Emission scenarios for a global hydrogen economy and the consequences for global air pollution     

Bas van Ruijven  Jean-Francois Lamarque  Detlef P. van Vuuren  Tom Kram  Hans Eerens 《Global Environmental Change》2011,21(3):983-994

Hydrogen is named as possible energy carrier for future energy systems. However, the impact of large-scale hydrogen use on the atmosphere is uncertain. Application of hydrogen in clean fuel cells reduces emissions of air pollutants, but emissions from hydrogen production and leakages of molecular hydrogen could influence atmospheric chemistry. This paper combines a global energy system model and a global atmospheric model to explore the range of impacts of hydrogen on atmospheric chemistry. We found that emissions of molecular hydrogen may range from 0.2 up to 10% (or 25-167 Tg hydrogen/yr) for a global hydrogen energy system. The lower end of this range would in fact be equal to current emissions from fossil fuel combustion. Hydrogen energy use leads to a clear decrease in emissions of carbon monoxide, nitrogen oxides and sulphur dioxide, but large-scale hydrogen production from coal may lead to net increase in emissions of nitrous oxide and volatile organic compound. Compared to a reference scenario, this would lead to positive impacts on surface concentrations of carbon monoxide, nitrogen oxides and ozone. However, if hydrogen leakage would not be minimised it leads to an increase in methane lifetimes and a decrease in stratospheric ozone concentrations.  相似文献   

Springtime effects in the mesosphere and ionosphere observed at northern midlatitudes     

V.M. Aushev  I.N. Fedulina  M.J. López-González  S.Sh. Ryazapova 《Planetary and Space Science》2006,54(6):559-571

Nighttime volume emission rates and rotational temperatures, obtained from simultaneous observations of molecular oxygen and hydroxyl airglow at Almaty (43.25°N, 76.92°E) and Sierra-Nevada (37.2°N, 356.7°E), along with ionospheric density derived from foF2 in the vertical sounding ionograms over Almaty are analysed to study the variability and coupling of parameters observed in the upper mesosphere and ionosphere during the period of February - April, 2000.Ionospheric critical frequency measurements and airglow observations by the Mesopause Rotational Temperature Imager (MORTI) at Almaty and the Spectral Airglow Temperature Imager (SATI) at Sierra-Nevada Observatories show an increase in long-period planetary wave (PW) activity from the end of February until the middle of March, 2000.Very good agreement was found in the temporal variations of emission rates and rotational temperatures from March 1-15, 2000 measured at the Almaty and Sierra-Nevada sites. Similar perturbations could also be seen in the ionospheric critical frequency (ΔfoF2) obtained as a difference between current foF2 values and an ionospheric background level.The perturbations observed have been interpreted employing the Met office stratospheric model results. Latitudinal structure of a quasi 5-day wave was identified, for which the first-symmetric-mode amplitude and symmetric behaviour of phase are in good agreement with theoretical prediction. The analysis of the Met office stratospheric data indicate the presence of westward-propagating PW with periods of ∼5 and 10 days during the period of interest. The temporal correlation between planetary scale oscillations observed in the datasets examined (ionospheric, optical and meteorological) suggest dynamical coupling with the stratosphere. A negative disturbance in ΔfoF2 of ∼25% observed 1 day before a sharp increase in the MORTI mesospheric rotational temperature registered on March 10 at Almaty, is also discussed in the context of the possible stratosphere/mesosphere/ionosphere coupling.  相似文献   

Analysis of the variations in the strength and position of stratospheric sudden warming in the past three decades          下载免费PDF全文

ZHANG Ludan  CHEN Quanliang 《大气和海洋科学快报》2019,(3):147-154

利用ERA-Interim再分析资料统计分析了1920–2016年期间北半球33次强平流层爆发性增温(SSW)事件和22次弱增温事件的强度和位置变化特征。发现SSW主要发生在二月,其纬向平均温度的最大经向梯度变化在1979–8319年和1998–2011年呈上升趋势,1984–1997年和2012–2016年呈下降趋势,但是整体呈现略微下降的线性趋势,并且强SSW事件的强度和持续时间的变化特征相似。一些SSW事件几乎同时在100 hPa到10 hPa上出现,一些SSW事件却首先出现在10 hPa上再向低层下传。另外,我们还发现这55个SSW事件的最大增温中心主要位于欧亚大陆30°E到120°E之间,这或许跟过去三十年中欧亚大陆的极涡转移有关。  相似文献   

平流层臭氧的温室效应及其气候影响     

阎邦华  许丽生  李青 《成都信息工程学院学报》1990,(4)

本文阐述大气中重要的“痕量气体”之一——臭氧(平流层臭氧)对地球表面和低层大气的温室效应及其全球气候的反馈影响;指出了云的辐射力的概念及其重要性,并讨论了“南极臭氧洞”现象。  相似文献   

Transport and the seasonal variation of ozone     

Richard B. Rood 《Pure and Applied Geophysics》1983,121(5-6):1049-1064

The transport mechanisms responsible for the seasonal behavior of total ozone are deduced from the comparison of model results to stratospheric data. The seasonal transport is dominated by a combination of the diabatic circulation and transient planetary wave activity acting on a diffusively and photochemically determined background state. The seasonal variation is not correctly modeled as a diffusive process. The buildup of total ozone at high latitudes during winter is dependent upon transient planetary wave activity of sufficient strength to cause the breakdown of the polar vortex. While midwinter warmings are responsible for enhanced ozone transport to high latitudes, the final warming marking the transition from zonal mean westerlies to zonal mean easterlies is the most important event leading to the spring maximum. The final warming is not followed by reacceleration of the mean flow; so that the ozone transport associated with this event is more pronounced than that associated with midwinter warmings.  相似文献   

Contribution of the MODIS instrument to observations of deep convective storms and stratospheric moisture detection in GOES and MSG imagery   总被引：1，自引：0，他引：1  

Martin Setvk  Robert M. Rabin  Pao K. Wang 《Atmospheric Research》2007,83(2-4):505-518

Past studies based on the NOAA/AVHRR and GOES I-M imager instruments have documented the link between certain storm top features referred to as the “cold-U/V” shape in the 10–12 μm IR band imagery and plumes of increased 3.7/3.9 μm band reflectivity. Later, similar features in the 3.7/3.9 μm band have been documented in the AVHRR/3 1.6 μm band imagery.The present work focuses on storm top observations utilizing the MODIS data. The MODIS instrument (available onboard NASA's EOS Terra and Aqua satellites) provides image data with significantly better geometrical resolution (in some of its bands) and broader range of spectral bands as compared to that from AVHRR/3 observations. One of the goals of this study is to evaluate the contribution of this new instrument to observations of convective storm tops. Besides the cloud top features linked to storm top microphysics and morphology, the paper also addresses the possibility of detection of lower stratospheric water vapor above cold convective storm tops. This issue is explored utilizing MODIS as well as GOES and MSG imagery.In addition, the paper discusses an alternative interpretation of the “cold-U/V” patterns at the top of intense storms by a mechanism of “plume masking” as suggested by some of the observations.  相似文献   

High resolution simulation of recent Arctic and Antarctic stratospheric chemical ozone loss compared to observations     

Om Prakash Tripathi  Sophie Godin-Beekmann  Franck Lefèvre  Marion Marchand  Andrea Pazmiño  Alain Hauchecorne  Florence Goutail  Hans Schlager  C. Michael Volk  B. Johnson  G. König-Langlo  Stefano Balestri  Fred Stroh  T. P. Bui  H. J. Jost  T. Deshler  Peter von der Gathen 《Journal of Atmospheric Chemistry》2006,55(3):205-226

Simulations of polar ozone losses were performed using the three-dimensional high-resolution (1^∘ × 1^∘) chemical transport model MIMOSA-CHIM. Three Arctic winters 1999–2000, 2001–2002, 2002–2003 and three Antarctic winters 2001, 2002, and 2003 were considered for the study. The cumulative ozone loss in the Arctic winter 2002–2003 reached around 35% at 475 K inside the vortex, as compared to more than 60% in 1999–2000. During 1999–2000, denitrification induces a maximum of about 23% extra ozone loss at 475 K as compared to 17% in 2002–2003. Unlike these two colder Arctic winters, the 2001–2002 Arctic was warmer and did not experience much ozone loss. Sensitivity tests showed that the chosen resolution of 1^∘ × 1^∘ provides a better evaluation of ozone loss at the edge of the polar vortex in high solar zenith angle conditions. The simulation results for ozone, ClO, HNO₃, N₂O, and NO _y for winters 1999–2000 and 2002–2003 were compared with measurements on board ER-2 and Geophysica aircraft respectively. Sensitivity tests showed that increasing heating rates calculated by the model by 50% and doubling the PSC (Polar Stratospheric Clouds) particle density (from 5 × 10⁻³ to 10⁻² cm⁻³) refines the agreement with in situ ozone, N₂O and NO _y levels. In this configuration, simulated ClO levels are increased and are in better agreement with observations in January but are overestimated by about 20% in March. The use of the Burkholder et al. (1990) Cl₂O₂ absorption cross-sections slightly increases further ClO levels especially in high solar zenith angle conditions. Comparisons of the modelled ozone values with ozonesonde measurement in the Antarctic winter 2003 and with Polar Ozone and Aerosol Measurement III (POAM III) measurements in the Antarctic winters 2001 and 2002, shows that the simulations underestimate the ozone loss rate at the end of the ozone destruction period. A slightly better agreement is obtained with the use of Burkholder et al. (1990) Cl₂O₂ absorption cross-sections.  相似文献   

The evolution of Pinatubo aerosols in the Arctic stratosphere during 1994–2000     

Masaharu Watanabe  Yasunobu Iwasaka  Takashi Shibata  Masahiko Hayashi  Motowo Fujiwara  Roland Neuber   《Atmospheric Research》2004,69(3-4):199-215

Balloon-borne aerosol measurements were performed with an optical particle counter between 1994 and 2000 at Ny-Ålesund (79°N), Svarbard. Throughout the observation period, continuous decay was found in the concentrations of particles with 0.4–0.6 μm in radius in the Arctic stratosphere, suggesting that Pinatubo aerosols remained even at the end of the 1990s. The decay rate was clearly higher for larger particle sizes, and higher at higher altitude (e-folding time of 970–526 days), suggesting a gravitational sedimentation effect. For smaller particles with R<0.4 μm, slight increases in concentration with time were found, which agreed with the measurements at mid-latitude. The sulfate mass mixing ratio in the Arctic stratosphere before 1998 showed values higher than those at middle latitude, while values were almost the same in both regions after 1998. A possible explanation of the latitudinal difference is a time lag (of 0.5–1 year) in the arrival of Pinatubo aerosols in the Arctic.  相似文献   

The vertical distribution of CFM and related species in the stratosphere     

A. Volz  D. H. Ehhalt  H. Cosatto 《Pure and Applied Geophysics》1978,116(2-3):545-553

Available data on halogenated molecules in the stratosphere will be reviewed. Presently vertical profiles of CFCl₃ and CF₂Cl₂ in the stratosphere exist to 50 km altitude. Only measurements in the lower stratosphere are reported for the other major halocarbons, CCl₄ and CH₃Cl. Profiles of the product species ClO, Cl, HCl, and HF exist to about 35 km.Comparison with theoretical profiles from 1-D models shows generally good agreement except for ClO where the earliest measured concentrations exceed the calculated ones considerably.  相似文献   

Stratospheric ozone response to a solar proton event: Hemispheric asymmetries     

Kaichi Maeda  Donald F. Heath 《Pure and Applied Geophysics》1980,119(1):1-8

Ozone depression in the polar stratosphere during the energetic solar proton event on 4 August 1972 was observed by the backscattered ultraviolet (BUV) experiment on the Nimbus 4 satellite. Distinct asymmetries in the columnar ozone content, the amount of ozone depressions and their temporal variations above 4 mb level (38 km) were observed between the two hemispheres. The ozone destroying solar particles precipitate rather symmetrically into the two polar atmospheres due to the geomagnetic dipole field These asymmetries can be therefore ascribed to the differences mainly in dynamics and partly in the solar illumination and the vertical temperature structure between the summer and the winter polar atmospheres. The polar stratosphere is less disturbed and warmer in the summer hemisphere than the winter hemisphere since the propagation of planetary wave from the troposphere is inhibited by the wind system in the upper troposphere, and the air is heated by the prolonged solar insolation. Correspondingly, the temporal variations of stratospheric ozone depletion and its recovery appear to be smooth functions of time in the (northern) summer hemisphere and the undisturbed ozone amount is slighily, less than that of its counterpart. On the other hand, the tempotal variation of the upper stratospheric ozone in the winter polar atmosphere (southern hemisphere) indicates large amplitudes and irregularities due to the disturbances produced by upward propagating waves which prevail in the polar winter atmosphere. These characteristic differences between the two polar atmospheres are also evident in the vertical distributions of temperature and wind observed by balloons and rocker soundings.  相似文献