A5004689329- Atmospheric chemistry and aerosols
- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- Air Quality Monitoring and Forecasting
- Air Quality and Health Impacts
- Astrophysics and Cosmic Phenomena
- Geophysics and Gravity Measurements
- Galaxies: Formation, Evolution, Phenomena
- Spectroscopy and Laser Applications
- Radio Astronomy Observations and Technology
- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Atmospheric aerosols and clouds
- Astronomy and Astrophysical Research
- Advanced Chemical Sensor Technologies
- Marine and coastal ecosystems
- Water Quality Monitoring and Analysis
- Microbial Applications in Construction Materials
- Water Resource Management and Quality
- Particle physics theoretical and experimental studies
- Vehicle emissions and performance
- Meningioma and schwannoma management
- COVID-19 impact on air quality
- Radioactive contamination and transfer
- Calibration and Measurement Techniques
Royal Belgian Institute for Space Aeronomy
2018-2025
Universidad Nacional Autónoma de México
2014-2021
Stockholm University
2011-2013
AlbaNova
2011-2013
Technical University of Darmstadt
2004
Abstract. Ground-based multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurements of aerosols and tropospheric nitrogen dioxide (NO2) were carried out in Uccle (50.8∘ N, 4.35∘ E), Brussels, during 1 year from March 2018 until 2019. The instrument was operated both the UV visible wavelength ranges a dual-scan configuration consisting two sub-modes: (1) an elevation scan fixed viewing azimuthal direction (the so-called main direction) pointing to northeast (2) low angle...
Abstract. The second Cabauw Intercomparison of Nitrogen Dioxide measuring Instruments (CINDI-2) took place in (the Netherlands) September 2016 with the aim assessing consistency multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurements tropospheric species (NO2, HCHO, O3, HONO, CHOCHO and O4). This was achieved through coordinated operation 36 spectrometers operated by 24 groups from all over world, together a wide range supporting reference observations (in situ...
Abstract. Multi-axis differential optical absorption spectroscopy (MAX-DOAS) is a widely used measurement technique for the detection of variety atmospheric trace gases. Using inverse modelling, observation gas column densities along different lines sight enables retrieval aerosol and vertical profiles in boundary layer using appropriate algorithms. In this study, ability eight profile algorithms to reconstruct assessed on basis synthetic measurements. Five are based optimal estimation...
Abstract. Airborne imaging differential optical absorption spectroscopy (DOAS), ground-based stationary DOAS, and car DOAS measurements were conducted during the S5P-VAL-DE-Ruhr campaign in September 2020. The area is located Rhine-Ruhr region of North Rhine-Westphalia, western Germany, which a pollution hotspot Europe comprising urban large industrial sources. are used to validate spaceborne NO2 tropospheric vertical column density (VCD) data products from Sentinel-5 Precursor (S5P)...
Abstract. Volatile organic compounds (VOCs) are key precursors of particulate matter and tropospheric ozone. Although the terrestrial biosphere is by far largest source VOCs into atmosphere, emissions biogenic remain poorly constrained at regional scale. In this work, we derive top-down over Europe using weekly averaged TROPOMI formaldehyde (HCHO) data from 2018 to 2021. The systematic bias HCHO columns characterized corrected for based on comparisons with FTIR seven European stations....
We use the results of large-scale simulations reionization to explore methods for characterizing topology and sizes H ii regions during reionization. four independent ionized regions. Three them give us a full size distribution: friends-of-friends (FoF) method, spherical average (SPA) method power spectrum (PS) fraction. The latter three are complementary: while FoF captures distribution small-scale regions, which contribute only small amount total ionization fraction, SPA provides smoothed...
We present a detailed comparison of three different simulations the epoch reionization (EoR). The radiative transfer simulation (${\rm C}^2$-RAY) among them is our benchmark. Radiative codes can produce realistic results, but are computationally expensive. compare it with two semi-numerical techniques: one using same halos as ${\rm C}^2$-RAY its sources (Sem-Num), and conditional Press-Schechter scheme (CPS+GS). These vastly more efficient than C}^2$-RAY, use simplistic physical assumptions....
Abstract. We present a new numerical code, Mexican MAX-DOAS Fit (MMF), developed to retrieve profiles of different trace gases from the network instruments operated in Mexico City. MMF uses differential slant column densities (dSCDs) retrieved with QDOAS (Danckaert et al., 2013) software. The retrieval is comprised two steps, an aerosol and gas that profile forward model for gas. For simulations, VLIDORT used (e.g., Spurr 2001; Spurr, 2006, 2013). Both steps use constrained least-square...
Abstract. We present the inter-comparison of delta slant column densities (SCDs) and vertical profiles nitrous acid (HONO) derived from measurements different multi-axis differential optical absorption spectroscopy (MAX-DOAS) instruments using inversion algorithms during Second Cabauw Inter-comparison campaign for Nitrogen Dioxide measuring Instruments (CINDI-2) in September 2016 at Cabauw, Netherlands (51.97∘ N, 4.93∘ E). The HONO profiles, (VCDs), near-surface volume mixing ratios are...
The third Cabauw Intercomparison of UV-Vis DOAS Instruments (CINDI-3) took place from May 21st to the 24th June 2024 at Experimental Site for Atmospheric Research (CESAR), a semi-rural observational facility managed by Dutch Meteorological Institute close cities Rotterdam and Utrecht in Netherlands. Its main objective was intercompare MAX-DOAS instrument types targeting nitrogen dioxide, ozone, aerosols several other reactive gases such as formaldehyde, glyoxal BrO, with aim assess their...
MAX-DOAS, direct sun DOAS and FTIR measurements are increasingly used as fiducial reference (FRM) for the validation of HCHO satellite observations. Understanding their strengths limitations, assessing consistency is therefore crucial to produce robust consolidated results. So far, only a few studies have explored complementarity between MAX-DOAS measurements.In present study, we take benefit instruments being simultaneously operated at Xianghe station (39.75° N, 116.96° E,...
Pollutants information can be retrieved from visible (VIS) and ultraviolet (UV) diffuse solar spectra exploiting Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) instruments. In May 2021, the Italian research institute CNR-ISAC acquired deployed a MAX-DOAS system SkySpec-2D. It is located in “Giorgio Fea” observatory San Pietro Capofiume (SPC), middle of Po Valley, where it has constantly zenith off-axis since 1st October 2021. This work presents tropospheric NO2 aerosol...
Abstract. The TROPOspheric Monitoring Instrument (TROPOMI), aboard the Sentinel-5 Precursor (S5P) satellite launched in October 2017, is dedicated to monitoring atmospheric composition associated with air quality and climate change. This paper presents global retrieval of TROPOMI tropospheric formaldehyde (HCHO) nitrogen dioxide (NO2) vertical columns using an updated version Peking University OMI NO2 (POMINO) algorithm, which focuses on improving calculation mass factors (AMFs). algorithm...
Abstract. Instruments for air quality observations on geostationary satellites provide multiple per day and allow the analysis of diurnal variation in important pollutants such as nitrogen dioxide (NO2). The South Korean instrument GEMS (Geostationary Environmental Monitoring Spectrometer), launched February 2020, is first that able to observe NO2. measurements have a spatial resolution 3.5 km × 8 cover large part Asia. This study compares 1 year tropospheric NO2 vertical column density...
Abstract. Instruments for air quality observations on geostationary satellites provide multiple per day and allow the analysis of diurnal variation important pollutants such as nitrogen dioxide (NO2) over large areas. The South Korean instrument GEMS GK2B satellite was launched in February 2020 is first orbit that delivers hourly daytime NO2. measurements with a spatial resolution 3.5 km x 8 cover part Asia. This study compares one year tropospheric NO2 vertical column density (VCD)...
The UV–Visible Working Group of the Network for Detection Atmospheric Composition Changes (NDACC) focuses on monitoring air-quality-related stratospheric and tropospheric trace gases in support trend analysis, satellite validation model studies. Tropospheric measurements are based MAX-DOAS-type instruments that progressively emerged years 2010 onward. In interest improving overall consistency NDACC MAX-DOAS network facilitating its further extension to benefit validation, ESA initiated, late...
We present a study of the impact bright quasar on redshifted 21-cm signal during epoch reionization (EoR). Using three different cosmological radiative transfer simulations, we investigate if quasars are capable substantially changing size and morphology H ii regions they born in. choose stellar luminosities in way that is favourable to seeing such an effect. find even most luminous our models not able increase its native region beyond those large produced by clustered sources alone....
Abstract. In this study we focus on the retrieval of aerosol and trace gas vertical profiles from multi-axis differential optical absorption spectroscopy (MAX-DOAS) observations for first time over Thessaloniki, Greece. We use two independent inversion algorithms profile retrievals: Mexican MAX-DOAS Fit (MMF) Mainz Profile Algorithm (MAPA). The former is based optimal estimation method (OEM), while latter follows a parameterization approach. evaluate performance MMF MAPA, validate their...
Abstract. We present a database of MAX-DOAS (Multi-AXis Differential Optical Absorption Spectroscopy) ground-based observations NO2 and H2CO tropospheric vertical column densities (VCDtropo) performed for the first time in city Kinshasa. These measurements were conducted between November 2019 July 2021 processed using standardized inversion tools developed ESA FRM4DOAS (Fiducial Reference Measurements Ground-Based DOAS Air-Quality Observations) project. The retrieved geophysical quantities...
We present an extension to the short-characteristic ray-tracing and non-equilibrium photoionization code C2-Ray. The new version includes effects of helium improved multifrequency heating. motivation for this work is be able deal with harder ionizing spectra, such as from quasar-like sources during cosmic reionization. review basic algorithmic ingredients C2-Ray before describing changes implemented, which include a treatment full on-the-spot (OTS) approximation, secondary ionization,...
Dark halo substructure may reveal itself through secondary, small-scale gravitational lensing effects on light sources that are macrolensed by a foreground galaxy. Here, we explore the prospects of using Very Long Baseline Interferometry (VLBI) observations multiply-imaged quasar jets to search for submilliarcsecond-scale image distortions produced various forms dark substructures in 103–108 M⊙ mass range. We present simulations relevant angular resolutions attainable with existing European...
An instrument based on the Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) technique was designed and constructed to measure scattered sunlight in UV-visible region at different elevation angles. Slant column densities (SCDs) of specific gas absorbers such as nitrogen dioxide (NO2) formaldehyde (HCHO) are derived from measured spectra. In this contribution, technical characteristics performance instruments, their deployment a newly formed observational network within...
Abstract. Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) is a well-established ground-based measurement technique for the detection of aerosols and trace gases particularly in boundary layer lower troposphere: ultraviolet- visible radiation spectra skylight are analysed to obtain information on different atmospheric parameters, integrated over light path from space instrument. An appropriate set recorded under viewing geometries ("Multi-Axis") allows retrieval...