Alexander van Eijk

POSITION: PROFESSOR | ATMOSPHERE DYNAMICS OF THE COASTAL ZONE TNO UNIT: DEFENCE, SAFETY & SECURITY (ELECTRONIC DEFENCE) UNIVERSITY: ECOLE CENTRALE DE NANTES, LHEEA   TNO LOCATION: THE HAGUE – WAALSDORP EMAIL: LEX.VANEIJK@TNO.NL TEL: +31888664093

RESEARCH AREA

In a military context, situational awareness, i.e., an understanding of how well you can see and how well you can be seen, is crucial. Turbulence degrades image quality and absorption by aerosols reduces contrast, which reduces the maximum distance at which you can see. The research focuses on a small-scale description of atmospheric flow processes, with emphasis on turbulence. For this, we use a series of numerical (weather prediction) tools from coarse to high resolution. This framework is used to model the dispersion of aerosols, in particular those generated at the sea surface, in the lower atmosphere while taking into account the features of the heterogeneous terrain (land-sea transition, orography, etc.). It is our ambition to understand the necessary and sufficient detail of this numerical modeling to optimize computational requirements and the physical footprint that can be handled.

Within TNO, this work is predominantly embedded within DSS but it also relates to other TNO areas: turbulence degrades the quality of (laser) communication systems, and aerosols are important to climate and air quality.

RECENT RESULTS

The results in 2020 pertain primarily to theoretical / modelling studies, because experimental efforts in the field were negatively impacted by the Covid pandemic. Two modeling studies addressed the aerosol loading of the atmosphere in coastal areas (Ligurian sea, Italy; False Bay, South Africa), establishing the conditions resulting in polluted and/or clean air events. Furthermore, a theoretical study was initiated to relate numerical weather data to the strength of optical turbulence, with the aim to forecast spatially and temporally resolved link availability and bit-error-rate for satellite optical communication. Numerical simulations of optical turbulence strength focused on the urban environment, as well as the remote region of West Africa for which few in-situ observations are available.

PHD SUPERVISION

• Faith February, Characterization of aerosol leadings at the southern tip of Africa, University of Cape Town (main supervisor: Katye Altieri) (Government funding)
• Thomas Kociok, Sahara dust Haboobs and effect on visibility - Karlsruhe Institute of Technology (main supervisor: Peter Knippertz) (Funded by Fraunhofer IOSB)

TOP PUBLICATIONS

• Tedeschi, A.M.J. van Eijk, J. P. Piazzola and J.T Kusmierczyk-Michulec (2017). Influence of the surf zone on marine aerosol concentration in coastal area. Boundary-Layer Meteorol., 163:327–350, doi:10.1007/s10546-016-0229-7
• Calmet, P.G. Mestayer, A.M.J. van Eijk and O. Herlédant (2017). A coastal bay summer breeze study. Part 2: High-resolution numerical simulation of sea-breeze local influences. Boundary-Layer Meteorol. 167:27-51, doi: 10.1007/s/10546-017-0319-1
• Oosterwijk, A., S. Heikamp, A. Manders-Groot, A.M.J. van Eijk (2019). Comparison of modelled atmospheric aerosol content and its influence on high-energy laser propagation . SPIE Proc. 11133, 111330C, doi: 10.1117/12.2529949

LINKS

• Ecole Centrale de Nantes, LHEEA / DUAC (department): https://www.ec-nantes.fr/shaking-the-future/dauc-research-group-dynamics-of-the-coastal-urban-atmosphere-182072.kjsp?RH=1492603320193
• Ecole Centrale de Nantes, chair page : https://www.ec-nantes.fr/industrial-chairs/tno-centrale-nantes-chair-197018.kjsp?RH=1488471051634
• Google Scholar : https://scholar.google.nl/citations?user=S8u-o78AAAAJ&hl=nl