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)


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)(November 2017)

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)







(Juni 2015)



“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.”


“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 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)

"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)

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)



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)

"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)