北京居民对雾霾的感知及其旅游意愿和行为倾向研究

近年来,中国大陆频现大范围的空气污染问题,雾霾成为公众高度关注的热点,雾霾及其旅游影响成为新的学术研究问题。本文利用问卷调查的手段,借助问卷星和微信的问卷设计和传播平台,深入研究了北京居民对雾霾影响的感知及其旅游需求和决策行为倾向。研究表明：1）北京居民对雾霾的健康影响、心理影响和生活影响有强烈的感知,大多数北京居民认为北京的雾霾问题十分严重;2）严重雾霾的持续困扰下,北京居民有着逃离意愿强烈,雾霾刺激和强化了北京居民的旅游需求;3）北京居民对雾霾的感知有着明显的群体差异,高收入、高学历、在企事业单位工作和中青年人对雾霾的感知和态度尤其强烈。最后,作者讨论了本研究对于旅游营销的现实意义。     

地面臭氧光化学过程规律的初步研究

给出了1996年夏季在广东肇庆鼎湖山对光化辐射、地面O3、NO、NO2浓度的观测结果,对影响地面O3、NO、NO2的主要因子进行了分析。晴天,地面O3、NO、NO2浓度有明显的日变化;阴天,它们的日变化比较复杂。晴天和阴天,在lnQUVB/m和lnQvis/m(其中QUVB为紫外B辐射,Qvis为可见光辐射,m为大气质量)与地面O3、NO,NO2浓度、整层大气水汽含量(q1、q2、q3、q4)之间存在着很好的相关关系。利用得到的关系式计算了地面O3浓度,在紫外和可见光波段,计算值与观测值符合得都比较好。     

光化学烟雾的形成、危害及防治

光化学烟雾是大气污染的一种，它不仅危害人们的健康，而且严重威胁着生态系统的平衡。本文从光化学烟雾的形成机理、日变化曲线、危害及对其的防治对策等方面进行阐述，以便大家能够对光化学烟雾有一个完整、系统的认识。     

MODEL STUDY OF THE EFFECT OF SOIL NO EMISSIONS ON SURFACE OZONE

The effect of soil NO emissions on surface ozone in autumn in East China has been studied byusing TCTM(Troposphere Chemical Transport Model)with the input of meteorological variablesfrom RAMS.The chemical mechanism for ozone variation caused by soil emissions has also beeninvestigated.The model results reveal that soil NO emissions are important to regional ozoneformation and distribution and the effect of soil NO emissions shows spatial inhomogeneity.Ozoneover most areas in northern China decreases with maximum average decrement reaching 5 ppbwhile it increases over most areas of central and southern China with maximum average incrementreaching 7 ppb caused by soil NO emissions.This situation of ozone variation is mainly determinedby nonlinear photochemical mechanism.For the low NOx areas(≤3 ppb),ozone increases as NOxincreases;for the high NOx areas(>3 ppb),ozone decreases as NOx increases.The effect of soilNO emissions on ozone depends on the transition value and NOx concentrations.     

High PAN concentrations during nonsummer periods: A study of two episodes in Creteil (Paris), France

The effect of sunlight on air containing hydrocarbons and nitrogen oxides leads to a very complex series of reactions which form, among other secondary pollutants, peroxyacetylnitrate (PAN). This compound is believed to be the most useful indicator of photochemical pollution, and has been monitored for several months at the University of Creteil (Paris, France). Although it is commonly accepted that high PAN levels occur more frequently in summer, our results show elevated PAN concentrations during nonsummer periods, precisely during two episodes in October 1985 and February 1986. A close examination of these episodes indicates that, in addition to local photochemical production, long-range transport of polluted air masses can occur in winter, revealing the influence of emissions from central Europe.     

Water-Soluble dicarboxylic acids, ketoacids and dicarbonyls in the atmospheric aerosols over the southern ocean and western pacific ocean

Water-soluble dicarboxylic acids (DCAs), ketoacids, and α-dicarbonyls in the marine aerosol samples collected over the Southern Ocean and western Pacific Ocean were determined. Oxalic acid was the most abundant species, followed by malonic acid and then succinic acid. It is suggested that aerosol concentrations of the organics over the Southern Ocean in this work represent their global background levels. Over the Southern Ocean, total concentrations of DCAs ranged from 2.9 to 7.2 ng m⁻³ (average: 4.5 ng m⁻³), ketoacids from 0.14 to 0.40 ng m⁻³ (av.: 0.28 ng m⁻³), and dicarbonyls from 0.06 to 0.29 ng m⁻³ (av.: 0.11 ng m⁻³). Over the western Pacific, total concentrations of DCAs ranged from 1.7 to 170 ng m⁻³ (av.: 60 ng m⁻³), ketoacids from 0.08 to 5.3 ng m⁻³ (av.: 1.8 ng m⁻³), and dicarbonyls from 0.03 to 4.6 ng m⁻³ (av.: 0.95 ng m⁻³). DCAs over the western Pacific have constituted a large fraction of organic aerosols with a mean DCAs-C/TC (total carbon) of 7.0% (range: 0.59–14%). Such a high value was in contrast to the low DCAs-C/TC (av.: 1.8%; range: 0.89–4.0%) for the Southern Ocean aerosols. Based on the relative abundances and latitudinal distributions of these organics, we propose that long-range atmospheric transport is more important over the western Pacific Ocean, in contrast, in situ photochemical production is more significant over the Southern Ocean although absolute concentrations of the organics are much lower.     

Regional Air Quality Modelling in Canada – Applications for Policy and Real-Time Prediction

Acid rain and photochemical smog are two regionalair-quality issues that have received considerableattention in the last two decades due to their harmfuleffects. Health impacts of particulate matter (PM) inthe atmosphere is another issue of concern.Sulphur dioxide emission controls were introducedin both Canada and the U.S.A. to reduceacid-deposition-related damage. While these emissionreductions have already resulted in reduced sulphatedeposition, based on results from modelling studiesmuch of southeastern Canada is still expected toexperience damaging levels of acid deposition evenafter all currently legislated emission controls arefully implemented. Moreover, there has not been acorresponding reduction in the acidity ofprecipitation. This may be attributable to aconcurrent reduction in base-cation concentration inprecipitation.Models were also developed to understand theformation, transport and diffusion of troposphericozone. The models have been used to provide policyguidance for emission control options to reduceground-level ozone to acceptable limits. In thesummer of 1997 a Canadian pilot project was initiatedto provide real-time forecasts of ground-level ozonein the southeastern part of the province of NewBrunswick in eastern Canada.With the emergence of fine Particulate Matter(PM_2.5) as a health concern, efforts are underwayin Canada to develop a unified' regional air-qualitymodel that will address the combined impacts ofvarious pollutants in the atmosphere. In this effortthe atmosphere is viewed as a single entity where theimpacts of multiple pollutants are considered at thesame time.     

Stable Carbon Isotope Ratios and the Photochemical Age of Atmospheric Volatile Organic Compounds

Abstract

The dependence of ozone formation on the mixing ratios of volatile organic compounds (VOCs) and nitrogen oxides (NO_x) has been widely studied. In addition to the atmospheric levels of VOCs and NO_x, the extent of photochemical processing of VOCs has a strong impact on ozone levels. Although methods for measuring atmospheric mixing ratios of VOCs and NO_x are well established and results of those measurements are widely available, determination of the extent of photochemical processing of VOCs, known as photochemical age (PCA), is difficult. In this article a recently developed methodology for the determination of PCA for individual compounds based on the change in their stable carbon isotope composition is used to investigate the dependence between ozone and VOC or NO_x mixing ratios at a rural site in Ontario, Canada, during fall and winter. The results show that under these conditions the variability in VOC mixing ratios is predominantly a result of the varying impact of local emissions and not a result of changes in the extent of atmospheric processing. This explains why the mixing ratio of ozone shows no systematic dependence on the mixing ratios of VOCs or NO_x in this environment and at this time of the year.     

基于多元线性回归算法的雾霾预测模型的研究

对乌鲁木齐市环境监测站2013—2015年冬季逐日AQI、PM_2.5、PM₁₀、SO_2、NO_2、CO、O_3数据进行相关分析,并利用MATLAB编程工具进行多元回归统计分析,建立了多元回归统计预测模型。对2015年1—3月乌鲁木齐雾霾天气进行预测试验,发现预测值与实际值有较好的拟合效果和预报效果。实验证明,在大气层结稳定的冬季将当天的大气污染物浓度作为因子,用多元线性回归算法建立预测模型对次日雾霾天气进行预测是一种有效的雾霾统计预报手段,本文试图用MATLAB编程工具建立动态多元回归预测模型,编写了自动预测系统软件,测试取得了较好的预测效果。