Aerosol optical properties of regional background atmosphere in Northeast China

Abstract Aerosol optical properties from 2005 to 2008 at the Longfengshan regional background station in Northeast China were measured and analyzed. The annual mean of aerosol optical depth (AOD) at 440 nm for the four years was about 0.27 ± 0.25, 0.39 ± 0.37, 0.35 ± 0.34, and 0.38 ± 0.38, respectively, and the corresponding annual mean for the Angstrom exponent between 440 nm and 870 nm was about 1.43 ± 0.48, 1.23 ± 0.37, 1.53 ± 0.47, and 1.55 ± 0.42. The average monthly AOD440nm showed similar seasonal variation with a maximum in spring and a minimum in autumn. The monthly means of AOD at 440, 675, 870 and 1020 nm increase from the January to March with the maxima about 0.77 ± 0.04, 0.65 ± 0.04, 0.58 ± 0.06, 0.57 ± 0.07, respectively and decrease from September to February with the minima about 0.32 ± 0.12, 0.22 ± 0.09, 0.15 ± 0.08, and 0.13 ± 0.07 in January. The monthly mean of Angstrom exponent shows a minimum in March (0.97 ± 0.52) and a maximum in September (1.66 ± 0.29). Both the AOD and Angstrom exponent presents single peak distributions of occurrence frequencies. The Longfenshan data showed high AODs (>1.00) both clustering in the fine mode growth wing and the coarse mode. Two typical cases under dust and haze conditions showed that the AOD under dusty day decreased from 2.20 to 1.20 and the Angstrom exponent increased from 0.10 to 1.00. On the contrast, the AOD under haze day remained relatively stable about 0.90 and the Angstrom exponent was around 1.40. The 3-day backtrajectory analysis at Longfengshan illustrated that the air-masses near ground on the dust day were from Bohai Sea and passed through Liaodong Peninsula and Northeast plain in China. But the air-masses on 500 m AGL were originated from western Mongolia and crossed Gobi deserts, Otindag Sand Land and Horqin Sand Land in Northeast China. The air-masses at Longfengshan near ground 500 m and 1000 m AGL on the haze days were from North China Region and passed through Northeast Heavy Industrial Base in Northeast China.

[1]  T. Eck,et al.  Accuracy assessments of aerosol optical properties retrieved from Aerosol Robotic Network (AERONET) Sun and sky radiance measurements , 2000 .

[2]  Junji Cao,et al.  Regional modeling of organic aerosols over China in summertime , 2008 .

[3]  L. Gomes,et al.  Aerosol optical properties and its radiative forcing over Yulin, China in 2001 and 2002 , 2009 .

[4]  Zhanqing Li,et al.  Significant reduction of surface solar irradiance induced by aerosols in a suburban region in northeastern China , 2007 .

[5]  Renjian Zhang,et al.  Characteristics of elemental composition of PM2.5 in the spring period at Tongyu in the semi-arid region of Northeast China , 2008 .

[6]  Ian G. McKendry,et al.  Characterization of soil dust aerosol in China and its transport and distribution during 2001 ACE-Asia: 2. Model simulation and validation , 2003 .

[7]  T. Eck,et al.  Comparison of Moderate Resolution Imaging Spectroradiometer (MODIS) and Aerosol Robotic Network (AERONET) remote-sensing retrievals of aerosol fine mode fraction over ocean , 2005 .

[8]  T. L. Wolfe,et al.  An assessment of the impact of pollution on global cloud albedo , 1984 .

[9]  Alexander Smirnov,et al.  Columnar aerosol optical properties at AERONET sites in central eastern Asia and aerosol transport to the tropical mid‐Pacific , 2005 .

[10]  J. Coakley,et al.  Climate Forcing by Anthropogenic Aerosols , 1992, Science.

[11]  Mao Jietai,et al.  Study on the Distribution and Variation Trends of Atmospheric Aerosol Optical Depth over the Yangtze River Delta in China , 2007 .

[12]  Yang Li,et al.  Horizontal visibility trends in China 1981–2005 , 2007 .

[13]  Dongfang Wang,et al.  Characterization of soil dust aerosol in China and its transport and distribution during 2001 ACE‐Asia: 1. Network observations , 2003 .

[14]  Chen Hongbin,et al.  Aerosol properties and their spatial and temporal variations over North China in spring 2001 , 2005 .

[15]  T. Eck,et al.  An emerging ground-based aerosol climatology: Aerosol optical depth from AERONET , 2001 .

[16]  F. Bréon,et al.  Aerosol Effect on Cloud Droplet Size Monitored from Satellite , 2002, Science.

[17]  Yasushi Fujiyoshi,et al.  Sky Radiometer Measurements of Aerosol Optical Properties over Sapporo, Japan , 2003 .

[18]  Xiangao Xia,et al.  Aerosol optical properties and their radiative effects in northern China , 2007 .

[19]  X. Y. Zhang,et al.  Analysis of 40 years of solar radiation data from China, 1961–2000 , 2005 .

[20]  Shi Guang-yu,et al.  Approximations of the Scattering Phase Functions of Particles , 2006 .

[21]  Li Yi,et al.  Chemical characteristics of precipitation at three Chinese regional background stations from 2006 to 2007 , 2010 .

[22]  Alexander Smirnov,et al.  Cloud-Screening and Quality Control Algorithms for the AERONET Database , 2000 .

[23]  T. Eck,et al.  Classification of aerosol properties derived from AERONET direct sun data , 2006 .

[24]  Zhang,et al.  Sources of Asian dust and role of climate change versus desertification in Asian dust emission , 2003 .

[25]  Yang Sun,et al.  [AOD and angstrom parameters of aerosols observed by the Chinese sun hazemeter network from August to December 2004]. , 2006, Huan jing ke xue= Huanjing kexue.

[26]  Jietai Mao,et al.  Characteristics of distribution and seasonal variation of aerosol optical depth in eastern China with MODIS products , 2003, Science Bulletin.

[27]  J. Hansen,et al.  Global warming in the twenty-first century: an alternative scenario. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[28]  O. Boucher,et al.  A satellite view of aerosols in the climate system , 2002, Nature.

[29]  P. Goloub,et al.  Instrument calibration and aerosol optical depth validation of the China Aerosol Remote Sensing Network , 2009 .

[30]  A. Smirnov,et al.  AERONET-a federated instrument network and data archive for aerosol Characterization , 1998 .