Aerosol properties over an urban site in central East China derived from ground sun-photometer measurements     

Qi Liu  WeiDong Ding  Lei Xie  JinQiang Zhang  Jun Zhu  XiangAo Xia  DongYang Liu  RenMin Yuan  YunFei Fu 《中国科学:地球科学(英文版)》2017,60(2):297-314

Sun-photometer measurements at Hefei, an urban site located in central East China, were examined to investigate the variations of aerosol loading and optical properties. It is found that aerosol optical thickness (AOT) keeps higher in winter/spring and gets relatively lower in summer/autumn. The large AOT in winter is caused by anthropogenic sulfate/nitrate aerosols, while in spring dust particles elevate the background aerosol loading and the excessive fine-mode particles eventually lead to severe pollution. There is a dramatic decline of AOT during summer, with monthly averaged AOT reaching the maximum in June and soon the minimum in August. Meanwhile, aerosol size decreases consistently and single scattering albedo (SSA) reaches its minimum in July. During summertime large-sized particles play a key role to change the air from clean to mild-pollution situation, while the presence of massive small-sized particles makes the air being even more polluted. These complicated summer patterns are possibly related to the three key processes that are active in the high temperature/humidity environment concentrating on sulfate/nitrate aerosols, i.e., gas-to-particle transformation, hygroscopic growth, and wet scavenging. Regardless of season, the increase of SSA with increasing AOT occurs across the visible and near-infrared bands, suggesting the dominant negative/cooling effect with the elevated aerosol loading. The SSA spectra under varying AOT monotonically decrease with wavelength. The relatively large slope arises in summer, reinforcing the dominance of sulfate/nitrate aerosols that induce severe pollution in summer season around this city.  相似文献   

南京地区旅游景点天气预报技术研究          下载免费PDF全文

郑和文  朱双  范淦清 《气象》1997,23(11):55-56

从旅游景点的特点出发，用天气观测事实，结合天气学原理，研制了既科学又切合实际，具有可操作性的旅游景点天气预报的制作技术。将邻近气象站的天然预报作为景点天然预报  相似文献   

Statistical downscaling of reference evapotranspiration in Haihe River Basin: applicability assessment and application to future projection     

Wanqiu Xing  Quanxi Shao  John Taylor  Yimin Ding  Jianyu Fu 《水文科学杂志》2017,62(1):15-27

Future changes in reference evapotranspiration (ET₀) are of increasing importance in assessing the potential impacts on hydrology and water resources systems of more pronounced climate change. This study assesses the applicability of the Statistical Downscaling Model (SDSM) in projecting ET₀, and investigates the seasonal and spatial patterns of future ET₀ based on general circulation models (GCMs) across the Haihe River Basin. The results indicate that SDSM can downscale ET₀ well in term of different basin-averaged measures for the HadCM3 and CGCM3 GCMs. HadCM3 has a much superior capability in capturing inter-annual variability compared to CGCM3 and thus is chosen as the sole model to assess the changes in future ET₀. There are three homogeneous sub-regions of the Haihe River Basin: Northwest, Northeast and Southeast. Change points are detected at around 2050 and 2080 under the A2 and B2 scenarios, respectively. The Northwest is revealed to have a slight to strong increase in ET₀, while the Northeast and the Southeast tend to experience a pattern change from decrease to increase in ET₀.