帕米尔高原东部PM10输送路径及潜在源分析

基于HYSPLIT后向轨迹模式和NCEP的GDAS数据（2019年3月~2020年2月）,对抵达帕米尔高原东部的48h后向气团轨迹按季节聚类,其PM₁₀和PM_2.5年均值分别为（29.4±16.4）,（9.3±5.1）μg/m³,大气颗粒物以PM₁₀为主,结合同期PM₁₀浓度数据,分析不同路径对帕米尔高原东部PM₁₀聚集的贡献,并利用潜在源贡献因子法（PSCF）和浓度权重轨迹法（CWT）,揭示研究期间帕米尔高原东部不同季节PM₁₀的潜在源分布及其贡献水平.结果表明：帕米尔高原东部PM₁₀输送路径的季节特征明显,春季来自中亚的西风气流对应PM₁₀高值,夏季来自中国新疆西部的气流也对应较高PM₁₀值,秋季各轨迹对应PM₁₀值相当,冬季来自南亚方向气流对应PM₁₀高值.PM₁₀春季贡献源区主要位于中国新疆西部、阿富汗东北部、巴基斯坦东北部、塔吉克斯坦中部及东部地区,夏季主要位于中国新疆西部喀什与和田北部地区,秋季主要位于土库曼斯坦东部、乌兹别克斯坦东南部、巴基斯坦北部、阿富汗北部与塔吉克斯坦南部接壤地区,冬季主要位于巴基斯坦东北部、印度北部以及阿富汗北部.     

帕米尔高原东部PM10输送路径及潜在源分析

基于HYSPLIT后向轨迹模式和NCEP的GDAS数据（2019年3月~2020年2月）,对抵达帕米尔高原东部的48h后向气团轨迹按季节聚类,其PM₁₀和PM_2.5年均值分别为（29.4±16.4）,（9.3±5.1）μg/m³,大气颗粒物以PM₁₀为主,结合同期PM₁₀浓度数据,分析不同路径对帕米尔高原东部PM₁₀聚集的贡献,并利用潜在源贡献因子法（PSCF）和浓度权重轨迹法（CWT）,揭示研究期间帕米尔高原东部不同季节PM₁₀的潜在源分布及其贡献水平.结果表明：帕米尔高原东部PM₁₀输送路径的季节特征明显,春季来自中亚的西风气流对应PM₁₀高值,夏季来自中国新疆西部的气流也对应较高PM₁₀值,秋季各轨迹对应PM₁₀值相当,冬季来自南亚方向气流对应PM₁₀高值.PM₁₀春季贡献源区主要位于中国新疆西部、阿富汗东北部、巴基斯坦东北部、塔吉克斯坦中部及东部地区,夏季主要位于中国新疆西部喀什与和田北部地区,秋季主要位于土库曼斯坦东部、乌兹别克斯坦东南部、巴基斯坦北部、阿富汗北部与塔吉克斯坦南部接壤地区,冬季主要位于巴基斯坦东北部、印度北部以及阿富汗北部.     

西宁市大气污染来源和输送季节特征

在2016~2018年西宁市大气污染物PM₁₀和PM_2.5季节污染特征分析的基础上,利用HYSPLIT模式和GDAS资料计算了逐日72 h气流后向轨迹,通过聚类分析确定气流输送路径及其对日均PM₁₀和PM_2.5质量浓度的影响,运用TrajStat软件提供的潜在源贡献因子分析法（PSCF）和浓度权重轨迹分析法（CWT）,探讨不同季节影响西宁市PM₁₀和PM_2.5质量浓度的潜在源区分布及贡献.结果表明,输送来源位置多分布在西宁的西-北方向和东-北方向,周边及邻近区域垂直高度较低.输送路径主要受西风、偏西风、西北、西南和偏东气流的影响.距离短、高度低和移速慢的气流轨迹出现概率最高,是最主要的输送路径,该路径在春夏秋三季来源于青海,冬季则源自新疆,省内输送占主导地位,且不同输送轨迹对PM₁₀和PM_2.5浓度影响不同.污染气流主要来自青海省内源、新疆外源及新疆以西的境外源,源地多沙漠和戈壁等脆弱地带分布.潜在源区范围及贡献大小有明显季节差异,冬季范围广且贡献最大,春秋次之,夏季最小.最主要潜在源区位于青海北部、中部和东部地区、新疆南部、中部和东部,其周边地区为中等贡献潜在源区.     

深圳地区海岸复杂地形下大气输送与扩散模拟

利用边界层预报模式提供的非定常的风场和湍流场，采用实用的考虑风切变的烟团模式模拟了海岸复杂地形下高架点源排放ＳＯ２的地面浓度变化特征。联接模式细致地考虑了地面反射，混合层穿透和反射。结果反映了风场湍流场的非均匀非定常对浓度分布有较大影响。     

Vertical distributions of tropospheric SO2 based on MAX-DOAS observations: Investigating the impacts of regional transport at different heights in the boundary layer

Information on the vertical distribution of air pollutants is essential for understanding their spatiotemporal evolution underlying urban atmospheric environment. This paper presents the SO₂ profiles based on ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements from March 2018 to February 2019 in Hefei, East China. SO₂ decrease rapidly with increasing heights in the warm season, while lifted layers were observed in the cold season, indicating accumulation or long-range transport of SO₂ in different seasons might occur at different heights. The diurnal variations of SO₂ were roughly consistent for all four seasons, exhibiting the minimum at noon and higher values in the morning and late afternoon. Lifted layers of SO₂ were observed in the morning for fall and winter, implying the accumulation or transport of SO₂ in the morning mainly occurred at the top of the boundary layer. The bivariate polar plots showed that weighted SO₂ concentrations in the lower altitude were weakly dependent on wind, but in the middle and upper altitudes, higher weighted SO₂ concentrations were observed under conditions of middle-high wind speed. Concentration weighted trajectory (CWT) analysis suggested that potential sources of SO₂ in spring and summer were local and transported mainly occurred in the lower altitude from southern and eastern areas; while in fall and winter, SO₂ concentrations were deeply affected by long-range transport from northwestern and northern polluted regions in the middle and upper altitudes. Our findings provide new insight into the impacts of regional transport at different heights in the boundary layer on SO₂ pollution.     

舟山本岛大气污染输送过程的数值模拟分析

利用HYSPLIT-4后向轨迹模式和NCEP(美国国家环境预报中心)的2012年GDAS(全球资料同化系统)气象数据,结合NO₂、PM_2.5、PM₁₀和SO₂等常规大气污染物的质量浓度数据,对舟山本岛2012年4月、7月、10月和12月的大气污染输送过程进行了模拟,并通过聚类分析和潜在源区分析〔包括PSCF(潜在源贡献)和CWT(浓度权重轨迹)计算〕,确定大气污染传输路径及影响源区. 结果表明:舟山本岛气流后向轨迹呈明显的季节变化特征,4月主要受来自黄海海面气流轨迹的影响,其占总轨迹数的36.7%,ρ(PM₁₀)为(53.24±24.33)μg/m3;7月以途经琉球群岛和东海气流轨迹为主,占总轨迹数的48.4%,对ρ(NO₂)、ρ(PM_2.5)、ρ(PM₁₀)和ρ(SO₂)贡献分别为(24.63±6.33)、(28.60±4.83)、(52.89±18.76)和(8.67±3.11)μg/m3;10月气流轨迹主要来自于东海海面,占总轨迹数的49.2%;12月气流则主要来自辽宁南部和黄海,占总轨迹数的66.1%,对ρ(NO₂)、ρ(PM_2.5)、ρ(PM₁₀)和ρ(SO₂)贡献分别为(28.48±15.14)、(58.71±14.10)、(69.83±38.94)和(20.83±13.28)μg/m3. 舟山本岛PM_2.5的潜在源主要为毗邻城市间局地污染,集中于浙江沿海城市及杭州湾、上海等地.      

Transboundary transport of atmospheric pollutants through the eastern alps

Some preliminary analyses have shown that the Brenner Pass can be important in the transport of atmospheric pollutants through the Alpine chain, due to either breeze circulation or inflows of air masses. In one cross-section of the valley near the pass, meteorological and chemical measurements were taken, starting in 1986. The local breeze was studied but it was recognized to be of minor importance. The transport of pollutants through the pass was, on the whole, modest except during some inflows that only lasted for a few days. Meteorological situations have been registered when windborne pollutants are transported either to or from Italy, as was recognized from the trajectory analysis. The air masses coming in from central and eastern Europe generally contain higher concentrations of SO₂ than NO₂, while the opposite is true when the air masses originate in the Po Valley where the large use of methane enriches the air with NO₂.     

2017年10月海南省一次臭氧污染特征及输送路径与潜在源区分析

为了探讨2017年10月海南省一次O₃污染过程的气流轨迹、输送路径和潜在源区,采用海南省18个市县的AQI值、6类大气污染物质量浓度资料以及相关气象观测资料,结合HYSPLIT后向轨迹模型进行分析.结果表明:①2017年10月海南省有13个市县首要污染物为O₃的天数比例超过80%,其中9个市县达100%.2017年10月26日澄迈县和儋州市AQI值分别为171和151,均达中度污染等级,7个市县达轻度污染等级.②气象要素与AQI和污染物质量浓度之间均存在较好的相关关系,ρ(O₃)、AQI与相对湿度的相关系数分别为-0.701和-0.685,均通过了99.9%的信度检验.③卫星反演结果表明,此次污染过程与外源输送关系密切.影响气流主要来自内陆地区的长距离气流、中短距离气流和来自东南沿海的中短距离气流,三支气流影响时段对应的海口市AQI值分别为83、69和61,对应的ρ(O₃)分别为和135.0、119.6和102.3 μg/m3.④通过计算PSCF(潜在源贡献因子)和CWT(浓度权重轨迹)发现,广东省为海南省的主要潜在贡献源区,湖南省、江西省、江苏省、浙江省和福建省等地区也有一定的潜在贡献.研究显示,2017年10月海南省出现的O₃污染过程中,污染物来源以外源输送为主.      

边界层方案与垂直混合对京津冀地区O3模拟的影响研究

采用WRF-Chem模式中的3种边界层方案YSU、MYJ和ACM2对2019年6月京津冀及周边地区典型O₃污染月份开展模拟研究.详细对比了各方案对地面气象要素、NO₂和O₃浓度时空分布,以及温湿风要素和O₃浓度垂直分布的模拟效果.结果表明：3种方案对地面气象要素的时空分布和温湿风要素的垂直变化模拟较为合理.MYJ方案模拟地面气象要素整体效果最佳.各方案对边界层高度的日变化特征模拟较好,相关系数为0.58~0.69,但存在白天偏高、夜间偏低的现象,YSU方案相比效果最佳.3种边界层方案对NO₂浓度模拟普遍高估,而O₃模拟结果则出现低估.白天模拟偏差较小而夜间偏差较显著.模拟最佳的是ACM2,其次为YSU和MYJ.3种方案均较好地模拟出了O₃的垂直分布特征,但整体低估了O₃浓度.对上午O₃垂直分布的模拟差异较下午更为明显.此外,基于YSU方案设置了3个敏感实验,通过调整化学模块所用的湍流扩散系数阈值,对比分析了垂直混合过程改变对O₃浓度模拟的影响,模拟的变化只反映由于边界层的垂直混合过程改变造成的污染差异,而不是由于热动力场的调整造成的变化.模拟结果表明3个方案均可改善区域上地面NO₂和O₃的模拟性能,尤其是对原3种边界层方案模拟O₃均明显低估的华北平原地区提升效果最显著,平均偏差降低了23.7%.在垂直方向上,湍流扩散系数阈值的调整增加了早间近地面模拟的O₃浓度,改善了模拟偏低的现象,但同时增大了高层O₃浓度的负偏差.敏感性方案显著改善了夜间的模拟,白天则并不明显.这些结果显示出湍流扩散系数对O₃垂直混合的重要影响.因此,改进湍流扩散系数的参数化对O₃模拟是必要的.     

大气PM10跨界输送的自组织动力机制——以舟山市为例

我国城市间大气污染物的相互输送作用非常显著.舟山市大气污染物主要来源于长三角地区,本地源影响较小.因此,本文将以舟山市为例,应用频度统计分析方法,研究舟山市大气PM10污染演化宏观动态的统计分布规律.结果发现,舟山市大气PM10小时平均浓度的波动并非随机,而是在0.065~0.324 mg·m-3范围内具有标度不变特征,统计上服从典型的分形幂律分布.同时,为了阐明该分形幂律分布的产生动力机制,基于自组织临界理论,建立了大气PM10跨界输送模型.该模型以污染输送机制、二次颗粒物生成机制、城市内污染迁移扩散机制、大气自净机制这4个主导动力机制为核心,组建了非线性关联迭代算法.新的自组织动力模型的模拟结果定量地解释了舟山市大气PM10污染浓度的分形幂律统计分布规律的产生根源.同时,本研究结合区域风场等气象因素,深入讨论了大气PM10跨界输送的自组织行为机制.     

重庆市冬季PM_(2.5)及气态污染物的分布特征与来源

利用重庆市大气污染物监测站2013年冬季(2013年11月—2014年1月)的实测数据,分析PM2.5及相关气态污染物(SO2、NO2、O3)的时空特征,并采用轨迹聚类与PSCF(潜在源贡献因子)分析污染物来源.结果表明:除ρ(O3)以外,其他3种污染物质量浓度的月际变化趋势基本一致,均呈12月升高、1月降低的特征;污染物空间分布不均,其中ρ(PM2.5)和ρ(NO2)在工业区和人口密集区较高,ρ(SO2)南高北低,ρ(O3)城区低于郊区.ρ(SO2)、ρ(NO2)与ρ(PM2.5)均呈显著正相关,其中ρ(SO2)与ρ(PM2.5)的R(相关系数)在城、郊区分别为0.71、0.65,ρ(NO2)与ρ(PM2.5)在城、效区的R分别为0.73、0.56;而ρ(O3)与ρ(PM2.5)未表现出显著相关.ρ(SO2)、ρ(NO2)与ρ(PM2.5)的相关性高低可在一定程度上说明二次气溶胶的污染程度,ρ(O3)与ρ(PM2.5)的相关性受到PM2.5来源和污染程度的影响.轨迹分析结果显示,重庆市2013年冬季主要受东北方向气流影响;聚类分析表明,重庆市11月没有表现出明显的PM2.5外来输送特征,但12月和1月的PM2.5外来输送特征明显,并且不同方向的气流污染物浓度差异也较大.PSCF分析发现,重庆市冬季PM2.5、SO2、NO2、O3主要来源于本地和周围城市局地传输,同时还受南宁、贵阳、遵义、达州等地的影响.     

巢湖水体氮磷营养盐时空分布特征

在不同汛期对巢湖水体进行了网格化样品采集,研究了巢湖水体中氮磷营养盐的含量与时空分布规律,确定了巢湖水体的主要污染因子.结果表明,巢湖入湖河流中TP、TN和NO-3-N指标均超过了Ⅴ类水标准,南淝河和十五里河中TP、TN、NH+4-N和NO-3-N表现出丰水期低于平水期、枯水期的季节性变化特征,在其他河流则呈现出丰水期高于枯水期、平水期的特征;巢湖湖体氮磷营养盐浓度的分布存在时空差异,西部湖区中氮磷营养盐含量远高于东部湖区;TP、TN和NH+4-N表现出在枯水期高于平水期和丰水期的变化特征,而NO-3-N在丰水期的含量较高;巢湖水体的主要污染因子为TN和NH+4-N,这些污染物从西往东质量浓度不断减少.     

Intensive studies of Sierra Nevada cloudwater chemistry and its relationship to precursor aerosol and gas concentrations

Measurements of inorganic aerosol and gas phase species are presented for three sites in central California during a 4 day period in April 1988. The measurement sites were located along an east-west transect at Visalia, Ash Mountain, and Lower Kaweah, with elevations of 90, 550 and 1900 m, respectively. Aerosol compositions were nearly neutral at all locations, however large concentrations of NH₃ at Visalia contributed significant excess alkalinity to the air mass sampled there. Concentrations of all major species were observed to decrease with elevation during most of the sampling periods. Concentrations at the upper two sites exhibited diurnal fluctuations, with peaks in the late afternoon, consistent with the transport of pollutants from San Joaquin Valley sources by daytime upslope winds. Concentrations of most of these species reached a maximum at the elevated sites on 28 April, as a weak cold front approached, reducing the atmospheric stability over the valley floor. Concentrations at Visalia on this day were somewhat lower than those observed earlier in the week.Clouds intercepting the mountain slopes on 28 April were sampled at two locations. The coudwater pH at both sites was observed to fall throughout the event, dropping as low as 4.34. Precursor concentrations of aerosol NO₃⁻, SO₄^2- and NH₄⁺, and gas phase HNO₃ and NH₃, were sufficient to account for the observed cloudwater loadings of NO₃⁻, SO₄^2- and NH₄⁺. In-cloud measurements made near the cloud base indicated a considerable S(IV) oxidation potential in the form of H₂O₂, but only low S(IV) concentrations. Cloudwater concentrations of formic acid were approximately three times acetic acid concentrations. Carbonyl concentrations were dominated by formaldehyde and glyoxal.     

大气PM2.5中水溶性离子在线观测技术的应用研究

为了解北京大气PM2.5污染状况,评估大气细颗粒物快速捕集-化学成分在线分析系统(RCFP-IC)在追踪污染生成-消散过程中的适用性,于2011年3月对北京PM2.5中NO3-、SO24-、NH4+和Cl-这4种污染型水溶性离子浓度变化进行了连续高时间分辨率观测,并结合同期气象要素的变化,探讨了污染过程形成的原因.结果表明,一个月的观测期内捕捉到了5次较为明显的污染过程,4种水溶性离子的浓度变化趋于一致,并呈现出典型的"慢积累、快清除"的锯齿型污染物浓度时间序列变化特征.NO3-和NH4+在典型污染事件中峰值浓度是清洁时期浓度的10倍以上,而SO24-和Cl-污染峰值浓度仅为清洁时期的2～4倍.停暖后4种离子浓度较采暖期下降了15%～60%.RCFP-IC与高分辨率飞行时间气溶胶质谱(HR-TOF-AMS)同期观测结果变化趋势具有高度的一致性,但RCFP-IC定量水溶性离子浓度更为准确.     

紊流作用下泥沙释放磷的试验及数值模拟

为研究水体紊动对泥沙释放污染物的影响,引入近似均匀紊流模拟装置,开展不同强度紊动作用下泥沙运动释放磷动态过程及基本规律的试验,研究表明:紊动扩散作用对泥沙解吸释放磷有着十分重要的影响,紊动较弱时,泥沙尚未起动,床面泥沙颗粒吸附的磷元素解吸至孔隙水中,在垂向紊动扩散作用下输送至上覆水中,将使得上覆水中溶解态磷浓度增大;紊动作用较强时,泥沙逐渐悬扬至水体中,悬浮泥沙颗粒吸附的磷元素直接解吸至上覆水中,泥沙浓度越高,溶解态磷含量增长速率越大,达到平衡的时间越短.通过耦合紊流模型、水流泥沙数学模型、污染物对流扩散模型和Langmuir吸附动力学方程建立了紊动作用下泥沙释放磷的垂向一维数学模型,针对试验条件进行数值模拟,模拟结果与试验数据吻合较好,平均相对误差低于10%,可为模拟天然水体中泥沙悬浮释放磷的时空演化提供参考.     

Measurement of hydrogen peroxide and organic hydroperoxide concentrations during autumn in Beijing, China

Gaseous peroxides play important roles in atmospheric chemistry. To understand the pathways of the formation and removal of peroxides, atmospheric peroxide concentrations and their controlling factors were measured from 7:00 to 20:00 in September, October, and November 2013 at a heavily trafficked residential site in Beijing, China, with average concentrations of hydrogen peroxide (H₂O₂) and methyl hydroperoxide (MHP) at 0.55 ppb and 0.063 ppb, respectively. H₂O₂ concentrations were higher in the afternoon and lower in the morning and evening, while MHP concentrations did not exhibit a regular diurnal pattern. Both H₂O₂ and MHP concentrations increased at dusk in most cases. Both peroxides displayed monthly variations with higher concentrations in September. These results suggested that photochemical activity was the main controlling factor on variations of H₂O₂ concentrations during the measurement period. Increasing concentrations of volatile organic compounds emitted by motor vehicles were important contributors to H₂O₂ and MHP enrichment. High levels of H₂O₂ and MHP concentrations which occurred during the measurement period probably resulted from the transport of a polluted air mass with high water vapor content passing over the Bohai Bay, China.     

杭州市机动车NO_x排放清单的建立及其对空气质量的影响

以杭州市主城区为例,对车辆信息(包括车流量和车辆构成、车辆控制技术水平、车辆行驶工况、车辆启动分布等)进行了调研和测试,并根据IVE模型计算了机动车NOx的排放清单.结果表明,2004年杭州市主城区机动车NOx排放总量为25 100 t,其中,轻型客车、出租车、公交车、重型货车和轻型货车的年排放量分别为5 800,1 100,7 300,9 200和1 700 t.在此基础上,通过AERMOD模型模拟了城市机动车源NOx年均质量浓度以及城市空气中总的NOx年均质量浓度空间分布,得出机动车排放的NOx对总的NOx年均质量浓度的贡献率为40.91%,并对贡献率的空间分布进行了分析.     

邯郸市黑碳气溶胶浓度变化及影响因素分析

根据2013年3月—2017年2月邯郸市河北工程大学站点的黑碳气溶胶、PM2.5、大气污染物的小时浓度数据及常规气象数据,对邯郸市黑碳浓度的时间变化特征及影响因素进行分析.结果表明,4年来邯郸市黑碳浓度呈逐年下降的趋势:与2013年相比,2014—2016年黑碳气溶胶浓度分别下降了5%、16%、24%;邯郸市黑碳气溶胶浓度的季节变化趋势基本一致且季节变化特征明显,冬季黑碳气溶胶浓度最高,秋季次之,春夏两季最低,其中,冬季平均浓度分别是春、夏、秋季的2.07、2.77、1.49倍;其日变化呈单峰单谷状,且4个季节的日变化趋势相同,峰值均出现在6:00—8:00,谷值均出现在14:00—15:00.黑碳与PM2.5的相关系数r为0.860,相关性显著,说明黑碳气溶胶和PM2.5的来源大部分是一致的;风速和风向对黑碳气溶胶浓度也有影响,黑碳气溶胶浓度随风速增加而降低;4个季节高频风向为南-西南方向,且该风向下黑碳气溶胶浓度均较高,冬季南-西南风向下的黑碳浓度最高;应用后向轨迹对研究时段内4段重污染期间的气流轨迹进行模拟发现,邯郸市黑碳气溶胶浓度较高的主要原因是本地源排放和近距离传输,远距离传输贡献较小.     

A non-local closure model for vertical mixing in the convective boundary layer

A simple non-local closure model for vertical mixing in Convective Boundary Layers (CBL) has been developed specifically for application in regional or mesoscale atmospheric chemistry models. The model, named the Asymmetrical Convective Model (ACM), is based on the concept that vertical transport within the CBL is inherently asymmetrical. Upward transport by buoyant plumes originating in the surface layer is simulated by mixing from the lowest model layer directly to all other layers in the CBL. Downward transport, however, proceeds only to the next layer in order to emulate gradual compensatory subsidence. The ACM is similar to the model developed by Blackadar (1978, 4th Symp. on Atmospheric Turbulence, Diffusion and Air Quality, pp. 443–447, Reno, Am. Meteorol. Soc.) but differs in its treatment of downward transport. The realism of the ACM is tested through comparisons to large-eddy simulations of several idealized test cases. These tests show that while the ACM shares the Blackadar model's ability to simulate rapid transport upward from the surface layer to all levels in the CBL, it is clearly superior in its treatment of material emitted from elevated sources either within or above the CBL. The ACM is also tested in the context of the Regional Acid Deposition Model (RADM) both to determine sensitivity to different CBL mixing schemes and to compare to vertically resolved aircraft measurements. These tests demonstrate quicker upward transport of ground-level emissions by the ACM as compared to the eddy diffusion scheme currently used in RADM. The ACM also affects ozone photochemistry in the boundary layer resulting in lower ozone concentrations in areas of high NO_x emissions.     

南京北郊O3、NO2和SO2浓度变化及长/近距离输送的影响

利用2008年1月—2010年12月南京北郊O₃、NO₂和SO₂质量浓度连续观测资料结合后向轨迹模式,采用聚类分析对轨迹进行分类和KZ滤波器对数据组分进行分离的方法,讨论了南京北郊气体污染物(O₃、NO₂和SO₂)的质量浓度变化规律及长/近距离输送对该地区污染气体的影响.结果表明,南京北郊春末夏初(5、6月)O₃月均浓度出现最大值,12月出现最小值;NO₂在春季(3—5月)月平均浓度相对较高,8月份浓度全年最低,而SO₂浓度在6、7月出现最低值.不同季节气体污染物浓度日变化各有特点,O₃呈单峰分布,12:00—15:00出现浓度最大值;NO₂浓度高值则出现在夜间;SO₂在清晨出现最大值,另外,春秋冬季SO₂呈双峰型分布.长/近距离输送对南京北郊污染气体影响的分析表明,在西南方向的近距离输送影响下,该地区O₃浓度将会出现明显的高值;传输速度较慢的西北气流则会促使该地区形成高浓度的NO₂;长距离输送对O₃和NO₂的贡献与气团输送距离有关,说明该地区O₃和NO₂是区域性问题.另外,当在传输速度较慢的偏东气流的控制下,SO₂的浓度较高,说明SO₂的高浓度事件与偏东方向的近距离输送有关.