It is well known that thunderstorms create electric fields in the atmosphere. On the other hand, it might be surprising that insects also have this effect: they can charge the air to a similar extent if they are clustered together in dense swarms. This also affects the weather.
According to a study, a swarm of insects can generate as much electrical charge in the atmosphere as a thundercloud and thus influence the weather, among other things. In this way, the animals probably also contribute to the transport of air particles, reports a research team in the journal “iScience”. With regard to the effect that has hardly been taken into account so far, it should be considered that birds and microorganisms also carry charges and are widespread in the lower atmosphere – the extent of the resulting electrical interactions in the atmosphere must now be researched more closely.
There are many sources of electrical charge in the atmosphere that affect processes such as the formation of droplets and the elimination of dust and aerosols. The electric field there is correspondingly variable. So far, living beings or biological processes have not been taken into account as charge sources in models – although they do play a role in fluctuations in atmospheric electricity, the research team explains. It is known for many insect species that they carry an electrical charge of pico- to nanocoulombs per individual. Large concentrations of flying insects could thus be an important source of space charge in the atmosphere.
The scientists led by Ellard Hunting from the University of Bristol first measured the electric field in the vicinity of swarming honey bees. Such swarms can change the atmospheric electricity by 100 to 1000 volts per meter and increase the electric field strength that usually exists near the ground. “We’ve always studied how physics affects biology, but at some point we realized that biology could also affect physics,” says first author Hunting.
Based on the data obtained, the team developed a model to calculate the influence of other swarming insects such as flying ants, grasshoppers, migrating butterflies and mosquitoes. ‘How insect swarms affect atmospheric electricity depends on their density and size,’ explains co-author Liam O’Reilly of the University of Bristol.
For certain locusts, for example, where a swarm can contain 80 million animals in less than a square mile (2.6 km²), the impact on atmospheric electricity is likely to be much greater than for bee swarms. Swarms of desert locusts (Schistocerca gregaria) have the potential to alter their local electrical environment on a scale comparable to meteorological events such as a thundercloud.
The researchers write that this form of atmospheric space charge is not yet taken into account in current climate models. The atmospheric space charge enhances, among other things, the aggregation and movement of air particles, so it is conceivable that the charges generated by insects contribute to spatial changes in air particles. An influence on the long-distance transport of desert dust is possible.
