title: Influence of monsoons on atmospheric CO2 spatial variability and ground-based monitoring over India.
abstract: This study examines the role of Asian monsoons on transport and spatial variability of atmospheric CO2 over the Indian subcontinent, using transport modeling tools and available surface observations from two atmospheric CO2 monitoring sites Sinhagad (SNG) and Cape Rama (CRI) in the western part of peninsular India. The regional source contributions to these sites arise from the horizontal flow in conduits within the planetary boundary layer. Greater CO2 variability, greater than 15 ppm, is observed during winter, while it is reduced nearly by half during summer. The SNG air sampling site is more susceptible to narrow regional terrestrial fluxes transported from the Indo-Gangetic Plains in January, and to wider upwind marine source regions from the Arabian Sea in July. The Western Ghats mountains appear to play a role in the seasonal variability at SNG by trapping polluted air masses associated with weak monsoonal winds. A Lagrangian back-trajectory analysis further suggests that the horizontal extent of regional sensitivity increases from north to south over the Indian subcontinent in January (Boreal winter).
authors.affiliation: Centre for Climate Change Research, Indian Institute of Tropical Meteorology, Pune, India. Electronic address: yktiwari@tropmet.res.in.
authors.forename: Yogesh K
authors.initials: YK
authors.lastname: Tiwari
authors.affiliation: Centre for Climate Change Research, Indian Institute of Tropical Meteorology, Pune, India.
authors.forename: Ramesh K
authors.initials: RK
authors.lastname: Vellore
authors.affiliation: Centre for Climate Change Research, Indian Institute of Tropical Meteorology, Pune, India.
authors.forename: K
authors.initials: K
authors.lastname: Ravi Kumar
authors.affiliation: Centre for Australian Weather and Climate Research, CSIRO Marine and Atmospheric Research, Aspendale, Victoria, Australia.
authors.forename: Marcel
authors.initials: M
authors.lastname: van der Schoot
authors.affiliation: National Institute of Meteorological Research, Seoul, Korea.
authors.forename: Chun-Ho
authors.initials: CH
authors.lastname: Cho
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data; D001272:Atmosphere / Q000737:chemistry*; D002245:Carbon Dioxide / Q000032:analysis*; D004784:Environmental Monitoring; D007194:India; D012621:Seasons; D014919:Wind
chemical_list: D000393:Air Pollutants; D002245:Carbon Dioxide
keywords: Cape Rama; Carbon Tracker; FLEXPART; Sinhagad