Trend of Antarctic Ozone Hole and Its Influencing Factors

Influencing factors, and variations and trends of Antarctic ozone hole in recent decades are analyzed, and sudden change processes of ozone at Zhongshan station and the effect of atmospheric dynamic processes on ozone changes are also discussed by using the satellite ozone data and the ground-measured ozone data at two Antarctic stations as well as the NCEP/NCAR reanalysis data. The results show that equivalent effective stratospheric chlorine (EESC) and stratospheric temperature are two important factors influencing the ozone hole. The column ozone at Zhongshan and Syowa stations is significantly related with EESC and stratospheric temperature, which means that even though the two stations are both located on the edge of the ozone hole, EESC and stratospheric temperature still played a very important role in column ozone changes, and mean while verifies that EESC is applicable on the coast of east Antarctic continent. Decadal changes in EESC are similar with those of the ozone hole, and inter-annual variations of ozone are closely related with stratospheric temperature. Based on the relation of EESC and ozone hole size, it can be projected that the ozone hole size will gradually reduce to the 1980's level from 2010 to around 2070. Of course there might exist many uncertainties in the projection, which therefore needs to be further studied.

Ice Sheet Melt and Ozone Hole Variations on Three Solar Cycles Possible Anthropogenic Interactions

This paper investigated the information about Ice sheet melt and Ozone hole variations during three solar cycles. After performing the inquiry on the data, the final results pointed out that both phenomena varying accord with Earth’s seasonality. The sea melt extension depends on the season and if the ocean waters are warmer around the polar caps. We checked the suggestion that anthropogenic perturbations could influence the variations in both phenomena.

Numerical Experiment for the Impact of the Ozone Hole over Antarctica on the Global Climate

A numerical experiment has been carried out with IAP (Institute of Atmospheric Physics) 9-layer general circulation model to investigate the influence of the Antarctic Ozone Hole on the global climate. The results show that the changes of total amount of ozone over higher latitude and polar region of the Southern Hemisphere affect not only the climate in the Southern Hemisphere, but also that in the Northern Hemisphere significantly. In the next spring, although the total amount of ozone over Antarctica has returned to the normal value, the influences of Ozone Hole still exist.

NUMERICAL SIMULATION OF THE FORMATION MECHANISM OF THE ANTARCTIC OZONE HOLE

The global zonally averaged atmospheric chemistry model is developed in this paper.The formation mechanism of the Antarctic ozone hole is numerically simulated using the model to check the viewpoints on the formation mechanism.The results show that: (1)The Antarctic ozone hole is a special phenomenon resulting from the heterogeneous reactions on the surface of the polar stratospheric cloud particles,under the special conditions of temperature and circulation in Antarctic spring.The heterogeneous reactions reduce the NO_2 concentration,resulting in the decrease of ozone production rate.The ozone content decreases when its production is less than its destruction.This is the direct cause for the formation of the Antarctic ozone hole. (2)The impact of the polar vortex on the transport of trace species is not the determinative factor in the formation of the Antarctic ozone hole.but makes the intensity of the ozone hole changed. (3)The solar cycles have negligible influence on the intensity of the Antarctic ozone hole through photochemical reactions.

Anomalously low ozone of 1997 and 2011 Arctic spring: Monitoring results and analysis

Total ozone observations from the Total Ozone Unit （TOU） aboard the Chinese second generation polar orbiting mete- orological satellite, Fengyun-3/A （FY-3/A）, revealed that total column ozone over the Arctic declined rapidly from the beginning of March 2011. An extensive region of low column amount formed around mid March; monthly mean total column ozone in March 2011 was about 30% lower than the average observed during 1979-2010. Daily total column density of ozone near the center of low ozone area in mid March was less than 240 Dobson units, about half the total column ozone amount observed during the same period of the prior 10 years. We analyzed total column ozone data from different satellites during 1979-2011. Results show that the Arctic depletion of ozone in spring 2011 was initiated by the cold polar vortex in the lower stratosphere. The March mean total ozone over the Arctic has shown a decreasing trend over the past 32 years, and its variation is strongly correlated with the polar vortex. A similar low ozone process of spring 1997 was compared to that of 2011, but daily variations of total ozone in March over the Northern Hemisphere in 1997 and 2011 have different patterns.

The role of the Arctic and Antarctic and their impact on global climate change:Further findings since the release of IPCC AR4,2007

Changes in the climate of the Arctic and of the Antarctic have been of great concern to the international scientific and social communities since the release in 2007 of the Intergovernmental Panel on Climate Change Fourth Assessment Report （IPCC AR4）. Since then, many new findings have been reported from observations and research carried out in the Arctic and Antarctic during the fourth International Polar Year （IPY）. There is evidence that global warming is inducing rapid changes in the Arctic and Antarctic, in both a quantitative and qualitative sense, and that these regional changes could be used as indicators of global climate change. Declining Arctic sea ice could affect winter snowfall across much of the Northern Hemisphere by bringing harsher winters. Projections suggest that summertime Arctic sea ice will disappear by 2037. By the 2070s, the Antarctic ozone hole will recover to the level of the early 1980s, following the ban on the production of Freon earlier this century. With the loss of the shielding effect of the ozone hole, Antarctic surface temperatures will increase, ice sheets in East Antarctica will begin to melt, and the Antarctic sea ice will retreat. Therefore, sea level rise will become an increasingly serious issue this century. As sea surface temperature rises, the Southern Ocean will become less effective as a sink for atmospheric CO2 and the increase of surface CO2 will be faster than that in the atmosphere. Increased surface CO2 would lead to ocean acidification and affect ecological systems and food chains.

Prediction and Analysis of O3 Based on the ARIMA Model

Despite of the small amount in the atmosphere,ozone is one of the most critical atmospheric component as it protects human beings and any other life on the earth from the sun's high frequency ultraviolet radiation. In recent decades,the global ozone depletion caused by human activities is w ell know n and produces an " ozone hole",the most direct consequence of w hich is the increase in ultraviolet radiation,w hich w ill affect human survival,climatic environment,ecological environment and other important adverse impacts. Due to the implementation of the M ontreal protocol and other agreement,the total amount of ozone depleting substance in the atmosphere has been prominent reduced,w hich w ill lead to a new round of regional climate change.Therefore,predicting the changes of the total ozone in the future w ill have an important guiding significance for predicting the future climate change and making reasonable measures to deal w ith the climate change. In this paper,based on the ozone data of 1979 to 2016 in the southern hemisphere and ARIM A model algorithm,using time series analysis,w e obtain prediction effect of ARIM A model is good by Ljung-Box Q-test and R^2,and the model can be used to predict the future ozone change. With the help of SPSS softw are,the future trend of the total ozone can be predicted in the future 50 years. Based on the above experiment results,the global ozone change in the future 50 years can be forecasted,namely the atmospheric ozone layer w ill return to its 1980's standard by the middle of this century at the global scale.

Reaction probabilities of ClONO_2 on ice

The reaction probabilities of ClONO\-2 on ice surface were determined by using a flow tube reactor attached with a photoionization detector. The growth rate of HOCl was used to obtain reaction probabilities. The measured reaction probabilities depended on temperature and flow velocity. The reaction proceeded efficiently at temperature range of 190K to 200K. The reaction probability was 0 0023 at 198K ( v =100 cm/s). The result was in good agreement with that of Abbatt et al.

Measurement of NO_2 and analysis of relationship between stratospheric NO_2 and O_3 over Zhongshan Station,Antarctica

We have already continually taken the measurement of total column amount of O 3, NO 2 as well as stratospheric O 3, NO 2 over Zhongshan Station,Antarctica. This paper analyzes the seasonal variation of NO 2 and its relationship to O 3 during the Antarctic Ozone Hole in 1993～1995 and points out that the decrease of atmospheric NO 2 is one of the important reason to the strengthening of Antarctic Ozone Hole.

The observations on Polar Stratospheric Clouds at Zhongshan Station，Antarctica

lidar system (694 nm) was used to measure the stratospheric aerosol layer at Zhongshan Station (69°22'S, 76°22'E ) in 1993. A total of 53 sets of lidar data presented in this paper were obtained over a period of 224 days between March 27 and November 5, 1993. The average vertical profiles of stratospheric aerosol backscattering ratio and the integrated backscatter coefficient over the 12 km～30 km altitude range were reversed from the return signal of lidar. The results of observations show that the stratospheric aerosol content more noticeably enhanced in 1993 than that in 1990 due to Mt. Pinatubo eruption in Philippines in June of 1991. Polar Stratospheric Clouds (PSCs) were observed from late May until early August. The vertical profiles of stratospheric aerosol backscattering ratio at Antarctica in 1993 show a clear double-layer structure. One layer is at an altitude of about 12 km,the other is at an altitude of about 25 km. The upper layer is varied with season.

Potential impacts of UV exposure on lichen communities:a pilot study of Nothofagus dombeyi trunks in southernmost Chile

High-latitude terrestrial ecosystems face the triple threats of climate warming,increased exposure to UV arising from polar ozone depletion,and deforestation.Lichen communities of southernmost Chile are recognized for their high diversity,which includes nitrogen-fixing cyanolichens.Such lichens are common on forest trees,contribute nitrogen to forests,and are sensitive to exposure following deforestation(widespread in this region).In a pilot study of exposure effects on tree lichens,using nondestructive imaging methods,we compared lichen communities on trunks of isolated vs.forest tree trunks of southern Chilean beech(Nothofagus dombeyi,Nothofagaceae).We chose trees of similar diameter and trunk lean angle in conserved forest and nearby logged meadow on Navarino Island,XII Region Magallanes and Chilean Antarctica,Chile,within the annual southern ozone hole.Ninety-five percent of cyanolichen records,including Nephroma antarcticum,and 66%of records for other foliose lichens were from the forest,whereas pendulous usneoid lichens dominated N.dombeyi bark at the meadow site.Limitation of cyanolichen growth on isolated trees could affect ecosystem function in this poorly studied habitat.Possible factors contributing to strong community differences were increased light intensity,UV radiation,and wind stress,plus limited ability of lichens to colonize isolated trees in the logged meadow.UV radiation was likely an important stressor for some lichen species but not others.We recommend more extensive monitoring to pinpoint causes of differing lichen communities,and we encourage better protection of bark-dwelling lichens in southern hemisphere regions facing multiple threats.