| Title: | Distribution of volatile organic compounds over Indian subcontinent during winter: WRF-chem simulation versus observations |
| Author(s): | Chutia L; Ojha N; Girach IA; Sahu LK; Alvarado LMA; Burrows JP; Pathak B; Bhuyan PK; |
| Address: | "Centre for Atmospheric Studies, Dibrugarh University, Dibrugarh, India. Space and Atmospheric Sciences Division, Physical Research Laboratory, Ahmedabad, India. Electronic address: ojha@prl.res.in. Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram, India. Space and Atmospheric Sciences Division, Physical Research Laboratory, Ahmedabad, India. Institute of Environmental Physics (IUP), University of Bremen, Bremen, Germany. Centre for Atmospheric Studies, Dibrugarh University, Dibrugarh, India; Department of Physics, Dibrugarh University, Dibrugarh, India" |
| DOI: | 10.1016/j.envpol.2019.05.097 |
| ISSN/ISBN: | 1873-6424 (Electronic) 0269-7491 (Linking) |
| Abstract: | "We investigate the distribution of volatile organic compounds (VOCs) over Indian subcontinent during a winter month of January 2011 combining the regional model WRF-Chem (Weather Research and Forecasting model coupled with Chemistry) with ground- and space-based observations and chemical reanalysis. WRF-Chem simulated VOCs are found to be comparable with ground-based observations over contrasting environments of the Indian subcontinent. WRF-Chem results reveal the elevated levels of VOCs (e. g. propane) over the Indo-Gangetic Plain (16?ª+ppbv), followed by the Northeast region (9.1?ª+ppbv) in comparison with other parts of the Indian subcontinent (1.3-8.2?ª+ppbv). Higher relative abundances of propane (27-31%) and ethane (13-17%) are simulated across the Indian subcontinent. WRF-Chem simulated formaldehyde and glyoxal show the western coast, Eastern India and the Indo-Gangetic Plain as the regional hotspots, in a qualitative agreement with the MACC (Monitoring Atmospheric Composition and Climate) reanalysis and satellite-based observations. Lower values of R(GF) (ratio of glyoxal to formaldehyde <0.04) suggest dominant influences of the anthropogenic emissions on the distribution of VOCs over Indian subcontinent, except the northeastern region where higher R(GF) ( approximately 0.06) indicates the role of biogenic emissions, in addition to anthropogenic emissions. Analysis of HCHO/NO(2) ratio shows a NO(x)-limited ozone production over India, with a NO(x)-to-VOC transition regime over central India and IGP. The study highlights a need to initiate in situ observations of VOCs over regional hotspots (Northeast, Central India, and the western coast) based on WRF-Chem results, where different satellite-based observations differ significantly" |
| Keywords: | Air Pollutants/*analysis Climate *Computer Simulation Environmental Monitoring/*methods Ethane/analysis Forecasting Formaldehyde/analysis Glyoxal/analysis India Ozone/*analysis Propane/analysis *Satellite Imagery Seasons Volatile Organic Compounds/*analys; |
| Notes: | "MedlineChutia, Lakhima Ojha, Narendra Girach, Imran A Sahu, Lokesh K Alvarado, Leonardo M A Burrows, John P Pathak, Binita Bhuyan, Pradip Kumar eng England 2019/06/04 Environ Pollut. 2019 Sep; 252(Pt A):256-269. doi: 10.1016/j.envpol.2019.05.097. Epub 2019 May 23" |
