Preempt Wildfires

Pius Lee

We were all stunned by the apocalyptic scenes of devastation and destitution caused by wildfires in Maui, HI. The utter sense of desolation and desperation was overwhelmingly sad. It destroyed the idyllic Island of Maui. Many people are still in denial and disbelief when they look at the news reports. How could a booming town be wiped out in a few hours only to be remembered by scorched cars and barren home foundations without overlying structures. It is unthinkable to comprehend the mass destruction and loss of human lives in this land of dreamed vacations and secluded paradise on planet Earth.

Mediterranean Climate of Maui

The magnitude of the disaster is still under investigation as I am writing. I believed that the burn happened in the lee-side, sheltered side, of the Maui-Mountain-Range. Wind on the lee-side is void of moisture. Lee-side downslope dry air made the area especially susceptible to bush wildfires. The news media had been reporting from forensic evidence, the damage and rapid spread of wild fires were caused by swift dry wind swept over drought-stricken valleys of Maui. However, there are other factors to be concerned in order to reconstruct a scientifically viable replay of the catastrophic event to raise public awareness. Despite the vast oceans surrounding Maui, Maui’s climate is akin to that of the Bay Area, California or that in Israel pertaining to what is known as the “Mediterranean Climate (MC)”. Under MC conditions, relative humidity is often low and fire ignition possibility becomes a perennial concern. Bush fires can spread rather quickly especially in terrains with rugged topology. On the leeward side of a hill fӧhn winds, downslope katabatic winds deprived of moisture by precipitation on the windward side of the hill, are dry and warm. They are heavier than moisture-laden air. They rush down the slopes of the hill and can accelerate the spread of bushfires. Fӧhn winds are heavier than the ambient air and display gravity flow characteristics. The farther they advance, the speedier they become. As fӧhn winds are warmer, they dry the land and vegetation along their sweep.

A rugged terrain with a valley type topology would suffer a double ill-posed condition to accelerate the spread of bushfires. As the wind sweeps across the valley and begins to be decelerated in the opposite upslope, the upslope flow preheats and pre-dries the vegetation ahead of the fire. The upright flames shoot upwards and consume the vegetation on the ascending slope. A rule of thumb is that with a 20 degree uphill slope, the spread of bushfires there will be four times faster than that over flat terrains. The devastated Lahaina district on the Island is situated east of the West Maui-Mountain-Range. It enjoys the crisp dry air on the leeward side of the range yet the dry air caused rapid spread of bushfires.

Land Management Uses Preemptive Fires

Land management can make a huge difference in the prevention of wildfires. The concept of interactive interplay in wildfire-control land management is a worthy discipline to be considered by land officials and Interior Department personnel. This concept is being tested out and is still facing a lot of skepticism and indifference. The main reasons for the cold shoulders are understandable. It requires constant updating of information on the ground. It also requires excellent communications and transparencies among all governmental and nongovernmental entities involved in wildfire control. These requirements are particularly challenging for managers of large geographical swaths. For instance, these conditions are difficult to achieve in the outback of the Oceanic Continent, in the thick forest of the Amazon, and in the immense boreal forests of Siberia and Northern Canada. The concept needs time to confirm its durability and applicability.

Historical Camp-Fire in 2018

In a few southern states of the U.S.A., wildfires are rather frequent due to the onset of irregular extreme weather (Please see the last issue about El Niño cycles). The interactive land-management concept encourages frequent calculations of correlations of all the variables in: arborology, geography, meteorology and hydrology. To bring this statement in a close-up visual and anecdotal illustration, I would quote the loss of paradise in the Camp-Fire in Northern CA, in November 2018. In 2018, CA was in a 30 year record drought. The hydrological and meteorological conditions were ripe for precarious outbreaks of wildfires. Unfortunately in the time, the Californian forests suffered an onslaught of Bark Beetle infestation. These little insects were killing millions of trees across the state, especially the conifers. Dry dead trees became a common scene in CA forests, in some of them as large as 80% of the trees were dead. These dead trees were fuels awaiting ignition. The weather then was so hot that the CA authority controlled the electricity power-grid lest it caused sparks and became fire hazards. Behold! The Camp-Fire in 2018 broke out. It was the most expensive wildfire disaster in history at $12.5 billion dollars. It burned 150,000 acres, destroyed more than 14,000 homes and killed 85 people. It was extremely environmentally harmful as 5,500,000 tons of carbon dioxide (CO₂) was emitted in 17 days. The CO₂ emitted by Camp-Fire canceled out of the CO₂ emission saving achieved by all the Teslas on the road in the U.S. in 2023 had they all run to retirements. CO₂ is a major culprit of greenhouse gas that expedites global warming. With such a rapid rate of uncontrolled emission during wildfires, the natural sequestration mechanisms were overburdened. Much of the emitted CO₂ stayed in the atmosphere causing the greenhouse gas burden to increase. In terms of health impacts, the air in CA and the neighboring states deteriorated almost 10 times due to tens of times more air-borne PM_2.5 particulates. These small particulates harmed the human respiratory system. The cause of wildfires were manifold such as poor warning systems, low awareness among the general public, and the speed of the fire advance. In the Camp-Fire, the gale winds spread the fire was blowing at 75 miles per hour. People were simply caught unguarded. Again, I felt that land-management had a role to play and could mitigate some of the damage. Had the wildfires been conducted as prescribed burns and were done in staged and controlled manner, the natural sequestration could have worked better and the eventual increase of CO₂ in the atmosphere could have been significantly less than what happened.

Land Managers are Mandated Stewards

In some other southern states of the U.S. prescribed burns have been employed as a primary tool to prevent uncontrolled wildfires. A land manager treats the optimal prescribed burn problem as an Operational Optimization problem minimizing the cost. The manager can only execute his prescribed burn plan under calm and non-fire hazard meteorological conditions subjected to the permitting from state and federal environmental departments. An aggressive and well managed prescribed burn strategy is to rid dangerous potential fuels and proactively renew forest with young trees. Young trees are usually more fire resistant and insect resistant. Permit issuance for prescribed burns are based on projections for minimum fire hazard and minimum air pollution. It will factor in heat output from the burn to calculate buoyancy of the smoke plumes so that a global minimum of air pollution impact is assured. The smoke plume rise should be confined to certain heights to avoid long range transport of smoke. Nonetheless, the plume rise should not be too shallow to risk near-source high smoke concentrations. Permits are daily issued. The land manager must analyze and update his prescribed burn plans daily. With good ventilation and decent lower-atmosphere turbulent mixing, the harmful substances formed from wildfires can be handled in less chaotic manners than those in uncontrolled wildfires. Therefore, Prescribed-burn Managers are geo-environment-engineers doing good stewardship. They have a high calling: “The LORD God took the man and put him in the Garden of Eden to work it and take care of it” (Genesis 2:15).

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Author: Pastor Dr. Pius Lee is the Director of the Development Division of NYSTM. In 2021, he retired from the National Oceanic and Atmospheric Administration (NOAA) of the United States, and was selected the winner of NOAA’s Administrator’s Award for the Air Pollution Forecasting Research Group in 2020. Pastor Lee and Mrs. Ancy Thuyen-Anh, Lee have three sons and one daughter. The couple relocated from the capital, Washington, to New York to take up the post.