WASHINGTON – Scientists have discovered a striking similarity
between certain ocean currents on Earth and the bands that
characterize the surface of large, gaseous planets like Jupiter.
Boris Galperin of the University of South Florida’s College of Marine
Science in Saint Petersburg and colleagues in the United States,
Israel, and Japan report their findings later this month in
Geophysical Research Letters, published by the American
Geophysical Union.
“The banded structure of Jupiter has long been a subject of
fascination and intensive research,” says Galperin, a physical
oceanographer who analyzes turbulence theory and applies theory
and numerical modeling to analyze planetary processes. “The
visible bands on Jupiter are formed by clouds moving along a
stable set of alternating flows.”
Galperin and his colleagues have discovered that oceans on Earth
also harbor stable alternating bands of current that, when modeled,
are similar to the bands on Jupiter, due to the same kinds of “jets.”
“We think this resemblance is more than just visual,” says Galperin.
“The energy spectrum of the oceanic jets obeys a power
law that fits the spectra of zonal flows on the outer planets.”
The observation begs the question of whether these similar
phenomena are rooted in similar physical forces. “To answer this
question,” says Galperin, “one needs to determine what physical
processes govern the large-scale dynamics in both systems.”
According to Galperin, there is a similarity in the forcing agents for
planetary and oceanic circulations. The study maintains that both
sets of zonal jets — the ocean’s bands of currents and the bands of
Jupiter’s clouds — are the result of an underlying turbulent flow
regime common in nature.
Comparing the energy spectra on giant planets and in Earth’s
oceans can yield valuable information about the transport
properties of the oceans, says Galperin, especially about the
strongest currents in the mid-depth ocean. “The implications of
these findings for climate research on Earth and the designs of
future outer space observational studies are important,” he says.
The study was funded by the U.S. Army Research Office and the
Israel Science Foundation.
