A5066698734- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Atmospheric and Environmental Gas Dynamics
- Air Quality Monitoring and Forecasting
- Air Quality and Health Impacts
- Atmospheric aerosols and clouds
- Phase Change Materials Research
- Adsorption and Cooling Systems
- Solar Thermal and Photovoltaic Systems
- Water Quality Monitoring and Analysis
- Marine and coastal ecosystems
- Metal and Thin Film Mechanics
- Vehicle emissions and performance
- Spectroscopy and Laser Applications
- Building Energy and Comfort Optimization
- Meteorological Phenomena and Simulations
- Ocean Acidification Effects and Responses
- Maritime Transport Emissions and Efficiency
- Analytical Chemistry and Sensors
- Plant responses to elevated CO2
- Diamond and Carbon-based Materials Research
- Advanced ceramic materials synthesis
- Integrated Energy Systems Optimization
- Phosphorus and nutrient management
- Indoor Air Quality and Microbial Exposure
Universitat de Barcelona
2010-2025
Max Planck Institute for Chemistry
2015-2024
Michigan Disability Rights Coalition
2020
Institute of Environmental Assessment and Water Research
2018
Forschungszentrum Jülich
2016
University Medical Center of the Johannes Gutenberg University Mainz
2016
Johannes Gutenberg University Mainz
2000-2016
California Institute of Technology
2016
University of Aveiro
2014
Hospital Clínic de Barcelona
2014
Forest emissions of biogenic volatile organic compounds (BVOCs), such as isoprene and other terpenes, play a role in the production tropospheric ozone aerosols. In northern Michigan forest, direct measurement total OH reactivity, which is inverse lifetime, was significantly greater than expected. The difference between measured expected called missing increased with temperature, did emission rates for terpenes BVOCs. These measurements are consistent hypothesis that unknown reactive BVOCs,...
Tropospheric O 3 concentrations are functions of the chain lengths NO x (NO ≡ + 2 ) and HO (HO OH RO radical catalytic cycles. For a fixed source at low concentrations, kinetic models indicate rate production increases linearly with in limited). At higher predict ozone rates decrease increasing saturated). We present observations NO, , OH, H CO, actinic flux, temperature obtained during 1999 Southern Oxidant Study from June 15 to July 15, 1999, Cornelia Fort Airpark, Nashville, Tennessee....
OH and HO 2 mixing ratios total reactivity were measured together with photolysis frequencies, NO x , O 3 many VOCs, other trace gases during the midsummer 1999 SOS campaign in Nashville, Tennessee. These measurements provided an excellent opportunity to study (collectively called ), their sources sinks a polluted metropolitan environment. generally showed expected diurnal evolution, maxima around noon of up about 0.8 pptv 80 sunny days. Overall, daytime observed factor 1.33 1.56 times...
Abstract. During the DOMINO (Diel Oxidant Mechanism In relation to Nitrogen Oxides) campaign in southwest Spain we measured simultaneously all quantities necessary calculate a photostationary state for HONO gas phase. These comprise concentrations of OH, NO, and photolysis frequency NO2, j(NO2) as proxy j(HONO). This allowed us values unknown daytime source. source, normalized by NO2 mixing ratios expressed conversion (% h−1), showed clear dependence on with up 43% h−1 at noon. We compared...
Abstract. The GABRIEL airborne field measurement campaign, conducted over the Guyanas in October 2005, produced measurements of hydroxyl radical (OH) concentration which are significantly higher than can be simulated using current generation models atmospheric chemistry. Based on hypothesis that this "missing OH" is due to an as-yet undiscovered mechanism for recycling OH during oxidation chain isoprene, we determine about 40–50% (compared with 5–10% isoprene mechanisms) necessary order our...
Abstract. Direct measurements of OH and HO2 over a tropical rainforest were made for the first time during GABRIEL campaign in October 2005, deploying custom-built HORUS instrument (HydrOxyl Radical measurement Unit based on fluorescence Spectroscopy), adapted to fly Learjet wingpod. Biogenic hydrocarbon emissions expected strongly reduce mixing ratios as air is transported from ocean forest. However, surprisingly high both encountered boundary layer rainforest. The instrumentation...
Recent studies have shown that measured OH under NO x ‐limited, high‐isoprene conditions are many times higher than modeled OH. In this study, a detailed analysis of the HO radical budgets low‐NO , rural was performed employing box model based on Master Chemical Mechanism (MCMv3.2). The results were compared with measurements during international HOxComp campaign carried out in Jülich, Germany, summer 2005. Two different air masses influenced measurement site denoted as high‐NO (NO, 1–3...
Abstract. Measurements of OH and HO2 radicals were conducted in a pine-dominated forest southern Finland during the HUMPPA-COPEC-2010 (Hyytiälä United Photochemistry Particles Air – Comprehensive Organic Precursor Emission Concentration study) field campaign summer 2010. Simultaneous side-by-side measurements hydroxyl with two instruments using chemical ionization mass spectrometry (CIMS) laser-induced fluorescence (LIF), indicating small systematic disagreement, OHLIF / OHCIMS = (1.31 ±...
Abstract. Characterization of daytime sources nitrous acid (HONO) is crucial to understand atmospheric oxidation and radical cycling in the planetary boundary layer. HONO numerous other trace constituents were measured on Mediterranean island Cyprus during CYPHEX (CYprus PHotochemical EXperiment) campaign summer 2014. Average volume mixing ratios 35 pptv (±25 pptv) with a ∕ NOx ratio 0.33, which was considerably higher than reported for most rural urban regions. Diel profiles showed peak...
Abstract. As a major source region of the hydroxyl radical OH, Tropics largely control oxidation capacity atmosphere on global scale. However, emissions hydrocarbons from tropical rainforest that react rapidly with OH can potentially deplete amount and thereby reduce capacity. The airborne GABRIEL field campaign in equatorial South America (Suriname) October 2005 investigated influence HOx budget (HOx = + HO2). first observations HO2 over are compared to steady state concentrations...
Abstract. Atmospheric measurements of hydroxyl radicals (OH) are challenging due to a high reactivity and consequently low concentration. The importance OH as an atmospheric oxidant has motivated sustained effort leading the development number highly sensitive analytical techniques. Recent work indicated that laser-induced fluorescence molecules method based on assay by gas expansion technique (LIF-FAGE) for measurement in some environments may be influenced artificial generated within...
Abstract. This paper describes the background, instrumentation, goals, and regional influences on HUMPPA-COPEC intensive field measurement campaign, conducted at Boreal forest research station SMEAR II (Station for Measuring Ecosystem-Atmosphere Relation) in Hyytiälä, Finland from 12 July–12 August 2010. The prevailing meteorological conditions during campaign are examined contrasted with those of past six years. Back trajectory analyses show that site 2010 were characterized by a higher...
Abstract. Strongly enhanced tropospheric ozone (O3) mixing ratios have been reported in the Arabian Basin, a region with intense solar radiation and high concentrations of O3 precursors such as nitrogen oxides (NOx) volatile organic compounds (VOCs). To analyze photochemical production marine boundary layer (MBL) around Peninsula, we use shipborne observations NO, NO2, O3, OH, HO2, HCHO, actinic flux, water vapor, pressure temperature obtained during summer 2017 Air Quality Climate Basin...
Abstract. We analysed the extensive dataset from HUMPPA-COPEC 2010 and HOPE 2012 field campaigns in boreal forest rural environments of Finland Germany, respectively, estimated abundance stabilised Criegee intermediates (SCIs) lower troposphere. Based on laboratory tests, we propose that background OH signal observed our IPI-LIF-FAGE instrument during aforementioned is caused at least partially by SCIs. This hypothesis based correlations with temperature concentrations unsaturated volatile...
Emissions of volatile chemicals control the hydroxyl radical (OH), atmosphere's main cleansing agent, and thus production secondary pollutants. Accounting for all these can be difficult, especially in environments with mixed urban forest emissions. The first direct measurements atmospheric OH reactivity, inverse lifetime, were made as part Southern Oxidant Study (SOS) at Cornelia Fort Airpark Nashville, TN summer 1999. Measured reactivity was typically 11 s−1. 1.4 times larger than...
Abstract. Hydroxyl radicals (OH) are the major oxidizing species in troposphere. Because of their central importance, absolute measurements concentrations needed to validate chemical mechanisms atmospheric models. The extremely low and highly variable troposphere, however, make OH difficult. Three techniques currently used worldwide for tropospheric observations after about 30~years technical developments: Differential Optical Laser Absorption Spectroscopy (DOAS), Laser-Induced Fluorescence...
Abstract. Ozone (O3) is a photochemical oxidant, an air pollutant and greenhouse gas. As the main precursor of hydroxyl radical (OH) it strongly affects oxidation power atmosphere. The remote marine boundary layer (MBL) considered important region in terms chemical O3 loss; however surface-based atmospheric observations are sparse processes not well understood. To investigate photochemistry under clean background conditions Southern Atlantic Ocean, ship measurements NO, NO2, O3, JNO2,...