A5020121044- Atmospheric Ozone and Climate
- Atmospheric and Environmental Gas Dynamics
- Atmospheric chemistry and aerosols
- Geophysics and Gravity Measurements
- GNSS positioning and interference
- Ionosphere and magnetosphere dynamics
- Air Quality Monitoring and Forecasting
- Stellar, planetary, and galactic studies
- Climate variability and models
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- Spectroscopy and Laser Applications
- Calibration and Measurement Techniques
- Gas Sensing Nanomaterials and Sensors
- Air Quality and Health Impacts
- Meteorological Phenomena and Simulations
- Inertial Sensor and Navigation
- Historical Geography and Cartography
- Atmospheric aerosols and clouds
- COVID-19 impact on air quality
- Image and Video Quality Assessment
- Analytical Chemistry and Sensors
- Healthcare Systems and Challenges
- Adaptive optics and wavefront sensing
- Earthquake Detection and Analysis
Royal Meteorological Institute of Belgium
2016-2025
Imagerie par Résonance Magnétique Médicale et Multi-Modalités
2012
KU Leuven
2004-2010
Abstract Throughout spring and summer 2020, ozone stations in the northern extratropics recorded unusually low free troposphere. From April to August, from 1 8 kilometers altitude, was on average 7% (≈4 nmol/mol) below 2000–2020 climatological mean. Such ozone, over several months, at so many stations, has not been observed any previous year since least 2000. Atmospheric composition analyses Copernicus Atmosphere Monitoring Service simulations NASA GMI model indicate that large 2020...
Abstract. The ozone profile records of a large number limb and occultation satellite instruments are widely used to address several key questions in research. Further progress some domains depends on more detailed understanding these data sets, especially their long-term stability mutual consistency. To this end, we made systematic assessment 14 sounders that, together, provide than three decades global measurements. In particular, considered the latest operational Level-2 by SAGE II, III,...
Abstract We review the current state of knowledge ozonesonde uncertainty and bias, with reference to recent developments in laboratory field experiments. In past 20 years precision has improved by a factor 2, primarily through adoption strict standard operating procedures. The budget for ozone partial pressure reading contributions from stoichiometry, cell background current, pump efficiency temperature, sensing solution type, volume. Corrections historical data known issues may reduce...
Abstract. Water vapour plays a dominant role in the climate change debate. However, observing water over climatological time period consistent and homogeneous manner is challenging. On one hand, networks of ground-based instruments able to retrieve integrated (IWV) data sets are being set up. Typical examples Global Navigation Satellite System (GNSS) observation such as International GNSS Service (IGS), with continuous GPS (Global Positioning System) observations spanning last 15+ years,...
Abstract An international effort to improve ozonesonde data quality and reevaluate historical records has made significant improvements in the accuracy of global network data. However, between 2014 2016, total column ozone (TCO; O 3 ) at 14 37 regularly reporting stations exhibited a sudden dropoff relative satellite measurements. The TCO drop is 3–7% compared ground‐based TCO, 5–10% or more stratospheric profiles, compromising use recent for trends, although they remain reliable other uses....
Abstract The ozonesonde is a small balloon-borne instrument that attached to standard radiosonde measure profiles of ozone from the surface 35 km with ∼100-m vertical resolution. Ozonesonde data constitute mainstay satellite calibration and are used for climatologies analysis trends, especially in lower stratosphere where satellites most uncertain. electrochemical concentration cell (ECC) has been deployed at ∼100 stations worldwide since 1960s, changes over time manufacture procedures,...
Abstract This study quantifies the association between COVID‐19 economic downturn and 2020 tropospheric ozone anomalies above Europe western North America, their impact on long‐term trends. Anomaly detection for an atmospheric time series is usually carried out by identifying potentially aberrant data points relative to climatological values. However, detecting from sparsely sampled ozonesonde profiles (once per week at most sites) challenging due ozone's high temporal variability. We first...
Abstract. This study presents an updated evaluation of stratospheric ozone profile trends in the 60∘ S–60∘ N latitude range over 2000–2020 period using version Long-term Ozone Trends and Uncertainties Stratosphere (LOTUS) regression model that was used to evaluate such up 2016 for last WMO Assessment (2018). In addition derivation detailed as a function vertical coordinates, regressions are performed with datasets averaged broad bands, i.e. 60–35∘ S, 20∘ S–20∘ 35–60∘ N. The same methodology...
Abstract The recent Assessment of Standard Operating Procedures for Ozonesondes 2.0 (WMO/GAW Report #268) addressed questions homogeneity and long‐term stability in global electrochemical concentration cell (ECC) ozone sounding network time series. Among its recommendations was adoption a standard evaluating data quality ozonesonde Total column (TCO) derived from the sondes compared to TCO Aura's Ozone Monitoring Instrument (OMI) is primary indicator. Comparisons sonde with Microwave Limb...
Abstract. We developed a high-quality global integrated water vapour (IWV) dataset from 12 552 ground-based positioning system (GPS) stations in 2020. It consists of 5 min GPS IWV estimates with total number 1 093 591 492 data points. The completeness rates the are higher than 95 % at 7253 (58 %) stations. is an enhanced version existing operational provided by Nevada Geodetic Laboratory (NGL). enhancement reached employing accurate meteorological information fifth generation European...
Abstract. Although in principle ECC (electrochemical concentration cell) ozonesondes are absolute measuring devices, practice they have several “artefacts” which change over the course of a flight. Most artefacts been corrected recommendations Assessment Standard Operating Procedures for Ozone Sondes (ASOPOS) report (Smit et al., 2021), giving an overall uncertainty 5 %–10 % throughout profile. However, conversion measured cell current into sampled ozone still needs to be quantified better,...
Abstract. We validate the Ozone Monitoring Instrument (OMI) Profile (PROFOZ) product from October 2004 through December 2014 retrieved by Smithsonian Astrophysical Observatory (SAO) algorithm against ozonesonde observations. also evaluate effects of OMI row anomaly (RA) on retrieval dividing dataset into before and after occurrence serious RA, i.e., pre-RA (2004–2008) post-RA (2009–2014). The shows good agreement with ozonesondes in tropics midlatitudes for pressure < ∼ 50 hPa high...
Abstract The lifetime of ozone in the troposphere is approximately 3 weeks. Prevailing westerly winds at northern midlatitudes can transport air around globe that time. Hence, within these latitudes zonal similarity expected long‐term changes and seasonal cycles concentrations baseline ozone. We quantify degree by examining eight situ data sets near west coasts North America Europe, is, upwind those continents downwind Pacific Atlantic Oceans, where impacts local regional sources have been...
Abstract. The ground-based Global Positioning System (GPS) has been used extensively to retrieve integrated water vapour (IWV) and adopted as a unique tool for the assessments of atmospheric reanalyses. In this study, we investigated multi-temporal-scale variabilities trends IWV over Europe by using time series from 108 GPS stations more than 2 decades (1994–2018). We then reference assess six commonly reanalyses, namely Climate Forecast Reanalysis (CFSR); ERA5; ERA-Interim; Japanese 55-year...
Abstract. At Uccle, Belgium, a long time series (1991–2013) of simultaneous measurements erythemal ultraviolet (UV) dose (Sery), global solar radiation (Sg), total ozone column (Q_{O3}$) and aerosol optical depth (τaer) (at 320.1 nm) is available, which allows for an extensive study the changes in variables over time. Linear trends were determined different monthly anomalies series. Sery, Sg QO3 all increase by respectively 7, 4 3% per decade. τaer shows insignificant negative trend −8%...
Abstract. Vertical ozone profiles from combined spectral measurements in the ultraviolet and infrared range were retrieved by using data TROPOspheric Monitoring Instrument on Sentinel-5 Precursor (TROPOMI/S5P) Cross-track Infrared Sounder Suomi National Polar-orbiting Partnership (CrIS/Suomi-NPP), which are flying loose formation 3 min apart same orbit. A previous study of exclusively TROPOMI UV spectra showed that vertical resolution troposphere is clearly limited (Mettig et al., 2021). The...
Abstract. The Observatoire de Haute Provence (OHP) weekly electrochemical concentration cell (ECC) ozonesonde data have been homogenized for the period 1991–2021 according to recommendations of Ozonesonde Data Quality Assessment (O3S-DQA) panel. assessment ECC homogenization benefit has carried out using comparisons with other ozone-measuring ground-based instruments at same station (lidar, surface measurements) and colocated satellite observations O3 vertical profile by Microwave Limb...
Aims. We selected a large sample of O-B stars that were considered as (candidate) slowly pulsating B, β Cep, and Maia after the analysis their hipparcos data. analysed our new seven passband geneva data collected for these during first three years scientific operations mercator telescope. performed frequency 28 targets with more than 50 high-quality measurements to improve variability classification. For stars, we tried both identify modes search rotationally split modes.
In this paper we study the extended atmosphere of late-type supergiant α Orionis. Infrared spectroscopy red supergiants reveals strong molecular bands, some which do not originate in photosphere but a cooler layer material above it. Lately, these layers have been spatially resolved by near and mid-IR interferometry. paper, try to reconcile IR interferometric ISO-SWS spectroscopic results on Orionis with thorough modelling photosphere, layer(s) dust shell. From ISO near-IR observations, find...
Abstract. The ozonesonde stations at Uccle (Belgium) and De Bilt (the Netherlands) are separated by only 175 km but use different types (or manufacturers for the same electrochemical concentration cell (ECC) type), operating procedures, correction strategies. As such, these form a unique test bed Ozonesonde Data Quality Assessment (O3S-DQA) activity, which aims providing revised, homogeneous, consistent dataset with an altitude-dependent estimated uncertainty each revised profile. For ECC...
Abstract We assess the performance of different break detection methods on three sets benchmark data sets, each consisting 120 daily time series integrated water vapor differences. These differences are generated from Global Positioning System (GPS) measurements at sites worldwide, and numerical weather prediction reanalysis (ERA‐Interim) output, which serves as reference here. The includes homogeneous inhomogeneous sections with added nonclimatic shifts (breaks) in latter. Three variants...
Earth and Space Science Open Archive This preprint has been submitted to is under consideration at Science. ESSOAr a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing the latest version by default [v1]An Examination of Recent Stability Ozonesonde Global Network DataAuthorsRyan MichaelStaufferiDAnne M.ThompsoniDDebraKollonigeDavidTarasickRoelandVan MaldereniDHerman...
Abstract. This study presents an updated evaluation of stratospheric ozone profile trends in the 60° S–60° N latitude range over 2000–2020 period, using version Long-term Ozone Trends and Uncertainties Stratosphere (LOTUS) regression model that was used to evaluate such up 2016 for last WMO Assessment (2018). In addition derivation detailed as a function vertical coordinates, regressions are performed with data sets averaged broad bands, i.e. S–35° S, 20° S–20° 35° N–60° N. The same...