Extremely dry weather, unusually high temperatures and strong winds have conspired to spread massive wildfires in many countries over the past year.
In California, the still burning South fire has burned 5,332 acres since September 5. In Australia, 2.5 million acres were incinerated and six lives lost to bush fires in 2019.
That’s why a new study presented at the annual conference for science and the environment at Tel Aviv University should be of critical interest across the globe.
The Israeli researchers found a unique way to identify and warn people about conditions that promote fires: the smartphones we all have in our pockets.
Every smartphone has built-in sensors that measure environmental factors such as humidity, temperature, atmospheric pressure, magnetic field and acceleration. The humidity sensors, for instance, alert when the user tries to connect the phone to a wet charger.
For her doctoral dissertation under the guidance of Prof. Colin Price, head of the Porter School of Environmental Studies at Tel Aviv University, Hofit Shachaf used smartphone sensors to measure weather conditions that play an essential role in the formation of fires.
Shachaf’s study focused primarily on humidity data collected over a period of four years from roughly 40,000 smartphones a day worldwide by OpenSignal’s WeatherSignal Weather app.
Humidity is one of the most crucial weather indicators of fires. When humidity is low, plants and trees become more susceptible to fires, and the likelihood of a fire increases.
The data from November 2016 was characterized by exceptional dryness in Israel. The week during which many wildfires broke out during that month, humidity measured 5-10 percent, which explains how small fires or even flames could easily spark into a wildfire.
When the researchers compared this data to the corresponding period from 2013-2015, they saw a significant difference in the humidity levels measured by smartphones.
This shows that the mobile sensors provided a good indication of the exceptionally dry conditions.
Similar results were obtained after studying two other fires that occurred in recent years in Portugal and Macedonia.
The researchers then started monitoring real-time information collected by phone sensors.
“If we see unusual data and all variables indicate a high risk of fires, we can treat it as a warning sign and give immediate warning to the security and rescue forces,” says Shachaf.
Although smartphone sensors are less accurate than are meteorological stations, Shachaf says they are adequate to identify climate extremes. In addition, the widespread distribution of the devices gives the sensors an advantage over stationary weather stations.
“Phones provide masses of data,” Shachaf says. “In addition, meteorological stations cost a lot of money; thus, you don’t have them everywhere.People with their smartphones, on the other hand, get everywhere in the world. When every mobile device is used as a portable weather station, the coverage is much wider than that of the meteorological stations.”
Masses of data
The researchers next plan to study two additional variables that affect the likelihood of fires and can be measured by smartphone sensors: temperature and wind.
Following the discontinuation of the WeatherSignal app Shachaf used for her original study, the researchers are arranging collaborations with other applications that can give them the data to create reliable forecasts in real-time.
According to the researchers, this information would be collected anonymously and only if the user agrees to the terms.
Shachaf emphasizes that fire alerts are becoming more and more important as the climate crisis worsens, causing the frequency and severity of extreme weather events to increase.
“There are more powerful hurricanes in the world today, more intense droughts, and heavier rainfalls and floods. The same goes for Israel.As heatwaves and droughts become more severe in this region, we will see more and more fires, which is already the case in the rest of the world,” she concludes.