Physical and optical characteristics of atmospheric aerosols during ICARB at Manora Peak, Nainital: A sparsely inhabited, high-altitude location in the Himalayas

Journal of Earth system science

U C Dumka1¹  K Pandey3²  P Hegde1¹  P Pant1¹  K Krishna Moorthy2³  Ram Sagar1¹ 

[1] Aryabhatta Research Institute of Observational Sciences, Nainital, India.$$;Department of Physics, DSB College, Nainital, India.$$;Space Physics Laboratory, Vikram Sarabhai Space Center, Thiruvananthapuram 695 002, India.$$

关键词: Atmospheric aerosols;    Himalayan aerosols;    size distribution;    BC aerosols.;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

Collocated measurements of the optical and physical properties of columnar and near-surface aerosols were carried out from Manora Peak, Nainital (a sparsely inhabited, high altitude location, ∼2km above mean sea level, in the Himalayas), during the Integrated Campaign for Aerosols, gases and Radiation Budget (ICARB) under the Geosphere Biosphere Programme of the Indian Space Research Organization (ISRO-GBP). Under this, observational data of spectral aerosol optical depths (AOD), mass concentration of aerosol black carbon (𝑀B), mass concentration (𝑀𝑇) and number concentration (𝑁𝑡) of composite (total) aerosols near the surface and meteorological parameters were collected during the period February 15 to April 30, 2006. Though very low (> 0.1 at 500 nm) AODs were observed during clear days, as much as a fourfold increase was seen on hazy days. The Ångström exponent (𝛼), deduced from the spectral AODs, revealed high values during clear days, while on hazy days 𝛼 was low; with an overall mean value of 0.69 ± 0.06 for the campaign period. BC mass concentration varied between 0.36 and 2.87 𝜇 g m−3 and contributed in the range 0.7 to 1.8% to the total aerosol mass. Total aerosol number concentration and BC mass concentration showed diurnal variation with a midnight and early morning minimum and a late afternoon maximum; a pattern quite opposite to that seen in low altitude stations. These are attributed to the dynamics of the atmospheric boundary layer.

【 授权许可】

Unknown