Current Affairs

Issue

According to a new study by an international team of researchers, the Earth’s entire atmosphere contains the unusual sound that vibrates much like a ringing bell.

 

Background

The discovery could help scientists better predict weather patterns and understand the makeup of our atmosphere.

 

Details

• Energy moving through skies - from things like heat-produced pressure to the gravitational pull of celestial bodies - also creates waves.

• The atmospheric resonances were first proposed at the beginning of the 19th century by French physicist Pierre-Simon Laplace, whose dynamic theory of ocean tides has since allowed scientists to predict deformations in a planet’s atmosphere.

• The tones are created by massive pressure waves that travel around the globe. Each wave corresponds to each of these different resonant frequencies.

• If the waves travel through the air at the right height and speed, they can become in tune with the atmosphere, creating resonance.

• This allows the waves to form a pattern stable enough to vibrate across the entire global atmosphere, like sound waves ringing through a bell. 

• The team identified some of the wave sets as Rossby waves powered by inertia and others Kelvin waves. Some of them move eastwards, others westwards.

• The team also detected a small difference between observed and predicted frequencies of these resonating waves, which they concluded is caused by a Doppler shift .

• The new study includes a detailed analysis of pressure observations spanning 38 years. The researchers found dozens of separate waves circling the Earth in a checkerboard pattern.

• This finally resolves a longstanding and classic issue in atmospheric science, but it also opens a new avenue of research to understand both the processes that excite the waves and the processes that act to damp the waves.