PhD projects related to LATICE

Presentations of PhD candidates and PhD projects related to the LATICE research group.

Dynamic distribution modelling

Eva Lieungh (Affil: NHM)

Image may contain: Grass, Technology.
A photo from Eva's field work (taken by Siri Lie Olsen)

The focus of my PhD project is spatial vegetation dynamics and how these dynamics are represented in different models. I work with distribution models from the ecology literature, but also with CLM-FATES which is a dynamic, global vegetation model. Vegetation remains a large source of uncertainty in Earth System Models, so a major aim of my project is to make connections between ecology and climatological disciplines and try to transfer knowledge between different ways of modelling and theorizing about vegetation dynamics. I have two main study sites: one is a grassland ecosystem in Oslo and the other is a set of alpine grasslands in Western Norway. I use different types of models for each of my papers, but some common keywords are spatial dynamics, traits and interactions between species.

I'm located at the Natural History Museum, in a very interdisciplinary research group where I'm part of the LATICE and EMERALD projects as well as keeping an eye on vegetation mapping and other NHM activities. Olav Skarpaas is my main supervisor. 

 

Impacts of extreme winter events on vegetation mortality in the CLM and FATES

Marius Lambert (Affil: Geo)

Browning events: frost drought damage to Calluna vulgaris heathland in central Norway. (Photo credits: Rachael Treharne)

I started my PhD at the section of meteorology and oceanography (MetOs), Department of Geosciences, University of Oslo in 2019 under the supervision of Frans-Jan W. Parmentier, Frode Stordal, Kjetil S. Aas and Hui Tang. I am part of the WINTERPROOF project which closely collaborates with LATICE. During my PhD I will study the role of cold season processes (e.g. hardening of vegetation, frost droughts, winter greenhouse gas emissions from permafrost soils) in vegetation-permafrost feedbacks using the CLM and FATES. However, my contribution in LATICE is more specific and focusses mainly on modelling winter frost droughts causing damage to vegetation.

Frost droughts, through their effect on vegetation, have been identified as a strong driver of Arctic Browning. Field observations linked to such events have showed substantial damages in the Arctic. However models, including CLM and FATES have been mainly used to simulate tropical regions. Therefore, we will simulate frost droughts at higher latitudes and improve the models to accurately represent the ongoing processes.

 

Applications of ensemble-based data assimilation methods to the cryosphere

Kristoffer Aalstad (Affil: Geo)

Applications of ensemble-based data assimilation methods to the cryosphere. Photo: Kristoffer Aalstad

I'm a PhD candidate working at the Section for Geography and Hydrology (GeoHyd) at the Department of Geosciences.  I joined the LATICE in October 2015 since the group has a shared focus with the SATPERM project that funds my PhD. My interests lie in the field of land-atmosphere interactions. In my work I am applying ensemble-based data assimilation techniques, mainly variants of the ensemble Kalman Filter (EnKF), to the high latitude land surface.

Through the EnKF, I sequentially fuse model results with related remotely sensed observations. By doing so uncertainties in simulated cryospheric variables are constrained by observations. In the EnKF experiments I mainly make use of the internally developed CryoGrid modeling suite in conjunction with Moderate Resolution Imaging Spectrometer (MODIS) retrievals.

My PhD is supervised by Sebastian Westermann (LATICE member and postdoc at GeoHyd), I also collaborate with SATPERM partners such as the data assimilation and forecasting group at the Nansen Environmental and Remote Sensing Center (Bergen).

Kristoffer Aalstad had his disputation at Department of Geosciences, UiO on 24.10.2019.

 

A modelling investigation of the importance of Biogenic Volatile Organic Compounds (BVOC) emissions in the boreal zone

Sara Marie Blichner (Affil: Geo)

Feedbacks involving BVOC emissions.
Feedbacks involving BVOC emissions. Figure: Sara Marie Blichner

I am a PhD. student working in Meteorology and Oceanography Section (MetOs), Department of Geosciences. My project is on atmosphere-land interactions through biogenic volatile organic compound (BVOC) emissions from vegetation.

BVOC emissions are expected to increase as temperature increases. I am interested in the possible feedbacks on temperature through changes in BVOC concentrations, in particular involving ozone and secondary organic aerosols (through the aerosol direct and indirect effects).

My main tool is the Norwegian Earth System Model (NorESM). I will investigate how an expected change in boreal zone vegetation from climate change, will affect the BVOC emissions and what radiative forcing to expect from this. I will also be looking at the nucleation scheme in NorESM and changing it in accordance with recent empirical findings. Tropospheric ozone production can be enhanced by increased BVOC concentrations, and because ozone is a greenhouse gas, we have a positive feedback loop between temperature, BVOC emissions and ozone concentrations. I am interested in how strong this feedback is and how it will play out with vegetation change.

Supervisors: Terje Koren Berntsen (MetOs), Frode Stordal (MetOs), Anders Bryn (Natural History Museum) and Hui Tang (MetOs).

 

Radiative impacts on the cryosphere and its consequence on hydropower potential

Bikas Chandra Bhattarai (Affil: Geo)

I am a PhD working in Geography and Hydrology Section (Geo-hyd), Department of Geosciences, University of Oslo under the supervision of Associate Professor John Faulkner Burkhart and Forde Stordal.  I am interested in evaluating the radiative impact on hydrology. My PhD research topic is  “Radiative impacts on  the cryosphere and its consequence on hydropower potential”. I Joined LATICE in December 2015. I am intended to use SHYFT (Statkraft Hydrologic Forecasting Toolbox) for my research.

This work will require quantitative analysis of datasets from climate model output and preparation of observational datasets for model validation. For LATICE, I will be involved in the activities such as snowpack measurement from UAS and instrument setup. Now I am in contact with Norwegian Northern Research Institute (NORUT) and Statkraft.

 

Closing the water balance in glaciated and non-glaciated catchments

Sven Decker (Affil: Geo)

Middalselvi, Finse
Discharge station Middalselvi, Finse. Current instrumentations includes water pressure sensors sending data to base station and auto sampler to take water samples automatically once a day. Picture: Sven Decker

I am a PhD student working at the Section of Geography and Hydrology, Department of Geoscience, University of Oslo. My PhD started in October 2016 and is funded by LATICE. My research interests lie in the field of arctic and alpine hydrology, especially in hydrological land-atmosphere interactions. In my work I will investigate the importance of sublimation and evapotranspiration in high latitude catchments. My study site is near Finse, Norway, including to contrasting catchments – a glaciated and a non-glaciated.

Besides historical meteorological data (e.g. MET), I will use short time series from the Wireless Sensor Network (WSN), both the central and mobile LATICE Flux stations to set up a hydrological model for the area and to see what is the added value of short time series. For this, Statkraft’s Hydrological Forecasting Tool (SHyFT) will be used and supplemented by a advanced routine for calculating sublimation and evapotranspiration. In terms of model accuracy and complexity this model will be compared to WRF-Hydro in cooperation with the EvoGlac project.

My PhD is supervised by John F. Burkhart (co-leader of LATICE and Associate Professor), Jan Magnusson (NVE), Tor Sverre Lande (IFI) and Lena M. Tallaksen (leader of LATICE).

 

Imaging radar instrument for eco/cryo hydrological data collection improving observation density and observation accuracy in remote locations

Håvard Eriksrød (Affil: IFI)

Imaging radar instrument for eco/cryo hydrological data collection improving observation density and observation accuracy in remote locations. Photo: Håvard Eriksrød

PhD student at Nano group, Department of informatics. Graduated from NTNU in 2013 with an emphasis on microelectronics. Considered recreational analog designer by friends. Worked with adaptive radio systems at Kongsberg Defence for a couple of years. I joined the LATICE project November 2015. Primary research interests are broadband antennas, radio electronics, radars, and UWB.

PhD project on imaging radar instrument for snow and ice exploring coupled broadband antennas in combination with miniaturized radar technology. Exploring low-power short-range radio, radar-instrument may be interconnected for networking operation covering larger areas still operation on battery power (Wireless Sensor Networks).

 

Land-atmosphere interaction on the Norwegian mainland: 1: coupled model sensitivity studies; 2: validation and aggregation of forcing data for stand-alone energy-balance LSMs; 3: evapotranspiration estimates: complexity and vegetation dependence

Helene B. Erlandsen (Affil: Geo, NVE, met.no)

Land-atmosphere interaction on the Norwegian mainland. Photo: Helene B. Erlandsen

I am a PhD. student working in a collaboration project between the Norwegian Water Resources and Energy Directorate (NVE), Section for Geography and Hydrology at the Department of Geosciences, UiO, and the Norwegian Meteorological Institute on land atmosphere interaction in mainland Norway. The research project started in the fall of 2012, and the work has been contributing to LATICE since its formal start in January 2015.

The first part of the project looked at the sensitivity of the surface water and energy balance on Norway’s mainland, as modelled in a regional weather forecasting and climate model (WRF), to increases in snow and vegetation cover, and sea surface temperature (SST).  We are further working on compiling and validating a high (up to 1 km) resolution data suitable for energy balance modelling in Norway. The latter part of the project focuses on the effect of employing different formulas for well-watered evapotranspiration (ET) estimates, and further, the sensitivity of these formulas’ transpiration estimates to vegetation changes.

My supervisors are Lena M. Tallaksen, Ingjerd Haddeland, and Jørn Kristiansen. In my work with the WRF model I have benefited greatly from collaborations with Johanna Rydsaa and Kjetil S. Aas in MetOs.

 

Ecological Climatology and Distribution Modelling (Comparing and validating different approaches of vegetation modelling)

Peter Horvath (Affil: Geo, NHM)

Ecological Climatology and Distribution Modelling. Photo: Peter Horvath.

I am a PhD student working in collaboration with both the Department of Geosciences (MetOs) and the NHM on LATICE project. My specific contribution to the LATICE project is in the vegetation-atmospheric interactions. I will compare outputs from two different modelling approaches: Dynamic vegetation modelling and Distribution modelling, and then suggest possible ways of improving the parameterizations of dynamic global vegetation model (DGVM) in the boreal vegetation.

I will concentrate on modelling Plant Functional Types and on improving their representation in the DGVM. In addition, I will model tree and forest line in the boreal zone as its contribution to the arctic amplification seems to be very important. This will be done by studying historical data on the extent of tree and forest line in parts of Norway, supplemented by modelling of their current distribution. On these topics I’m working together with Frode Stordal and Hui Tang (MetOs) as well as Anders Bryn and Rune Halvorsen (NHM).

 

Modelling the role of permafrost in the carbon cycle

Håvard Kristiansen (Affil: Geo)

I am a PhD student affiliated with the Section for Geography and Hydrology at the Department of Geosciences. I am part of a group of researchers lead by Sebastian Westermann who are developing the Cryogrid permafrost model.

My task is to implement biogeochemical processes into the model, with an emphasis on the aggregation and decomposition of soil organic carbon. This is of interest because permafrost contains a lot of carbon, which may decompose into carbon dioxide (CO2) or methane (CH4) when the climate gets warmer and the permafrost thaws. CO2 and CH4 are greenhouse gases and their release into the atmosphere would therefore contribute to further climate warming. This effect is known as the permafrost carbon feedback.

Our first goal is to simulate how carbon has accumulated in permafrost since the last ice, and validate our model results against field observations of the amount and age of permafrost carbon. Such a model will allow us to test the relative influence of different variables such as temperature, drainage, rate of sedimentation etc. on the rates at which carbon enters and leaves the soil.

Our second goal is to simulate the net emissions of CO2 and CH4 given specific future climate trajectories in order to estimate the scale and relative importance of the permafrost carbon feedback over the next century.

My supervisors are Sebastian Westermann (UiO), Kjetil S. Aas (UiO) and Bo Elberling (University of Copenhagen).

 

Water isotopes

Mika Lanzky (Afill: Geo)

I am a PhD student student in Section of Geography and Hydrology (GeoHyd), Department of Geoscience at University of Oslo. I started in January 2018. I am funded through the NFR project SNOWPACE. Besides LATICE, I am also affiliated with Geophysical Institute at University of Bergen and Section for Meteorology and Oceanography at University of Oslo.

My research focuses on locating the source regions of the Norwegian snowpack using two different methods: Lagrangian moisture tracking and stable water isotopes. Finse research station is used as a field site, but also sampling of a larger part of Norway is planned.

The method used for moisture analysis tracking is WaterSip. Geographical differences in Norway will be investigated, and the moisture transport situation under different climate indices, for example NOA, will be explored. Snow samples will be taken during the winter season and at peak snow pack. These samples will be measured for stable water isotopes at FARLAB at UiB, both for δ18O and δD, but also for the even rarer  δ17O. The goal is to investigate whether the isotope main and derived parameters also can be used as a moisture source signal.

My supervisors are John F. Burkhart (GeoHyd, UiO, co-PI of SNOWPACE, Harald Sodemann (GFI, UiB, PI of SNOWPACE), Trude Storelvmo (MetOs, UiO), and Norbert Pirk (GeoHyd, UiO)

 

Detecting and attributing causes of temperature trends in Europe to either changes in atmospheric circulation or other factors (including land-atmosphere feedbacks)

Irene Brox Nilsen (Affil: Geo)

temperature trends in Europe to either changes in atmospheric circulation or other factors. Figure Irene B. Nilsen

I started my PhD work in hydrology at the Department of Geosciences in 2012, and have been contributing to LATICE since its formal start in January 2015. My PhD project focuses on recent trends in the temperature and precipitation, more specifically to attribute these trends either to changes in the atmospheric circulation, or to other factors. Other factors may include feedbacks between the land surface and the atmosphere, such as albedo feedbacks or soil moisture-temperature feedbacks.

The analyses are performed on each month individually to reveal strong trends related to short-term processes, for instance changes in snow storage. We detect regions and months experiencing significant trends that cannot be attributed to atmospheric circulation, and seek the cause of those trends. The Noah Land Surface Model is used to investigate the role of feedbacks between land and atmosphere under a changed climate. As a part of the PhD degree, I spent three months at IIASA in Austria to analyse sensible and latent heat fluxes in dry and wet years. 

My research interests include historical trends in hydroclimatology, climate change impacts on hydrology, extreme value and time series analysis. My supervisors are Lena Tallaksen, Chongyu Xu and Frode Stordal.

Irene Brox Nilsen had her disputation at Department of Geosciences, UiO on 14.11.2017.

 

Vegetation-atmosphere interactions in the northern European boreal region

Johanne H. Rydsaa (Affil: Geo)

Vegetation-atmosphere interactions in the northern European boreal region. Figure: Johanne H. Rydsaa

I am a PhD student at the Meteorology and Oceanography Section (MetOs), Department of Geosciences. I have been contributing to LATICE since its formal start in January 2015, and my focus is on Vegetation-hydrosphere-Atmosphere interactions in a changing climate. More specifically, I have studied the effects on the northern European boreal atmosphere, of biophysical changes in the land surface resulting from structural vegetation perturbations.

In this work I used the Weather Research and Forecasting model (WRF) with the NOAH land surface model, and applied structural changes to the boreal vegetation, based on observed and anticipated migration trends related to global warming. I have previously also studied the effect of near-surface ozone on vegetation using the same model, coupled with an online chemistry module (WRF-Chem).

My current project is related to the observed shrub expansion in tundra regions in Fennoscandia and its effect on the regional climate. My supervisors are Frode Stordal and Lena M. Tallaksen. In addition, I am collaborating with postdoc Hui Tang and Terje Berntsen from MetOs.

Johanne Hope Rydsaa had her disputation at Department of Geosciences, UiO on 29.9.2017.

 

Mapping and distribution modelling of nature types in Norway

Heidrun A. Ullerud (Affil: NHM)

Mapping and distribution modelling of nature types in Norway. Photo:Heidrun A. Ullerud

I’m doing a PhD in the Geo-ecological research group at the Natural History Museum (NHM). I started my PhD in July 2014, and have been part of LATICE since it started. The topic of my work is mapping and modelling of vegetation and nature types. I work with traditional mapping approaches, such as mapping in field and mapping from aerial photos, as well as with the more experimental distribution modelling of vegetation and nature types.

The intention of my work is to improve mapping methods and quality in the resulting maps. This relates to LATICE as my work can give a quality measure of actual field data for vegetation, and also speed up the mapping progress. My PhD is supervised by LATICE-members Anders Bryn and Rune Halvorsen at NHM.

 

 

 

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Published Feb. 1, 2016 2:57 PM - Last modified May 29, 2020 3:28 PM