The rapid shrinking of ice fields in the Arctic Ocean is no longer newsworthy for climate scientists.
In years past the state of Arctic sea ice was a major source of hand wringing in the scientific community as ice fields shrank further and faster. However it now appears to be widely accepted.
Worrying acceptance of less sea ice
“A decade ago, this year’s sea ice extent would have set a new record low and by a fair amount,” said Walt Meier, a sea ice scientist at NASA’s Goddard Space Flight Center. “Now, we’re kind of used to these low levels of sea ice – it’s the new normal.”
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“It’s melting earlier,” Meier says. “The ice is thinner, so it gets pushed around by the wind more. It’s more broken up. It used to be more of a big sheet of ice, and now [we’re seeing] chunks of ice.’
He likes the situation to the move from “a big ice cube” to “crushed ice.”
The most important thing for scientists that have accepted the declining extent of Arctic sea ice is to develop new ways of measuring it. Ice thickness can be measured using ships and submarines, but scientists would like to be able to do so using satellites. This is complicated by the salt content of seawater, which can make using radar difficult.
NASA developing new satellite
However NASA has come up with a satellite called “Ice, Cloud and Land Elevation Satellite-2” (ICESat-2) that will use lasers and a “a very precise detection instrument” which will measure how long the laser takes to rebound from the Earth. ICESat-2 will launch in 2018, but it won’t be able to measure every variable required by climate scientists. For example “above-water height versus below” will need to be measured differently.
Ice levels have been decreasing steadily, with a record low recorded in March. More ice was lost in May before June proved to be a relatively good month for the ice. However in August more ice was lost as the sun became more intense. This kind of pattern has become normal.
“We have a good handle on the sea ice area change,” said Thorsten Markus, Goddard’s cryosphere lab chief. “We have very limited knowledge how thick it is.”
Global weather patterns could be influenced by Arctic
To understand the extent of sea ice loss, we need to work out how much there is. Given that 10% of sea ice in the Arctic is above the water, with 90% below, it’s important to understand the volume and density of the ice.
“If we want to estimate mass changes of sea ice, or increased melting, we need the sea ice thickness,” said Markus. “It’s critically important to understanding the changes in the Arctic.”
There are also wider implications for the global climate, as the Arctic could change weather patterns around the world, says Meir.
“We’re already seeing evidence of that in terms of how the jet stream is changing,” the sea ice scientist told Reuters. “It’s becoming less of a west to east flow and more of a loopy flow, kind of more north to south which leads to more extreme event things like droughts, torrential rains and flooding.”
Scientists are working to improve our understanding of weather phenomena that have the potential to wreak havoc around the world, and the problem is not confined to faraway regions.