The Arctic staged a "Song of Ice and Fire" or further accelerate global warming
Global warming is causing the icy and snowy Arctic to become entangled in extremely hot weather. Amidst the heat waves, large-scale forest fires broke out in the Arctic Circle after last year. Satellite images from European Sentinel 3 show that the current wildfires in Siberia near the Arctic Circle are about 800 kilometers wide.
This summer, the Arctic region is undergoing a high-temperature "baking" experience. Canada’s last complete Arctic ice shelf collapsed and lost 40% of its area in just two days at the end of July. The temperature of Verkhoyansk, a small Russian town in Siberia located in the Arctic Circle, soared to 38 degrees Celsius on June 20 this year.
Accompanying the continued high temperatures in the Arctic are the Arctic fires. According to reports, the World Meteorological Organization recently issued an announcement stating that large-scale forest fires occurred in the Arctic Circle for the second consecutive year due to the long-term high temperature in Siberia. The most active forest fire is less than 8 kilometers from the Arctic Ocean.
There are even fires in the icy and snowy North Pole
Global warming is causing the icy and snowy Arctic to become entangled in extremely hot weather. According to the Spanish New Forum website, the spokesperson of the World Meteorological Organization Claire Nalis said at an online press conference in Geneva: "The temperature in some parts of Siberia has risen to over 30 degrees Celsius again recently, which is worse than many areas in Florida. Higher.” The organization also received reports about the rapid decrease in sea ice along the coast of Russia.
Naris said that Siberia is now being affected by high-pressure systems and heating masses, and they are in a state of stall, stranded in Siberia. In addition, ocean currents will drive powerful polar jets, moving hot and cold air masses in the northern hemisphere. As the Arctic warms, the polar front jets are now violently undulating in the northern and southern hemispheres, and in the summer they will inject warm air into the Arctic. Together, these reasons have led to long-term high temperatures in Siberia.
Guo Donglin, a researcher at the Institute of Atmospheric Physics, Chinese Academy of Sciences, told Science and Technology Daily that the temperature changes in the Arctic region are more sensitive than other regions in the world. According to data from the World Meteorological Organization, from 1901 to 2012, the rate of warming in the Arctic was twice the global average.
Amidst the heat waves, large-scale forest fires broke out in the Arctic Circle after last year. Satellite images from European Sentinel 3 show that the current wildfires in Siberia near the Arctic Circle are about 800 kilometers wide. At present, the fire front of the northernmost active Arctic wildfire has exceeded 71.6 degrees north latitude and is less than 8 kilometers away from the Arctic Ocean.
On July 22, there were about 188 fire spots in Siberia. Among them, the Russian Sakha Republic and Chukotka Autonomous Region in the northeastern part of Siberia were particularly intense. In the 18 years of data recorded by the European Union's Copernicus Atmospheric Monitoring Agency, the total carbon emissions caused by the fire since January this year reached the highest level.
Lightning and hot weather are a culprit and an accomplice
"The Arctic generally refers to the high latitudes of the northern hemisphere, with the characteristics of the Arctic climate. In recent years, due to the accelerated warming of the Arctic, which is suitable for the growth of some northern forests, the forest line has also continued to move north." Researcher at the Nanjing Institute of Soil Science, Chinese Academy of Sciences Chu Haiyan said.
"The Arctic Circle includes a large area of land north of the Eurasian continent and the American continent. There is no snow cover here every summer, and plants such as coniferous forests and tundra grow well, so there are objective conditions for fire." Nanjing Information Engineering Professor Le Xu from the University’s School of Environmental Science and Engineering introduced that there will be lightning in places with strong atmospheric convection. Arctic fires are basically triggered by natural factors such as lightning, but whether they will develop into fires, and the frequency, intensity and burning area of the fires Mainly depends on the temperature, the higher the temperature in spring and summer, the more conducive to the occurrence of fires.
The World Meteorological Organization said that since July, extreme high temperatures have appeared in the Arctic. Although there were always fires in Siberia during the previous summer, the time of this fire was one month earlier than in previous years, and the fire spread so quickly that it was difficult to extinguish.
Why did the fire this year come so early? Jiang Yiquan, an associate professor at the School of Atmospheric Sciences of Nanjing University, said: "Since May this year, the Arctic sea ice has been significantly less than the same period in history. It was once the fourth lowest in history. Among them, the Bering Sea, the Chukchi Sea and the Barents Sea are the most prominent." Xu pointed out that the melting of Arctic sea ice will cause more ocean area, which will absorb more light and heat, and exacerbate global warming.
Jiang Yiquan said that from January to June this year, the temperature in Siberia was 5 degrees Celsius higher than the average temperature. In June, it was significantly higher than the same period by about 10 degrees Celsius. The precipitation was also significantly less. Such meteorological conditions are conducive to the earlier occurrence of wildfires. .
Once the moisture dries the peatland there is a risk of smoldering
On the visible surface of the Arctic, blazing flames burn, and in the invisible underground, there is also the risk of flameless smoldering.
There are 3.556×106 square kilometers of peatland in the Arctic. The mineral content of peatland is below 20%-35%, and it is rich in organic matter such as moss and fallen leaves. Although the area of peat land only occupies 2%-3% of the surface area, its carbon storage accounts for about 25% of the earth's soil carbon storage.
According to an article, under normal circumstances, the moisture in peatland is sufficient to prevent the spread of fire, but if the moisture in the peatland is dried by the abnormal high temperature, it will become a flammable "big briquettes" that can be flameless Smoldering lasts for several months.
In a 2015 article in "Nature Earth Science", Biologist Tureski of the University of Guelph in Ontario, Canada, said that peatland smoldering can spread over the deciduous silt layer on the surface, slowly. About half a meter per week, instead of spreading like a forest fire that can reach 10 kilometers per hour. "But the peatland smolders much longer, so it can transfer heat to deeper layers of soil, and the overall consumption of carbon-containing fuel may be two orders of magnitude higher than that of a normal fire." Turski said.
Fire releases 56 million tons of carbon dioxide
The Great Northern Fire is also affecting the Arctic environment. The Arctic fire in June last year released 53 million tons of carbon dioxide, while the Arctic fire in June this year released 56 million tons of carbon dioxide. In addition, researchers have monitored and found that the Arctic fire smoke is composed of various pollutants, including carbon monoxide, nitrogen oxides, volatile organic compounds and solid aerosol particles. In the fire zone in northeastern Siberia, carbon monoxide content is abnormally high.
Le Xu pointed out that the black carbon aerosol contained in the smoke and dust emitted by the Arctic fires is highly absorbent, and floating in the atmosphere may have a heating effect on the Arctic surface, but the specific temperature rise needs further research; The surface of ice and snow will reduce the albedo of ice and snow, increase the absorption of sunlight, and promote the melting of Arctic sea ice.
Where does the carbon from the Arctic wildfires come from? Liz Hoy, a boreal forest fire researcher at NASA’s Goddard Space Flight Center, and the research team found that, unlike wildfires in low latitudes, most of the carbon emissions of Arctic wildfires come from burning organic soil, rather than burning Trees and shrubs.
"The temperature of the Arctic is low, and the decomposition rate of animals and plants after death will be slower. Therefore, carbon will be stored in the frozen soil. However, once the frozen soil is significantly melted, the buried carbon will be released in the form of methane and carbon dioxide, thereby exacerbating the global Warming." Le Xu said.
"According to the United Nations Intergovernmental Panel on Climate Change report, the Arctic permafrost temperature increased by 0.39±0.15 degrees Celsius continuously from 2007 to 2016. Under the high-emission scenario, the area of near-surface permafrost in the northern hemisphere will likely be reduced by 30% by 2100. —99%." Guo Donglin told a reporter from Science and Technology Daily.
Guo Donglin said that the melting of permafrost caused by global warming will also cause the reduction of underground ice, leading to dryness of the surface, and desertification may occur in some places. The reduction of underground ice will also cause thermal melt disasters, which will seriously affect the stability of human infrastructure.
So can humans prevent the spread of Arctic fires? "The interior of the Arctic Circle is sparsely populated, and it is difficult to extinguish fires by manpower. They can only be controlled by weather conditions such as rainfall and cooling. In the long run, energy conservation and emission reduction measures can be taken. Only effective control of carbon dioxide emissions can slow down the world. Only warming can fundamentally reduce the occurrence of Arctic fires." Le Xu said.