Mid-March
Several weather stations in Antarctica have warmed up nearly 40°C
meanwhile
Parts of the Arctic have also experienced unusually warm conditions
This is about 30°C higher than the average for the same period in previous years
The north and south poles have opposite seasons
Why do abnormal warming occur at the same time?
Is there a connection between the two?
Will polar warming be more frequent in the future?
What impact will it have on us?
To this
Chinese Academy of Meteorological Sciences, National Climate Center
as well as experts from the National Satellite Meteorological Center
Interpretation was made
——
Several weather stations in Antarctica have warmed up nearly 40°C The temperature in parts of the Arctic is 30°C higher
The data shows that as of March 18, a number of meteorological stations in Antarctica have warmed by nearly 40 °C, and the most intense heating is the Continental Antarctic Kunlun Station, located at the highest point of the Antarctic ice sheet, with a warming range of 38.1 °C in 4 days, and a temperature of -26.3 °C, which is 30.9 °C higher than the annual average temperature; the Dome C station located in the third highest glacier has warmed up 37 °C in 4 days, with a temperature of -11.8 °C, about 31.2 °C higher than the annual average temperature.
The temperature of 850 hPa monitored by fengyun-3 D star shows that the temperature on March 18 is about 8 °C-12 °C from the average temperature of the same period in the same period of the past four years (Courtesy of the National Satellite Meteorological Center)
According to Ren Suling, chief of the Remote Sensing Application Service Center of the National Satellite Meteorological Center, the monitoring of the Fengyun Meteorological Satellite shows that on March 18, the temperature of 850 hPa near Wilkes land on the Antarctic continent was controlled by a heating group, and the temperature of 850 hPa was about -20 °C to -10 °C, which was about 8 °C to 12 °C higher than the average temperature in the same period of the past four years; on March 20, as the weather system moved, the warm temperature of 850 hPa in the area weakened.
As of now, according to continental Antarctic meteorological observations, the temperature inland antarctica has fallen back to normal.
Fengyun-3 D-satellite monitored 850 hPa-day average temperature on March 20 (Courtesy of the National Satellite Meteorological Center)
On the other side of the globe, in parts of the Arctic, temperatures in mid-March were also about 30°C higher than the average for the same period in previous years, and in some areas the temperature even approached or reached freezing. Heat records were broken in some parts of Norway, and unprecedented temperatures were seen in Greenland and the Franz Joseph Islands in Russia.
On 15 March, the temperature in the Arctic region deviated from the average distance from the same period in 1979-2000 (unit: °C)
Previously, Walter Meier, a scientist at the National Ice and Snow Data Center (NSIDC), said that the current Antarctic and Arctic seasons are opposite, and it would not have seen hot weather at the north and south poles at the same time, so this is definitely a rather unusual thing in March.
Cause analysis: Multiple factors such as congestion high pressure, decreasing sea ice and warming
Zhou Bing, chief expert of the Climate Service of the National Climate Center, analyzed that from the perspective of ocean forcing factors, the surface ocean currents of the tropical Pacific Ocean and the Indian Ocean transport heat to Antarctica, which is affected by the circular terrain of the southern hemisphere, which strengthens the warming trend of temperature in some parts of Antarctica. Global warming and the destruction of the natural environment caused by human activities are the deeper causes of temperature anomalies in the Arctic and Antarctic.
Ding Minghu, deputy director of the Institute of Meteorological Sciences of the Qinghai-Tibet Plateau and Polar Regions of the Chinese Academy of Meteorological Sciences, said——
In fact, the anomalous warming phenomenon in Antarctica is mostly concentrated in the high altitude areas of the ice sheet in the southeast polar region, which may be caused by the intrusion of the Ross Sea into the Antarctic continent. The southern hemisphere ring mode weakened, the Amundsen low pressure became shallower, the Ross Sea blocked the high pressure and rapidly developed and invaded the eastern antarctic continent from the south, injecting warm and humid air flow from the Pacific Ocean into the central area of the Antarctic ice sheet, resulting in this abnormal warming.
He explained that the Antarctic continent is covered by thousands of meters of ice sheets all year round, and the radiation cooling of the ice sheets will form a strong and stable inversion layer. After the intrusion of the Ross Sea blockage, the warm and humid air flow it carries leads to changes in the structure of the inversion, and the energy exchange of the ice sheet near the ground is rapidly exchanged, resulting in heating. In addition, after the warm and humid air flow enters the Antarctic continent, it produces precipitation when it is cold, releasing a large amount of latent heat and exacerbating the temperature rise. At high altitudes, because of the lower condensation height, precipitation can release more heat, so the heating in high altitudes is more intense.
Previously, the overall temperature in Antarctica in February was 2.5 °C, and the sea ice area reached an all-time low, which Ding Minghu said was one of the driving forces behind the abnormal high temperature.
Sea ice is known to have a high albedo and can reflect large amounts of solar radiation. When the temperature is higher, the sea ice melts, resulting in less reflection to the sun, which absorbs more heat, resulting in a further increase in temperature, at which point the sea ice melts at an accelerated rate, forming a positive feedback mechanism. In February, the areas with the most severe anomalous reductions in Antarctic sea ice were concentrated in the Ross Sea, Amundsen Sea and Belins Gojin Sea, resulting in weaker Amundsen low pressure, weakening of the southern hemisphere ring mold, and obstruction of the Ross Sea to invade the Antarctic continent.
It is reported that Antarctica has long been known as the "stabilizer" of the global climate. On the one hand, a large amount of solar radiation is reflected through the high albedo of sea ice to maintain global temperature stability; on the other hand, the huge ice body of Antarctica has a heat absorption and heat storage function, which can stabilize the global atmospheric energy balance. Although Antarctica has a certain lag relative to global climate change, since 2016, this "stabilizer" has a sign of rapid change - the increase in extreme events, the impact of global change on Antarctica has also begun to reveal, this event is also one of the evidence of the frequent occurrence of Antarctic extreme events.
The available data do not indicate a dynamic link between the arctic and south pole anomalies
At present, the north and south poles have opposite seasons, but both have extreme high temperature weather and are relatively close in time, is there a correlation between the two?
In this regard, Ding Minghu believes that in recent decades, the Arctic has been in rapid change, and the heating in recent days has been concentrated in local areas, and the heating amplitude is small, and the extremes are not obvious compared with before. Previously, the heating of Antarctica was mostly concentrated in the southwest pole, and the temperature of the southeast pole did not change much over the years. Although there is precedent for abnormal warming due to the intrusion of the Ross Sea blockage, it is not so drastic. In fact, such a violent and rapid warming event has not been reported in any region since meteorological records were made.
Ding Minghu said:
This extreme warming event may mark that Antarctica has entered a stage of rapid change, which needs to be paid attention to and vigilant by the international community.
In addition, from the available data, there is no dynamic link between the phenomenon of warming in the North and South Poles, and its correlation still needs to be further studied.
The simultaneous "fever" of the North and the South is a strong signal of human damage to the climate or triggers a chain reaction
Over the past 100 years, temperature increases in parts of the Arctic and Antarctic have increased by 3-5 times or more than the global average. This phenomenon, which is like being focused by a magnifying glass, is called the "polar amplification effect" and makes the North and South Poles at the forefront and most vulnerable to the challenge of climate change.
Between 1880 and 2020, earth's surface temperatures were | at different latitudes (ordinate) and chronological (abscissa) (1951-1980 average). NASA
Simultaneous "fever" at both the north and south poles is a strong signal of human damage to the climate, and while high temperatures "must last for a considerable period of time to have a substantial impact," the risk of ice shelf collapse and glacier melting could trigger further ripple effects. Once the ice shelf is lost, ground ice located inland will flow into the ocean at a faster rate, causing sea levels to rise. The melting of the ice has led to a vicious circle: larger areas of seawater are exposed, increasing the absorption of solar energy, which leads to a faster warming of the atmosphere.
Zhou Bing said that the ecology of the Arctic and Antarctic regions is fragile, and a slight anomaly in the local climate may lead to the collapse of the ecology here. Polar temperature anomalies, if frequent, can have far-reaching effects – in addition to polar bears, penguins and other polar animals may face survival difficulties, and some germs in the ice may also be reborn.
Snow algae is an algae that grows in the polar snow, and when it freezes, it is in a dormant state, and once the ice and snow begin to melt, the snow will "bloom" and dye the snow red. Its large-scale appearance is also one of the manifestations of Antarctic warming.
High temperatures in the polar regions can also cause climate change, especially in the Arctic, which has a greater impact on the Northern Hemisphere.
Zhou Bing said:
Under normal circumstances, the Arctic should be very cold, the equator should be very hot, and a strong pressure gradient force is formed between one cold and one hot, making the westerly wind belt more powerful, so that the polar vortex is firmly bound to the Arctic region and will not easily go south. However, after the temperature rise in the Arctic region, the pressure gradient between the polar region and the equator is reduced, and the westerly wind belt is more unstable, resulting in large ridges and large grooves being more likely to form, so that the northern hemisphere is more likely to experience extreme cold weather in winter, for example, extreme cold weather will occur obviously in winter in recent years.
Global warming is a major challenge facing humanity
Needs all countries and regions around the world
And the joint efforts of each and every one of us
Otherwise, predictable
Like the polar anomalous warming
Extreme weather and climate events
It will be more and more
Source: CCTV News