(LOOTPRESS) – Changes made by humans to the environment have unexpected effects that are not always clear. One example is air pollution, which researchers have linked to an increase in lightning strikes during thunderstorms.
A team from James Madison University in Virginia analyzed data from over 500,000 thunderstorms in Washington, DC, and Kansas City over a span of 12 years. They discovered that higher levels of fine particles in the air, known as aerosols, corresponded to more lightning strikes.
While scientists have previously examined the link between aerosols and lightning, understanding this connection remains a challenge due to the many factors in the atmosphere that can influence it.
According to geographer Mace Bentley from JMU, pollution acts as a nucleus for cloud formation. The updrafts within a storm pull pollution particles into the clouds, and the movement of these particles can separate electrical charges, resulting in increased lightning.
The researchers focused on PM2.5 and PM10 particles, comparing their concentrations to instances of thunderstorm activity. They found that the amount of these particles was more significant than their size in influencing lightning frequency. Generally, more particles lead to more lightning, but if the particle concentration becomes too high, it can reduce lightning, likely due to diminished energy in the storm.
This study involved many variables, and other factors like air currents and land cover also affected the results. However, the patterns observed were consistent in both cities. Bentley noted that urban pollution appears to enhance thunderstorms and lightning globally.
The study revealed additional insights: thunderstorms were most frequent on Thursdays in both locations. In Washington, DC, Monday had the fewest thunderstorms, while Friday was the quietest in Kansas City. Furthermore, when atmospheric energy was high due to conditions like temperature and humidity, air pollution had a greater impact on lightning activity.
These findings enhance our understanding of how changes in air pollution can alter weather patterns. The researchers plan to investigate this relationship in other regions and incorporate more measurements to assess the effects of aerosols.
The authors emphasized their intent to analyze differences between thunderstorms triggered by urban pollution and those occurring in the wider area to evaluate pollution’s impact. The study has been published in Atmospheric Research.
