Research profiles of Junior Scientists involved in REKLIM

Patrick Ludwig, Karlsruhe Institute of Technology (KIT)

Patrick Ludwig received his doctoral degree at the Institute of Geophysics and Meteorology at the University Cologne in 2014. The topic of his PhD-thesis was about “Regional modelling of severe European winter storms”. In the following position within the “CRC806 – Our way to Europe”, the already gained experiences were extended by aspects of regional paleoclimate modelling. The main focus here was on the period of the Last Glacial Maximum (LGM, 21.000 years ago) in Europe. Particularly the connection of different fields of research (meteorology, climate research, geography, geology, archaeology) has proved to be beneficial to answer paleoclimate problems. Since August 2017, Patrick Ludwig is part of the working group ‘Regional climate and weather hazards’ at the Institute of Meteorology and Climate Research (IMK) at the Karlsruhe Institute of Technology (KIT). Here, the main focus is still on aspects of regional (paleoclimate) modelling and the understanding of mechanism leading to severe weather events. “In REKLIM, topic 6 plays an important role, since it provides multiple possibilities to combine these focus areas. Additionally, the interdisciplinary exchange between different research facilities provides impetus to address new research topics”, explains Patrick his enthusiasm for REKLIM. (Juli 2020)   

Philipp Franke (IEK-8/Research Center Jülich and Rhenish Institute for Environmental Research, University of Cologne)

Philipp Franke studied meteorology at the University of Cologne. In his Bachelor thesis he analyzed the channeling effect in valleys in dependence on the models horizontal resolution. In his Master thesis he initiated his doctoral work by a quantitative estimation of volcanic ash emissions. In the end of 2017 Philipp Franke finished his phd, which focused on the development of a stochastic analysis system for volcanic ash emissions. This included an ensemble-based data assimilation method for the uncertainty assessments of volcanic ash emissions. Therefore, the chemistry transport model EURAD-IM (EURopean Air pollution Dispersion – Inverse Model) was extended to an ensemble system. During his PhD he gained experience in parallel computing on high performance computer. After his PhD he is engaged as a post-doc at Research Center Jülich and Rhenish Institute for Environmental Research for the task of causer-specific optimization of national emission inventories using four-dimensional variational data assimilation. Besides, he proceeds developing the stochastic analysis version of the EURAD-IM with the application to more complex emission events like forest fires and mineral dust releases. (February 2018)

Anne Caroline Lange, Institute for Energy and Climate Research – Troposphere (IEK-8), Research Centre Jülich und Rhenish Institute for Environmental Research at the University of Cologne

Anne Caroline Lange studied meteorology at the University of Cologne between 2008 and 2013. In her Bachelor thesis (B. Sc. Geophysics and Meteorology), she worked on the evaluation of volcanic ash dispersion simulations and in her master thesis (M. Sc. Physics of the Earth and Atmosphere), she investigated the vertical distribution of volcanic ash with variational data assimilation analyses. Staying within this research area, she did her PhD in Meteorology working in the research group of “regional and inverse modeling” at the Institute for Energy and Climate research – Troposphere (IEK-8) at the Research Centre Jülich and at the Rhenish Institute of Environmental Research at University of Cologne. She completed her dissertation in early 2018. Her special expertise includes data assimilation of aerosols and chemical atmospheric compounds with a focus on the usage of remote sensing data. Therefore, she developed different observation operators for the chemistry transport model EURAD-IM (EURopean Air pollution Dispersion – Inverse Model). Furthermore, she investigated in detail the observability of air pollutants exploiting ensemble analyses. She experienced work abroad during a research visit at the European Centre for Medium-range Weather Forecasts in Reading (ECMWF) and as guest scientist at the Norwegian Institute for Air Research in Kjeller (NILU). As a Postdoc at IEK-8 at Research Centre Jülich, she gets mainly involved with the development aiming for the causer-specific optimization of anthropogenic emissions. Therefore, she concentrates among other things on the adequate usage of diverse observational systems even with regard to new satellite missions (e. g. EarthCARE). (February 2018)

 Svetlana Losa, Alfred Wegener Institute (AWI)


Svetlana Losa completed her PhD in Physics and Mathematics at the Russian State Hydrometeorological University (Department of Oceanography) in 1998. Since that time she has been working on coupled ocean physical/biogeochemical modelling and data assimilation at the St. Petersburg Branch of P.P.Shirshov institute of Oceanology (Russian Academy of Sciences, Russia), the Alfred Wegener Institute for Polar and Marine Research (Germany) and  the Dalhousie University, Department Oceanography  (Canada). In 2004 she joined the AWI Climate Department to conduct some researches on the synergy of modelling and observational studies within a number of EU projects (DIADEM, MERSEA, MyOcean) and National German projects (DeMarine Environment) focussing on developing ocean data assimilative forecasting systems for operational applications. Since 2015 Svetlana is in the AWI PHYTOOPTICS group led by Astrid Bracher and continues modelling ocean biogeochemistry in support to satellite retrievals on phytoplankton diversity under the rapidly changing climate in the Polar regions.
(November 2017)

Annika Vogel - IEK-8 (Troposphere), FZJ and Rhenish Institute for Environmental Research, Uni Cologne

Annika Vogel studied Geophysics and Meteorology (B.Sc.) and Physics of the Earth and Atmosphere (M.Sc.) with focus on Meteorology at the University of Cologne. As a student assistant in the chemical data assimilation group at the Rhenish Institute for Environmental Research (RIU) she was working on correlation modeling within the assimilation algorithm of the regional chemestry-transport-model EURAD-IM. For analyzing the chemical composition in the extratropical upper troposphere and lower stratosphere, she used in addition high-resolution remote-sensing observations from the GLORIA-instrument.
Since October 2016 she is PhD student at the Institute of Energy and Climate Research 8  (Troposphere) of the Research Center Jülich. Working on “Predictability of atmospheric reactive gas composition by probabilistic chemistry transport modeling”, the goal is the analysis of uncertainties in chemical predictions by EURAD-IM with stochastic modeling techniques.
(December 2016)

Ha Ho-Hagemann (HZG)

Ha Ho-Hagemann studied meteorology in the Honor Program for Talented Students of Hanoi National University in Vietnam, where she got her PhD. in 2008. After the PhD., she was a lecturer and researcher at Hanoi University of Sciences. Since August 2010, she is a postdoc at the Institute for Coastal Research at the Helmholtz-Zentrum Geesthacht. Her study of atmosphere-ocean-sea ice coupling fits into the REKLIM Topic 1. Air-sea interactions and feedback are very important processes to bridge two main components, atmosphere and ocean, of the climate system but they were often neglected in former stand-alone regional atmospheric or ocean models. Developing an air-sea coupled system model fills the gap at the interface of the atmosphere and the ocean where they exchange heat, moisture and momentum. Ha has successfully set up two coupled system models COSTRICE and CCLM+NEMO-Nordic for the North and Baltic Sea regions. Currently, she investigates the potential benefits of air-sea coupling within these models, especially with regard to the simulation of extreme events. This will also lead to an increased understanding of the generation of extreme events over Central Europe, which will be used to conduct future climate change projections over Europe.
(September 2016)

Anja Sommerfeld, Alfred-Wegener-Institut Helmholtz-Zentrum für Polar und Meeresforschung, Potsdam

more information available in German


Hannes Konrad (GeoForschungsZentrum Potsdam, GFZ)

more information available in German


Xu Zhou (Alfred-Wegener-Institut Helmholtz-Zentrum für Polar und Meeresforschung, Potsdam)

Xu Zhou studied at the Hebei University in Boading, China, with a major in Physics and continued his studies at the Institute of Geology and Geophysics, at the Chinese Academy of sciences in Peking with a major in Geophysics, focusing on mass density simulations of the middle to upper atmosphere. After receiving his master's degree he started his PhD study in January 2011 at the Alfred-Wegener-Institute Helmholtz Centre for Polar and Marine Research in the section Atmospheric Circulations. Within the framework of REKLIM Topic 1 he worked on the regional atmospheric-land coupling of HIRHAM5-CLM4.0, analysing atmosphere-land interaction processes and evaluating model results in respect of associated physical mechanisms.


Zoi Paschalidi, Rheinisches Institut für Umwelt-forschung, Universität zu Köln

Zoi Paschalidi has studied Applied Mathematics and Physical Sciences at the National Technical University of Athens, Greece. In November 2011, she started working in the Rhenish Institute for Environmental Research at the University of Cologne in the Chemistry Data Assimilation group of PD Dr. Hendrik Elbern, as PhD student in Meteorology. Her scientific activities were in the frame of REKLIM Topic 5 ‘Atmospheric composition and climate: Interactions from global to regional scales’ (former Topic 9), where the main intension was to demonstrate the feasibility of estimating the anthropogenic emissions over urban areas, within the planetary boundary layer (PBL), by 4D-var techniques in a regional dispersion model, the EURAD-IM. Last October, Zoi Paschalidi defended successfully her Dissertation on 'Inverse modelling for the tropospheric chemical state estimation by 4-dimensional variational data assimilation from routinely and campaign platforms'.


Ulrike Böttjer (Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, AWI)

more information available in German

Edith Maier (Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, AWI)

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Stephan Thober (Helmholtz-Zentrum für Umweltforschung, UFZ )

Stephan Thober studied mathematics at the university of Greifswald with a major in stochastic. He started his doctoral studies at the Helmholtz-Centre for Environmental Research after his diploma thesis in January 2011 within the WESS project ( in the group of Dr. Luis Samaniego. He investigated methods for the evaluation and stochastic disaggregation of climate model outputs for hydrological modelling. Stephan Thober then applied the developed methods within the REKLIM project in topic 6 "Modelling and Understanding of Extreme Meteorological Events"to evaluate the skill of seasonal meteorological forecasts for agricultural drought prediction.
(Juni 2015)

Insa Lohse, Institut für Energie- und Klimaforschung: Troposphäre, Forschungszentrum Jülich (FZJ)

more information available in German

Fabian Eder (Institut für Meteorologie und Klimaforschung – Atmosphärische Umweltforschung IMK-IFU, Karlsruher Institut für Technologie KIT)

more information available in German

Katharina Klehmet, Institute of Coastal Research, Helmholtz-Zentrum Geesthacht (HZG)

Katharina Klehmet studied Geography at the Rheinische Friedrich-Wilhelms University of Bonn with minors of Meteorology and Geophysics. After her Diploma thesis at the Max Planck Institute for Meteorology in Hamburg she began her PhD thesis at the Institute of Coastal Research at the Helmholtz-Zentrum Geesthacht in February 2010. Within topic 3 “Arctic Change” of the REKLIM project she worked on the reconstruction of recent and past climate in Siberia using the regional climate model COSMO-CLM. She focused on the consideration of snow cover in Siberia and its changes and variability during the last decades. Since January 2014 Katharina has been working as postdoc in the working group “regional atmospheric modelling” dealing with the investigation of temporal consistency of reanalyses over Siberia and their impact on dynamical downscaling among others.
“I like in REKLIM the aim to combine the expertise of all single research centers within the Helmholtz Association to jointly investigate the wide aspects of regional climate changes.”

Katrin Kohnert, Deutsches GeoForschungsZentrum (GFZ)

more information only available in German

Sebastian Goeller, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI)

Sebastian Goeller studied physics with particular emphasis on computational physics, statistical physics and nonlinear dynamics at the Humboldt University of Berlin. In his diploma thesis, he modeled foraging strategies and swarming behavior of animals. Following his studies, he worked as a software developer in the field of mobile communications until he started his doctoral studies within the REKLIM project at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, in Bremerhaven in June 2010. He draw up his PhD thesis in glaciology within the department of geosciences, where he investigated lakes and water flow beneath the Antarctic Ice Sheet with a special focus on the numerical modeling of interactions between subglacial hydrology and ice dynamics. Since January 2014, Sebastian has been working as a postdoc in the department of climate sciences, where his work concentrates on the coupling of sea-ice/ocean- and ice-shelf/ice-sheet-models in the region of the Antarctic Weddell Sea.
“REKLIM offers the outstanding possibility to link the different perspectives of the Helmholtz research centres on regional climate change and thus gain deeper insights into the complex climate system of the Earth“

(January 2015)

Daniel Klaus, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI)

Daniel Klaus is a physicist, who was educated at the University of Potsdam and has worked on his dissertation, belonging to REKLIM Topic 1, since April 2010. Validation and improvement of the Arctic cloud parameterization in the atmospheric regional climate model HIRHAM5 was based on reanalysis data as well as surface‐ and satellite‐based observations. The results have shown both the vast importance to realistically simulate the cloud cover, cloud levels and water phase of cloud particles and the key role of clouds for the surface energy budget in the Arctic. Even after finishing his doctorate in June 2014, Daniel Klaus stayed at AWI‐Potsdam and works now as a postdoc, extending also the
collaboration with the NASA Goddard Space Flight Center.
”REKLIM enables the interdisciplinary exchange and looks at the climate system from various angles. Nevertheless, the improvement of physical parameterizations in climate models on the basis of observations is a prerequisite for credible climate projections.” (Oktober 2014)

Celia Martin-Puertas, GFZ German Research Centre for Geosciences

Celia is interested in the Reconstruction of Past Global Changes in terms of climatic, environmental and human-induced shifts. She completed her BSc in Marine Science from University of Cádiz (Spain) in 2002, an MSc in Marine Geology in 2004, and a PhD focused on applying multiproxy analyses on lake sediments to reconstruct environmental and climate conditions during the Late Holocene in July 2008. After finishing her PhD, she moved to Potsdam to undertake a Postdoctoral research fellowship funded by the Alexander von Humboldt Foundation at German Research Centre for Geosciences. This project focused on detailed reconstruction of the Holocene climate evolution at seasonal resolution using annually laminated lake sediments (varve) in order to identify natural climate variability in central Europe and the role of solar forcing. Since 2012 she became a member of the REKLIM team as a postdoc researcher specialized in varved sediments and palaeoclimatology.
"Applying the REKLIM approach to combine proxy data and climate modeling for a better understanding of mechanisms, processes and regional climate patterns intensifying abrupt climate changes during interglacials-glacial transitions makes my research innovative and gives me the fruitful experience of collaborating with colleagues from other scientific disciplines”. (Juli 2014)

Corinna de Guttry, Helmholtz Zentrum Geesthacht

Corinna de Guttry is as PhD candidate at the department of “Human Dimensions of Coastal Areas” of the Helmholtz Zentrum Geesthacht. After completing an undergraduate degree in Natural Sciences, she earned an Erasmus Mundus Master Degree in Water and Coastal Management from the Universities of Plymouth (UK) and of Cadiz (Spain). Notwithstanding her background in natural sciences, she recognized very early that the role of social sciences does not consist of communicating “scientific knowledge” to the public. Rather, humanities and social research are essential in understanding the interaction between society and the environment and in providing the appropriate knowledge to manage it.
Within the context of REKLIM and Topic 10, her interest lies in unraveling the interplay between the framing of climate change on a regional level, culture and place: her research focuses on migrants’ perception of climate change in the hosting country. Corinna’s study is methodologically based on grounded and qualitative approaches, and applies environmental psychology and other theoretical frameworks to uncover how different groups of migrants living in Hamburg frame climate change. Despite the fact that migrants represent almost 15% of the population, they are largely absent in the research on climate change framing. In order to develop and implement appropriate adaptation measures, this part of the society should not continue being invisible, rather they are a great opportunity to reflect on our own constructs and worldviews.

“The fact that I am a migrant myself had certainly an impact on the decision of involving them in my study. The strength of REKLIM lies in the pooling of diverse scientific cultures and the creation of spaces to meet and exchange ideas. REKLIM provides an excellent and challenging opportunity to look at climate change from different perspectives and to try to productively merge them”. (Mai 2014)

Matthias Zahn, Helmholtz Zentrum Geesthacht

please see German version for more details.

Rémi Thiéblemont, GEOMAR

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Alexey Vlasov, Karlsruher Institut für Technologie

Alexey Vlasov has been studying meteorology at Russian State Hydrometeorological University in Saint-Petersburg, Russia. Within his bachelor and master thesises Alexey has been investigating atmospheric waves and dynamical coupling of atmospheric layers. He also been involved in several projects covering ionospheric physics, radio science and aerosol science. After his graduation at 2007 Alexey has been for several years workimg for the Arctic Research at Finnish Meteorological Institute in the field of upper-atmospheric and auroral research with particular focus on EISCAT incoherent scatter radars.
Since 2010 Alexey is a doctoral student in the global modeling group at the Institute for Meteorology and Climate Research of Karlsruhe Institute of Technology. The aim of his work within REKLIM Topic 5 "Chemistry-climate interactions on global to regional scale" is the investigation of the role of gravity waves in the transport of trace gases. Gravity wave drag is most relevant for the downward transport of NOx produced by energetic particles in the mesosphere and lower thermosphere region. The current activities are focused on the vertical extension of the climate-chemistry model system EMAC into the Mesosphere-Lower Thermosphere region. The full chemistry-climate model spanning from the surface to the lower Thermosphere should be able to simulate NOx intrusions and similar process from the very source up to the implications on the global and regional climate.
"For me the REKLIM is a great opportunity to extend my knowledge on the fields which are typically outside of the scope of the global modeling. To work with complex modelling systems like EMAC one should have a good picture of not only atmospheric processes, but also of processes in ocean, soil, lakes and rivers which are happening on the regional scale. It also important that REKLIM addresses social aspects of the climate and climate science". (February 2014)

Haiyan Lu (PhD), IMK-IFU, KIT

Haiyan Lu obtained her bachelor degree in Ecology in 2003 and her master degree in Soil Microbiology in 2010 at Lanzhou University, China. Since November 2010 she is working as a PhD in the department of Biogeochemical Processes at the Karlsruhe Institute for Technology, IMK-IMU in Garmisch-Partenkirchen, Germany. Her work is embedded into the REKLIM and TERENO projects and focuses on the impact of climate change on greenhouse gas emissions (CO2, N2O, CH4) from grassland soils in the TERENO Bavarian Alps / pre- Alps observatory by use of manual but also highly technical automatic chamber systems .
"Long-term region specific climate change research like in REKLIM allow obtaining highly relevant experimental data for overall knowledge improvement and testing and validation of numerical models applied in the framework of climate change feedback studies."

Torsten Sachs, Deutsches GeoForschungsZentrum

Torsten Sachs studied geoecology at Technische Universität Braunschweig before joining Alaska Pacific University Anchorage (USA) as a Fulbright graduate student in 2002 and obtaining a Master of Science in Environmental Sciences in 2003. After one year of employment at the Barrow Arctic Science Consortium (BASC) he moved to the Alfred Wegener Institute's Periglacial Research Section in Potsdam to start his PhD studies in 2005. Until January 2009 he worked on land-atmosphere interactions and studied methane emissions from permafrost landscapes on various spatial scales in the Lena River Delta, Siberia.
Since 2009 Torsten Sachs has been a young scientist at the GFZ German Research Centre for Geosciences and in 2012 he established his Helmholtz Young Investigator Group TEAM (Trace Gas Exchange in the Earth-Atmosphere System on Multiple Scales). His research focus is the quantification of greenhouse gas fluxes and understanding the underlying processes in circum-polar permafrost landscapes and re-wetted peatlands in northeastern Germany. Since 2011, airborne eddy covariance flux measurements have played an important role in the ongoing work to understand energy and gas fluxes between permafrost and atmosphere on a regional scale, e.g. within the framework of the joint AWI-GFZ AIRMETH campaigns (Airborne Measurements of Methane Flux) aboard the research aircraft Polar-5.
„REKLIM is an important contribution to interdisciplinary networking and focuses the attention
on the regional scale. Especially the latter is something I have missed before REKLIM – or something
I haven't noticed enough due to a lack of the former.“
(November 2013)