石家庄市大气污染物的季节性时空特征及潜在源区

为系统研究石家庄市季节性典型污染物的重污染传输特征,基于2018年12月~2019年11月46个环境监测站（PM_2.5、PM₁₀、O₃、NO₂、SO₂和CO）及17个气象站（温度、湿度和风速）的小时监测数据,利用插值（IDW）和相关方法,分析污染物的季节性时空特征;并结合GDAS数据,采用后向轨迹方法,研究污染物的季度传输格局和潜在源区.结果表明：①不同季节具有典型的污染物,季节性典型污染物和污染率依次为：春季（PM₁₀,48.91%）、夏季（O₃,81.97%）、秋季（PM₁₀和PM_2.5,47.54%和32.79%）和冬季（PM_2.5,74.44%）,其与气象条件变化有显著联系;②春季PM₁₀与风速呈负相关,呈西北高、东南低的空间格局,主要传输方向为南向（53.32%）,潜在源区（WPCWT_ij≥160 μg ·m^-3）为河北（冀）中南、河南（豫）中北及山西（晋）中部,且山东（鲁）西和陕西（陕）西北部的传输也会贡献（WPSCF_ij≥0.3）市域的PM₁₀浓度;③夏季O₃与温度呈正相关,与湿度呈负相关,传输通道方向为东南-南向（54.24%）,其潜在源区呈以石家庄市为中心,沧州和菏泽为两翼的新月形区域;④秋季和冬季PM_2.5与湿度呈正相关,冬季呈西低、东高态势分布,输送方向为：秋季（东北-东南,74.75%）,冬季（西北,55.47%）,主要污染源区（WPCWT_ij≥180 μg ·m^-3）集中在冀中南、豫北和晋中西部.     

北京地区大气氨时空变化特征

在北京城区和上甸子本底地区分别开展了为期3a和1a的NH3在线观测,并结合风向、风速、温度、相对湿度等气象因素的变化特征,分析了北京地区NH3浓度水平、年季特征及影响因素.结果 发现,北京城区和本底地区的NH3年均浓度分别为(32.5±20.8)×10-9V/V和(11.6±10.3)×10-9V/V,北京城区的NH3...     

粉尘点污染扩散模型的可视化研究

在分析和总结了瞬时点尘源在静止流体、均匀紊流和湍流条件下扩散模型的数学表达式和浓度分布方程的基础上,运用Matlab软件进行可视化处理,生成一系列的三维图形,可从不同的角度进行观察和分析,使之能够直观、形象的了解粉尘扩散过程,并从中了解到粉尘扩散的一些特点,该项研究对粉尘防治工作与危害预测都有重要的理论与实践意义。     

西北干旱区柴窝堡湖干涸湖底粉尘潜在扩散特征

运用HYSPLIT模型,结合美国环境预报中心(NCEP)和大气研究中心(NCAR)2000~2013年的再分析气象资料,对柴窝堡盆地粉尘潜在扩散的时间和空间特征进行了研究.结果表明:柴窝堡湖干涸湖底粉尘潜在扩散范围具有明显的季节分异.春季粉尘潜在扩散范围和密度最大,覆盖我国大部分地区,最远可达朝鲜半岛部分地区,其次是秋季,夏季粉尘潜在扩散以1000m为界表明出明显的高度差异,冬季粉尘潜在扩散范围和密度均是最小的.随高度增加,不同季节气流可能携带粉尘密度均呈降低趋势.受地形影响,粉尘潜在扩散有两个主要通道,100m以下主要向西南方向扩散,而100m以上主要向东南方向扩散.柴窝堡盆地干涸湖底大量的粉尘在气流携带下可以长时间远距离输送,在近源区沉降,严重影响乌鲁木齐及其周边地区,并可能加速天山山区的雪冰消融.     

南海浮游植物对沙尘和灰霾添加的响应

通过2016年5月~6月在南海3个站位开展的船基围隔培养实验,研究了沙尘和灰霾添加对南海浮游植物生长和群落结构变化的影响.结果发现,沙尘和灰霾添加由于提供了N、P等营养盐,整体上促进了浮游植物的生长,且促进程度与添加量密切相关.通过定量计算营养盐指数和叶绿素a累积浓度,发现培养期间叶绿素a累积浓度与沙尘添加浓度呈显著正相关关系（R²=0.87,P<0.01）;低浓度灰霾添加的作用与沙尘添加类似（R²=0.91,P<0.01）,但当灰霾浓度增大时,叶绿素a累积浓度的增加受到一定程度的抑制,这可能与灰霾中含有较高含量的毒性物质有关.各粒级浮游植物叶绿素a浓度的变化表明,沙尘和低浓度灰霾添加使浮游植物优势种群由超微型向小型和微型转变;在高浓度灰霾添加组,由于营养盐与毒性物质的综合作用,浮游植物粒级结构变化不明显.超微型浮游植物细胞丰度测定结果表明,沙尘对聚球藻、原绿球藻和超微型真核浮游植物均表现出促进作用,高浓度灰霾添加能够抑制聚球藻和超微型真核浮游植物的生长.     

沙尘和灰霾沉降对黄海春季浮游植物生长的影响

大气沉降可为上层海洋带来生物可利用性的营养元素(如N、P、Fe等),从而改变浮游植物的初级生产过程及群落结构,并影响海洋的碳循环.于2014年春季在南黄海开展2次船基围隔培养实验,通过人工添加沙尘、灰霾颗粒及多种营养盐来模拟大气沉降对海洋表层浮游植物生长的影响,结果表明:南黄海北部B07站浮游植物生长主要受到磷限制;南黄海中部H10站则主要受氮限制.沙尘添加在B07站和H10站均显著促进小型和微型浮游植物生长,对微微型浮游植物生长的促进作用不明显.灰霾添加在B07站对浮游植物生长总体呈现抑制作用,且主要抑制小型和微型浮游植物生长,对微微型浮游植物则为先抑制后促进;在H10站对浮游植物的影响整体呈现先抑制后促进,培养前期对各粒级浮游植物均有抑制作用,培养后期对微型和微微型浮游植物有促进作用.     

Rural vulnerability to environmental change in the irrigated lowlands of Central Asia and options for policy-makers: A review

Climate change, land degradation and drought affect millions of people living in drylands worldwide. With its food security depending almost entirely on irrigated agriculture, Central Asia is one of the arid regions highly vulnerable to water scarcity. Previous research of land and water use in the region has focused on improving water-use efficiency, soil management and identifying technical, institutional and agricultural innovations. However, vulnerability to climate change has rarely been considered, in spite of the imminent risks due to a higher-than-average warming perspective and the predicted melting of glaciers, which will greatly affect the availability of irrigation water. Using the Khorezm region in the irrigated lowlands of northwest Uzbekistan as an example, we identify the local patterns of vulnerability to climate variability and extremes. We look at on-going environmental degradation, water-use inefficiency, and barriers to climate change adaptation and mitigation, and based on an extensive review of research evidence from the region, we present concrete examples of initiatives for building resilience and improving climate risk management. These include improving water use efficiency and changing the cropping patterns that have a high potential to decrease the exposure and sensitivity of rural communities to climate risks. In addition, changes in land use such as the afforestation of degraded croplands, and introducing resource-smart cultivation practices such as conservation agriculture, may strengthen the capacity of farmers and institutions to respond to climate challenges. As these can be out-scaled to similar environments, i.e. the irrigated cotton and wheat growing lowland regions in Central Asia and the Caucasus, these findings may be relevant for regions beyond the immediate geographic area from which it draws its examples.     

Dry deposition of PM10 over the Yellow Sea during Asian dust events from 2001 to 2007

Dry deposition velocities and fluxes of PM10during Asian dust events over the Yellow Sea from 2001 to 2007 were investigated using observation data in Qingdao, China and Jeju, Korea. The dry deposition velocities of PM10 during dust events over the Yellow Sea ranged from 0.19 to 8.17 cm/sec, with an average of 3.38 cm/sec. Dry deposition fluxes of PM10during dust events over the Yellow Sea were in the range of 68.5–2647.1 mg/(m2·day), with an average of 545.4 mg/(m2·day), which is 2–10 times higher than those reported by other studies for both dust and non-dust periods. It was estimated that 2.6 × 1011–48.7 × 1011g dust particles deposit to the Yellow Sea during dust events through dry deposition every year. Compared with the results in previous studies, it was found that the dry deposition of PM10over the Yellow Sea during dust events in the years with high frequency of dust could account for a large or overwhelming fraction of the annual total dry deposition. Backward air mass trajectory analysis showed that dust events influenced Jeju mainly originated from the desert regions located in Mongolia and Inner Mongolia, China. There were 119 backward trajectories influenced both Qingdao and Jeju during 15 dust events from 2001 to 2007, accounting for 61.3% of the total trajectories of 194, indicating that Qingdao and Jeju were usually on the same pathway of dust transport downwind from source areas.     

Human Settlements on the Northern Shores of Lake Aral and Water Level Changes

The shore of Lake Aral in Kazakhstan is a perfect area for studying the human adaptation strategy to past climate changes. New archaeological material, gathered along the northern shores during the expedition of the INTAS project CLIMAN, is briefly presented. Changes in settlement activity during the Atlantic and Subboreal are related to lake level changes of the Aral Sea. A previ-ously proposed lake level maximum needs to be revised. In particular the lake level stand at 72/73 m, with an assumed age of 5000 BP is definitely refused. Based on the presented data the maximum lake level most probably never reached beyond 57/58 mean average sea level (masl). Furthermore the regression during the 15^th–16^th centuries has been underestimated. It may have been lower than the present day level. Thus the present desiccation of the Aral Sea is historically not unique, as a similar regression, probably induced by man as well, has occurred at least once during history. A readjustment of the water level is, therefore, possible at any time.     

黄渤海气溶胶光学厚度的多源卫星遥感产品精度分析和时空分布特征研究

以黄渤海上空大气为目标研究区,基于AERONET观测网,获取该区域2015-2017年的气溶胶光学厚度(AOD)实测数据,并对可见红外成像辐射计VIIRS,中分辨率成像光谱仪MODIS,静止水色卫星成像仪GOCI与新一代地球同步气象卫星AHI H8的AOD遥感产品展开精度验证.同时,利用长时间的遥感影像探究并分析AOD...     

A comparison of characteristics of aerosol from dust storms in Central Asia with soil-derived dust from other regions

Aerosol samples from dust storms were collected in Tadzhikistan (Soviet Central Asia) during September 1989, as a part of the joint U.S.S.R.-U.S. Dust Experiment. Physico-chemical characteristics of deposited dust were compared with those of soil-derived dust collected in other regions. Particle mass-size distributions appear to be characterized by a common log-normal mode between 1 and 10 μm. Chemical composition of the sampled material shows that the dust is particularly rich in calcium and silicon and poor in iron. Estimated mineral composition of dust indicates that this enrichment in Ca and Si for the Soviet Asian dust must be related to high contents of carbonate and quartz, respectively. Different Fe/Al also suggest a specific chemical composition for clay minerals in the Asian dust.     

阿拉伯半岛沙尘时空分布特征及气象条件

通过对阿拉伯半岛地面90个气象站20年沙尘天气、AI指数及风场的时空分布特征结合气象条件分析，确定该区域沙尘天气的发生规律及传输路径.结果表明：永久多尘地区是半岛扬沙发生最频繁的区域，从2月开始扩张，并在6月达到最大.浮尘的时空分布与扬沙类似，但还存在希贾兹山脉北部和波斯湾沿岸的高值中心，3月与永久多尘地区的高值区连成一片，6~7月达到最大，然后开始收缩并分裂成几个小中心.AI指数存在一个像倒箭头的相对高值中心，其变化具有明显的单峰分布，强度和范围在6月最大.10~4月和5~9月半岛分别盛行顺时针、逆时针旋转的风向，它们将沙尘远程传输到下游地区.天气学分析表明，冷锋入侵半岛使得来自北方的冷空气快速锲入暖空气之下，是导致沙尘天气出现的主要原因；后向轨迹聚类分析显示，半岛存在3类传输路径，其重要性依次为西北方向撒哈拉沙漠的远程传输、反气旋风场将来自伊拉克或伊朗的沙尘远程传输和本地的沙尘源传输.     

北非沙尘天气时空分布特征及其远程传输路径

通过对北非地面300个气象站20a沙尘暴、浮尘、风场及冬夏季气溶胶指数（AI）的时空分布分析,探讨了其远程传输路径,结果表明：1）北非在阿尔及利亚、毛里塔尼亚、尼日尔和乍得中部、埃及东部、苏丹北部、博德莱洼地存在6个主要沙源区,3月沙尘暴范围和强度最大,8~11月最小.从11月起逐渐在萨赫勒地区形成了一条浮尘带,其强度和范围在3月最大,其后逐渐收缩并在6~10月分裂成3~4个小带.2）受冬春季地面高压影响,萨赫勒浮尘带由其北部发生的沙尘暴远距离传输而来.4~8月,来自赤道的南风北抬并与来自大西洋的西北风在萨赫勒中西部交汇,形成静风区并导致浮尘带收缩、断裂.3）北非存在2条沙尘主传输路径,其中Ⅰ起自阿尔及利亚,向东到地中海、埃及和苏丹,然后转向萨赫勒,从东向西传到大西洋;Ⅱ起自阿尔及利亚,向南传输到毛里塔尼亚,向西传到大西洋;同时在主传输路径Ⅰ上还出现了4个分支路径.