OBSERVATION AND INVESTIGATION OF VARIABILITIES OF BASELINE CO2 CONCENTRATION OVER WALIGUAN MOUNTAIN IN QINGHAI PROVINCE OF CHINA*

In-situ measurement of atmospheric CO₂ was made at the top of the Waliguan Mountain(36°17'N,100°54'E,3816 m asl).where the air is not directly affected by the local anthropogenic and natural sources,by using a nondispersive infrared(NDIR)analyzer and following the procedures proposed by WMO.The CO₂ in the flask samples collected on the mountain was also analyzed in a laboratory.The measurements uncover the daily,monthly and seasonal variabilities and the baseline level of the CO₂ in the air over the "clean" area of Chinese hinterland.Results suggest that the CO₂ concentration over the East Asia continent has evident periodical variation,similar to that of global distribution.In 1992,an annual mean baseline CO₂ concentration of 356.4 ppm over the continent was obtained.The annual mean value was 357.2 ppm for 1993.Some relationships between the CO₂ concentration at Waliguan and the weather conditions,especially,wind speed and direction are found through the observation.     

贺兰山地区大气冰核浓度的测量及初步分析

根据 1 994年在银川和阿拉善左旗观测得到的冰核资料 ,给出了两地不同天气条件下的大气冰核浓度 ,分析并讨论了冰核浓度与风、降水、天空状况等的关系 ,给出了飞机在空中测量冰核的结果。     

北京市几种主要污染物浓度与气象要素的相关分析

利用 1 999年 1 1月 1日至 2 0 0 3年 7月 30日间 ,北京市几种主要污染物SO2 、NO2 及PM1 0 浓度逐日资料和风速、温度及降水的逐日资料 ,分别对北京市几种主要污染物浓度与同期气象要素之间的关系进行了分析。通过分析注意到 ,污染物浓度与同期气象要素之间通常存在非常明显的非线性关系 ;因而采用非线性回归方程来描述污染物浓度与气象要素之间的依赖关系 ,这一改进使污染物浓度与气象要素之间的相关性有了明显的提高 ,同时使回归方程的误差减小。     

黄山大气气溶胶浓度和尺宽谱分布特征

1988年9月与1989年5月,我们用DL-8318型多道光学粒子计数器在黄山光明顶气象站进行了大气气溶胶的观测。初步得出:黄山大气气溶胶粒子浓度较低,其谱分布模式符合Junge提出的幂指数律谱分布函数,平均相对误差为19%,相关系数为0.99。     

区域大气污染物浓度分布预报的一种模式及其试验

本文就区域尺度大气污染物浓度预报，提出一种以天气气候学分型为基础，结合大气污染物输放散区域污染物浓度区域分布逐日预报模式；并用该模式作预报试验，结果表明：模式的预报结果能达到一定的正确率，具有实用价值。     

PRELIMINARY STUDY OF VARIATION OF SO_2 AND AEROSOL PARTICLE BACKGROUND CONCENTRATIONS IN THE EASTERN CHINA

The average concentrations of sulphur dioxide,sulfate aerosol and TSP were about 8—10 ppb,15.08 μg m~(-3),and241.40 μg m~(-3) respectively,which were measured at the Lin'an regional background station during August—November,1991.The higher concentrations of SO_2 and SO_4~(2-) maybe acidify the rainfall.It has a great influence uponthe human health and ecosystem.The simulated results indicate that the distributions of SO_2 and SO_4~(2-) were deter-mined by local emission sources.Average aerosol particle number density was 2.0×10~4 cm~(-3).It shows that social devel-opment and human activities strongly affect the atmospheric background level.     

O_3浓度变化对我国主要作物产量的可能影响

该文介绍了Ｏ＿３浓度变化对农作物的影响机制，如Ｏ＿３对作物光合与呼吸、生理生化过程和代谢物质、细胞透性、体内各类醇、组织器官以及其它功能的影响，根据美国ＮＣＬＡＮ近１０年的试验资料建立的Ｏ＿３浓度与作物产量的准线性关系，推算和评价了Ｏ＿３浓度变化对我国主要作物产量的可能影响。     

MIROC_Hires模式模拟我国极端降水非均匀性在CO2浓度增加下的响应

利用日本东京大学气候系统研究中心、日本环境研究所和日本地球环境研究中心联合研制的全球海气耦合气候系统模式(MIROC_Hires)输出的逐日降水资料,探讨CO2浓度增加下我国极端降水非均匀性的响应及其可能机制。结果表明:(1)就气候平均而言,CO2浓度增加后,我国南部地区极端降水事件的发生更为集中,而北方地区的极端降水事件分布较平均。(2)从年际变率来看,我国南部地区极端降水事件集中度在"A1B试验"中偏小,年际之间的差异不大,而北方地区的极端降水集中度增加,年际之间变化剧烈。(3)CO2浓度增加后,南方和北方地区在水平和垂直上的增温幅度不一致,且整层大气平均的稳定度呈现出南北反相差异。这种不均匀增暖的分布很可能是导致我国极端降水非均匀性在CO2浓度增加后变化的原因。     

PRELIMINARY STUDY OF VARIATION OF SO2 AND AEROSOL PARTICLE BACKGROUND CONCENTRATIONS IN THE EASTERN CHINA

The average concentrations of sulphur dioxide,sulfate aerosol and TSP were about 8-10 ppb,15.08 μg m^-3,and 241.40 μg m^-3 respectively,which were measured at the Lin'an regional background station during August-November,1991.The higher concentrations of SO₂ and SO₄^2- maybe acidify the rainfall.It has a great influence upon the human health and ecosystem.The simulated results indicate that the distributions of SO₂ and SO₄^2- were determined by local emission sources.Average aerosol particle number density was 2.0×10⁴ cm^-3.It shows that social development and human activities strongly affect the atmospheric background level.     

辐射熏烟浓度预测研究

讨论了辐射熏烟过程及其浓度预测中的几个问题,介绍了熏烟地面浓度绝对最大值及其空间分布的正确计算方法。分析了影响它们的各种因素和高浓度区的延伸范围。     

北京地区PM10污染的气象特征

选用北京城郊5个代表站2000年可吸人颗粒物PM10逐时浓度监测资料,较为系统地统计分析了北京地区主要空气污染物一PM10的时空分布特征,其中包括PM10平均浓度和各等级出现频率的逐月变化、采暖期和非采暖期平均浓度的逐时变化.揭示了各代表站PM10污染年、日变化趋势、采暖期和非采暖期日变化之间的差异,并分析了PM10浓度与地面常规气象要素的相关性.     

气溶胶浓度影响暖雨过程的数值模拟试验

本试验利用ＲＡＭＳ非静力平均模式对１９９５年８月上旬南京地区一次雷阵雨过程进行了不同气溶胶浓度背景下的模拟。初步表明，活化云凝结核浓度增加，可以延缓暖雨过程，减少降水量约２０－３０％，同时，云更持久维持。     

中国东部降水的极端特性及其气候特征分析

基于1960—2017年观测数据分析了中国东部降水极端特性的地区差异、季节和气候学特征及变化格局,探讨了与全球变化和区域气候变率的关联性。结果表明,极端性降水的演化与降水均值或总量的气候型态、降水集中性和持续性密切关联,尤其雨带迁移和雨型演替是影响极端性降水地区差异与时空演变的根本因素。气候变化背景下,中国东部极端性降水强度和频次变化存在较好的协同一致性,近60年来在长江以南,强度加大的地区极端性降水亦趋于频发。同时,两者季节特征和地区差异明显。春季东北地区及华北北部极端性降水强度和频次均有明显增加。近60年来夏季极端性降水强度和频次的趋势变化在长江以南均以增加为主,以北以下降为主。秋季极端性降水强度和频次在华北地区亦呈增加趋势。冬季华南和江南地区极端性降水强度和频次趋势变化均以增加为主。华北地区及以北和内蒙古的西部冬季极端性降水强度增加显著,但频次变化不明显。而东北地区北部冬季极端性降水在强度减小的情形下,其频次仍趋显著增加。特别是中国降水主要集中在夏季,自1980年代以来中国东部夏季多雨带南移,雨型以北方型和中间型占优,转换为以长江型和华南型为主,多雨带的极端性降水群发性强,影响指数显著增加。此外,太平洋年代际振荡(PDO)暖位相及ENSO暖事件期间,长江以北夏季极端性降水的影响指数会显著降低。而东亚夏季风的减弱则有利于长江中下游等地区夏季极端性降水的频发和群发,极端性降水强度加大,其影响的危险性趋于增强。      

CO_2浓度倍增对大豆叶片和总生物量的影响研究

该文利用ＯＴＣ－１型开顶式气室中进行的ＣＯ＿２浓度倍增对大豆影响的试验资料，详细分析了当大气中ＣＯ＿２浓度倍增时，对大豆叶片和总生物量的影响情况，并对大豆总生物量的时间动态变化进行了模拟。结果表明，当大气中ＣＯ＿２浓度倍增时，大豆全生育期将缩短，３叶和分枝的ＤＶＳ值变大，而结荚和鼓粒的ＤＶＳ值变小；总生物量和绿叶重增加显著，但在同一个ＤＶＳ值时，绿叶率（ＧＲ）、黄叶率（ＹＲ）的差异不明显；大豆的总生物量变化均遵循自然增长曲线，且处理和对照有极好的线性正相关关系；总生物量的积温当量提高，并且使大豆总生物量的最大积温当量出现的时间推迟，有利于植株积累更多的营养物质。     

飞机催化区风的实时测量

通过飞机飞行起点及终点的经纬度同时利用机载GPS实时的位置参数，给出了求取飞机所在云区空气流速和流向的计算关系及计算程序。为实时跟踪催化影响区平流扩散，影响区位置控制提供了重要依据。这比用邻区定时定点探空规定层风向风速时空外推值要合理准确。给出了飞机航线的设计和云区流速和流向对PMS粒子浓度计算的影响及可能误差。     

IMPACTS OF OZONE CONCENTRATION CHANGES ON CROPS AND VEGETABLES IN CHINA

The controlled simulation experiments revealed that ozone concentration increases cause various degrees of injury to leaves of crop and vegetable.The injury to vegetables is greater than that to crops.Ozone can dramatically affect stomatal conductance,photosynthetic rate and transpiration rate,and consequently the yield of crops.No matter how long exposure time was, stomatal conductance increased and photosynthetic and transpiration rates decreased with increases in ozone concentration.When ozone concentration was 100 nmol/mol,yields of rice and winter wheat declined by 27.1% and 60.5% respectively.When up to 200 nmol/mol,there was a significant reduction of yields:a decline up to 33.7% for rice and 81.3% for winter wheat.On the other hand,ozone benefits the improvement of grain quality such as amino acid and protein.     

上海夏季近地面臭氧浓度及其相关气象因子的分析和预报

为了揭示城市近地面臭氧浓度的变化特征及其相关气象因素,尝试进行近地面臭氧浓度预报。通过对2005年夏季（6～9月上旬）上海徐家汇地区近地面臭氧的观测与分析,建立了用于夏季臭氧浓度预报和高浓度臭氧污染事件预警的一种简便、实用的统计回归方法。结果表明：天气条件对臭氧形成具有明显的作用,臭氧浓度晴天最大、多云天次之、阴雨天最小;臭氧具有明显的日变化特征,12：00～14：00之间为最大值,凌晨3：00～5：00之间有一很小的次峰,5：00～6：00之间为最小值。产生高浓度臭氧污染是多项因子的综合结果,一般在高压系统的影响下,晴天少云,紫外辐射较强,相对湿度较低,气温较高,地面和高空吹偏北风,且风速较小的情形时容易产生高浓度臭氧污染。引进高浓度臭氧潜势指数和风向影响指数两个指标,并综合考虑多种气象要素,通过逐步回归建立的臭氧浓度预报方程,对逐日最大臭氧浓度具有较好的拟合效果和可预报性。     

IMPACTS OF OZONE CONCENTRATION AND EXPOSURE TIME CHANGES ON RICE YIELDS*

The impacts of O₃ concentration change on rice yields for different lengths of exposure time are studied by means of the OTC-1 open-top chamber.The resuhs indicate that when O₃ concentration increased from 50 ppb to 200 ppb during the time period of 20 to 80 days in the experiment,the rice yield was reduced by 6.78% to 33.72%.Two main influencing factors for rice yields are the increased O₃ concentration and the extended exposure time.Using a logarithm function to simulate the impacts of O₃ concentration on rice yields is better than using a the Weibull function.     

AN ANALYSIS OF THE AEROSOLS IN THE LOWER-LEVEL ATMOSPHERE OVER BEIJING NORTHERN SUBURBS IN WINTER*

The physical and chemical characteristics of the aerosol samples were studied.The samples were collected on the 3 platforms (at levels 8 m,100 m and 320 m respectively) of IAP (Institute of Atmospheric Physics,Chinese Academy of Sciences) observation tower during the periods from January 1 to 16 and from February 20 to March 2,2001.The concentrations of TSP (total suspended particles),chemical components and size distribution for aerosols were calculated.The effects of the meteorological conditions on the aerosol concentrations and its distributions werestudied.The main aerosol sources from which the aerosols in the samples collected came were investigated.The conclusion was drawn preliminarily as follows.The TSP concentrations decreased with height.Over 70% of the aerosol mass were distributed in the fine particle group (d<2.1μm).The top 20 aerosol elements with high concentration are listed from high to low according to their concentrations,and they are S,Fe,Ca,K,A1,Na,Mg,Zn,Cl,Ba,P,Ti,Pb,Mn,As,Cu,V,Br,Cr,and Sb.The aerosol element concentrations decreased with height,too.The mass of volatile elements was mainly distributed in the fine particle group.The ion mass was distributed in the same way as the element mass.From the point of view of contribution to the air aerosols,both anthropogenic and natural sources are important for Beijing.     

冰晶繁生对雷暴云非感应起电影响的数值模拟

为了研究冰晶繁生在雷暴云发展过程中对非感应起电过程的影响,利用三维雷暴云模式在理想层结环境下,对雷暴云内各种水成物粒子、电荷以及电场分布情况进行数值模拟。模拟结果表明:在雷暴云发展和成熟阶段,有繁生过程参与的雷暴云中下部存在一个冰晶聚集区域,从而使得云内冰晶的数量较无繁生过程增大约1 5%～18%,且聚集的区域范围更大;同时,繁生过程的加入也使得霰粒子数量也比无繁生过程时增大约20%;霰冰非感应电荷转移的正区一般位于霰粒子浓度高值区附近,而负区位于冰晶和霰粒子浓度高值区相重合的区域;冰晶繁生过程通过影响雷暴云中冰晶和霰粒子浓度和分布位置,使得雷暴云非感应起电的强度和位置发生改变,导致云内起电过程提前约5～6 min。