A5011361785- Atmospheric chemistry and aerosols
- Air Quality and Health Impacts
- Air Quality Monitoring and Forecasting
- Atmospheric Ozone and Climate
- Atmospheric aerosols and clouds
- COVID-19 impact on air quality
- Vehicle emissions and performance
- Atmospheric and Environmental Gas Dynamics
- Meteorological Phenomena and Simulations
- Advanced Chemical Sensor Technologies
- Geomagnetism and Paleomagnetism Studies
- Magnetic and Electromagnetic Effects
- Catalytic Processes in Materials Science
- Geology and Paleoclimatology Research
- Wind and Air Flow Studies
- Energy, Environment, Economic Growth
- Methane Hydrates and Related Phenomena
- Impact of Light on Environment and Health
- Spectroscopy and Chemometric Analyses
- Climate change and permafrost
- Fluid Dynamics and Turbulent Flows
- Health, Environment, Cognitive Aging
- Water Quality Monitoring and Analysis
- Safety and Risk Management
- Cryospheric studies and observations
Paul Scherrer Institute
2020-2024
Institut national de l'environnement industriel et des risques
2023
Vifor Pharma (Switzerland)
2023
Indian Institute of Technology Kanpur
2017-2018
Vikram Sarabhai Space Centre
2010
Delhi, the capital of India, suffers from heavy local emissions as well regional transport air pollutants, resulting in severe aerosol loadings. To determine sources these we have quantified mass concentrations 26 elements airborne particles, measured by an online X-ray fluorescence spectrometer with time resolution between 30 min and 1 h. Measurements PM10 PM2.5 (particulate matter <10 μm < 2.5 μm) were conducted during two consecutive winters (2018 2019) Delhi. On average, Al to Pb made up...
Abstract Simultaneous measurements of volatile organic compounds (VOCs) using two PTR‐TOF‐MS instruments were conducted at urban and suburban sites New Delhi during the winter 2018. The time series VOC mixing ratios show substantial variations mainly influenced by local emissions meteorological conditions. Mixing methanol (∼28 ppbv), acetaldehyde (7.7 acetone (10.6 isoprene (2.8 ppbv) monoterpenes (0.84 site higher than those site, while levels aromatic VOCs almost similar. strong nighttime...
Abstract. In recent years, the Indian capital city of Delhi has been impacted by very high levels air pollution, especially during winter. Comprehensive knowledge composition and sources organic aerosol (OA), which constitutes a substantial fraction total particulate mass (PM) in Delhi, is central to formulating effective public health policies. Previous source apportionment studies identified key primary OA (POA) showed that secondary (SOA) played major role but were unable resolve specific...
The oxidative potential (OP) of particulate matter (PM) is a major driver PM-associated health effects. In India, the emission sources defining PM-OP, and their local/regional nature, are yet to be established. Here, address this gap we determine geographical origin, PM, its OP at five Indo-Gangetic Plain sites inside outside Delhi. Our findings reveal that although uniformly high PM concentrations recorded across entire region, local formation processes dominate pollution. Specifically,...
The oxidative potential (OP) of ambient particulate matter (PM) is a metric commonly used to link the aerosol exposure its adverse health effects. In this study, we report first-ever real-time measurements PM2.5 OP based on dithiothreitol (DTT) assay in Delhi, during late winter season (February 2019). chemical composition PM was also measured using various collocated online instruments identify components driving OP. hourly averaged entire campaign ranged from 0.49 3.60 nmol min–1 m–3, with...
Abstract. Characteristics and sources of volatile organic compounds (VOCs) were investigated with highly time-resolved simultaneous measurements by two proton-transfer-reaction time-of-flight mass spectrometers (PTR-ToF-MS) at an urban a suburban site in New Delhi, India, from January to March 2018. During the measurement period, high mixing ratios VOCs trace gases observed, nocturnal strong day–night variations. The positive matrix factorization (PMF) receptor model was applied separately...
Abstract. In recent years, intense haze events in megacities such as Beijing have received significant attention. Although secondary organic aerosol (SOA) has been identified a major contributor to events, knowledge of its sources and formation mechanisms remains uncertain. We investigate this question through the first field deployment extractive electrospray ionisation time-of-flight mass spectrometer (EESI-TOF) Beijing, together with an Aerodyne long-time-of-flight (L-TOF AMS)....
Abstract. We present highly time-resolved (30 to 120 min) measurements of size-fractionated (PM10 and PM2.5) elements in two cities Asia (Delhi Beijing) Europe (Krakow London). For most elements, the mean concentrations PM10 PM2.5 are higher Asian (up 24 28 times, respectively) than Krakow often Delhi Beijing. Among European cities, shows elemental 20 27 London. Hourly maximum Pb Zn reach up 1 µg m−3 Delhi, substantially at other sites. The enrichment factor an element together with size...
Aromatic hydrocarbons (ArHCs) and oxygenated aromatic (ArHC–OHs) are emitted from a variety of anthropogenic activities important precursors secondary organic aerosol (SOA) in urban areas. Here, we analyzed compared the composition SOA formed oxidation mixture VOCs by OH NO3 radicals. The VOC was composed toluene (C7H8), p-xylene + ethylbenzene (C8H10), 1,3,5-trimethylbenzene (C9H12), phenol (C6H6O), cresol (C7H8O), 2,6-dimethylphenol (C8H10O), 2,4,6-trimethylphenol (C9H12O) proportion where...
Aerosol number size distributions, along with thermodynamic and dynamic parameters, were measured from the surface to 600 m using a tethered balloon, Helikite. The field measurements carried out at Villum Research Station in Northern Greenland 23rd March 2nd May 2024. During transition winter spring, three types of atmospheric regimes identified: (1) background regime profile uniformly distributed aerosols, represented by low particle concentrations as well distributions vertical axis...
Atmospheric volatile organic compounds (VOCs) influence air quality and climate by participating in chemical reactions that convert them into low-volatility species. These species can contribute to the formation of new particles or condense onto existing aerosol mass. In presence NOx, VOC also lead production ground-level ozone. Despite their significance, measurements VOCs remote regions such as Arctic remain scarce, leaving critical gaps our understanding sources, sinks, chemistry these...
Aerosol-Cloud Interactions (ACI) play an important role in the hydrological cycle and are strong modulators of cloud radiative forcing climate. Nevertheless, they remain poorly understood constrained despite decades research, because many processes feedbacks highly uncertain challenging to describe regional global climate models. Even less is natural aerosol ACI a post-fossil future, where anthropogenic emissions vastly reduced but emerging &#8220;natural&#8221; sources modulated by...
Abstract. Characteristics and sources of volatile organic compounds (VOCs) were investigated with highly time-resolved simultaneous measurements by two proton-transfer-reaction time-of-flight mass spectrometers (PTR-ToF-MS) at an urban a suburban site in New Delhi, India from January to March 2018. During the measurement period, high mixing ratios VOCs trace gases observed, nocturnal strong day-night variations. The positive matrix factorization (PMF) receptor model was applied separately...
Abstract. Atmospheric pollution in urban regions is highly influenced by oxidants due to their important role the formation of secondary organic aerosol (SOA) and smog. These include nitrate radical (NO3), which typically considered a nighttime oxidant, chlorine (Cl), an extremely potent oxidant that can be released morning chloride-rich environments as result nocturnal build-up nitryl chloride (ClNO2). Chloride makes up higher percentage particulate matter Delhi than has been observed...
Abstract. In recent years, intense haze events in megacities such as Beijing have received significant study. Although secondary organic aerosol (SOA) has been identified a major contributor to events, knowledge of its sources and formation mechanisms remains uncertain. We investigate this question through the first field deployment extractive electrospray ionisation time-of-flight mass spectrometer (EESI-TOF-MS) Beijing, together with an Aerodyne long (L-TOF AMS). Measurements were...
Abstract. Atmospheric pollution in urban regions is highly influenced by oxidants due to their important role the formation of secondary organic aerosol (SOA) and smog. These include nitrate radical (NO3), which typically considered a night-time oxidant, chlorine (Cl), an extremely potent oxidant that can be released morning chloride-rich environments as result nocturnal build-up nitryl chloride (ClNO2). Chloride makes up higher percentage particulate matter Delhi than has been observed...