共查询到20条相似文献，搜索用时 93 毫秒
1.
《Comptes Rendus Geoscience》2018,350(7):442-447
The Montreal Protocol has controlled the production and consumption of ozone-depleting substances (ODSs) since its signing in 1987. The levels of most of these ODSs are now declining in the atmosphere, and there are now initial signs that ozone levels are increasing in the stratosphere. Scientific challenges remain for the Montreal Protocol. The science community projected large ozone losses if ODSs continued to increase, and that ozone levels would increase if ODSs were controlled and their levels declined. Scientists remain accountable for these projections, while they continue to refine their scientific basis. The science community remains vigilant for emerging threats to the ozone layer and seeks scientific evidence that demonstrates compliance with Montreal Protocol. As ODSs decrease, the largest impact on stratospheric ozone by the end of the 21st century will be increases in greenhouse gases. The associated climate forcings, and the human responses to these forcings, represent major uncertainties for the future of the stratospheric ozone layer. 相似文献
2.
《Comptes Rendus Geoscience》2018,350(7):403-409
The stratospheric ozone layer is expected to recover as a result of the regulations of the Montreal Protocol on chlorine and bromine containing ozone-depleting substances (ODSs). Model simulations project a return of global annually averaged total column ozone to 1980 levels before the middle of the 21st century, well before the ODSs will return to 1980 levels. This earlier ozone return date is due to the effects of rising greenhouse gas (GHG) concentrations. GHGs influence ozone directly by chemical reactions, but also indirectly by changing stratospheric temperature and the Brewer–Dobson circulation. Based on projections of chemistry–climate models, this article summarizes the effects of GHGs on stratospheric and total column ozone in the mid-latitude upper stratosphere, Arctic and Antarctic spring, and the tropics. The sensitivity of future ozone change to the GHG scenario is discussed, as well as the specific role of a future increase in nitrous oxide and methane. 相似文献
3.
《Comptes Rendus Geoscience》2018,350(7):410-424
The Montreal Protocol has halted 99% of global production of chemical substances that deplete stratospheric ozone, which protects life on earth from the harmful effects of ultraviolet (UVB) radiation. UVB causes skin cancer and cataracts, suppresses the human immune system, destroys plastics, and damages agricultural crops and natural ecosystems. Because ozone-depleting substances (ODSs) are powerful greenhouse gases, the Montreal Protocol also protects climate. From the authors’ perspectives in multiple roles as environmental entrepreneurs, practitioners, and authorities, this paper explains how individuals, companies, and military organizations researched, developed, commercialized and implemented alternatives to ODSs that are also safer for climate. With the benefit of hindsight, the authors reflect on what was neglected or done badly under the Montreal Protocol and present lessons learned on how Montreal Protocol institutions can be renewed and revitalized to phase down hydrofluorocarbons (HFCs). 相似文献
4.
《Comptes Rendus Geoscience》2018,350(7):354-367
In the 1980s, ground-based monitoring of the ozone layer played a key role in the discovery of the Antarctic Ozone Hole as well as in the first documentation of significant winter and spring long-term downward trends in the populated mid-latitude regions. The article summarizes the close-to-hundred-year-long history of ground-based measurements of stratospheric ozone, and more recent observations of constituents that influence its equilibrium. Ozone observations began long before the recognition of the impact of increasing emissions of manmade ozone-depleting substances on ozone and therefore on UV levels, human health, ecosystems and the Earth climate. The historical ozone observations prior to 1980s are used as a reference for the assessments of the state of the ozone layer linked to the enforcement of the Montreal Protocol. In this paper, we describe the worldwide monitoring networks and their ozone observations used to determine long-term trends with an accuracy of a few percent per decade. Since 1989, the ground-based monitoring activities have provided support for the amendments of the Montreal Protocol (MP). They include monitoring of (a) the ozone total column and the vertical distribution at global scale, (b) the ozone-depleting substances (ODS) related to the MP such as chlorofluorocarbons (CFCs), and their decomposition products in the stratosphere, and (c) the atmospheric species playing a role in ozone depletion, e.g., nitrogen oxides, water vapor, aerosols, polar stratospheric clouds. We highlight important accomplishments in the atmospheric monitoring performed by the Global Atmosphere Watch program (GAW) run under the auspices of the World Meteorological Organization (WMO) and by the Network for the Detection of Atmospheric Composition Change (NDACC). We also address the complementary roles of ground-based networks and satellite instruments. High-quality ground-based measurements have been used to evaluate ozone variabilities and long-term trends, assess chemistry climate models, and check the long-term stability of satellite data, including more recently the merged satellite time-series developed for the detection of ozone recovery at global scale, which might be further modified by climate change. 相似文献
5.
《Comptes Rendus Geoscience》2018,350(7):347-353
After the well-reported record loss of Arctic stratospheric ozone of up to 38% in the winter 2010–2011, further large depletion of 27% occurred in the winter 2015–2016. Record low winter polar vortex temperatures, below the threshold for ice polar stratospheric cloud (PSC) formation, persisted for one month in January 2016. This is the first observation of such an event and resulted in unprecedented dehydration/denitrification of the polar vortex. Although chemistry–climate models (CCMs) generally predict further cooling of the lower stratosphere with the increasing atmospheric concentrations of greenhouse gases (GHGs), significant differences are found between model results indicating relatively large uncertainties in the predictions. The link between stratospheric temperature and ozone loss is well understood and the observed relationship is well captured by chemical transport models (CTMs). However, the strong dynamical variability in the Arctic means that large ozone depletion events like those of 2010–2011 and 2015–2016 may still occur until the concentrations of ozone-depleting substances return to their 1960 values. It is thus likely that the stratospheric ozone recovery, currently anticipated for the mid-2030s, might be significantly delayed. Most important in order to predict the future evolution of Arctic ozone and to reduce the uncertainty of the timing for its recovery is to ensure continuation of high-quality ground-based and satellite ozone observations with special focus on monitoring the annual ozone loss during the Arctic winter. 相似文献
6.
Sophie Godin-Beekmann 《Comptes Rendus Geoscience》2010,342(4-5):339-348
This article provides an overview of the various satellite instruments, which have been used to observe stratospheric ozone and other chemical compounds playing a key role in stratospheric chemistry. It describes the various instruments that have been launched since the late 1970s for the measurement of total ozone column and ozone vertical profile, as well as the major satellite missions designed for the study of stratospheric chemistry. Since the discovery of the ozone hole in the early 1980s, spatial ozone measurements have been widely used to evaluate and quantify the spatial extension of polar ozone depletion and global ozone decreasing trends as a function of latitude and height. Validation and evaluation of satellite ozone data have been the subject of intense scientific activity, which was reported in the various ozone assessments of the state of the ozone layer published after the signature of the Montreal protocol. Major results, based on satellite observations for the study of ozone depletion at the global scale and chemical polar ozone loss, are provided. The use of satellite observations for the validation of chemistry climate models that simulate the recovery of the ozone layer and in data assimilation is also described. 相似文献
7.
Didier Tanré 《Comptes Rendus Geoscience》2010,342(4-5):403-411
Here we review the methods presently available and expected in the near future for retrieving the tropospheric aerosol properties using remote sensing. Since all aerosol properties cannot be derived from space, measurements performed from the surface of the Earth are used to adjust the parameters that are not directly accessible and to limit the variability of the parameters that present a weaker sensitivity. The aerosol properties derived include the column concentration (expressed by the aerosol optical depth), the size (given by distribution of the aerosol in 2 to 3 size modes or measurement of the Angström coefficient), composition (expressed by the refractive index), shape and vertical profile. The article is restricted to aerosols that are within the troposphere since the techniques used for stratospheric aerosols are very specific. 相似文献
8.
9.
Nandita D. Ganguly 《Journal of Earth System Science》2008,117(1):79-82
The Indian reserve of coking coal is mainly located in the Jharia coal field in Jharkhand. Although air pollution due to oxides
and dioxides of carbon, nitrogen and sulphur is reported to have increased in this area due to large-scale opencast mining
and coal fires, no significant study on the possible impact of coal fires on the stratospheric ozone concentration has been
reported so far. The possible impact of coal fires, which have been burning for more than 90 years on the current stratospheric
ozone concentration has been investigated using satellite based data obtained from Upper Atmospheric Research Satellite (UARS
MLS), Earth Observing System Microwave Limb Sounder (EOS MLS) and Ozone Monitoring Instrument (OMI) in this paper. The stratospheric
ozone values for the years 1992–2007, in the 28–36 km altitude range near Jharia and places to its north are found to be consistently
lower than those of places lying to its south (up to a radius of 1000 km around Jharia) by 4.0–20%. This low stratospheric
ozone level around Jharia is being observed and reported for the first time. However, due to lack of systematic ground-based
measurements of tropospheric ozone and vertical ozone profiles at Jharia and other far off places in different directions,
it is difficult to conclude strongly on the existence of a relationship between pollution from coal fires and stratospheric
ozone depletion. 相似文献
10.
臭氧变化及其气候效应的研究进展 总被引：10，自引：0，他引：10
综述了近２０年来臭氧变化的规律和机制及其气候效应等领域的研究进展,指出对流层臭氧（主要在北半球）增加、平流层臭氧减少和臭氧总量减少是全球臭氧的变化趋势,原因主要是人类活动导致的ＮＯｘ、ＮＭＨＣ、ＣＯ、ＣＨ４等对流层臭氧前体物的增加和ＮＯｘ、Ｈ２Ｏ、Ｎ２Ｏ、ＣＦＣｓ等平流层臭氧损耗物质的增加。臭氧变化引起的气候效应表现在对流层臭氧的增加将带来地表和低层大气的升温,平流层臭氧的减少则可能导致地表和低层大气的升温或降温。将全球或区域气候模式和大气化学模式进行完全耦合来研究臭氧变化的气候效应是一种十分有效的手段,具有广阔的应用前景。 相似文献
11.
Zia Ul-Haq Muhammad Ali Syeda Adila Batool Salman Tariq Zarmina Qayyum 《Journal of Earth System Science》2016,125(6):1273-1284
An integrated assessment of emissions of some important refrigerant ozone depleting substances (ODSs) (CFC-11, CFC-12, HCFC-141b and HFC-134a) and their contributed ozone depletion potentials (ODPs) and global warming potentials (GWPs) have been made in the megacity Lahore (Pakistan) for the period from 2005 to 2013. During the production of 6.488 million refrigerator units, the cumulative estimated emissions of CFC-11, CFC-12, HCFC-141b and HFC-134a were 129.7, 6.8, 1257 and 104 mega grams (1 Mg = 106 grams). The estimated GWP (CO2-eq) and ODP (CFC 11-eq) associated with production phase emissions of these four gases were 616.07, 73.52, 910.96, and 87.36 kilotonnes, and 129.7, 6.8, 139.4, and 0 tonnes, respectively. ODP of HFC-134a is considered to be zero. In addition, the repair and maintenance of 81.2 thousand units resulted in 10.8 Mg emissions of CFC-12 with 10.8 tonnes ODP(CFC 11-eq) and 117,802 tonnes GWP (CO2-eq) that were higher than the HFC-134a emissions recorded at 4.3 Mg causing 4563 tonnes GWP(CO2-eq). A decrease in ODP (CFC 11-eq) and GWP (CO2-eq) at the rate of ?8.3% and ?8.2% per year is observed to be contributed by all the selected ODSs during the study period. 相似文献
12.
全球变化条件下的平流层大气长期变化趋势 总被引：5，自引：0，他引：5
两个因素将对21世纪平流层气候变化产生重要作用。一个是温室气体增加,另一个是平流层臭氧的可能恢复。温室气体增加的辐射效应一方面造成地面和对流层变暖,另一方面却导致平流层变冷,而臭氧层恢复的辐射效应则导致平流层变暖。在温室气体增加和臭氧恢复这两种相反因素作用下的平流层温度如何变化是所关心的主要问题。为了预估平流层温度在21世纪的变化,使用了辐射—对流模式进行了敏感性实验,另外,也对他人进行的化学—气候耦合模式（CCM）模拟结果进行了分析。这些模拟结果表明,在21世纪平流层中上层（60～1 hPa）将变冷,而下层（150～60 hPa）变暖。这说明在平流层中上层温室气体的冷却效应将起主导作用,而臭氧恢复的加热效应在平流层下层相对更为重要。CCM的模拟结果表明,臭氧恢复最显著的区域在平流层上层（3 hPa附近）,与最大降温区一致,说明温室气体增加将有利于平流层上层臭氧恢复。CCM的模拟结果还表明,平流层两极地区在冬半年存在变暖的现象。根据已有的研究结果,极区变暖与平流层行星波活动增强有关,动力、热力和化学之间的正反馈作用也有可能对极区变暖有重要的贡献。 相似文献
13.
大气中的水汽输送对于全球的水分循环、气候系统、生态环境等具有重要意义。水汽输送是影响中国旱涝空间分布的重要因素，其年际和年代际变化与厄尔尼诺-南方涛动、海温、北大西洋涛动、太平洋年代际涛动等因素对东亚大气环流的调控作用有关。本文就近期关于中国地区水汽输送年际和年代际变化的部分研究工作进行了回顾和评述，包括影响中国东部降水年际和年代际变化的水汽输送机制、影响梅雨特征年代际变化的水汽输送机制、热带海温对中国上空水汽输送的影响机制等问题。此外，本文回顾了近期与青藏高原地区水汽输送机制有关的研究进展。 相似文献
14.
平流层爆发性增温中平流层环流及化学成分变化过程研究 总被引：3，自引：1，他引：2
利用欧洲中期天气预报中心（ECMWF）气象分析场、欧洲空间局ENVISAT/MIPAS卫星观测资料以及平/对流层大气化学输送模式MOZART 3综合分析了2003—2004年冬季北半球爆发性增温事件对于平流层大气环流、物质输送以及对流层顶附近臭氧通量等多方面的影响。结果表明：①本次增温过程持续时间长、强度大,平流层极涡从高层向下逐层分裂,增温效应作用到大气较低层,当纬向东风形成并维持后极涡又自上向下逐层恢复;②SSW过程前后行星波活动频繁,有长时间多次的上传,且以1波作用为主,2波对其进行补充;③在θ PVLAT坐标中分析发现SSW扰动过程中平流层中存在一对向极、向下的传播模态,相应的对流层中有一向赤道的传播模态,不同符号的纬向风、温度异常信号沿这两个模态传播,且上、下层传播模态在时间上存在着一定的联系;④增温过程中行星波活动引起的向极输送以及极区垂直运动的变化,共同影响了平流层的物质输送过程,从而导致北半球平流层N2O、O3、CH4、H2O等微量气体成分的垂直、水平分布发生显著变化;⑤增温过程中活跃的行星波可以造成平流层Brewer Dobson环流增强,同时导致高纬度地区（60~90°N）穿越对流层顶的臭氧通量（Cross Tropopause Ozone Flux, CTOF）显著增强,与行星波相联系的等熵物质运动引起“middleworld”区域内向赤道的臭氧通量也有所增强。 相似文献
15.
大气中的水汽输送对于全球的水分循环、气候系统、生态环境等具有重要意义。水汽输送是影响中国旱涝空间分布的重要因素，其年际和年代际变化与厄尔尼诺-南方涛动、海温、北大西洋涛动、太平洋年代际涛动等因素对东亚大气环流的调控作用有关。本文就近期关于中国地区水汽输送年际和年代际变化的部分研究工作进行了回顾和评述，包括影响中国东部降水年际和年代际变化的水汽输送机制、影响梅雨特征年代际变化的水汽输送机制、热带海温对中国上空水汽输送的影响机制等问题。此外，本文回顾了近期与青藏高原地区水汽输送机制有关的研究进展。 相似文献
16.
Xiufeng Yin Shichang Kang Benjamin de Foy Dipesh Rupakheti Maheswar Rupakheti Zhiyuan Cong Xin Wan Guoshuai Zhang Qianggong Zhang 《地学前缘(英文版)》2021,12(6):294-298
Air pollutants can be transported to the pristine regions such as the Tibetan Plateau,by monsoon and stratospheric intrusion.The Tibetan Plateau region has limited local anthropogenic emissions,while this region is influenced strongly by transport of heavy emissions mainly from South Asia.We conducted a comprehensive study on various air pollutants(PM2.5,total gaseous mercury,and surface ozone)at Nam Co Station in the inland Tibetan Plateau.Monthly mean PM2.5 concentration at Nam Co peaked in April before monsoon season,and decreased during the whole monsoon season(June-September).Monthly mean total gaseous mercury concentrations at Nam Co peaked in July and were in high levels during monsoon season.The Indian summer monsoon acted as a facilitator for transporting gaseous pol-lutants(total gaseous mercury)but a suppressor for particulate pollutants(PM2.5)during the monsoon season.Different from both PM2.5 and total gaseous mercury variabilities,surface ozone concentrations at Nam Co are primarily attributed to stratospheric intrusion of ozone and peaked in May.The effects of the Indian summer monsoon and stratospheric intrusion on air pollutants in the inland Tibetan Plateau are complex and require further studies. 相似文献
17.
Jean-François Royer Daniel Cariolle Fabrice Chauvin Michel Déqué Hervé Douville Rong-Ming Hu Serge Planton Annie Rascol Jean-Louis Ricard David Salas Y Melia Florence Sevault Pascal Simon Samuel Somot Sophie Tyteca Laurent Terray Sophie Valcke 《Comptes Rendus Geoscience》2002,334(3):147-154
Two climate simulations of 150 years, performed with a coupled ocean/sea-ice/atmosphere model including stratospheric ozone, respectively with and without heterogeneous chemistry, simulate the tropospheric warming associated with an increase of the greenhouse effect of carbon dioxide and other trace gases since 1950 and their impact on sea–ice extent, as well as the stratospheric cooling and its impact on ozone concentration. The scenario with heterogeneous chemistry reproduces the formation of the ozone hole over the South Pole from the 1970s and its deepening until the present time, and shows that the ozone hole should progressively fill during the coming decades. To cite this article: J.-F. Royer et al., C. R. Geoscience 334 (2002) 147–154. 相似文献
18.
The cosmogenic nuclide beryllium-10 (10Be), recovered from ice cores, is often used to study solar activity on long timescales. However, the 10Be signal is also influenced by factors other than the Sun. To identify and quantify various contributions to the 10Be signal, two Antarctic snow records from the Vostok and Concordia sites spanning the last 60 years were studied at a sub-annual resolution. Three factors that contribute to the 10Be signal were identified. First, a significant period of approximately 11 yr that can be associated with the modulation of 10Be production by solar activity was detected in both records. The solar imprint constitutes 20-35% of the variance within the total signal. The 11-yr 10Be snow component was attenuated by a factor of ∼0.5 and was delayed by ∼1.4 yr compared to the 10Be production expected within the polar atmosphere. The result could be interpreted as the composite response of a stratospheric 10Be reservoir with an 11-yr modulation that was attenuated and delayed (with respect to 10Be polar production) and to a tropospheric 10Be reservoir with an 11-yr modulation that was not attenuated or delayed. Then, peaks in 10Be concentrations that were ∼66% and ∼35% higher than the average concentration were observed during the stratospheric volcanic eruptions of Agung (in 1963) and Pinatubo (in 1991), respectively. In light of these new results, published 10Be ice core records could be reinterpreted because spikes in 10Be concentration appear at the time of several stratospheric events. The data indicate that stratospheric volcanic eruptions can impact 10Be transport and deposition as a result of the roles played by the sedimentation of sulfate aerosols and the formation and rapid settling of polar stratospheric clouds (PSC). Also, an interannual variability of ∼4 yr was determined in both 10Be records, corresponding to ∼26% of the variance within the signal at Vostok. As with species of marine origin (sodium), this 4-yr variability is interpreted as a tropospheric modulation. The 4-yr variability could be associated with atmospheric circulation associated with the coupled Southern Ocean ocean-atmosphere system. The results presented here, from sites within the high Antarctic plateau, open new possibilities for ice core dating over the last few centuries and for the reconstruction of past solar activity in relation to climate. 相似文献
19.
《Comptes Rendus Geoscience》2018,350(7):341-346
The comprehensive investigation of polar ozone photochemistry and dynamics has required data obtained from as full a complement of available platforms as possible (ground-based, balloon, aircraft, and satellites). Perhaps the most detailed process studies have been conducted using measurements from aircraft, taking advantage of their targeting capabilities coupled with the potential for enabling measurements at high spatial and temporal resolution. The US National Aeronautics and Space Administration (NASA) conducted the first airborne science investigation of polar ozone in an effort to establish the causes of the recurring seasonal depletion of the Earth's stratospheric ozone layer over Antarctica that was identified in the mid-1980s. Subsequent airborne studies in the polar regions of both hemispheres benefitted from extensive successful collaborations among international scientists and the integration of the aircraft measurements with those obtained using ground-based, balloon-borne, and satellite instruments. This article provides an historical perspective of NASA's utilization of its airborne assets to advance our understanding of the chemical and physical processes that control the abundance of stratospheric ozone in both the Antarctic and Arctic. 相似文献
20.
《Comptes Rendus Geoscience》2018,350(7):432-434
NASA has a long and significant history in observations and data analysis research for understanding the short- and long-term changes in ozone in the atmosphere. For nearly 40 years, NASA has overseen satellite observations of stratospheric ozone. These observations have been augmented by ground-based remote sensing, balloon borne, and aircraft observations of ozone and ozone-related species and by continuous observations of ozone depleting substances. Together, they form the evidential basis for understanding ozone changes over these past four decades. Also, NASA has continuously funded laboratory, modeling and data analysis activities to better understand the observations obtained by NASA and other programs. NASA has plans to continue these activities in the future, at a level consistent with available funding, other Earth Science observational priorities, and more importantly, with a goal of ensuring that data exist to understand changes in ozone in the future as the abundances of ozone depleting substances decrease and those of greenhouse gases increase. 相似文献