"As massive bushfires raged across eastern Australia in January 2020, a deadly
haze settled over Melbourne, an obvious signal for residents to stay indoors.
Bouncing over their heads, though, was a less conspicuous signal: Cellular data
was flying through the air in an odd pattern, one that scientists may be able
to use to better understand and predict severe smoke events in the future.
The cell signals above Melbourne were interacting with an atmospheric quirk
known as a temperature inversion. Normally, you’ll find warmer temperatures
near the ground, where the sun is heating the surface, and cooler temperatures
higher up in the atmosphere. But, true to its name, a temperature inversion
When a layer of smoke rolled across the city, it absorbed the sun’s energy,
keeping much of that radiation from heating the surface. This created a layer
of hot, dry, smoky air that sat atop the cooler air at ground level. “You have
this double process,” says Monash University atmospheric scientist Adrien
Guyot, lead author of a new paper in the journal AGU Advances describing the
research. “You have the warming up of the layer, and the fact that the ground
is not being warmed as it is normally.”
This did weird things to the signals transmitting between the cellular antennas
atop Melbourne’s buildings. (Guyot and his colleagues were looking specifically
at antenna-to-antenna communication in the network, not at how people’s mobile
phones were connecting to them.) Usually when these antennas talk to each
other, the signal flies more or less straight between them. But a temperature
inversion creates a kind of atmospheric cap, dramatically bending the signal
toward the ground."
Via Stuart Richman.
*** Xanni ***
Chief Scientist, Xanadu
Partner, Glass Wings
Manager, Serious Cybernetics