1. Invited talk titled “Sensor-based Streaming Analytics and Near-Real Time source Apportionment of Air Pollution” in Online International Conference on Aerosol Air Quality, Climate Change and Impact on Water Resources and Livelihoods in the Greater Himalayas, webinar hosted by ARIES Nainital (September 14, 2020).
  2. Panel discussion on “Air Pollution Data and Science” in Confederation of Indian Industry (CII) 15th Sustainability Summit (September 10, 2020).
  3. Invited talk titled, “Tracking Sources of Air Pollution in Real-Time” CERCA Webinar on the occasion of International Day of Clean Air for Blue Skies (September 7, 2020).
  4. Invited talk titled, “Unraveling Tiny Monstrous Organic Aerosols: Key to Achieve Blue Skies and Improved Human Health” in ACS Science Talks: Virtual Lecture Series (August 28, 2020).
  5. Invited talk tilted, “Importance and need for reliable and robust data for improving air quality” in India Clean Air Summit hosted by Center for Study of Science, Technology and Policy, CSTEP (August 25, 2020).
  6. Invited talk titled “Air Quality in New Delhi during the COVID-19 induced lockdown” in The Impacts of COVID-19 Lockdowns on India’s Air Quality, webinar hosted by World Bank and NCAP Knowledge Network, (July 28, 2020).
  7. Invited talk titled “Published results of Air Quality Experiment in Delhi”, meeting organized by Global Strategic Communications Council (GSCC), (July 23, 2020).
  8. Invited lecture titled “Implementation of National Clean Air Programme” in National Clean Air Program, Princeton University’s first annual conference on Global India, Princeton University (USA,
    March 27, 2020).
  9. Invited talk titled, “Combination of dynamic real-time source apportionment and low-cost sensors for air pollution reduction” in Earth Science Lecture Series, IIT Gandhinagar (Ahmedabad, January
    6, 2020).
  10. Invited talk titled, “Development and adoption of low-cost sensor-based nationwide air quality monitoring networks” in Workshop Brainstorming Session on Low-cost Sensor based Real-time Air
    Quality Monitoring with advances in IoT, Machine Learning and AI, Prithvi Bhavan, India Habitat Centre (Delhi, January 2, 2020).
  11. Invited talk titled, “Air Quality Improvement through Dynamic Source Apportionment” in 4 th Indian International Conference on Air Quality Management, IIT Bombay (Mumbai, December 19, 2019).
  12. Invited talk titled, “Dynamic Source Apportionment for Air Quality Improvement” in India CEO Forum for Clean Air at India Habitat Centre (New Delhi, December 17, 2019).
  13. Invited speaker in the panel discussion on “Alignment of CSR with SDGs with sector focus on Air Pollution” in CII National CSR Summit, Hyatt Regency (New Delhi, December 12, 2019).
  14. Invited talk titled, “Role of sensor technology in policymaking”, stakeholder consultation workshop on ‘Low-Cost Air Quality Monitoring Sensors in India: Applications and Way Forward’ organized by Shakti Sustainable Energy Foundation at Casuarina Hall, India Habitat Centre (New Delhi, August 7, 2019).
  15. Keynote talk titled, “New initiatives to measure and understand air pollution in Northern India: Hybrid approach based on high end mass spectrometer and low cost sensors, in6th SEE event on Air Pollution organized by IIT Kanpur and the Alumni Association of IITK (IIT Kanpur, January 10, 2019).
  16. Keynote talk titled, “New initiatives to measure and understand air pollution in Northern India: Hybrid approach based on high end mass spectrometer and low cost sensors” in 3-Days International Conference on ‘Advanced Technologies for Industrial Pollution Control, (ATIPC – 2018)’ at Indian Institute of Engineering Science and Technology (IIEST), Shibpur (Kolkata, December 18, 2018).
  17. Invited talk titled, A collaborative project SATVAM to understand air quality in India and new learnings of pollution sources in Gangetic Plains” in Evening Networking Reception with Duke faculty and conference delegates at Desire hotel Le Meridien (Delhi, December 13, 2018).
  18. Invited talk titled, “Aerosol-cloud-rainfall interactions over India, in Indian Aerosol Science and Technology Association (IASTA), conference at IIT Delhi (Delhi, November 26, 2018).
  19. Invited talk titled, “Urban and aerosol-induced short to long term changes in rainfall in Indian summer monsoon region and associated implications to climate” in 63rd Sir Albert Charles Seward Memorial Lecture, Birbal Sahni Institute of Palaeosciences (Lucknow, November 14, 2018).
  20. Invited talk titled, “Current state of play of air pollution-challenges and gaps for cities of Lucknow and Kanpur” in National Workshop Scoping Study on Clean Air at Hotel Claridges (New Delhi, June 15, 2018).
  21. Invited talk titled, “Delhi air quality experiment” in Stakeholder Consultation Workshop on NCAP organized by Ministry of Environment, Forest and Climate Change alongwith CPCB, World Bank and TERI at Ganga Auditorium, Vayu Wing, Indira Paryavaran Bhawan, Jor Bagh in (Delhi, April 18, 2018).
  22. Invited talk titled, Aerosol-surface forcing-Rainfall associations over Gangetic Plains, in “National Conference on Recent Advances in Environmental Sciences, (NCRAES-2018)” at School of Environmental Science, Jawaharlal Nehru University in (Delhi, March 22, 2018).
  23. Invited talk titled, Problem, measurement and sources- The air quality conundrum in DainikJagran Clean Air Conclave at Hotel Hilton Gargen In (Lucknow, February 17, 2018).
  24. Invited talk titled, Sensor based technologies for air pollution monitoring in Technologies for management and abatement of air pollution at Ministry of Environment, Forest and Climate
    Change (Delhi, February 13, 2018).
  25. Popular Lecture titled, The state of air pollution in Indo-Gangetic Plains and possible solutions, Dayalbagh Educational Institute, (Agra, December 22, 2017).
  26. Invited talk titled, Cities Infrastructure & Sustainability cities in a training program as part of joint SRU-Clarkson-ICMR initiative to build capacities in the areas of Air Quality, Climate and Health, at the SRU-ICMR Center for Advanced Research, SRU (Chennai, December 19-20, 2017).
  27. Panelist, Washington University St Louis Forum on Energy, Environment and Agriculture at Leela Palace Hotel (New Delhi, December 15-16, 2017).
  28. Invited talk titled, Aerosol-cloud-surface-radiation-rainfall-climate interactions over Indian Monsoon region, in “5th Rajasthan Science Congress” at Amity University, (Jaipur, October 13, 2017).
  29. Invited talk titled, Aerosol-surface forcing-Rainfall associations over Gangetic Plains, in National Workshop on “Urban Climate: Science, impacts and Adaptation” at Indian Institute of Technology-Bubaneswar (Bhubaneswar, September 21-22, 2017).
  30. Invited talk titled, Aerosol impact on weather to climate scales over IG Basin: Results from observational and modeling based analysis, in International conference on Understanding, Predicting and projecting the Climate change over Asian Region (UPCAR), at S.V. University (Tirupati, June 26-28, 2017)
  31. Invited talk titled, Chemical properties of geoengineering aerosols, in National Roundtable Discussion on Geoengineering and India: Science and Policy, at Indian Institute of Technology-Delhi (New Delhi, June 23, 2017).
  32. Keynote talk titled, ‘Hygroscopicity-CCN-clouds and rainfall associations over Ganga Plains’ at Wadia Institute of Himalayan Geology (Dehradun, May 18, 2017).
  33. Lead talk titled, ‘Direct and indirect effects of aerosols on radiative forcing and rainfall over Indo-Gangetic plains in International Conference on Aerosol Climate Change Connection (AC3) at Bose
    Institute (Darjeeling, April 25, 2017).
  34. Invited talk titled, ‘Scale and adequacy of monitoring needed in Indian cities’, in Global Strategic Communications Council (GSCC) Air Quality Workshop at Juniper Hall, IHC (New Delhi, April 12, 2017).
  35. Invited talk titled, ‘Aerosol direct and indirect effects in Gangetic plains’, in Brainstorming Meeting on Climate change research in India: Progress, challenges, opportunities and way forward, BHU
    (Varanasi, February 23, 2017).
  36. Invited talk titled, ‘Aerosol-Cloud-Surface-Radiation-Rainfall interactions over Indo-Gangetic Plains (IGP)’ in Indo-Dutch International conference ‘Climate and Atmospheric Sciences & Applications’ at Indian Institute of Technology-Delhi(New Delhi, February 21, 2017).
  37. Invited talk titled ‘Aerosol pollution: Implications to health, economy and climate’, INSPIRE-2017 Programme at Amity University (Lucknow, February 15, 2017).
  38. Lead talk titled ‘Air pollution sources in India: Measurement and latest findings’ Workshop on Air Quality at Hotel Westinn (Varanasi, December 12, 2016).
  39. Invited talk titled ‘Coupling of aerosol-land-cloud-rainfall system over Gangetic Plains: Observations and modeling analysis” Indo-UK Water Center (IUKWC) workshop at IITM (Pune, November 30, 2016).
  40. Invited talk titled ‘Variability in aerosol properties, their direct and indirect effect over Gangetic Plains’ Seminar at Centre for Ecology and Hydrology, UK (Wallingford, September 17, 2016).
  41. Invited talk titled ‘Air pollution sources in India: measurements and latest findings, Air Quality in Indian Cities at Taj Hotel (Lucknow, May 25-26, 2016).
  42. Invited talk titled ‘Organic aerosols (OA) in Gangetic Basin: Composition, Chemistry, CCN, Radiative and health effects’, Workshop on biosphere-atmosphere interactions and impacts on climate and air quality and the iLEAPS SSC meeting in IISER, Mohali (Chandigarh, March 21, 2016).
  43. Invited talk titled ‘Air pollution implications to health, climate, agriculture and economy’, Surya Roundtable Meeting on Climate Credit Pilot Project at India International Centre (New Delhi, March
    15, 2016).
  44. Invited talk titled ‘Aerosol’s impact on health and climate of Gangetic Plain’, INSPIRE 2016 Programme at Amity University (Gwalior, January 21, 2016).
  45. Invited talk titled ‘Smoke, Dust, and Haze: Implications to health, climate, and economy’, INAE Kanpur Chapter Seminar at Indian Institute of Technology-Kanpur (Kanpur, January 20, 2016).
  46. Invited talk titled ‘Discoloration of the TajMahal, Adverse Health effects and Climate Forcing due to Municipal Solid Waste and Dung Cake Burni’, Workshop on Developing Smart, Healthy and Sustainable Cities: Learnings from US, China and India at The Lalit Hotel (New Delhi, January 11, 2016).
  47. Invited talk titled ‘Hydro climate of gangetic system’ India-UK Workshop on Future Ganga: Science Needs for Water Security at Tal Mahel Hotel (New Delhi, December 3, 2015).
  48. Invited talk titled ‘The human-ganga biome interactions: Unravelling the influences of environmental pollutants on humans and a living river’ Workshop on Non Putreying Properties of Ganga Water at All India Institute of Medical Sciences (New Delhi, November 16, 2015).
  49. Invited talk titled ‘Dust, other ions can cause health problem’ Birbal Sahni Institute of Palaeobotany (Lucknow, August 24, 2015).
  50. Contributed talk ‘Particulate pollution and daily surface rainfall: Observational study over Indian summer monsoon region’ AGU Chapman conference on Evolution of the Asian Monsoon and its
    Impact on Landscape, Environment and Society: Using the Past as the Key to the Future, (The Chinese University of Hongkong, June 14-18, 2015).
  51. Contributed talk ‘Optical properties of brown carbon and its impact on earth’s radiative budget’ Workshop for Developing Priority Themes and Activities for IGAC Monsoon Asia and Oceania Networking Group (IGAC-MANGO), Asian Institute of Technology (Bangkok, Thailand, June 11- 12, 2015).
  52. Invited participant ‘Science-Policy Dialogue’, organized by the Scientific Advisory Panel of the Climate and Clean Air Coalition (CCAC) to Reduce Short-Lived Climate Pollutants (SLCP), Headquarters of World Meteorological Organization (Geneva, May 20-21, 2015).
  53. Contributed talk titled ‘Size resolved fog water chemistry and its atmospheric implications’ European Geosciences Union (Vienna, Austria, April 12-17, 2015).
  54. Invited talk titled ‘Aerosol’s impacts on climate, health, agriculture and monuments’, Chandigarh Science Congress, Punjab University (Chandigarh, February 25, 2015).
  55. Invited talk titled ‘Aerosol-cloud-rainfall associations over India’, International Workshop on Climate Change, Ansal University (Gurgaon, January 12, 2015).
  56. Invited talk titled ‘Atmospheric observations and laboratory studies of carbonaceous aerosols’, Indian Aerosol Science and Technology Association, Biennial Conference, (Banaras Hindu University, Varanasi, November 12, 2014).
  57. Invited talk titled ‘Brown carbon absorption and its Impact on atmospheric radiative forcing’, ABC (Atmospheric Brown Clouds) – SLCP (Short-Lived Climate Pollutants) symposium in Tokyo, (Japan, July 21-23, 2014).
  58. Theme Leader and organiser, Clean Air, Indo-German Frontiers of Engineering,Clean Potsdam, (Germany, June 23-25, 2014).
  59. Invited talk ‘1 st Workshop on Climate Science and Policy Workshop, Indian Institute of Technology-Bombay, (Mumbai, March 6-7, 2014).
  60. Invited talk ‘Scientific basis for knowledge to action’, Policy Conclave on Reducing Vehicular Emissions to Improve Air Quality at Taj Hotel, (New Delhi, February 4, 2014).
  61. Invited talk titled ‘Observations and monitoring needs’, Policy conclave on reducing vehicular emissions to improve air quality at Taj Hotel, (New Delhi, February 4, 2014).
  62. Invited Interdisciplinary Lecture titled ‘Atmospheric aerosol measurements: India perspective’, National Space Science Symposium, Dibrugarh University, (Assam, February 1, 2014).
  63. Plenary lecture on Long-term field observations and laboratory studies of atmospheric aerosols from Kanpur, Indo-Gangetic Basin, in 8th Asian Aerosol Conference, Australian Technology Park,
    Sydney, (Australia, December 3, 2013).
  64. Invited talk on ‘Aerosol measurements: India perspective’, India-California Air-Pollution Mitigation Program: Initiative for Mitigating Air Pollution from the Transportation Sector, Scripps Institute of
    Oceanography and The Energy and Resource Institute, Oakland, CA, (USA, October 22, 2013).
  65. Invited talk on ‘Role of chemical composition on CCN activity and Evaluation of microphysics parameterizations in WRF against CAIPEEX profiles’ In CAIPEX Science meeting, Indian Institute of Tropical Meteorology, (Pune, October 17, 2013).
  66. Invited talk titled ‘Long-Term field observations and laboratory studies of atmospheric aerosols from Kanpur, Indo-Gangetic Basin’, Center for Climate Change, Indian Institute of Technology-Bombay (Mumbai, October 9, 2013).
  67. Invited talk on ‘Evaluation of WRF-chem simulations during an extreme rainfall event over Indo-Gangetic Plain’, in Monsoon Research and Prediction, Indo French Centre for Promotion of Advance Research in coordination with MoES, (New Delhi, October 5, 2013).
  68. Invited talk in a ‘CAIPEEX-Phase III – IGP campaign meeting’ organized by Indian Institute of Tropical Meteorology, (Pune, August 30, 2013).
  69. Invited talk in a workshop “Mars Orbiter Mission” organized by Physical Research Laboratory, (Ahmedabad, July 26-27, 2013).
  70. Invited talk in a workshop ‘First Annual Regional Atmospheric Science (FARAS)’ organized by International Center for Integrated Mountain Development (ICIMOD), (Kathmandu, June 13-14, 2013).
  71. Invited lecture in Naraina Group of Institution, (Kanpur, June 11, 2013).
  72. GCR Generated Aerosol Electrification and the Effects on Cloud Microphysics in Earth and Planetary Atmospheres, Laboratoire de Physique etChimie de l’Environnement et de l’Espace,
    CNRS, Orleans, (France, July 4, 2012).
  73. Invited talk titled ‘Climate impacts of aerosol over Ganga Basin’ in a Alpine Summer School on Climate, Aerosols and the Cryosphere jointly organized by CNRS, France, ISAC-CNR, Italy and NSF, USA at Valsavarenche, Valle d’Aosta (Italy, June 27, 2012).
  74. Invited talk in a workshop organised by International Center for Integrated Mountain Development (ICIMOD), Kathmandu, (Nepal, April 2-3, 2012).
  75. Invited talk titled ‘Climate impacts of aerosols’ in a conference jointly organized by Department of HSS, IITK and Liberty Institute, Delhi on ‘Climate Change: Science and Society’, (IITK March 30-31, 2012).
  76. Invited lecture in national seminar on Interdisciplinary application of weather and climate-Computational Perspective, C-DAC, (Pune, January 25, 2012).
  77. Invited talk in US – India Workshop on Air Quality and Climate in Administrative Staff College of India, (Hyderabad, Sept. 12-14, 2011).
  78. Lead Speaker in Indo-German Frontier of Engineering, (Khandala, June 2011).
  79. Invited talk at Bhabha Atomic Research Center, (Mumbai, June 09, 2011).
  80. Invited talk, QIP Course, Indian Institute of Technology Delhi (Delhi, May 2011).
  81. Invited talk in Brain Storming Session on Technology Vision 2035, IT-BHU, (Varanasi, May 2011).
  82. Invited lecture in Brain Storming Session on Mars, Physical Research Laboratory, (Ahmedabad, March 2011).
  83. Invited Lecture, Colloquium, National Physical Laboratory, (New Delhi, March 2011).
  84. Invited talk, National Atmospheric Research Laboratory, Department of Space, (Gadanki, February 2011).
  85. Invited lecture in local chapter of Institution of Engineers, Harcourt Butler Technical University (Kanpur, 2010).
  86. Invited talk, Geophysical Fluid Dynamical Laboratory, Princeton University, (US, June 2010).
  87. Invited lecture, Planetary Exploration Program of ISRO, Physical Research Laboratory, (Ahmedabad, May 2009).
  88. Invited Colloquium, Physical Research Laboratory, (Ahmedabad, May 2009).
  89. Lead Speaker, Third Indo-US Frontier of Science (Agra, March 1-4, 2009).
  90. Invited Lecture at Aryabhatta Research Institute of Observational Sciences (ARIES), (Nainital, October 2008).
  91. Lecture at Air Force Administrative College, (Coimbatore, December 2007).
  92. Five lectures delivered at the Winter School on Modeling of Planetary Atmospheres organised by Physical Research Laboratory, (Ahmedabad, January 2007).
  93. Invited seminar at Center for Climate System Modeling, The University of Tokyo, (Japan, July 2006).
  94. Invited talk in Department of Chemical Engineering, Institute of Technology, (Banaras Hindu University, Varanasi, February 2006).
  95. Invited talk in workshop on Nanoparticle Aerosol Science and Technology (NAST): Emerging Trends and Priorities (IIT Mumbai, December 2005).
  96. Invited lecture at Center for Atmospheric and Oceanic Sciences, IISc, (Bangalore, September 2005).
  97. Five invited lectures in the 4th PG course on Space and Atmospheric Science of CSSTEAP (Center for Space and Technology Education in Asia and Pacific), (Physical Research Laboratory, Ahmedabad, July 2005).
  98. Invited seminar given at Aeronomy Laboratory National Oceanographic and Atmospheric Administration, (Boulder, US, June 2004).
  99. Academic Staff College, Banaras Hindu University(Varanasi, March 2004).
  100. Invited lecture in local chapter of Institution of Engineers, Harcourt Butler Technical University (Kanpur, January 2004).