Column Amounts of ClONO2, HCl, HNO3, and HF from Ground-Based FTIR Measurements Made Near Kiruna, Sweden, in Late Winter 1994     

TH. Blumenstock  H. Fisher  A. Friedle  F. Hase  P. Thomas 《Journal of Atmospheric Chemistry》1997,26(3):311-321

During SESAME phase I ground-based FTIR measurements were performed atEsrange near Kiruna, Sweden, from 28 January to 26 March 1994. Zenith columnamounts of ClONO₂, HCl, HF, HNO₃,O₃, N₂O, CH₄, and CFC-12 werederived from solar absorption spectra. Time series of ClONO₂and HCl indicate a chlorine activation at the end of January and around 1March. On 1 March a very low amount of HCl of 2.09times; 10¹⁵molec. cm^-2 was detected, probably caused by a second chlorineactivation phase starting from an already decreased amount of HCl. The ratioof column amounts of HCl to ClONO₂ decreased inside the vortexfrom about 1 in January to 0.4 in late March compared to values of about 2outside the vortex. Although the Arctic stratosphere was rather warm in winter1993/94 and PSCs occurred seldom, chlorine partitioning into its reservoirspecies HCl and ClONO₂ changed during that winter andClONO₂ is the major chlorine reservoir at the end of thewinter as in cold winters like 1991/92 and 1994/95.  相似文献   

First-Order Chemistry in the Surface-Flux Layer     

L. Kristensen  C. E. Andersen  H. E. Jørgensen  P. Kirkegaard  K. Pilegaard 《Journal of Atmospheric Chemistry》1997,27(3):249-269

We have discussed the behavior of a non-conserved scalar in the stationary, horizontally homogeneous, neutral surface-flux layer and, on the basis of conventional second-order closure, derived analytic expressions for flux and for mean concentration of a gas, subjected to a first-order removal process. The analytic flux solution showed a clear deviation from the constant flux, characterizing a conserved scalar in the surface-flux layer. It decreases with height and is reduced by an order of magnitude of the surface flux at a height equal to about the typical mean distance a molecule can travel before destruction. The predicted mean concentration profile, however, shows only a small deviation from the logarithmic behavior of a conserved scalar. The solution is consistent with assuming a flux-gradient relationship with a turbulent diffusivity corrected by the Damköhler ratio, the ratio of a characteristic turbulent time scale and the scalar mean lifetime. We show that if we use only first-order closure and neglect the effect of the Damköhler ratio on the turbulent diffusivity we obtain another analytic solution for the profiles of the flux and the mean concentration which, from an experimental point of view, is indistinguishable from the first analytic solution. We have discussed two cases where the model should apply, namely NO which, by night, is irreversibly destroyed by interaction with mainly O₃ and the radioactive ²²⁰Rn. Only in the last case was it possible to find data to shed light on the validity of our predictions. The agreement seemed such that a falsification of our model was impossible. It is shown how the model can be used to predict the surface flux of ²²⁰Rn from measured concentration profiles.  相似文献   

Tropospheric Ozone in a Global-Scale Three-Dimensional Lagrangian Model and Its Response to NOX Emission Controls     

W. J. Collins  D. S. Stevenson  C. E. Johnson  R. G. Derwent 《Journal of Atmospheric Chemistry》1997,26(3):223-274

A three-dimensional Lagrangian tropospheric chemistry modelis used toinvestigate the impact of human activities on the tropospheric distributionofozone and hydroxyl radicals. The model describes the behaviour of 50 speciesincluding methane, carbon monoxide, oxides of nitrogen, sulphur dioxide andnineorganic compounds emitted from human activities and a range of other sources.Thechemical mechanism involves about 100 chemical reactions of which 16 arephotochemical reactions whose diurnal dependence is treated in full. The modelutilises a five minute chemistry time step and a three hour advection timestepfor the 50,000 air parcels. Meteorological data for the winds, temperatures,clouds and so on are taken from the UK Meteorological Office global model for1994 onwards. The impacts of a 50% reduction in European NO_Xemissions onglobal ozone concentrations are assessed. Surface ozoneconcentrations decrease in summertime and rise in wintertime, but to differentextents.  相似文献   

VARIATION OF TOTAL OZONE IN LOWER LATITUDE AREA OF CHINA     

张秀年  常有礼  陈辉  郭世昌  孙正友 《热带气象学报(英文版)》2004,10(2):171-177

By using the observational O3 data of Kunming and Hong Kong during the period of 1997 – 2001, the paper studies the distribution and variation of total ozone in low latitude region of China. The study shows that the characteristics of variation in Kunm…  相似文献   

Kinetics of the Gas-Phase Reactions of OH Radicals, NO3 Radicals and O3 with Three C7-Carbonyls Formed From The Atmospheric Reactions of Myrcene, Ocimene and Terpinolene     

Jillian Baker  Janet Arey  Roger Atkinson 《Journal of Atmospheric Chemistry》2004,48(3):241-260

Rate constants for the gas-phase reactions of OH radicals, NO₃ radicals and O₃ with the C₇-carbonyl compounds 4-methylenehex-5-enal [CH₂=CHC(=CH₂)CH₂CH₂CHO], (3Z)- and (3E)-4-methylhexa-3,5-dienal [CH₂=CHC(CH₃)=CHCH₂CHO] and 4-methylcyclohex-3-en-1-one, which are products of the atmospheric degradations of myrcene, Z- and E-ocimene and terpinolene, respectively, have been measured at 296 ± 2 K and atmospheric pressure of air using relative rate methods. The rate constants obtained (in cm³ molecule^–1 s^–1 units) were: for 4-methylenehex-5-enal, (1.55 ± 0.15) × 10^–10, (4.75 ± 0.35) × 10^–13 and (1.46 ± 0.12) × 10^–17 for the OH radical, NO₃ radical and O₃ reactions, respectively; for (3Z)-4-methylhexa-3,5-dienal: (1.61 ± 0.35) × 10^–10, (2.17 ± 0.30) × 10^–12, and (4.13 ± 0.81) × 10^–17 for the OH radical, NO₃ radical and O₃ reactions, respectively; for (3E)-4-methylhexa-3,5-dienal: (2.52 ± 0.65) × 10^–10, (1.75 ± 0.27) × 10^–12, and (5.36 ± 0.28) × 10^–17 for the OH radical, NO₃ radical and O₃ reactions, respectively; and for 4-methylcyclohex-3-en-1-one: (1.10 ± 0.19) × 10^–10, (1.81 ± 0.35) × 10^–12, and (6.98 ± 0.40) × 10^–17 for the OH radical, NO₃ radical and O₃ reactions, respectively. These carbonyl compounds are all reactive in the troposphere, with daytime reaction with the OH radical and nighttime reaction with the NO₃ radical being predicted to dominate as loss processes and with estimated lifetimes of about an hour or less.  相似文献   

An Algorithm for the Determination of All Significant Pathways in Chemical Reaction Systems     

Ralph Lehmann 《Journal of Atmospheric Chemistry》2004,47(1):45-78

When the output of a complex chemical model is analysed, a typical topic isthe determination of pathways, i.e., reaction sequences, that produce ordestroy a chemical species of interest.A representative example is the investigation of catalytic ozone destruction cycles in the stratosphere.An algorithm for the automatic determination of pathways in any given reactionsystem is presented. Under the assumption that reaction rates are known, it finds all significant pathways, i.e., all pathways with a rate above a prescribed threshold.The algorithm forms pathways step by step, starting from single reactions.The chemical species in the system are consecutively considered as `branching points'.For every branching-point species, each pathway producing it is connected witheach pathway consuming it.Rates proportional to `branching probabilities' are calculated.Pathways with a rate that is smaller than a prescribed threshold arediscarded.If a newly formed pathway contains sub-pathways, e.g., null cycles, it is split into these simpler pathways.In order to demonstrate the performance of the algorithm, it has been applied to the determination of catalytic ozone destruction cycles and methaneoxidation pathways in the stratosphere.  相似文献   

A Review of Research on Human Activity Induced Climate ChangeⅠ. Greenhouse Gases and Aerosols     

王明星  刘强  杨昕 《大气科学进展》2004,(3)

Extensive research on the sources and sinks of greenhouse gases, carbon cycle modeling, and the characterization of atmospheric aerosols has been carried out in China during the last 10 years or so. This paper presents the major achievements in the fields of emissions of greenhouse gases from agricultural lands, carbon cycle modeling, the characterization of Asian mineral dust, source identification of the precursors of the tropospheric ozone, and observations of the concentrations of atmospheric organic compounds. Special, more detailed Information on the emissions of methane from rice fields and the physical and chemical characteristics of mineral aerosols are presented.  相似文献   

An asynchronous Geoprocessing Workflow and its application to an Antarctic ozone monitoring and mapping service     

Chao Yang  Zhong Xie  Zhanya Xu 《International Journal of Digital Earth》2016,9(2):156-170

The integration of Sensor Web Enablement services with other Open Geospatial Consortium (OGC) Web Services as Geospatial Processing Workflows (GPW) is essential for future Sensor Web application scenarios. With the help of GPW technology, distributed and heterogeneous OGC Web Services can be organized and integrated as compound Web Service applications that can direct complicated earth observation tasks. Under the Sensor Web environment, asynchronous communications between Sensor Web Services are common. We have proposed an asynchronous GPW architecture for the integration of Sensor Web Services into a Web Service Business Process Execution Language workflow technology. We designed a Sensor Information Accessing and Processing workflow, an asynchronous GPW instance, to take an experiment of observing and mapping ozone over Antarctica. Based on our results, our proposed asynchronous workflow method shows the advantages of taking environmental monitoring and mapping tasks.  相似文献   

A modeling study of effective radiative forcing and climate response due to tropospheric ozone     

Bing Xie  Hua Zhang  Zhili Wang  Shuyun Zhao  Qiang Fu 《大气科学进展》2016,33(7):819-828

This study simulates the effective radiative forcing(ERF) of tropospheric ozone from 1850 to 2013 and its effects on global climate using an aerosol–climate coupled model, BCC AGCM2.0.1 CUACE/Aero, in combination with OMI(Ozone Monitoring Instrument) satellite ozone data. According to the OMI observations, the global annual mean tropospheric column ozone(TCO) was 33.9 DU in 2013, and the largest TCO was distributed in the belts between 30°N and 45°N and at approximately 30°S; the annual mean TCO was higher in the Northern Hemisphere than that in the Southern Hemisphere;and in boreal summer and autumn, the global mean TCO was higher than in winter and spring. The simulated ERF due to the change in tropospheric ozone concentration from 1850 to 2013 was 0.46 W m~(-2), thereby causing an increase in the global annual mean surface temperature by 0.36℃, and precipitation by 0.02 mm d~(-1)(the increase of surface temperature had a significance level above 95%). The surface temperature was increased more obviously over the high latitudes in both hemispheres, with the maximum exceeding 1.4?C in Siberia. There were opposite changes in precipitation near the equator,with an increase of 0.5 mm d~(-1)near the Hawaiian Islands and a decrease of about-0.6 mm d~(-1)near the middle of the Indian Ocean.  相似文献   

卫星臭氧资料的发展与应用     

刘寅  邹晓蕾 《气象学报》2016,74(1):1-17

随着卫星探测技术的进步、天气学和气候学理论的不断完善,以及高性能计算机广泛应用,卫星臭氧资料的种类得到极大丰富并被应用到多个研究领域中,取得了一系列重要成果。文中介绍了主要星载臭氧探测仪的发展概况,回顾了卫星臭氧资料在气象领域的应用研究成果,主要包括卫星臭氧资料在气旋或低压过程中、全球或区域臭氧的气候分布及变化特征、高原臭氧分布及变化特点、数值应用等方面的应用研究,并展望了卫星臭氧资料研究的未来发展趋势。   相似文献