Ozone depletion in other areas

The ozone over the Arctic has also decreased in recent decades, but so far no "ozone hole" like the Antarctic has been seen. Although the current North Pole does not have a real ozone "hole," the losses of Arctic ozone in 1997 and 2011(Fig .1) basically reached the edge of generating ozone holes. On 02 October 2011, NASA reported that analogous ozone hole occurred over the Arctic at that spring for the first time, which was about five times the size of California. It was the first time for Arctic to rival Antarctica's ozone depletion. According to the observations from the surface, balloons and satellites showed that the Arctic region suffered 40% of the ozone layer loss from the winter of 2010 until late March 2011. The depletion of the ozone layer in the Arctic also came from the presence of nitrite clouds (similar to Antarctica) that allowed ozone-depleting substances to be converted into active chemicals through chemical reactions with sunlight, thus destroying the ozone layer. The emergence of analogous ozone holes over the Arctic led to the population explosion to higher but non-persistent levels of ultraviolet light through Eastern Europe, Russia and Mongolia. They also negatively affected phytoplankton in the oceans, which multiplied in northern Arctic circles in spring. Unlike the Antarctic, a large amount of depletion in the Arctic stratospheric ozone is not an annual recurrent phenomenon, and the Arctic weather conditions vary greatly every year. In the extreme case, the possibility of an Arctic ozone hole can not be ruled out when the Arctic stratosphere is warmer and lasts longer due to climate change. There are no permanent residents except the expedition members in the Antarctic region, while the majority of human beings live in the northern hemisphere. Once the ozone layer is over the Arctic, the impact on human beings will far exceed that of the Antarctic.

       Figure .1 Arctic total ozone column in 2010 (left) and 2011 (right) (Source: NASA).

The third ozone depletion region in the world is the Qinghai-Tibet Plateau. Scientific Bulletin published a paper entitled "Micro-Ozone Holes over Qinghai-Tibet Plateau in December 2003." It is proved by scientific findings that in the previous years (Bian, et al., 2006), Three Poles "will be a big discussion of the ozone hole which has been the actual "miniature ozone hole" or "low value of ozone "event officially concluded. Supported by a number of key projects by the Chinese Academy of Sciences for knowledge innovation as well as the projects funded by the National Natural Science Foundation of China, Bian Jianchun and other studies have shown that there was a very large area of extremely low ozone over the Qinghai-Tibet Plateau from December 14 to December 17, 2003 (Fig .2). The area of  total amount of ozone less than 220 DU (1 standard atmospheric pressure, temperature of 0 ℃, 10 microns thick ozone defined as 1DU) is more than 2.5 million square kilometers. The low value center is only 190DU, which decreases by 25% compared with historical average over the previous period (255DU). It showed that this was the first report of a micro-ozone hole or very low ozone value event over the Qinghai-Tibet Plateau. Zhou Xiuji and Chinese Academy of Meteorological Sciences have participated in the observations and studies. In their opinions, this is the first time in the world that an unusual low value area of atmospheric ozone in the middle and low latitudes occurs obviously. As low and middle latitudes are densely populated areas, the reduction of high-level ozone leads to increased ultraviolet radiation reaching the ground, directly endangering human health, increasing the incidence of skin diseases and eye diseases, and reducing the yield of crops. Therefore, although the depletion of atmospheric ozone in the Qinghai-Tibet Plateau is not as powerful as the Antarctic "ozone hole", it is more practical to study its effects on global ecosystem. According to the research results of meteorology in the Qinghai-Tibet Plateau, there is a strong convection over the Qinghai-Tibet Plateau in the center of the South Asia High in the summer. It can be assumed that the Tibetan Plateau is an important channel for transporting low-level matter to the stratosphere in the troposphere during the summer. Low-level pollutants within a few hundred kilometers of the surrounding area may converge on the Tibetan Plateau and rise to the stratosphere on the plateau, causing photochemical reactions to destroy ozone and reducing the total amount of ozone.

Figure .2 Qinghai-Tibet total ozone column in 2003 (Bian, et al., 2006).