京津冀一次重度雾霾天气能见度及边界层关键气象要素的模拟研究

本文利用GRAPES_CUACE大气化学模式对京津冀地区2015年12月重度雾霾过程进行了模拟和评估。京津冀地区能见度和PM_2.5模拟值与观测值的对比表明:该模式能较好地模拟京津冀地区能见度和PM_2.5的逐日变化情况,但模式存在对伴随着重污染发生的低能见度模拟偏高的问题。以12月5~10日的重度雾霾过程为重点,针对地面风速、边界层高度、相对湿度、PM_2.5及其对能见度的影响进行了详细分析,研究结果表明:污染过程中大部分地区过程平均风速低于2 m s-1,边界层平均高度低于600 m,相对湿度较高。模式低能见度模拟偏高可能因为:（1）模式模拟重雾霾时段的PM_2.5极大值浓度偏低。（2）模拟相对湿度存在系统性偏低的误差,这一误差对能见度的影响表现为两方面,一是相对湿度会通过影响可溶性气溶胶的吸湿增长过程影响气溶胶质量浓度,导致气溶胶消光系数的计算偏低;二是目前模式中采用的能见度的参数化公式考虑了相对湿度对气溶胶吸湿增长的影响,没有考虑雾滴的直接消光作用。     

Weekday AOD smaller than weekend AOD in eastern China on the basis of the MODIS AOD product

Theoretical and Applied Climatology - A weekly cycle of surface particulate matter (PM) characterized by smaller values during weekends and larger values during weekdays was reported in eastern...     

Haze trends over the capital cities of 31 provinces in China, 1981–2005

This paper presents the patterns and trends of haze over 31 provincial capitals in China between 1980 and 2005. The haze measurements were based on human visual range observations at 31 synoptic meteorological stations operated by the China Meteorological Administration (CMA). The high haze regions were found in largely populated cities such as Chongqing, Beijing, and Shenyang, while the low haze regions were located in the cities with small populations such as Lhasa, Kunming, and Guiyang in southwestern China and Haikou in southern China. The haziness of the 12 cities shows a significantly (95%) decreasing trend, while that of the 13 cities shows a significantly increasing trend over the 25-year study period. The increases are evident in the eastern and southwestern cities in China. It has also been found that there is a decreasing haze trend in winter but an increasing trend in summer for many cities. Nonetheless, the causality for the reduction of aerosol emissions has not been established. This report is the first survey and preliminary analysis done on haze patterns and trends from 1980 to 2005 over the capital cities of 31 provinces in Mainland China.     

山西省2001年干旱影响分析

对山西省2001年春夏连旱，河川径流锐减，水资源短缺以及干旱给农业生产造成的影响进行了分析，同时围绕抗旱减灾，搞好水利工程，提出了一些看法和建议。     

中国大陆黑碳气溶胶排放清单

The detailed high-resolution emission inventory of black carbon (BC) from China in the year 2000 was calculated. The latest fuel consumption data including fossil and biomass fuels, and socio-economic statistics used were obtained from government agencies, mostly at the county level, and some new emission factors (Efs) from local measurements were also used. National and regional summaries of emissions were presented at 0.2°×0.2°resolution. Total BC emission was 1499.4 Gg in 2000, mainly due to the burning of coal and biomass. The BC emission estimated here is higher than those in previous studies, mainly because the emissions from coal burning by rural industries and residences were previously underestimated. More BC aerosols were emitted from eastern China than western China. A strong seasonal dependence was observed for BC emissions, with peaks in January and December and low emissions in July and August; and this seasonality is mainly due to patterns in residential heating and the open burning of crop residues.     

大气边界层高度确定及应用研究进展

大气边界层高度是表征边界层特征的重要参量,影响边界层内水热、物质、能量的垂直分布,也是数值模拟、环境评估中的重要参数。从湍流运动、热力作用、动力作用以及物质分布等多视角总结了大气边界层高度的定义及确定方法,回顾了采用直接观测手段和遥感手段确定大气边界层高度的不同方法,对比了大气边界层高度不同获取手段的优缺点,梳理了大气边界层高度参数化方案,探讨了大气边界层高度确定中存在的问题,并提出未来相关研究和应用可能突破方向。      

国际沙尘暴研究计划进展显著

该项目已经获得世界气象组织（WMO）正式批准，由中国气象科学研究院张小曳研究员作为科学指导委员会联合主席负责牵头组织，执行期为10年。该项目执行2年以来已经在国际沙尘暴预报、预警和科学研究领域取得诸多进展。2006年10月31日至11月1日在上海召开了国际沙尘暴计划科学指导委员会第2次会议。来自中国、美国、德国、加拿大、韩国、西班牙、蒙古、埃及8个国家的20多位科学指导委员会委员以及会议特邀专家出席了会议。     

Approximations of the scattering phase functions of particles

Based on anomalous diffraction theory and the modified Rayleigh-Debye approximation, a physically realistic model in bridging form is described to approximate the scattering phase function of particles. When compared with the exact method, the bridging technique reported here provides a reasonable approximation to the Mie results over a broader range of angles and size parameters, and it demonstrates the advantage of being computationally economic. In addition, the new phase function model can be essentially extended to other shapes and conveniently used in more complicated scattering and emission problems related to the solutions of the radiative transfer equations.     

CE318型太阳光度计标定方法初探

初步探索了CE318型太阳光度计的室内和野外标定方法, 并对两种方法的标定结果进行对比。基于积分球辐射源的辐亮度标定方法, 对CE318型太阳光度计不同波段天空散射辐射通道进行标定实验; 分别采用Langley标定法和标准仪器相对标定方法, 对CE318型太阳光度计的不同波段太阳直接辐射通道进行了标定实验。实验结果显示:天空散射辐射通道的标定结果在670 nm, 870 nm和1020 nm波段与仪器出厂时给定的标定结果偏差不超过6%, 而440 nm波段处得到的标定结果要高于出厂时给定的结果, 偏离幅度约18.9%。太阳直接辐射各通道的标定结果普遍大于出厂时给定的结果, 说明滤光片老化较为严重, 需要进行更换, 以保证观测精度。由于标准仪器相对标定方法对太阳直接辐射通道的标定结果明显优于Langley法, 因此利用标准仪器相对标定方法对中国气象局太阳光度计站网仪器进行定期标定更能够保证仪器观测数据的准确性。