Eigil Kaas

Eigil Kaas


Medlem af:

    Research interests

    My main fields of interest are in climate research and numerical weather prediction (NWP) with special foci on climate dynamics/physics and numerical methods used in atmospheric models, and on coupled atmospheric chemistry transport models.

    Ongoing main professional duties

    • Scientific Advisory Committee (SAC) of the European Centre for Medium Range Weather Forecasts (ECMWF) with special duty on (future) dynamical core(s).

    • Chairman for the “BFI”-gruppe 28: Geofag og Klima (geofysik, geologi, naturgeografi, meteorologi, geoinformation og jordobservation, landinspektørvidenskab, GIS, polarforskning).

    • (Until recently) Section head of the Climate and Computational Geophysics Section at the Niels Bohr Institute.

    • I am member of CONCITO – Denmark's green think tank


    Teaching activities

    I am currently teaching and responsible for the following semester (block) courses:

    • Atmospheric Physics (Geofysik 1) (block 1 Sep-Nov). This an undergraduate course introducing atmospheric physics and dynamics based on the popular book by Wallace and Hobbs.

    • Dynamical Meteorology (block 2 Nov-Jan). This is an undergraduate course introducing the various types of waves in the atmosphere, and, based on Boussinesq and/or quasi-geostrophic approximations, also the large scale dynamical structures and instabilities of the atmosphere.

    • General circulation of the atmosphere (block 3 Feb-Apr). This is a fundamental course in atmosphere and climate physics. It is a graduate course aiming at analysing and understanding the averaged global circulation and structure/state of the atmosphere. The course also covers balances of energy and angular momentum, dynamically caused variability and meridional transports of, e.g., heat.

    • Dynamical models for climate and Numerical Weather Prediction (NWP) (block 4 Apr-Jun). This is graduate course on atmospheric dynamical modelling and data assimilation for use in climate research and numerical weather prediction (NWP).

    • Previously (since 2006) I taught the following courses:
    • Climate Models, Observations of the Past and the Present, and Projected Climate Change including Sea Level Rise (MSc)

    • Geofysisk fluiddynamik (BSc)

    • Introduktion til geofysik (Geofysik1) (Bsc)

    • Klimadynamik (Bsc)

    • Klimafysik (Bsc)

    • Numerical methods in atmosphere and ocean models (MSc)

    • Satellite geophysics (MSc)

     I have also been teacher on, and co-organiser of various PhD summer schools.

    Ongoing PhD projects

    • Sissal Vágsheyg Erenbjerg (planned 2020) is studying the ocean flow through fjords at the Faroe Islands. The purpose of the project is to improve simulation/prediction of water flow/quality with special emphasis on lice attacks in salmon farms. In collaboration with Fiskaaling, Faroe Islands.

    • Peter Valentin Ukkonen (planned 2021/22) is using machine learning techniques (neural nets) to reduce the computational costs of radiative transfer parameteristion in NWP models – more specifically the IFS. This is part of the ESCAPE-2 project in collaboration with DMI and ECMWF.

    • Emy Alerskans (planned 2022) is an industrial PhD who will develop a system for ultra-local weather forecasts designed for farmers and other agricultural applications. The industrial collaborator is Fieldsense, and also DMI is involved.

    PhD students/projects finalised 2009-2019

    • Ida Margrethe Ringgaard (2019) studied the interaction between varying Arctic sea ice and the global climate system with special emphasis on changes in the Europe and the Northern Hemisphere. Funded by the Ice2Ice project and in collaboration with CIC and DMI.

    • Kasper Hintz (2019) was an industrial PhD partly funded by the Danish Innovation Foundation. From the beginning the project was in collaboration with the private company Vaavud. However, due to financial issues DMI took taken over after about one year. The idea in this project was to use unconventional crowd sourced data – mainly wind and pressure – to enhance the skill in nowcasting, i.e., forecasts with a lead time of a few hours.

    • Martin Olesen (2019) uses the HIRHAM model to downscale past and present weather conditions over Greenland with special emphasis on the role of sea ice variations in the Nordic Seas. Funded by the Ice2Ice project and in collaboration with CIC and DMI. Current occupation: Researcher at DMI.

    • Alexander Kurganskiy (2017) developed and tested a new module for simulation and forecasts of pollen concentration in the Enviro-HIRLAM model system. This project was a collaboration with DMI and the Russian State Hydrometeorological University, RSHU in St. Petersburg. Current occupation: Postdoc at Worchester University, UK.

    • Brian Sørensen (finalised 2013). Brian work on, and developed, fundamental components of the ENVIRO-HIRLAM system. The main emphasis was on improving the dynamical coupling between pollutants and the dynamical model core. This project was part of CEEH (www.ceeh.dk). Current occupation: Geophysicist at the Danish Defence Centre for Operational Oceanography (FCOO)

    • Ayoe Buus Hansen (2013). Ayoe combined a locally mass conserving semi-Lagrangian transport scheme with the atmospheric chemical modules used at the National Environmental Research Institute. This project was part of CEEH (www.ceeh.dk). Current occupation: Scientist in the Volcanic and Chemical team in the ADAQ group at the UK-Metoffice.

    • Ivana Cvijanović. Ivana studied the climate dynamics related to abrupt climate change with main focus on potential atmospheric re-organisations. Current occupation: Postdoc at the Physical and Life Sciences Directorate, at the Lawrence Livermore National Laboratory (US)

    • Ulrik Smith Korsholm (in collaboration with DMI). Ulrik modelled the indirect effects of aerosol. Ulrik is co-developer of the ENVIRO-HIRLAM model at DMI. Current occupation: Director of Research and Development at the DMI.

    • Till Rasmussen. Till analysed and modelled the Sea Ice in the Nares Strait between Greenland and Canada (in collaboration with Nicolai Kliem, DMI). Current occupation: Scientist at the Danish Meteorological Institute.

    Ongoing master degree projects

    • Patrick Bülow (planned 2019) analyses the possible relationship between sudden drops – so called Forbush decreases – in galactic Cosmic Ray (GCR) flux, and the cloud cover on Earth. The idea in the project is to use Re-analysis data to separate that part of the cloud cover variations which can be ascribed to short term weather variations (noise) and to subtract that from the satellite based actual cloud cover. In this way a more clean (GCR-cloud) signal should be obtained. In collaboration with Jakob Svensmark .

    • Luwei Shen (planned 2019) will use EP-flux analysis to understand the relationship between Northern Hemisphere atmospheric blocking and stratospheric conditions (e.g. sudden warmings). She is using data from the EC-Earth model (delivered by DMI) and also reanalyses from ERA5.

    • Wiebke Margitta Kolbe (planned 2020). Numerical simulations with the WRF-model. The project deals with parameterisation of various processes in the WRF-model (Weather and Research Forecasting model).

    • Kasper Tølløse (planned 2021). Kasper uses machine learning techniques for parameterisation of turbulent fluxes in the atmospheric boundary layer in an NWP model (WRF).

    • Martin Bjørn Pedersen (planned 2021). Martin will study variations and changes in extra-tropical storm/wind activity in the Northern hemisphere based on the new ERA5 re-analysis data dataset, and possibly also in climate model simulations of future climate.

    Finalised master theses (finalised 2008-2018)

    • Anesten Devasakayam (2018) worked on an explicit filter for stabilising non-hydrostatic models based on the fully compressible Euler equations with a new explicit time-splitting time scheme. This is an alternative to the use of (semi-)implicit discretisation. This was a follow up on the thesis by Emy Alerskans. Current occupation: forecaster at DMI.
    • Anna Sofia Helena Karlsson (2018) studied the relative role of latent heat heat release in extra-tropical cyclogenesis. The main emphasis was on comparing conditions at present day with those in a warmer climate. Anna is working with the WRF model. Current occupation: Weather News – Copenhagen.

    • Anne Helene Koch Borrits (2018) worked with the DMI slippery road forecasting system. Anne developed and tested a processing and quality control system for thermal mapping data measurements taken along roads of the Danish road network. The project was carried out in collaboration with the Danish Road Directorate and DMI. Current occupation: forecaster at DMI.

    • Andreas Nikolai Pedersen (apr 2018) investigated the impact of climate change on severe precipitation. Andreas performed case studies with severe convective precipitation using the WRF model. The idea is to change the initial conditions and the lateral boundary conditions to study the impact of increased temperature and related increased specific humidity on the amount of precipitation in each case. Current occupation: forecaster at DMI.

    • Lisa Lea Jach (2017) worked on the coupling/exchange of energy and moisture between various types of land-surfaces and the atmosphere. Lisa worked with the WRF model in collaboration with university of Hohenheim, Germany. Current occupation: PhD student at Univ. of Hohenheim.

    • Peter Valentin Ukkonen (2017) used information from a regional climate model to model extreme precipitation in a warmer climate, Peter used machine learning techniques for parameterization of deep convection. Current occupation: Finnish Military service but starts as PhD student at NBI in late autumn 2018.

    • Joshua Rahbek (2016) worked on physically based statistical downscaling of extreme precipitation events in a warmer climate with special focus on precipitation changes in the UK. Current occupation: Business Intelligence Consultant at Vision IT ApS

    • Kyle Matthew Honsinger (2016) analysed changes of large scale climate variability in a warmer climate as simulated with the EC-Earth climate model. The main result obtained was that a change in ENSO variability significantly impact and enhance the interannual climate variability over the North Pacific. In collaboration with Shuting Yang at DMI. Current occupation: Business Development/ Business Intelligence Specialist at Swire Blue Ocean A/S.

    • Emy Alerskans (2016) combined the use of a new explicit filter for stabilising non-hydrostatic models based on the fully compressible Euler equations with a new explicit time-splitting time scheme. This is an alternative to the use of (semi-)implicit discretisation. Current occupation: Scientific employee at the Danish Meteorological Institute

    • Johanna Eggeling (2016) analysed relationships between temperature and the occurrence of extreme precipitation over the Brittish Isles. Current occupation: unknown.

    • Andreas Michael Lang (2016) worked on the impact of Sea ice thickness in the Arctic. Andreas modified the atmospheric component of the EC-EARTH global climate model so that it can take into account the influence of gradually reduced sea ice thickness. In collaboration with Shuting Yang at DMI. Current occupation: PhD student at Max Planck Institute for Meteorology, Hamburg, Germany.

    • Mathilde Thorn Ljungdal (2016) used termistor-string measurements from arctic drifters (buoys on drifting Arctic sea ice) to estimate the heat conductivity and actual heat flux through the ice. The results were used to validate corresponding time series of total surface heat flux in the ERA interrim re-analysis data set. Drifter data were made available by Leif Toudal at DMI. Current occupation: High school teacher in physics and natural geography (in Paderup and Støvring, DK)

    • Kasper Hintz (2015) assimilated (nudged) high resolution precipitation radar data information into the HIRLAM system at DMI aiming at improving short-term forecasts of heavy precipitation (“Nowcasting”). His special focus was on the importance of the length of the model time step which appeared to be quite important for resolving the most intensive convection. In collaboration with DMI. Current occupation: Industrial PhD student at DMI/NBI.

    • Abdulai Ademola Kayode (2015) used GPS data collected at the Greenland ice sheet. “Demi” (his nickname) reprocessed the data using “Bernese” software using alternative parameters for ionospheric and tropospheric correction. The application was on the use of GPS to quantify surface movements of the Greenland Ice Sheet. Current occupation: Quality assurance programmer in Nordea Bank Data

    • Zhenhua Sun (2013, 30 ECTS) used high temporal resolution atmospheric data to drive a simple hydrological model, which was set up for conditions in the city of Århus. The aim was to investigate the role of green infrastructures on the hydrology and pollution. Current occupation: unknown private enterprise in China.

    • Rune H. Gjermundbo (2013) is using an atmospheric GCM coupled to a mixed layer ocean model to study mechanisms responsible for Arctic amplification with main emphasis on understanding the relative role of local (i.e. Arctic) versus remote (i.e. tropical) processes/mechanisms. External (main) supervisor: Peter Lang Langen (DMI/DKC). Current occupation: Senior Engineer at Gas Storage Denmark

    • Kaija Jumppanen Andersen (2013) is using satellite altimetry to calculate geostrophic currents and changes therein in the North Atlantic over the last decades. Comparisons with estimated sea level atmospheric pressure (SLP) and wind stress are made and a simple model describing sea level as function of SLP is being set up. External supervisor: Ole Baltazar Andersen (DTU Space). Current occupation: Scientist in The Danish Coastal Authority.

    • Danny Høgsholt (2013) applied a combined time-splitting using a forward-backward approach with a semi-Lagrangian scheme in order to solve the fully compressible Euler equations in simple 2-dimensional convective plume model. Current occupation: Scientist in Danske Commodities.

    • Cecilie Drost Aakjær (2013) analysed the dynamics of Arctic Ocean freshwater storage in the EC-Earth coupled climate model. External supervisors: Steffen M. Olsen and Torben Schmith (DMI). Current occupation: PhD student (DTU Space)

    • Bjarke Tobias Olsen (2013) studied mixing in models employing the Hybrid Eulerian – Lagrangian (HEL) method for solving continuity equations. The main emphasis was to identify an optimal degree of flow-dependent mixing in order to obtain realistic cascades of energy etc. to small scales. Current occupation: PhD student (DTU wind energy)

    • Heidi Villadsen (2013) used the EC-Earth model to study the climatic impact of reduced surface albedo of snow and sea ice due to black carbon depositions. External supervisors: Jens Hesselbjerg Christensen (DMI) and Jørgen Brandt,Department of Environmental Science (AU). Current occupation: PhD student Aarhus University (ENVS)

    • Rasmus Anker Pedersen (2013) used an atmospheric GCM with different prescribed sea-ice concentrations to study the impact of sea ice reductions on the Arctic tropospheric temperature changes. External (main) supervisor: Peter Lang Langen (DMI/DKC). Current occupation: PostDoc, NBI

    • Philip Tarning-Andersen (2012) studied aerosol-cloud microphysics in a one dimensional atmospheric model, with emphasis on a simple parameterization of effective droplet radius in warm clouds (In collaboration with Ulrik Smith Korsholm, DMI). Current occupation: Meteorologist at DMI.

    • Karis Anneke Kürstein Glibbery (2011) used different satellite data sets for outgoing long wave radiation (OLR) to verify the long wave feedbacks in the EC-Earth climate model running at DMI (In collaboration with Shuting Yang, DMI). Current occupation: Engineer at Rambøl

    • Matilde Marie Brandt Jensen (2011) studied and analysed Arctic sea ice thinning over the period 1979-2008 using a number of different remote sensing based data (In collaboration with Rasmus Tonboe, DMI). Current occupation: Researcher at DMI

    • Maria Elisabeth Wulff (2011). Maria used ice core data for recent years and observed precipitation at Greenland SYNOP stations to identify a correction data base for the precipitation simulated in the HIRHAM regional climate model. The correction is needed to obtain reasonable atmospheric data for driving an ice sheet model (not part of the study). (In collaboration with Gudfinna Adalsgeirdottir and others at the Danish Climate Centre, DMI). Current occupation: Advanced R&D Engineer, Novo Nordisk

    • Leif Skovbo (2009). Leif investigated the realism of certain verifiable feedbacks in IPCC climate models and used this to perform a model weighting for future climate scenarios. Current occupation: unknown.

    • Ayoe Buus Hansen (2009). Ayoe performed a two-dimensional intercomparison of semi-Lagrangian transport schemes and the ASD algorithm used in the atmospheric chemical modules at the National Environmental Research Institute. This project was part of CEEH (www.ceeh.dk). Current occupation: Scientist in the Volcanic and Chemical team in the ADAQ group at the UK-Metoffice.

    • Joakim Refslund Nielsen (2009). Joakim implemented and tested a new anti-diffusive monotonic filter in combination with a locally mass conserving semi-Lagrangian transport scheme in the HIRLAM model used at DMI. Current occupation: Meteorologist / Hydrologist at Wattsight, Arendal, Norway

    • Brian Sørensen (2009). Brian implemented and tested a new quasi-Lagrangian vertical coordinate in combination with a locally mass conserving semi-Lagrangian transport scheme in the HIRLAM model used at DMI. Current occupation: Geophysicist at the Danish Defence Centre for Operational Oceanography (FCOO)

    • Allan Christensen (2009). Allan implemented and tested a locally mass conserving semi-Lagrangian transport scheme in the HIRLAM model used at DMI. Current occupation: Administrative Assistant in Via Trafik Rådgivning A/S (Birkerød, DK)





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