Measurements of particulate matter （PM）, i.e., PM10, PM2.5, and PM1, have been performed on the Can- ton Tower, a landmark building in Guangzhou, at heights of 121 and 454 m since November 2010, using a GRIMM 180 aerosol particle spectrometer （Germany）. Analyses of data from November 2010 to May 2013 showed that the annual average values of PM10, PM2.5, and PM 1 at the observation height of 121 m above the ground were 44.1, 38,2, and 34.9 μg/m3, respectively, and those at 454m above the ground were 35.7, 30,4, and 27.5 μg/m3, respectively. By considering the values of the secondary concentration limits given in the Ambient Air Quality Standards issued in 2012, it was observed that the annual average values of PM10 at the observation heights of 121 and 454 m, as well as those of PM2.5 at 454 m, reached those standards. Furthermore, the over-standard amplitude of the annual average value of PM2.5 at the observation height of 121 m was 9.1%. During the observation period, the maximum daily average val- ues of PM10, PM2.5, and PMI at the observation height of 121 m were 183.3, 144.8, and 123.8 μg/m3, respectively, and those at 454 m were 102.8, 92.7, and 86.4 μg/m3. The daily average values of PM10 at the observation height of 454 m were not above the standards. The over-standard frequencies of the daily average values of PM10 and PM2.5 at the observation height of 121 m were 0.6% and 10,7% respectively, and the over-standard amplitudes were 9.0% and 24.4%, respectively. The over-standard frequency of the daily average value of PM2.5 at the observation height of 454 m was 2.0%, and the over-standard amplitude was 10.4%. Accordingly, it can be stated that the air at the observation height 454 m above the ground did not reach the secondary limit of the new standards. The pollution was most serious during winter, and the air was relatively cleaner during summer, Overall, the vertical distributions of PM10, PM2.5, and PMI decreased with height. The lapse rates showed the following sequence： PMIO 〉 PM2.5 �
Xuejiao DengFei LiYuanhong LiJianyong LiHongzhi HuangXiantong Liu
Recent studies show that the rapid increases in urbanization and human activities in the PRD region have impor...
Xuejiao Deng1, Xuexi Tie2, Xiuji Zhou3, Dui Wu1, Liuju zhong4, Haobo Tan1, Fei Li1, Xueyan Bi1, Tao Deng11 Institute of Tropical and Marine Meteorology / Key Open Laboratory for Tropical Monsoon,China Meteorological Administration, Guangzhou, China 2 National Center for Atmospheric Research, Boulder, CO, USA 3 Chinese Academy of Meteorological Sciences, CMA, Beijing, China 4 Guangdong Environmental Monitoring Center, EPA, Guangzhou, China
The UV attenuation due to atmospheric aerosols in Guangzhou was quantitatively assessed using surface ultraviolet radiation (UV,295-385 nm) observation,sun photometer and radiation models.Observations showed that the annual average value of aerosol optical depth (AOD) was 1.19 in UV spectral region of 340 nm,the annual average occurrence frequency of aerosol optical depth AOD 340 nm >1.0 was 55%,and the annual average attenuation rate of surface UV direct radiation of 340 nm was 68%.It was proven in the observation of surface UV radiation and model evaluation that annual average attenuation of UV due to atmosphere was 75%,and that reached 72% in the dry season (October,November,December and January);while average attenuation of UV due to atmospheric aerosols reached 62% in the dry season.It was indicated that very significant UV attenuations due to atmospheric aerosols existed in Guangzhou urban agglomeration,and at least half of UV radiation was attenuated due to atmospheric aerosols.Such large-amplitude attenuation will have a significant impact on urban ecosystem and species chemical cycles,especially photochemical reaction processes.
DENG XueJiaoZHOU XiuJiTIE XueXiWU DuiLI FeiTAN HaoBoDENG Tao
