https://www.sciencenews.org/article/climate-change-bering-sea-ice-winter-melt-lowest-level
Winter Ice Shrank To Its Lowest Level In 5,500 Years In The Bering Sea In 2018
New Data shows Sea ice in the Bering Sea, in the south Atlantic shrank to its smallest winter size in 5,500 years in 2018. Sea ice loss in the summer is something that normally captures attention but winter ice in the region has seen a significant decline. In February of 2018 and 2019, there was a 60-70% decline in the average amount of sea ice than the average February-to-May ice from 1979 to 2017. The original theory for this decline was that it was from unusual short term atmospheric conditions. But new studies suggest that human-caused climate change is also a significant influence on this loss of sea ice.
Scientist Miriam Jones and her team collected cores of peat from St. Matthew island, a remote location in the Bering Sea west of Alaska. Inside the peat, there are remains of partially decomposed plants and oxygen-bearing cellulose-containing clues to the history of the region’s climate. The rain that falls on the island contains two different types of oxygen isotopes: oxygen 18 and oxygen 16. The relative abundance of these isotopes in the rainfall varies depending on the conditions of the atmosphere. As plants take up this oxygen, they record these changes. By analyzing the number of oxygen isotopes in the cellulose over time, the team was able to record changes in precipitation and atmospheric circulation going back 5,500 years in time.
With this information, the team was then able to establish a link between this oxygen isotope and the extent of sea ice in the region. Bering sea ice is known to be tied directly to wind direction changes. The researches created a computer simulation that included the climate conditions from 1979-2018, the oxygen isotope values during that time, and satellite observations of sea ice. Findings showed that the amount of oxygen-18 increased. When there was more sea ice, there was less oxygen-18.
This information then allowed the researchers to link the amount of oxygen 18 in the peat to the extent of sea ice for thousands of years. The team found that the oxygen 18 values recorded in winter 2018 were highest, and the amount of sea ice was the smallest it's been in the last 5500 years.
The researchers also found that in preindustrial times, wintertime sea ice was gradually decreasing from natural changes in incoming sunlight in winter. But the team also found that CO2 concentrations in the atmosphere were closely correlated with the volume of ice. As the CO2 levels climbed past 280 ppm post during the industrial revolution, the oxygen 18 levels also began to rise with the corresponding sea ice decline.
Within 10 to 15 years, the region may have no ice at all during the warmer months. Arctic Sea ice tied for second-lowest on record in September 2019 with 2007 and 2016. First place going to 2012. The loss of ice is also speeding up the rate of warming within the region. Caused by a process called “Arctic Amplification”, Polar amplification is the phenomenon that any change in the net radiation balance tends to produce a larger change in temperature near the poles than the planetary average.
How does polar amplification work?
What impact does the level of oxygen in the atmosphere have on the temperature of the planet?
What are the unforeseen consequences of sea ice loss?
Polar amplification is when the balance of radiation changes, resulting in significant changes near the poles, rather than locations of average climate. As dissolved oxygen levels decrease more sunlight gets through to Earth's surface and trapped near the surface. The trapping of heat warms ocean water which leads to less dissolved oxygen from water vapor, there is an inverse relationship, so when oceans warm atmospheric oxygen is better able to trap more heat. CO2 and Oxygen 18 levels increase as sea ice is lost. The loss of sea ice leads to increased ocean levels.
ReplyDelete- Carissa Bersche
The consequences of sea ice loss is a increase of the sea level which will negatively affect islands and parts of continents that are close to the sea line and are lower than the sea level. I also know that their are ice that we use for fresh water, if they melt into the salt water then we lose the small amount of drinking water we do have.
ReplyDelete-Angeline Upchurch
Polar amplification works when the radiation net balance changes resulting in polar changes such as warming. Also the less oxygen the more sunlight that can get through to evaporate water/ melt ice. Some results of this can be wildlife decline and destroy crops and dry out land because some land relies on this ice.
ReplyDelete-Tyler A.
Sea ice loss means that sea levels will rise. When sea levels rise, it poses a threat to wildlife and to communities who live near the sea/coasts. Wildlife such as polar bears, walruses, etc. are in dangerous as their natural habitat is on ice and so are their food sources. If certain wildlife populations decline it interferes and causes the food chain to become unbalanced. This negatively impacts ecosystems and environments. Overall, the consequences for ice loss is drastic and dire.
ReplyDelete-Trinity Mathis
The loss of sea ice will contribute to higher sea levels which would ruin coastal communities. It would also affect Earth's rotation because as ice melts and move away from the earth poles, the Earth's axis also changes, but this doesn't really impact humans.
ReplyDelete-Ilori
The melting of sea ice into our oceans will cause the sea level to rise and that has the potential to devastate cities, families, and organisms. -Shirin Saha
ReplyDelete