Exkursion 2023 Bericht

15th October 2023 - Garzweiler opencast mine
It feels a bit like being on the moon, or in the middle of a war zone: A huge crater, many square kilometres wide and more than 100m deep. Everywhere just brown and black earth, big machines, conveyor belts. In the distance large clouds that rise from the towers of two power plants. But it is not a war zone we are looking at. It is the brown coal opencast mine Garzweiler II in North Rhine-Westphalia.
For more than 100 years lignite has been mined here in the area around Garzweiler. Here, the company RWE Power produces each year approximately 25 million tons of lignite on an area of 31km² between Bedburg, Grevenbroich, Jüchen, Erkelenz and Mönchengladbach. There are an estimated 1.3 billion tons of lignite in the entire of Garzweiler II. The coal is transported to the Neurath power plant, among other places, where it is used to produce energy.
Garzweiler II is part of the Rhenish lignite mining area, which is the biggest in Europe. In this region lignite was formed under pressure and airtight seal in the past 30 – 5 million years. Lignite is produced from turf. Hard coal is older than lignite and comes later in the process of coalification. Unfortunately, lignite is even more climate-damaging than hard coal. To gain 1 kWh of energy, 980-1230kg CO2 are emitted. For hard coal it is “only” 790-1080 kg. Since lignite has a lower energy value than hard coal (7300-12.000 kJ/kg for lignite vs. 32.000-36.000 kJ/kg), you need three times more lignite than hard coal for the same amount of energy.
Aside from the huge amounts of CO2 that are emitted in order to gain energy from coal, especially lignite, and the devastating impacts that has on global climate, there are also other disadvantages of opencast mining. Many villages had and have to be evacuated to make room for the giant pit. Thousands of people lost their home, the houses they had perhaps lived in for generations. For the mining process the groundwater level must be lowered, which poses problems to the sourrounding nature. Furthermore, ecosystems are destroyed for the coal mines.
The mining work in Garzweiler II is supposed to come to an end by 2030. Germany wants to phase out coal energy by 2038, better before 2030. Then all mines such as Garzweiler II can be recultivated or renaturalized, e.g. as a lake, and new ecosystems can be created.

16th October 2023 - Research Centre Jülich
On the second day of the excursion we visited the Forschungszentrum Jülich. It was founded in 1956 as a nuclear research institute. Over the years, the research has expanded to more areas, so that today Jülich is a large-scale research centre with 11 institutes and about 80 sub-institutes. The original nuclear research has been rebuilt further back within the last years, so now a tree could be planted in the place of the first reactor. Overall, the large area of the facility includes a variety of materials such as a supercomputer, a weather tower, a daylight simulation chamber and much more.
If possible, the research is also applied directly, for example in the heat circuit, which keeps the facility at a good temperature. Furthermore the research in Jülich can be experienced by students in JuLab, a program for schools to visit Jülich.
On our day in the research facility we visited two institutes, the Institute of Energy and Climate Research and the Institute of Advanced Simulation.

IEK-7 - Stratosphere
After arrival in Jülich at the Institute for Energy and Climate Research in the department Stratosphere (IEK-7) we were first welcomed by Dr. Christian Rolf. The head of department, Prof. Dr. Martin Riese, then gave us a presentation on the main areas of research and the working groups at IEK-7. The working groups conduct research in the areas of:
- water vapor and clouds,
- ultra-trace substances,
- remote sensing,
- theory and simulation and
- climate data analysis.
Dr. Rolf Müller gave us a deeper insight into the Theory and Simulation department with a presentation on "The Chemical Langrangian Model of the Stratosphere (CLaMS)." CLaMS, which was developed by scientists at IEK-7, is used to analyze satellite data, aircraft and balloon measurements.
With a short video about the research campaign PHILEAS (Probing High Latitude Export of Air from the Asian Summer Monsoon) we were given an insight into the work during a measurement campaign. The measurement campaign, which took place in the summer of 2023, was led by research center Jülich and Johannes Gutenberg University Mainz. In order to investigate the climate impact of the Asian summer monsoon, measurement flights were conducted with the HALO (High Altitude and Long Range Research Aircraft) research aircraft.
We were able to get to know one of the measuring instruments used on the measurement campaign during the final laboratory visits. The infrared spectrometer GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere) is able to measure a variety of trace gases and the temperature three-dimensionally. It belongs to the remote sensing working group and was presented to us by Dr. Jörn Ungermann.
With the measuring instrument FISH (Fast In-situ Stratospheric Hygrometer), which is also used for aircraft measurements, the water content of the air can be determined. The working group Water Vapor and Clouds deals with changes in cloud cover and water content in the tropopause and their effects on the Earth's radiation budget. Dr. Christian Rolf presented the measuring instrument FISH for airplane campaigns as well as the measuring instrument CFH (Cryogenic Frost Point Hygrometer), which is used in balloon campaigns to determine the water vapor content of the air.
Likewise, AirCore instruments can be attached to the weather balloon to collect air samples from the entire air column or from specific altitudes as the weather balloon descends. Dr. Johannes Laube gave us an insight into the measuring instruments as well as into the evaluation of the air samples with the help of highly specialized instruments in the laboratory of the ultra-trace substances working group, with which the trace substance concentrations are determined.

IEK-8 - Troposphere
The Institute for Energy and Climate Research (IEK-8: Troposphere) in Jülich investigates mainly anthropogenic and natural emissions, aerosol production and the composition of the atmosphere.
The research contains for instance field campaigns, zeppelin measurements and airborne research. One important part of the studies at IEK-8 is the SAPHIR chamber.
The SAPHIR chamber (Simulation of Atmospheric Photochemistry In a large Reaction Chamber) is a closed tank enveloped in two layers of teflon film. The gas mixture inside of the chamber is constantly stirred and the cylindrical tank has a light impermeable outer shell, that can be opened to trigger photochemical reactions in real conditions. It is mostly used to simulate atmospheric conditions to study natural and anthropogenic emissions e.g. Ozone.
A second experiment is the SAPHIR-Star (Star= Stirred Atmospheric flow Reactor), which uses artificial light sources to research on single photo-chemical reaction. This enables to find out about formation of secondary organic aerosol and gas phase chemistry in the atmosphere.

Supercomputing Centre
In 1961 the central Institute for Applied Mathematics was established in Jülich. From this the Institute for Advanced Simulation developed, which received the first German supercomputer in 1987, which at that time had a high performance. Today, the institute operates three generations of systems: JUWELS, JUSUF and JURECA; as a new system is developed every 4 to 5 years and computing power is used for more research projects every year. The computing
power is used by scientists from various nations and research fields. So for example at the time of our visit, approximately 15% of JUWELS’ capacity was used for Earth System Research. If a scientist wants to contribute a project for editing, the research centre team helps the user to optimise the code to be used and thus to advance the research.
After the technical and user-related details, our guide at the topic of super computing, Dr. Sabine Grießbach, explained the relationship to climate research. Before the first computers were invented, it was nearly impossible to forecast the weather. To do a 6 hour forecast a person would have to calculate for around 6 weeks. Now that we have computers we can do the calculations faster and more efficient. Thus the calculations can get more complicated and different variables can be accounted for, like ground influence, sea ice and aerosols. Large-scale models can now be created from measurement data and simulations. At last we visited the hardware, although we could not enter the room itself due to high temperatures. We were informed about the peculiarities of the cooling system and the extinguishing system.The cooling takes place with 30°C to 40°C hot water, which is heated by 20°C as it passes through the room and thus no condensation occurs on the computers. The special feature of the extinguishing system is that it is not equipped with water but with argon, so that during use only the burning components can be damaged, but not the surrounding hardware.
We ended our tour with a little game that showed us the importance of a good network between the individual modules and ended the day at Forschungszentrum Jülich.

17th October 2023 - University of Wageningen
After breakfast at the Fletcher Hotel-Restaurant De Wageningsche Berg on the morning of October 17th, we went straight to the nearby University of Wageningen, the most sustainable university in the world. We arrived there at 8:30 a.m. and were directly taken to the Department of Environmental Sciences, the headquarters of the Meteorology and Air Quality Group (MAQ), where some lectures were prepared for us. First, we were given an insight into the various research areas. The group ́s research aims to contribute to the further understanding of atmospheric processes and their relevance for weather, atmospheric composition and climate. The focus lies on land-atmosphere interactions, especially plant interactions, the atmospheric boundary layer and connections with hydrology.
At the University of Wageningen you can study for a bachelor's degree in environmental sciences and soil, water and atmosphere. The university also offers the master's degree programs climate studies, earth and environment and environmental sciences. Every year 30 to 40 students start these courses. A total of 12,000 people study at that very international university. Studying in Wageningen offers close contact with teachers, practical training, excursions, field work and practice groups.
After the lectures, at 9:30 am, we were given the opportunity to get an insight into some PhD theses at a poster session. Over coffee and cookies, we were able to talk to the respective students about their work until 10:30 a.m. Afterwards, we made our way to the university's own weather station in bright sunshine.
Weather Station De Veenkampen
The De Veenkampen weather station is a fully automatic weather station that belongs to the University of Wageningen. Wageningen University has been carrying out meteorological observations since 1919. However, due to urban expansion, the station has had to be relocated twice and is now located in a nature reserve west of Wageningen. The undisturbed
location in a natural wetland and grassland area in the center of the Netherlands allows representative observations of the rural background climate. The Netherlands is very densely populated, so De Veenkampen station, with its very central, rural and undisturbed location far from built-up areas, highways, forests and wind turbines, represents a unique and important location for weather observations and measurements in the Netherlands.
The De Veenkampen weather station was put into operation in 2010. It provides the longest global radiation record in the Netherlands. In addition, continuous measurements of the total energy budget (i.e. the sensible and latent heat flow), the ground heat flow and the radiation budget (including direct and diffuse solar radiation, as well as short-wave and thermal radiation observations) are recorded here. Furthermore, continuous measurements of the groundwater level, soil moisture and soil temperature profile up to a depth of 1.5 m are carried out. In addition to measuring devices for precipitation, fog and dew collectors, we were introduced to measuring devices for wind direction and speed. Also worth mentioning is the building belonging to the measuring station, which was built into a low hill. Here you will find measuring devices that record the continuous flow of greenhouse gases in the atmosphere. This includes continuous observations of air pollution from soot and other substances containing carbon and nitrogen.

17th October 2023 - KNMI
After the visit in Wageningen we met with our busdriver and took off towards the KNMI (Koninklijk Nederlands Meteorologisch Instituut). Upon arrival we were welcomed and a tight program of talks and tours throughout the institute started. Our first speaker of the day shortly presented the KNMI to us, talking about its history, departments and tasks. These include monitoring the seismology of the Netherlands, weather- and climate prediction, monitoring the weather 24/7 and scientific research. What came as a surprise is that the KNMI does not only provide weather-services for the dutch mainland but also overseas provinces that are located in the Caribbean. The weather on these islands (Bonaire, Sint Eustatius and Saba) is rather different to the european one. For example it is important to monitor and predict the movement of hurricanes. For this purpose, the KNMI works together with the US-meteorologic institution, the NWS. The second speaker of the day was a geophysicist who gave a talk about the seismological branch of the KNMI and gave us some general information about their measurement network and examples on how earthquakes can be detected. He showed us a video of of how an earthquake that happened in Japan was detected in the US. Contrary to our believe, the Netherlands are not free of earthquakes although these are mostly not due to tectonics but rather man-made earthquakes due to former gas-extraction in the north of the country.
It followed a talk on ocean- and climate research. The speaker talked to us about the importance of the ocean in climate modeling and the climate model they are using: the EC Earth (operated by member-states of the European Union). It is an earth system model which includes modules for simulating dynamic vegetation, atmospheric chemistry, interactive aerosols, ocean bio-geochemistry, the carbon cycle and the Greenland ice shield. The vertical data for the ocean model is measured by the Argo program – an international program that collects information from inside the ocean using a fleet of robotic instruments that drift with the ocean currents and move up and down between the surface and a mid-water level.
A short break was then followed by a final talk on the weather and climate models that are being used at the KNMI and how these models are nested into each other. As a global model the ECMWF IFS is used (European Center for Medium Range Weather Forecast Integrated Forecast System – operated by the European Union) and using data from the ECMWF IFS as boundary conditions, the local model HARMONIE is used (developed by a collaboration of European countries for high-resolution regional weather forecasts). We also discussed how machine learning tools will change the way weather predictions are made and whether numerical models are soon to be outdated.
After this discussion our group was split up and our group was led into the 3D-visualisation department in which we could see synoptic maps with 3D glasses. This was made possible by a program called weather-explorer 3D. In our opinion this program holds a lot of potential - especially in the realm of teaching by giving one more dimension to synoptic maps, therefore simplifying understanding. It was especially interesting to see the radar images of precipitation in a frontal zone in 3D.
The last stop was a small tour around the synoptic department where 4 meteorologists are on station at all times to monitor the weather over the sea, give weather-forecasts for commercial air-traffic and for the Netherlands itself. Besides that they are also responsible for issuing weather warnings if the need arises.
Then all groups found back together in the conference rooms where last questions were answered and soon we were back on the road again.

18th October 2023 - University of Utrecht
On the fourth day of the excursion, we took the tram from the hotel to Utrecht University. After we were warmly welcomed, we were introduced to the various working groups of the Institute for marine and atmospheric research Utrecht (IMAU) with a few short presentations.

The working groups are divided into:
- Ice and climate
Here, the effects of changes in the atmosphere on ice and snow surfaces are the subject of research. In particular, the questions of how, where and how quickly ice melt occurs are the focus here.
- Atmospheric dynamics
In this working group, employees try to gain a better understanding of the interactions between different components of the climate. They achieve this by evaluating current climate models and developing new ones.
- Oceans and climate
The main focus of this area is to achieve a better understanding of ocean transport and the interactions between different climate zones and components of the climate.
- Coastal and shelf sea dynamics
As the name suggests, the researchers here are concerned with the dynamics in coastal and shelf regions. Of particular interest here are interactions between water movements, sediment transport and soil changes in these regions.
- Atmospheric physics and chemistry
The last working group deals with investigations into the chemical composition of the atmosphere and how it is changed by humans. Interactions between atmospheric chemistry and the Earth's climate also play a role here.
After this series of lectures, we were divided into 3 groups and shown 3 different measurement laboratories each. Various samples of atmospheric air and ice samples are examined here. The majority of the investigations are carried out using mass spectrometry, for which mass spectrometers with particularly strong magnets are used at the IMAU.
We then took a short walk through the university's botanical garden, as this is where the institute's weather station is located. The station measures typical meteorological parameters such as wind, temperature, precipitation and radiation, but is only set up when it is being used for measurements. The station is not stationary, therefore it can be dismantled when it is not needed or set up elsewhere if a measurement campaign is due.
After this brief introduction to the weather station, we returned to the institute building. There we were served a typical "Dutch lunch", which we all enjoyed very much. This was the end of an informative morning session and we drove to Noordwijk for a free afternoon.

18th October 2023 - ESA - ESTEC (Noordwijk)
We arrived in Noordwijk ann Zee at the afternoon, after a longer bus drive from Utrecht. The city is located at the North Sea. Our aim for the evening was the European Space Research and Technology Centre (ESTEC) form the European Space Agency (ESA). At the entrance of the ESTEC complex, we met our guide and speaker for this tour Robert Willemsen. First, we had to check in, got our visitor passes and went to a presentation room. After a short welcome by Mr. Willemsen, he started with a presentation about ESA and the ESTEC in Noordwijk in general. The ESA runs missions and programs for a better understanding of earth and space. Examples are satellites from the “Galileo” system for navigation on earth, “Aelous” for observation of global winds, aerosol and clouds, and the
participation on the International Space Station (ISS).
The ESTEC forms the so-called “technical heard”, for development in the areas of science, earth observations, telecommunication, explorations and more. To get a better inside view to the work, we made a virtual tour through the satellite test center. There we saw the possibility of ESTEC to test all major components before satellites start to space. Launch forces can be tested by acoustic vibrations, a strong shaking in all directions with a perfect centered load. Those facilities can be used, from commercial companies too. Space environment get simulated by a pitch-black chamber, possible to cool down at very low temperatures and a sun-simulator working with mirrors, for the solar radiation. Important for every mission is signal contact and sending/receiving data during all time. For this electronics, telecommunication and antennas are tested in a signal absorbing room.
After these presentations, it was time for the exhibition. In the hall were many exciting and impressive models. At the beginning stood smaller, but still huge reconstructions of ESA’s Ariane and Vega rockets. Straight in front following a real-size and accessible model of Columbus-module from ISS. Also, the room contained a prototype landing module for moon, a mars test surface for automatic driving, robotic arms form outside the ISS, a reduced complete ISS model lifted under the ceiling and a lot more.
Before we left this building, we saw a guided video tour on ISS hosted by ESA astronaut Alexander Gerst. The last part of the ESTEC tour, took place in a building for laboratories and development. Mr. Willemsen explained, materials and components are analyzed for space travel. An important role has the 3D printing with material like moon dust, for construction in future on the lunar surface. The final was a space plane still in improving. In future, this will transport payloads, but will also be reusable.

19th October 2023 - Measurement Site Cabauw
On October 19, 2023, we had the opportunity to visit the meteorological mast of the Royal Netherlands Meteorological Institute (KNMI) in Cabauw, near Lopik in the province of Utrecht. The 213m high mast was 50 years old a few weeks before our visit, on September 29, 2023, and is an important part of atmospheric boundary layer research.
The history of the KNMI-mast goes back to the 1960s. At that time, increasing air pollution led to an increased interest in researching the atmospheric boundary layer and its effects on daily life. The KNMI mast plays a important role in this research as it provides data from different altitudes and helps to close gaps in local measurements of the lower atmosphere. This enables a better understanding of the processes in the boundary layer. Measurements on the mast have led to breakthroughs in knowledge, such as how heat exchange between the Earth's surface and the atmosphere works. Over the years, the mast in Cabauw has thus become an important starting point for atmospheric research, validations for models or satellites and long-term measurements.
When we arrived, we received a very friendly welcome and were given an introduction to the history and construction of the KNMI-mast. The tower has hydraulic booms almost 10 meters long on its sides, which make it possible to install meteorological instruments and also to maintain them thanks to the movable arms. Standard meteorological instruments are attached at the booms at different heights: 10 m, 20 m, 30 m, 40 m, 80 m, 140 m and 200 m. An elevator is located inside, which allows the individual levels to be reached. After the introduction, we were guided through some measuring fields and the measuring principles of some instruments were explained to us.
There are several measuring fields around the tower, including a meteorological field, a remote sensing station, wind profilers and an energy balance field. In addition to the standard meteorological parameters, the meteorological field also measures the amount of precipitation, soil moisture, soil temperature and snow depth. There is also a 10 meter high tower for smaller scale measurements up to 10 meters high.
After the tour, we went back to our bus. Before we left, we took a few photos of the mast and of the sheep and swans that were running around the measuring fields and making sure the grass stayed short.

19th October 2023 - Technical University Delft
On October 19th we visited Delft University of Technology (or TU Delft) as the last item on the itinerary of our field trip to the Netherlands. Delft is located between Den Haag and Rotterdam and has a population of around 100 000 people; TU Delft itself is attended by around 25 000 students and consists of eight faculties making it the fifth largest university in the Netherlands. The focus of our visit was on the department Geosciences & Remote Sensing which is part of the faculty of Civil Engineering & Geosciences.
When we arrived at noon, we were welcomed by Bas van de Wiel - professor in “Atmospheric Physics” at the department - with a nice lunch buffet.
After lunch the programme started with the first out of four very informative presentations. Pouriya Alinaghi explained how Clustering affects cloud radiative effects of shallow cumuli. This was followed by a so called Poster Session in the hallway of the faculty. These sessions, where PhD candidates create and present posters about their current research projects and studies, are a regular part of the PhD studies in TU Delft.
In the second presentation Dr. Joris Timmermans described how he and his group analysed the Kunming-Montreal biodiversity framework in order to find items in the framework whose monitoring need products related to remote sensing which do not exist yet and therefore provide research and development opportunities for the group. This showed a different, more economically motivated and also quite interdisciplinary approach towards science at technical universities in contrast to regular universities like JGU Mainz.
Dr. Jose Dias Neto on the other hand discussed a more technical topic in the third presentation and explained how Convective Momentum Transport is linked to different cloud-regimes. He also gave a short glimpse into the measured data of RADAR in LIDAR instruments located in Cabauw (-> see report of Cabauw tower).
In the last presentation, Yi Dai introduced his PhD project about frost prevention in fruit orchards using wind machines. Once again, the technical and interdisciplinary approach towards research topics at TU Delft became clear.
We were also able to get a brief impression of Campus life at TU Delft, especially in the Faculty of Civil Engineering & Geosciences’ building. There, additionally to the regular work stations, a small cafeteria with apparently very tasty vegan muffins was paired with some extraordinary design elements like a train compartment in the hallway as well as a football table providing the students with many different opportunities to fill their downtime between lectures or just hang out. Another interesting feature at TU Delft were the ‘Free Zones’ outside, whose actual purpose remained a mystery to us. The rest of campus reminded us a lot of JGU Mainz, probably because many of its buildings seemed to have been constructed at a similar time as e.g., Kreuzbau or NatFak.
All in all, although the exhaustion of the field trip had caught up with more than a few of us by this point, our visit at TU Delft was very informative and felt like a nice conclusion of the academic part of our field trip to the Netherlands.