RMI publications
https://orfeo.belnet.be/handle/internal/23
2024-03-29T11:26:24ZValidation of Absorbing Aerosol Height product from GOME-2 using CALIOP data, European Aerosol Conference
https://orfeo.belnet.be/handle/internal/9801
Validation of Absorbing Aerosol Height product from GOME-2 using CALIOP data, European Aerosol Conference
De Bock, Veerle; Pardo Cantos, Irene; Laffineur, Quentin; Mangold, Alexander; Tilstra, Gijsbert; Tuinder, Olaf; Delcloo, Andy
The Absorbing Aerosol Height (AAH) is a new GOME-2 product for aerosol detection developed within the Atmospheric Composition Satellite Application Facility (ACSAF). It uses the Absorbing Aerosol Index (AAI) and derives the actual height of the absorbing aerosol layer in the O2-A band using the Fast Retrieval Scheme for Cloud Observables (FRESCO) algorithm (Tilstra et al. 2010). This
AAH product could be used to monitor volcanic eruptions globally and to provide the height of the ash layers (e.g. within the framework of aviation safety).
To determine the quality of the AAH, a new quantitative validation exercise has been done, using the extracted height of the different aerosol layers from CALIOP and comparing this to the AAH from GOME-2. The results from different case studies will be presented.
Validation of the Absorbing Aerosol Height product from GOME-2 using CALIOP data
https://orfeo.belnet.be/handle/internal/9800
Validation of the Absorbing Aerosol Height product from GOME-2 using CALIOP data
De Bock, Veerle; Pardo Cantos, Irene; Laffineur, Quentin; Mangold, Alexander; Tilstra, Gijsbert; Tuinder, Olaf; Delcloo, Andy
The Absorbing Aerosol Height (AAH) is a new GOME-2 product for aerosol detection developed within the Atmospheric Composition Satellite Application Facility (ACSAF). It uses the Absorbing Aerosol Index (AAI) and derives the actual height of the absorbing aerosol layer in the O2-A band using the Fast Retrieval Scheme for Cloud Observables (FRESCO) algorithm (Tilstra et al. 2010). This
AAH product could be used to monitor volcanic eruptions globally and to provide the height of the ash layers (e.g. within the framework of aviation safety).
To determine the quality of the AAH, a new quantitative validation exercise has been done, using the extracted height from the different aerosol layers from CALIOP and comparing this to the AAH from GOME-2. The results from different case studies will be presented.
Solar UV Irradiance in a Changing Climate: Trends in Europe and the Significance of Spectral Monitoring in Italy
https://orfeo.belnet.be/handle/internal/9799
Solar UV Irradiance in a Changing Climate: Trends in Europe and the Significance of Spectral Monitoring in Italy
Fountoulakis, Ilias; Diémoz, Henri; Siani, Anna-Maria; Laschewski, Gudrun; Filippa, Gianluca; Arola, Antti; Bais, Alkiviadis F.; De Backer, Hugo; Lakkala, Kaisa; Webb, Ann, R.; De Bock, Veerle; Karppinen, Tomi; Garane, Katerina; Kapsomenakis, John; Koukouli, Maria-Elissavet; Zerefos, Christos S.
Review of the existing bibliography shows that the direction and magnitude of the long-term trends of UV irradiance, and their main drivers, vary significantly throughout Europe. Analysis of total ozone and spectral UV data recorded at four European stations during 1996–2017 reveals that long-term changes in UV are mainly driven by changes in aerosols, cloudiness, and surface albedo, while changes in total ozone play a less significant role. The variability of UV irradiance is large throughout Italy due to the complex topography and large latitudinal extension of the country. Analysis of the spectral UV records of the urban site of Rome, and the alpine site of Aosta reveals that differences between the two sites follow the annual cycle of the differences in cloudiness and surface albedo. Comparisons between the noon UV index measured at the ground at the same stations and the corresponding estimates from the Deutscher Wetterdienst (DWD) forecast model and the ozone monitoring instrument (OMI)/Aura observations reveal differences of up to 6 units between individual measurements, which are likely due to the different spatial resolution of the different datasets, and average differences of 0.5–1 unit, possibly related to the use of climatological surface albedo and aerosol optical properties in the retrieval algorithms.
Lees–Edwards boundary conditions for translation invariant shear flow: Implementation and transport properties
https://orfeo.belnet.be/handle/internal/9798
Lees–Edwards boundary conditions for translation invariant shear flow: Implementation and transport properties
Bindgen, Sebastian; Weik, Florian; Weeber, Rudolf; Koos, Erin; de Buyl, Pierre
Molecular dynamics (MD) simulations represent a powerful investigation tool in the field of soft matter. By using shear flows, one can probe the bulk rheology of complex fluids, also beyond the linear response regime, in a way that imitates laboratory experiments. One solution to impose a shear flow in particle-based simulations is the Lees–Edwards technique, which ensures that particles experience shear by imposing rules for motion and interactions across the boundary in the direction of the shear plane. Despite their presentation in 1972, a readily available public implementation of Lees–Edwards boundary conditions has been missing from MD simulation codes. In this article, we present our implementation of the Lees–Edwards technique and discuss the relevant technical choices. We used ESPResSo, the extensible simulation package for research on soft matter, for molecular dynamics simulations which can be used as a reference for other implementers. We illustrate our implementation using bulk dissipative particle dynamics fluids, compare different viscosity measurement techniques, and observe the anomalous diffusion in our samples during continuous and oscillatory shear, in good comparison with theoretical estimates.