Co-Convenor of biennial conference of Indian Aerosol Science and Technology Association, International Conference on 'Aerosol, Clouds and Indian Monsoon' held at IIT Kanpur, November 15th - 17th, 2004. Co-Convenor of Tiger-Z (Indo-NASA Joint Field Experiment) workshop held at IIT Delhi during January 7th - 8th, 2009. Organised IITK-Archaeological Survey of India Joint workshop on 'Study of Impacts of Atmospheric Haze on Taj Mahal Monument' under Indo-US Science and technology forum at IIT Kanpur during February 17th, 2012. Organized Theme Meeting on 'Aerosol Behavior Studies in a Nuclear Reactor under Severe Accident Conditions' held at IIT Kanpur, February 23rd - 25th, 2016. Organized DBT-RCUK Workshop: Biological solution to reducing industrial waste, environmental inefficiency and pollution in India, organized by Centre for Environmental Science & Engineering (CESE), IIT Kanpur, March 21-23, 2017. Organized DST-UKIERI workshop on “An Introduction to Earth Observation Techniques: Applications to the Land and Atmosphere” held at Indian Institute of Technology Kanpur from March 26-28, 2018.   Training / Summer School An invited DST Training School on 'Aerosol-Cloud Interaction' was held at IIT Kanpur from March 7th-15th, 2009. The school was attended by more than 25 students and scientists from various IITs, Universities and research laboratories such as NPL, SPL, IITM, IMD etc. The Summer School on 'Sustainable Cities' was held at IIT Kanpur organized by Centre for Environmental Science and Engineering from June 2nd - 27th , 2013 in collaboration with U. of Minnesota, Georgia Tech, NAE, Yale, NCAR and U. Colorado sponsored by USAID and NSF. The school was attended by more than 30 students and Scientists from IITs, collaborators Universities, ROI and ICLEI etc.