NASA is working on improving air quality forecasts in a place in the United States better known for it’s pineapples and white and black sand beaches moreso than its smog. Dr. Vincent Realmuto, who earned a PhD in Geosciences from the University of Arizona, is the leader of a team taking a closer look at pollution in Hawaii. The Hawaii-based team involves NASA, the Jet Propulsion Laboratory, the United States Geological Society, and a private company called FlySpec, Inc., whose goals include helping to improve both the forecast and the warning time for air pollution advisories.
To accomplish this goal, the team is using various tools, such as sensors placed near the vent of the Kilauea volcano on the Big Island of Hawaii, the ER-2 aircraft, and eventually a Hyperspectral Infrared Imager (HyspIRI) that will be installed on a satellite, to track sulfur dioxide plumes and small particulates that cause poor air quality on Hawaii. HyspIRI, and the precursor missions aboard the aircraft ER-2, will have two imagers as part of the project,. The first is a visible imager that sees in detail what our own eyes would see while the secondis a thermal infrared multispectral imager, meaning it can see heat energy as well as other wavelengths of electromagnetic energy.
Sacramento Valley in California or regions near Salt Lake City in Utah can get in stagnant weather pattern where air pollutants are trapped and can’t escape these valleys, causing poor air quality. In the summer, East coast locations like the I-95 corridor from Washington D.C. northeastward into Boston can get a similar weather pattern where pollutants from motorized vehicles and factories are not dispersed as well as they normally are and elderly, young and asthmatic people can have difficulty breathing. In Hawaii, a different pollutant source as well as a different weather pattern can combine to cause similar air pollution issues at times.
Along the East coast during summer or almost anytime during the year in the Los Angeles basin, air pollution is often called “smog”, which is a combination of the words smoke and fog. In Hawaii, there is a similar term called “vog”, which refers to volcanic fog. In vog, sulfur dioxide gas reacts with water droplets, creating sulfuric acid aerosol particles in the air. Dr. Realmuto said, “Sulfur dioxide is a toxic gas released by certain volcanoes that, once in your nose, mouth and/or lungs, can coat them with a film that has a metallic taste to it. After a short period of exposure, you start to feel a mild burn from the interaction of the acid with body tissue. If you are exposed to the gas at high enough levels, you will begin to cough and have a very difficult time breathing.”
Dr. Realmuto explained, “Right now, the data we collect and use to help the Department of Health of Hawaii, the Environmental Protection Agency, and the University of Hawaii issue health warnings is quite sparse. There are too many empty spaces where a sulfur dioxide plume or particulate matter cloud can slip through the cracks and not be detected, or not be detected well enough. The goal with HyspIRI is to fill all of these cracks in thanks to a bird’s eye view from space. We can then have a better idea on where these pollutants are and where they are going. That better data can lead to more accurate air pollution models, such as the Vog model from the University of Hawaii.”
Dr. Realmuto said the weather of Hawaii plays a huge role in the air quality of the state. “In Hawaii, we have 2 major wind patterns. A trade wind pattern where the winds blow consistently out of the northeast and then there is everything else, called Kona winds. Basically, we think of Kona winds as a wind pattern in which the prevailing wind across the Islands are not out of the Northeast. Generally, it will be from the west, southwest or even south. We have the biggest problems with air quality in Hilo and even Honolulu with Kona winds. Luckily, the tradewinds dominate the weather pattern and occur around 90% of the time. But that other 10% of the time can not be ignored.“
Dr. Realmuto continued, “HyspIRI, and even the precursor mission onboard the aircraft ER-2 with those pair of imagers, will be so helpful to our project. We will see the sulfur dioxide gas plumes and the particulate matter clouds in incredible detail in only a few minutes what would take us hours or even days right now. The definition and quality of the images of the plume or cloud will not suffer; in fact, it will improve. We will be able to see a much wider, bigger picture than ever before. The hope is that this project will dramatically improve the accuracy of the air quality warnings, which in turn will mean more people will take them seriously. The whole boy who cried wolf analogy you know. The hope is we can be so accurate as to tell people when, down to a few minutes, when the air quality will turn bad and how long the poor air quality will last, when it will be safe to come outdoors. We also have the hope of telling people whether it will be a minor, medium or major air quality event in terms of concentration of the sulfur dioxide particles and/or particulates. To be as precise in our warnings is a huge goal of ours and something that we are simply not able to do at this time.”