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1.
《Comptes Rendus Geoscience》2018,350(7):368-375
Thanks to the Montreal Protocol, the stratospheric concentrations of ozone-depleting chlorine and bromine have been declining since their peak in the late 1990s. Global ozone has responded: The substantial ozone decline observed since the 1960s ended in the late 1990s. Since then, ozone levels have remained low, but have not declined further. Now general ozone increases and a slow recovery of the ozone layer is expected. The clearest signs of increasing ozone, so far, are seen in the upper stratosphere and for total ozone columns above Antarctica in spring. These two regions had also seen the largest ozone depletions in the past. Total column ozone at most latitudes, however, does not show clear increases yet. This is not unexpected, because the removal of chlorine and bromine from the stratosphere is three to four times slower than their previous increase. Detecting significant increases in total column ozone, therefore, will require much more time than the detection of its previous decline. The search is complicated by variations in ozone that are not caused by declining chlorine or bromine, but are due, e.g., to transport changes in the global Brewer–Dobson circulation. Also, very accurate observations are necessary to detect the expected small increases. Nevertheless, observations and model simulations indicate that the stratosphere is on the path to ozone recovery. This recovery process will take many decades. As chlorine and bromine decline, other factors will become more important. These include climate change and its effects on stratospheric temperatures, changes in the Brewer–Dobson circulation (both due to increasing CO2), increasing emissions of trace gases like N2O, CH4, possibly large future increases of short-lived substances (like CCl2H2) from both natural and anthropogenic sources, and changes in tropospheric ozone. 相似文献
2.
《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
3.
《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
4.
《Comptes Rendus Geoscience》2007,339(11-12):784-798
In this review article, we explore how surface-level ozone affects trees and crops with special emphasis on consequences for productivity and carbon sequestration. Vegetation exposure to ozone reduces photosynthesis, growth, and other plant functions. Ozone formation in the atmosphere is a product of NOx, which are also a source of nitrogen deposition. Reduced carbon sequestration of temperate forests resulting from ozone is likely offset by increased carbon sequestration from nitrogen fertilization. However, since fertilized croplands are generally not nitrogen-limited, capping ozone-polluting substances in the USA, Europe, and China can reduce future crop yield loss substantially. 相似文献
5.
《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
6.
新一代对地观测系统的发展 总被引：7，自引：2，他引：7
对地观测系统(EOS，Earth Observation System)是获取空间对地信息、促进地球系统科学和空间信息科学等学科发展的支柱。长期以来，人们就期望着对自己居住的地球有一个全面深刻的了解，研究这种从几十年到几百年时间尺度的全球变化，依赖于观测系统和观测技术的发展。因此有必要建立一个对地球整体的观测系统，利用空间优势，获取有关地球体系及其各个组成部分的详细数据或信息。
近50年来，世界对地观测技术得到了迅猛的发展。NASA针对全球变化研究对建立长期的数据采集系统的实际需求，于20世纪80年代初开始规划地球观测系统（EOS）计划，并于90年代初实施。它包括一系列卫星、自然科学知识组成和一个数据系统，支持一系列极地轨道和低倾角卫星对地球的陆地表面、生物圈、大气和海洋进行长期观测。地球观测卫星系列是EOS计划的最基本和最重要的环节。EOS卫星系列计划在今后的10年内陆续发射一系列的太阳轨道环境遥感卫星，构成连续15年的数据采集系统，其规模在地球观测卫星发展史上是空前的。在EOS计划的基础上NASA规划了ESE战略计划，将继续发展国际新一代对地观测系统。迄今为止，Terra、Aqua和Arua卫星已经发射成功，引起地球遥感科学界的瞩目，为地球科学研究提供重要的数据资源。 相似文献
7.
《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
8.
黄河三角洲进积与滨海湿地地质环境演替模式 总被引：1，自引：0，他引：1
本文通过对黄河三角洲5个钻孔岩芯的沉积学观测、微古分析、14C测年,同时结合历史记录及遥感资料,分析了本区末次冰后期以来的沉积序列,重建了近10ka以来古环境演变过程,分析了古环境演化对滨海湿地演替的控制作用。本文着重讨论了黄河三角洲进积与湿地形成演替规律,总结了从水生系统、浅海湿地系统、潮滩湿地直至上三角洲平原湿地向陆地生态系统的演替模式。同时通过对现代黄河三角洲与老黄河三角洲演化模式进行对比,提出气候变化、人类活动会加速和改变湿地地质环境演替进程和方向的一般规律。笔者等还进一步提出,由于人类活动的影响,1855年之后湿地演替速率明显加快,约达8~33倍。古环境的重建与滨海湿地响应机制研究可更清楚地理解湿地如何对未来环境变化进行响应,包括海平面上升,从而为滨海湿地保护与管理实践活动提供科学导向。 相似文献
9.
《Comptes Rendus Geoscience》2018,350(7):376-383
Although catalytic chemistry involving ozone-depleting substances (ODSs) is currently a primary driver impacting the abundance of stratospheric ozone, water vapor and aerosols are constituents that also affect stratospheric ozone. Variability in both water vapor and aerosols can induce variability in ozone, and although small relative to that due to trends in ODSs, in the future may become a much more important source of ozone variability. 相似文献
10.
Experiences and perspective in compiling long-term remote sensing data sets on landscapes and biospheric processes 总被引：1，自引：0，他引：1
Samuel N. Goward Prof. Dr. 《GeoJournal》1990,20(2):107-114
Remote sensing has been employed to study the Earth's landscapes for more than a century. Over the last thirty years major changes in all aspects of the technology, as well as scientific understanding of the measurements, have revolutionized use of these data for terrestrial research. The emergence of biophysical interpretations of land remotely sensed data has created great interest in the potential of these data to study the dynamics of landscapes and biospheric processes as contributors to global change. However, the evolutionary history of land remote sensing, particularly in the Landsat era, has in many ways worked against this use of the data. Until recently, there was little appreciation of the need to compile long-term historical records of these observations. There are currently no formal scientific institutional systems dedicated to preserving and distributing the long-term record of Earth observations acquired by Landsat, AVHRR or other land observing systems. As the International Geosphere-Biosphere Program begins, this issue should be one of the first priorities of the participants. 相似文献
11.
The paper presents the nature of variations of tropospheric and total ozone column retrieved from the Convective Cloud Differential (CCD) technique, Ozone Monitoring Instrument (OMI), and Total Ozone Mapping Spectrometer (TOMS) data, National Aeronautics and Space Administrations (NASA), USA, respectively; surface temperature, relative humidity, total rainfall, ozone precursors (non-methane hydrocarbon, carbon monoxide, nitrogen dioxide, and sulphur dioxide) that are collected from India Meteorological Department (IMD), Alipore, Kolkata; solar insolation obtained from Solar Geophysical Data Book and El-Niño index collected from National Climatic Data Center, US Department of Commerce, National Oceanic and Atmospheric Administration, USA. The effect of these climatic parameters and ozone precursors on ozone variations is critically analyzed and explained on the basis of linear regression and correlation. It has been observed that the maximum, minimum and mean temperature, relative humidity, solar insolation, tropospheric, and total ozone column (TOC) showed slight increasing tendencies from October 2004 to December 2011, while total rainfall and El-Niño index showed little decreasing tendencies for the same period. Amongst selected climatic parameters and ozone precursors, the solar insolation and the average temperature had a significant influence on both, the tropospheric ozone and total ozone column formation. The solar insolation had contributed more in tropospheric ozone than in total ozone column; while El-Niño index had played a more significant role in total ozone column build up than in tropospheric ozone. Negative correlation was observed between almost all ozone precursors with the tropospheric and total ozone. The tropospheric ozone and total ozone column were also significantly correlated. The level of significance and contribution of different climatic parameters are determined from correlation technique and Multiple Linear Regression (MLR) method. The related chemical kinetics for ozone production processes has been critically described. 相似文献
12.
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
13.
B. H. Subbaraya K. S. Appu K. P. Chatterjee A. F. Chizhov V. D. Grinchinkov A. Jayaraman G. A. Khokin V. A. Kononkov I. S. Moshnikov V. Narayanan S. P. Perov O. V. Shtrikov Y. V. Somayajulu C. R. Sreedharan K. S. Zalpuri 《Journal of Earth System Science》1987,96(1):25-40
A total of seventeen vertical profiles of ozone were obtained during an Indo-USSR collaborative experiment on ozonesonde intercomparison conducted at Thumba during March 1983. The vertical distribution of ozone was measured using rocket-borne, balloon-borne as well as ground-based instruments. Four different rocket ozonesondes from India and USSR and the balloon ozonesonde were used to makein situ observations of ozone concentrations in addition to the Dobson spectrophotometric observations of total ozone and Umkehr. The rocket and the balloon launchings were effected in three salvos and measurements were made at different times of the day as well as during night. The results of all these measurements are used to obtain a mean ozone vertical distribution over Thumba foT the spring equinoxial period. The mean profile shows the maximum ozone concentration at 27 km with a value of (3.86±0-52)×1012 molecules per cc. Comparison of this mean profile with available satellite data for the equatorial regions shows that, in general, the Thumba values are lower by 10–15% at altitudes below 40 km and larger at altitudes above 50 km compared to the satellite results. The data also show evidence for a day-to-day variability and a possible day-to-night variability in the ozone vertical distribution with the night-time values higher than the daytime values at all altitudes above 35 km and the difference is found to increase with the increasing altitude. 相似文献
14.
《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
15.
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
16.
Chris A. Mattmann Duane Waliser Jinwon Kim Cameron Goodale Andrew Hart Paul Ramirez Dan Crichton Paul Zimdars Maziyar Boustani Kyo Lee Paul Loikith Kim Whitehall Chris Jack Bruce Hewitson 《Earth Science Informatics》2014,7(1):1-12
The Regional Climate Model Evaluation System (RCMES) facilitates the rapid, flexible inclusion of NASA observations into climate model evaluations. RCMES provides two fundamental components. A database (RCMED) is a scalable point-oriented cloud database used to elastically store remote sensing observations and to make them available using a space time query interface. The analysis toolkit (RCMET) is a Python-based toolkit that can be delivered as a cloud virtual machine, or as an installer package deployed using Python Buildout to users in order to allow for temporal and spatial regridding, metrics calculation (RMSE, bias, PDFs, etc.) and end-user visualization. RCMET is available to users in an “offline”, lone scientist mode based on a virtual machine dynamically constructed with model outputs and observations to evaluate; or on an institution’s computational cluster seated close to the observations and model outputs. We have leveraged RCMES within the content of the Coordinated Regional Downscaling Experiment (CORDEX) project, working with the University of Cape Town and other institutions to compare the model output to NASA remote sensing data; in addition we are also working with the North American Regional Climate Change Assessment Program (NARCCAP). In this paper we explain the contribution of cloud computing to RCMES’s specifically describing studies of various cloud databases we evaluated for RCMED, and virtualization toolkits for RCMET, and their potential strengths in delivering user-created dynamic regional climate model evaluation virtual machines for our users. 相似文献
17.
中国大气臭氧探空仪的研制和应用 总被引：9，自引：1，他引：9
地球大气中的臭氧一直是全球气候和环境变化研究中的重要内容。大气臭氧探空系统是当前直接获得地球大气臭氧垂直结构资料的直接探测系统，同时也是为卫星臭氧探测和激光雷达臭氧探测等提供对比和定标的有力手段。中国大气臭氧探空仪的研制工作起步较晚且进展缓慢，这在一定程度上妨碍了中国大气臭氧高空探测业务化的进程。首次报道了中国大气臭氧高空探测业务化进展状况，重点报告中国自行研制的大气臭氧探空仪的结构和技术性能指标，讨论了中国大气臭氧探空仪主要技术性能指标与芬兰Vaisala臭氧探空仪的比对结果，并给出该系统在北京、南极等地区应用施放中所得到的部分探测结果。同时对中国大气臭氧高空探测业务化方面的近期任务提出了建议。 相似文献
18.
《Atmósfera》2014,27(4):377-384
Clean air is a basic requirement for human health and wellbeing. The Kenya Meteorological Department has established air pollution monitoring activities in various sites in Nairobi, at Dagoretti Corner meteorological station and at Mount Kenya. Different pollutants are measured including ozone. The increased concentration of greenhouse gases in the atmosphere has influenced the weather and climate. This study examined the variations of surface ozone over Dagoretti Corner, Nairobi for a 12-month period ending July 2013, exactly one year after the start of data acquisition. The trend was studied using time series analysis of ozone concentration on both an hourly and monthly basis. The ozone data was then combined with meteorological data and temperature to find correlations between the two. Overall, the air quality of Nairobi, represented by Dagoretti Corner meteorological station is good as compared to the World Meteorological Organization ozone standards. The highest concentration of ozone is observed in the afternoon and the minimum at dawn on a daily basis. On seasonal scale, the highest levels are recorded in the cold months. This information helps to reduce exposure to the gas and thus to reduce its impacts on living things. The study recommends the reduction of exposure to the gas during the times when it has been observed to be highest in order to minimize its impacts. 相似文献
19.
Based on NEX-BCC_CGM1.1 global daily statistics downscaling climate data set, the latest release by American National Aeronautics and Space Administration (NASA), which has representative concentration path, by using linear fitting and empirical orthogonal function (EOF) analysis methods, the simulation capacity on precipitation and temperature in Qinling and its surrounding areas of this data sets was estimated and the possible changes of the precipitation, daily maximum and minimum temperature in the next stage under the two scenarios of Rcp4.5 and Rcp8.5 were analyzed. Results showed that: ①The inter-annual trend of average daily precipitation, maximum temperature, minimum temperature is simulated well by NEX-BCC_CGM1.1. The spatial distribution was in accordance with the observations. The deficiency is that the elements value and extreme frequency have systemic bias compared with the observations. ②Average daily precipitation will have increasing trend in the future in Qinling and its surrounding areas under the two scenarios of Rcp4.5 and Rcp8.5. For different level precipitation frequency, light rains will reduce and rainstorms will increase in the future. The spatial modes of precipitation in the future are shown as the variation of the uniform increase in the whole region (EOF1) and anti-phase change in northern and southern Qinling (EOF2). EOF1 will be positive phase in medium-term in the Mid-21st century, where there will be significantly more means precipitation. ③Under the two scenarios, temperature warming trend is obvious, daily maximum temperature increasing trend is greater than minimum temperature, and the amplitude of temperature increase under Rcp8.5 is higher than Rcp4.5. The frequency of daily maximum temperatures greater than 36 ℃ will increase and low temperature less than -15 ℃ will reduce in the future, at the same time, high temperature (low temperature) increase (decrease) rate is more pronounced under Rcp8.5. Average daily maximum and minimum temperatures are shown uniform warming in the whole region (EOF1) and anti-phase change in northern and southern Qinling under two scenarios, but the spatial distribution has great difference. 相似文献
20.
黑河流域近两千年人—水—生态演变研究进展 总被引：2，自引：0，他引：2
理解流域历史时期的人—水—生态演变过程和规律,对其当前和未来的管理规划极为重要。通过梳理近几十年来有关学者对西北干旱区典型内陆河流域——黑河流域过去2 000年的水环境、人类活动、生态环境演变及其耦合研究等方面的成果,发现单个方面的研究均已较为普遍和成熟,并且积累了大量的素材和数据,但是缺乏以流域为单元,从长时间尺度综合考虑人—水—生态相互作用,定量分析人—水—生态协同演化过程的研究成果。今后的研究,一是应当着重于数据挖掘方法的探索,对已有成果进一步挖掘并进行对比和校正,构建一套长时间序列的可靠的人类活动、水文和生态数据集;二是应当着重于动力学模型的构建,增加生态—水文系统与人类活动的互馈机制描述,刻画人—水—生态的协同演化过程,从而达到通过揭示流域过去2 000年的人—水—生态协同演化过程,为流域当前和未来的管理提供历史镜鉴,为国内外的其他类似流域提供参考。社会水文学的提出无疑将极大地促进流域人—水—生态演变研究的发展。 相似文献