the highest concentration of just people living life,” says Bacca, “Public transportation and factories increase all of that. But even things like people mowing lawns and driving cars add to the pollutants.” Secondarily, heat: “When you start to see those hotter days, then it just leads to a higher likelihood that you’re going to have ozone in the area,” Bacca continues.

Weather Patterns & Ground-Level Ozone Formation

Weather patterns significantly influence ground-level ozone. They determine who gets hot weather, and they also determine where the ground-level ozone will go. Bacca provides an example for further understanding: “On really hot days, it can create ozone in places like Chicago. But if the wind is blowing out of the Southwest, Chicago doesn’t feel the full effects of that. Instead, it runs into West Michigan along the lakeshore, which is a cleaner place. It doesn’t produce a lot of pollutants compared to Chicago, but it gets that kind of leftover dregs from Chicago. So typically, we have to look at weather patterns to see who is going to be the hottest in the nation, and that’s determined by the jet stream. In the summertime, our jet stream is usually much farther to the north in Canada, which allows a lot of the heat to build into spots like the Great Lakes. It also determines who gets the leftovers after ozone forms.”

This isn’t to say that all ozone is bad and all air is polluted. Stratospheric ozone is considered the “good” ozone. It occurs naturally in our upper atmosphere and creates a protective layer, protecting us from harmful ultraviolet rays caused by the sun. However, it’s very much related to weather patterns: “The temperature in the upper air is a factor because during the day, when you have some turbulence out there, if it’s cooler up there, that cooler air will mix down. It’s going to be clean. It helps dilute ozone,” says Haywood.

But as we all know, we can’t control the weather, so how do we get a handle on the ground-level ozone being transported all over? That’s where the experts come in, says Haywood: “We need EPA to be able to step in, and it’s got to be a multi-state solution to that problem.”

Consequences of High Ground-Level Ozone Levels

Ground-level ozone is a potent air pollutant that can have detrimental effects on human and animal health, ecosystems, and the environment. As we learn more through detailed studies on the direct impact of ground-level ozone, what is known thus far is that high ground-level ozone can:

Impact Human Health

Certain groups are more at risk from ground-level ozone exposure, including people with asthma, children, older adults, and outdoor workers. Those with specific genetic traits or lower intake of vitamins C and E are also vulnerable. Children are particularly at risk due to their developing lungs and have a higher likelihood of outdoor activity during high ozone levels. They also have a higher prevalence of asthma compared to adults.

Some of the health problems caused by high ground-level ozone for humans are:

• Airway constriction, leading to wheezing and shortness of breath.
• Induces coughing and sore throat.
• Makes deep breathing difficult and painful.
• Inflames and damages airways.
• Increases susceptibility to lung infections.
• Aggravates lung diseases like asthma, emphysema, and chronic bronchitis.
• Increases the frequency of asthma attacks.

Although all humans are at risk, some are more than others, says Bacca: “Air quality is usually worse in urban environments and especially ones that don’t have the ability to change things with extra funds. So, usually, the people that are impacted are the people that need help the most.”

Impact Vegetation & Plant Life

According to the National Park Service, ground-level ozone significantly harms plants, affecting both crops and natural vegetation. It enters through leaf openings, known as stomata, and causes oxidative damage to plant tissues during respiration. This damage makes it harder for plants to produce and store food, as ground-level ozone causes deteriorated leaves and decreases plant survival.

Many factors can exacerbate ground-level ozone damage, including soil moisture levels, the presence of other pollutants, pests, diseases, and other environmental stresses. The impact of ground-level ozone on natural vegetation has been recorded across the U.S., with notable effects in the eastern regions and California.

Reductions in plant cover impact everyone. Trees and other vegetation help improve air quality by absorbing pollutants like excessive nitrogen dioxide and ozone through their leaves and needles. With less plant cover, the ability to filter and clean the air decreases.

Impact Wildlife & Ecosystems

Ground-level ozone can affect entire ecosystems and biodiversity, harming insects, wildlife, and soil. Ground-level ozone is very closely tied to vegetation and has just as much of an impact on wildlife and ecosystems as wildlife depends on plants to thrive and survive. As exposure increases, the production of roots, seeds, and other vegetation that animals need to survive decreases.

There is much more to learn, and many studies are being conducted about the impacts of ground-level ozone on wildlife and ecosystems. The more that is being discovered, the more ozone season becomes important to ensure the stability and safety of all living things.

Mitigation & Prevention Strategies
There are several practical steps we can take to reduce ozone pollution. For Jim Haywood, paying attention to alerts is the first step: “We send a note to the National Weather Service. They put it up on their banner page for hazards. But honestly, the best thing, and this is what I tell people, is that all of those require somebody to go out and look for the information and want to make it as easy as possible. We have a system called AirNow EnviroFlash. You can Google it or look it up on our website and subscribe to it.” The EnviroFlash platform allows you to choose how you want to be notified of Action Days or air quality updates, for example, through text or email – whatever is most convenient for you!

During ozone season, particularly on Ozone Action Days, the main objective is to minimize your contribution to ozone pollution and safeguard air quality. Here are some steps Ellen Bacca says you can take:

Opt for Alternative Transportation: Carpool, use public transit, bike, or walk instead of driving alone. Fewer cars on the road mean reduced emissions that contribute to ozone formation. “Maybe don’t start your car and have it running a whole bunch on Ozone Action Days,” says Ellen, “Or if you can, walk down the road or down to the ice cream shop in the evening; just go that route. Find realistic ways to cut down on emissions.”

Refuel Wisely: Avoid filling up your vehicle during the day. If refueling is necessary, do it early in the morning or late in the evening to prevent gasoline vapors from evaporating and reacting with sunlight to create ozone: “Again, public transportation is good. Just keeping an eye on how your energy usage.”

Conserve Electricity: Reduce the use of appliances, lights, and electronics during peak hours, especially air conditioning: “Try to keep the air conditioner not overly cold,” says Ellen, “Just kind of keep it at a nice temperate setting. Turn off the lights in your house because everything you’re doing to reduce the amount of energy consumption will lessen the amount that the energy providers have to work and produce pollutants to provide you with that energy. And in the long run, these are all things that help you out, too.”

Lowering your energy consumption helps reduce emissions from power plants, which can contribute to ozone levels. “When you produce pollutants, many times on these Clean Air Action Days, they stay put. So, if you don’t want to be breathing bad stuff, just don’t put bad stuff out close by. Find realistic ways to keep your house, so to speak, clean, like your neighborhood cleaner, and you will reap the benefits of that.”

 Reschedule outdoor activities: If possible, move outdoor activities to a day with better air quality. If you need to be outside, try to do so in the early morning or late evening when ozone levels are lower.

Minimize the use of gas-powered equipment: Avoid using gasoline-powered lawnmowers, leaf blowers, and similar tools on Ozone Action Days. If necessary, use them during cooler parts of the day. Ellen’s advice: “You don’t have to mow your lawn on really hot days. It’s permission granted for you to wait until a different day!”

Spread the word: Share information about Ozone Action Days with friends, family, and coworkers; encourage them to take similar steps to help improve air quality. Watching your local meteorologist, like Ellen, or paying attention to the EPA website (and signing up for EnviroFlash!) will help you stay updated.

Ozone season is a critical time that requires heightened awareness and proactive measures to protect both the environment and public health. By understanding the causes and impacts of ozone pollution, we can take practical steps to mitigate its effects and contribute to cleaner air and a healthier planet!

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