The southern hemisphere ozone hole split in 2002

Among the most important aspects of the atmospheric pollution problem are the anthropogenic impacts on the stratospheric ozone layer, the related trends of the total ozone content drop and the solar ultraviolet radiation enhancement at the Earth's surface level. During September 2002, the ozone hole over the Antarctic was much smaller than in the previous six years. It has split into two separate holes, due to the appearance of sudden stratospheric warming that has never been observed before in the southern hemisphere. The analysis of this unprecedented event is attempted, regarding both the meteorological and photochemical aspects, in terms of the unusual thermal field patterns and the induced polar vortex disturbances.     

A new inventory for two-wheel vehicle emissions in West Africa for 2002

Rather surprisingly, urban atmospheric particulate levels in West Africa compare with measured concentrations in Europe and Asia megacities (Liousse, C., Galy-Lacaux, C., Assamoi, E.-M., Ndiaye, A., Diop, B., Cachier, H., Doumbia, T., Gueye, P., Yoboue, V., Lacaux, J.-P., Guinot, B., Guillaume, B., Rosset, R., Castera, P., Gardrat, E., Zouiten, C., Jambert, C., Diouf, A., Koita, O., Baeza, A., Annesi-Maesano, I., Didier, A., Audry, S., Konare, A., 2009. Integrated Focus on West African Cities (Cotonou, Bamako, Dakar, Ouagadougou, Abidjan, Niamey): Emissions, Air Quality and Health Impacts of Gases and Aerosols. Third International AMMA Conference on Predictability of the West African Moosoon Weather, Climate and Impacts. Ouagadougou, Burkina Faso. July 20–24). This pollution mainly derives from road traffic emissions with, in some capitals (e.g. Cotonou), the strong contribution of two-wheel vehicles. Two key questions arise: are presently available emission inventories (e.g. Junker, C., Liousse, C., 2008. A global emission inventory of carbonaceous aerosol from historic records of fossil fuel and biofuel consumption for the period 1860–1997. Atmospheric Chemistry Physics, 8, 1–13; Bond, T.C., Streets, D.G., Yarber, K.F., Nelson, S.M., Woo, J.H., Klimont, Z., 2004. A technology-based global inventory of black and organic carbon emissions from combustion. Journal of Geophysical Research, 1009, D14203, DOI:10.1029/2003JD003697) able to account for these emissions? And, if not, how can we remedy this? The aim of this paper is to develop a methodology to estimate emissions produced by two-wheel vehicles in West Africa for 2002 in a context where reliable information is hardly available. Fuel consumption ratios between two-wheel engines (in this work) and all vehicles issued from UN database (http://data.un.org/Data.aspx?d=EDATA&f=cmID%3aMO%3btrID%3a1221) are as high as 169%, 264% and 628%, for Burkina Faso, Mali and Chad respectively, indicating that this global database does not properly account for regional specificities. Moreover, emission factors for black carbon (BC) and primary organic carbon (OCp) have been measured for two-stroke engines in Benin (Guinot, B., Liousse, C., Cachier, H., Guillaume, B., et al. New emission factor estimates for biofuels and mobile sources. Atmospheric Environment, in press.), giving significantly higher values than in Europe. This is particularly true for OCp, and consequently the calculated emissions for two-stroke engines are also significantly larger than total road traffic previously estimated in global inventories (Junker and Liousse (2008) with United Nations database for 2002; Bond et al., 2004). The ensuing discussion illustrates the importance of two-stroke engines in the West Africa transport sector and the strong need for inventory updating.     

The Adhesion of Solid Particles to Solid Surfaces,I. a Review

Prior exposure to ozone has been reported to increase the mortality in mice from aerosolized streptococci. The experiments described herein were undertaken to determine the effect of meteorological variables on this ozone-streptococcus model. The work was performed in replicate experiments employing four treatments. The treatments consisted of exposure to (1) ambient temperature and air, (2) ambient temperature and ozone, (3) cold and ambient air, and (4) cold and ozone, and streptococcus. The streptococcus was administered to each treatment as an aerosolized culture for 30 minutes and yielded approximately 30,000 organisms per mouse. The cold exposure was three hours at 6 to 9°C, and the ozone exposure was 0.7 to 0.9 ppm for three hours. Results indicate a significant increase in mortality attributable to the influence of cold.     

Review of indoor emission source models. Part 1. Overview

Indoor emission source models are mainly used as a component in indoor air quality (IAQ) modeling, which, in turn, is part of exposure and risk modeling. They are also widely used to interpret the experimental data obtained from environmental chambers and buildings. This paper compiles 52 indoor emission source models found in the literature. Together, they represent the achievements that IAQ modelers have made in recent years. While most models have a certain degree of usefulness, genuine predictive models are still few, and there is undoubtedly much room for improvement. This review consists of two parts. Part 1--this paper-provides an overview of the 52 models, briefly discussing their validity, usefulness, limitations, and flaws (if any). Part 2 focuses on parameter estimation, a topic that is critically important to modelers but has not been systematically discussed.     

微囊藻毒素污染控制技术的研究进展

主要对水环境中微囊藻毒素污染的产生、毒性和去除方法进行了综述，在如何高效去除MCS方面具有重要意义。     

Review of Statistics of Extreme Values with Applications to Air Quality Data Part I. Review

In the field of air pollution control, the rare event is often of more significance than the common event. This is evidenced by the content of air quality standards which define acceptable upper limits of air pollution concentrations and acceptable frequencies with which such concentrations can be exceeded. The principles of extreme value statistics provide important tools for analyzing air quality data in an appropriately significant context.

The purpose of this paper is twofold. First the principles of extreme value statistics are reviewed. The presentation is decidedly utilitarian; no attempt is made to derive more than the simplest propositions. The underlying assumptions of the theory are carefully pointed out and discussed. Particular emphasis is placed on the second largest value and its relation to the largest value. Exact probability distributions, and approximations to them, are derived in terms of the total population probability function. The more familiar and useful asymptotic distributions and their uses are presented and discussed. Part II of the paper will present applications of the theory to air quality data.     

Review of indoor emission source models. Part 2. Parameter estimation

This review consists of two parts. Part 1 provides an overview of 52 indoor emission source models. Part 2--this paper-focuses on parameter estimation, a topic that is critical to modelers but has never been systematically discussed. A perfectly valid model may not be a useful one if some of its parameters are difficult to estimate in the absence of experimental data. This is true for both statistical and mass transfer models. Forty-eight methods are compiled and reviewed in this paper. Overall, developing methods for parameter estimation has fallen behind the development of models. Such imbalance is the main reason that many models have been left on the shelf since they were published.