Max Planck Institute for Meteorology

Max Planck Institute for Meteorology

Concerns that human activity was contributing to climate change and mankind's fragmentary knowledge of climate dynamics led to the foundation of the Max Planck Institute for Meteorology in Hamburg in 1975. Since then, scientists at the Institute have been studying how physical, chemical and biological processes and human behaviour contribute to global and regional climate changes. The scientists develop numerical models and measurement methods to explain the natural variability of the atmosphere, the oceans and the biosphere, and to assess the influence of land use changes, industrial development, urbanisation and other human influences. Together with the Max Planck Institute for Biogeochemistry in Jena and the Max Planck Institute for Chemistry in Mainz, they strive to provide a better understanding of the chemical and biological factors that determine the concentrations of greenhouse and other trace gases in the atmosphere, and how they interact with the terrestrial and marine biospheres.


Bundesstr. 53
20146 Hamburg
Phone: +49 40 41173-0
Fax: +49 40 41173-298

PhD opportunities

This institute has an International Max Planck Research School (IMPRS):
IMPRS on Earth System Modelling

In addition, there is the possibility of individual doctoral research. Please contact the directors or research group leaders at the Institute.

Department The Land in the Earth System more
Department The Ocean in the Earth System more
Department The Atmosphere in the Earth System more
“Global warming doesn’t stop when the emissions stop”
Thorsten Mauritsen from the Max Planck Institute for Meteorology has worked out how much time we have left to reach the Paris climate goal more
The time window for the 1.5-degree target is closing
Even if all climate-relevant emissions were immediately stopped, the Earth would warm up to around 1.1 degrees by the end of this century more
More rain in winter, more droughts in summer
A new report summarizes how climate change is affecting the water cycle in Germany more
My contribution to Arctic sea ice melt
Measurements reveal the relationship between individual CO2 emissions and the Arctic's shrinking summer sea ice more
Warmer Mediterranean turns the Sahel green
Anthropogenic climate change contributes to fanning of the West African monsoon by moisture from the Mediterranean more
Voters prefer to be represented by extortioners
A climate game and a game theory model show that people prefer representatives who adopt an extortionate strategy in negotiations more
"The demands have been tabled, it is now up to the politicians to act"
The UN climate summit in Paris begins on November 30. What expectations do politicians and scientists have of this major event? What challenges does global warming present for humanity at a global and local level? Jochem Marotzke and Martin Claußen, Directors at the Max Planck Institute for Meteorology in Hamburg, discussed these issues at the Max Planck Länderforum with Hamburg’s science minister Katharina Fegebank and Oliver Geden from the “Stiftung Wissenschaft und Politik” in Berlin. more
Global warming slowdown: No systematic errors in climate models
The rate of global warming in the 21st century has been significantly slower than all the models had predicted. Evidently, this was merely due to random variations. more
“I doubt that we will meet the two-degree target”
Interview with Max Planck director Jochem Marotzke on the IPCC report. more
Without further incentives selfish behaviour will continue to dominate more
Climate change: it’s only intermission
Global warming continues, even if the worst-case prognosis has become slightly less probable more
Atlantic circulation remains stable for now
World’s first predictions of oceanic overturning circulation: Atlantic flows will not undergo significant change in the next four years more
“Climate change mitigation through the freeloader effect”
An interview with Jochem Marotzke about the UN Climate Change Conference in Durban. more
The fate of the big rain

The fate of the big rain

September 23, 2011
Max Planck researcher are investigating the interplay of dry season and monsoon in India and the future outlook for water resource availability more
New carbon dioxide emissions model
Meteorologists have determined exactly how much carbon dioxide humans can emit into the atmosphere while ensuring that the earth does not heat up by more than two degrees more

Nowhere does climate change make its presence felt more strongly than in the Arctic. The volume of sea ice there has fallen drastically in recent decades. Climate models have been far from accurate in conveying the full extent of this loss. This is set to change now – not least because Dirk Notz and his research group at the Max Planck Institute for Meteorology in Hamburg are constantly improving their understanding of the processes that influence the formation and melting of sea ice.

What will the Earth’s climate be like 10 or 15 years from now? Researchers have yet to find a satisfactory answer to this question – especially as random changes that occur in such medium-term periods play a significant role. Natural fluctuations are probably also the reason why global temperatures have hardly risen at all in the past 15 years. Jochem Marotzke from the Max Planck Institute for Meteorology in Hamburg and his colleagues all across Germany are working intensively on a system designed to generate reliable forecasts for the coming years.
Global warming is changing the world – environmentally, economically and politically. Climate service providers seek to help decision makers respond appropriately to this
multifaceted change. Our authors were significantly involved in setting up the Climate Service Center in Hamburg. Here they describe the work these kinds of institutions do and the challenges they face when it comes to communicating their information.

On Thin Ice

3/2014 On Location
White caps above and below – it goes without saying that these are part of our image of the blue planet. But for how much longer? In the case of the North Pole, at least, whose cover consists entirely of sea ice, it is an essential question. After all, nowhere in the world is climate change as visible as it is in the Arctic. Never before, since reliable records have been available, was the September minimum – the expansion of the Arctic Sea ice at the end of the summer – as low as it was in 2012. The Arctic ice is not only an indicator of climate change, but also an important factor in the climate system: the smaller the ice areas become in the Arctic summer, the less sunlight is reflected and the more is absorbed by the ice-free ocean. In winter, the ice insulates the relatively warm water from the much colder air; without this “cap,” the ocean would release gigantic volumes of heat into the atmosphere. The ice cover is therefore extremely important for the temperatures at the North Pole. Dirk Notz from the Max Planck Institute for Meteorology in Hamburg would like to explain the role of the sea ice, its complex internal structure, and thus also the conditions necessary for its formation and stability. To this end, he and his team measure, among other things, the thickness of the ice on the ice floes and its composition of pockets of freshwater ice, brine and gas. All of the data is included in complex numerical simulations. The most important discovery to date: Contrary to what was originally feared, there doesn’t appear to be any tipping point in the climate system, after which it would be impossible to prevent the complete loss of the Arctic ice cap. According to the model calculations, the state of the sea ice is closely related to the prevailing climate conditions at all times. This also means that if greenhouse gas emissions continue to increase at the current rate, then by the end of the century, the Arctic will be completely free of ice in September at the latest.
The hydrological cycle tirelessly distributes water between land, ocean, atmosphere and cryosphere. Stefan Hagemann and his colleagues at the Max Planck Institute for Meteorology in Hamburg study the exact details of how this happens. They investigate the various feedback mechanisms between wetlands, artificial irrigation, permafrost and climate.
Human society has begun an ominous large-scale experiment, the full consequences of which will not be foreseeable for some time yet. Massive emissions of man-made carbon dioxide are heating up the Earth. But that’s not all: the increased concentration of this greenhouse gas in the atmosphere is also acidifying the oceans. Tatiana Ilyina and her staff at the Max Planck Institute for Meteorology in Hamburg are researching the consequences this could have.
Fire has existed on earth ever since land plants colonized the continents. To date, however, surprisingly little is known about the role that fire plays in the global climate system – even though vegetation fires have always influenced the climate with their emissions. Silvia Kloster from the Max Planck Institute for Meteorology is looking to close this gap in our knowledge. She is researching the complex relationship between fire and climate. Humans also play a key role in this closely woven web.
A gigantic heat pump is at work in the Atlantic Ocean, pushing tropical waters north and supplying Europe with a pleasantly warm climate. Jochem Marotzke, Director at Hamburg’s Max Planck Institute for Meteorology, analyzed this current, laying the foundation for an improved climate model.
Climate change will very likely result in southern Europe becoming much drier. Ironically, however, significant global warming could lead to an increase of vegetation in the Sahara – as has frequently occurred in the past.
When climatologists look into the past, they intend to learn for the future. Victor Brovkin and his team at Hamburg’s Max Planck Institute for Meteorology reconstruct historical climate changes and analyze what processes reinforce those changes. Their discoveries are helping to predict the future of the Blue Planet.
Climate change affects people both globally and regionally. Pankaj Kumar, for example, who works at the Climate Service Center and the Max Planck Institute for Meteorology in Hamburg, is investigating the interplay of dry season and monsoon in India. He wants to discover the future outlook for water resource availability on the subcontinent. Aiding him in this quest is the REMO software program developed by Daniela Jacob and her team at the Hamburg-based institute.
Personal Portrait: Thorsten Mauritsen
Through agriculture and livestock farming, mankind had an impact on the climate even before the Industrial Revolution, albeit to a much smaller extent than today.

Dirk Notz

MPR 3 /2008 Environment & Climate
There are many reasons why Dirk Notz, who was recently appointed head of a research group at the Max Planck Institute for Meteorology in Hamburg, loves all questions relating to climate – one of them being the nature experience he gains on his adventure-packed expeditions to the Arctic.

Forest and climate – potentials and side-effects of future afforestation

2017 Pongratz, J.; Sonntag, S.
Climate Research

Reforestation is a widely discussed measure to combat the increase of atmospheric CO2 concentrations. Earlier studies inferred from the effects of past land use changes to those of future reforestation. The global model simulations presented here show however that the potential of reforestation to sequester CO2 in a warm, CO2-rich world may be larger than anticipated. Adaptation to climate change continues to be necessary, but climate extremes may be dampened by reforestation.


ICON: A new model for the investigation of the role of small clouds in the global climate system

2016 Giorgetta, Marco(1); Stevens, Bjorn(1); Dipankar, Anurag(1), Adamidis, Panos(2) (1): Max-Planck-Institut für Meteorologie (2): Deutsches Klimarechenzentrum
Climate Research Earth Sciences

The newly developed ICON atmosphere model features two important improvements compared to older models. Firstly the choice of the non-hydrostatic equations allows to simulate small scale circulations as they occur in convective clouds and their environment. Secondly the numerical methods have been chosen such that even massively parallel supercomputers can be exploited. Both features together provide new perspectives for the research on the dynamics of convective clouds and their interaction with large-scale circulations and the global climate.


The hiatus in global temperature trends: No systematic error in climate models

2015 Marotzke, Jochem
Climate Research Earth Sciences
Observations suggest a hiatus in global surface temperature since 1998, whereas most climate models simulate continued warming. What causes this difference? Do climate models respond too sensitively to the increase in greenhouse-gas concentrations such as that of CO2, and thus overestimate climate change systematically? Or has the discrepancy arisen by chance? A study just published by the Max Planck Institute for Meteorology (MPI-M) gives a clear answer: There is no evidence for systematic model error. more

How climate change is accelerated by nutrient limitation

2014 Goll, D. S.; Brovkin, V.
Climate Research Earth Sciences

Earth System models do not account for the limited availability of essential plant nutrients. Currently, about one third of the fossil fuel CO2 emissions is taken up by land ecosystems, but there is no guarantee that this ecosystem service will continue into the future. This study accounts for the first time for the availability of nitrogen and phosphorus on land. It shows that the omission of nutrient limitation in the models leads to an overestimation of carbon dioxide uptake by vegetation in future. Reduced CO2 uptake due to nutrient limitation will accelerate global warming.


Understanding how small-scale turbulence controls stratocumulus clouds

2014 Mellado, Juan-Pedro
Climate Research Earth Sciences
Turbulence controls how the atmospheric boundary layer mixes with the overlying free troposphere. This process is particularly important when stratocumulus clouds cap the atmospheric boundary layer. The details of how this mixing occurs have been investigated using direct numerical simulations. Specifically, the mixing due to evaporative cooling and local wind shear, and that due to radiative cooling, have been quantified separately, providing estimates for their relative strengths based on the bulk properties inside and above the cloud. more

Ocean biogeochemistry in the framework of climate engineering

2013 Ilyina, Tatiana
Climate Research Earth Sciences

Climate Engineering employs technical methods to mitigate climate change without lowering anthropogenic CO2 emissions. One of these methods, the artificial increase of ocean alkalinity, has been proposed to enhance the oceanic uptake of atmospheric CO2 and counteract the ongoing ocean acidification. We used a global biogeochemical model to show that artificial ocean alkalinity input must be 200 times higher than the input by natural weathering flux to hold the global seawater pH close to today’s value. The effects on ocean biogeochemistry would be substantial.


Impact of irrigation on the South Asian summer monsoon

2012 Hagemann, Stefan; Saeed, Fahad
Climate Research
The Indian subcontinent is one of the most intensely irrigated regions of the world. Using the regional climate model REMO distinct feedbacks of the monsoon circulation with irrigation processes could be shown. With irrigation, a significant model bias in temperature and mean sea level pressure over NW India/Pakistan was removed. Moreover conditions were created favourable for currents from Bay of Bengal to intrude deep into western India and Pakistan that have been unrealistically suppressed before. Thus, the representation of irrigated water is unavoidable for a realistic monsoon simulation. more

Limited climate response of very large volcanic eruptions

2011 Timmreck, Claudia
Climate Research
Extremely large volcanic eruptions have been linked to global climate change, biotic turnover, and, for the Younger Toba Tuff eruption 74,000 years ago, near‐extinction of modern humans. One of the largest uncertainties of the estimated climate effects in previous model studies involves the aerosol size distribution. A huge sulfate load causes higher collision rates, larger particle sizes, and rapid fall out, which in turn greatly affects radiative feedbacks. Incorporating aerosol microphysical processes into global model simulations results in a smaller climate effect than estimated before. more

The big melt: sea ice in a changing climate

2010 Notz, Dirk
Climate Research Earth Sciences
Scientists are currently puzzled by the behavior of Arctic sea ice: Following a sharp and unexpected decline in summer 2007, the ice-covered area has increased both in 2008 and in 2009. At MPI for Meteorology, scientists carry out research to understand these ups and downs. They also examine what their results mean for the future evolution of the polar bear's habitat. For their studies, the researchers use sophisticated computer models, but they also carry out field measurements in the Arctic to better understand the physical properties of sea ice. more

Preindustrial agriculture: climate change without oil and coal

2009 Pongratz, Julia; Reick, Christian H.
Climate Research Earth Sciences
The vegetation covering the continents has a decisive influence on the climate. Through the uptake of CO2 from the atmosphere, plants play a central role in the global carbon cycle. Furthermore, they influence the exchange of energy, water, and momentum between the atmosphere and the land surface. Via land use, humans are altering these processes. The study presented here investigates the expansion of agriculture over the last millennium. It shows that humans had a strong influence on climate, especially on the regional scale, already before industrialization began. more

Influence of pollution on climate change – new insights from satellite data and climate models

2008 Kinne, Stefan; Quaas, Johannes
Climate Research Earth Sciences
Particles suspended in the atmosphere, so-called aerosols, reflect sunlight and alter cloud properties. In the global mean anthropogenic pollution aerosol by these direct and indirect effects cools the climate. The studies presented here in which new comprehensive remote sensing data are used show that for the direct as well as for the indirect effect former estimates for the climate effect of anthropogenic aerosol have been exaggerated. more

Stability of the Atlantic Meridional Overturning Circulation

2007 Jungclaus, Johann; Baehr, Johanna; Haak, Helmuth; Jacob, Daniela; Koenigk, Torben; Marotzke, Jochem
Climate Research Earth Sciences
The evolution and stability of the meridional overturning circulation in the Atlantic under global warming conditions, its observational characteristics, and the detectability of such anthropogenic changes have been investigated with the MPI-M climate model. For realistic projections of the climate evolution in the 21st century, the model indicates a reduction of 30-42%, but no total breakdown of the overturning circulation. Natural variability on time scales of days to decades requires long-term observations in the Atlantic to detect a potential decrease. more

Earth System Research Partnership

2006 Marotzke, Jochem; Andreae, Meinrat; Heimann, Martin
Climate Research Earth Sciences
Earth system research is the science of global change, whether caused naturally or by humans. Earth system research requires the amalgamation of previously unrelated scientific disciplines and the appreciation of the Earth as a system of interacting compartments. In-situ measurements, satellite remote sensing, and numerical modelling are the pillars of Earth system research and have advanced dramatically in recent years. The Earth System Research Partnership is the association of the Max Planck Institutes dedicated to Earth system research, with further contributions by several Max Planck and other institutes. more

Long-range transport of persistent chemicals and distribution among various environment media – model investigations

2006 Lammel, Gerhard; Semeena, V.S.; Feichter, Johann; Guglielmo, Francesca; Leip, Adrian
Chemistry Earth Sciences
Many environmental pollutants are slowly degrading (persistent) and very mobile. Results of simulations using a global multicompartment model which is based on an atmosphere general circulation model are presented. The integration of soils, vegetation, air, ocean and ice is mandatory in order to describe the environmental fate, i.e. transports and transformations, of slowly degrading and semivolatile substances. This class of substances includes the so-called persistent organic pollutants (POPs) and other pesticides and industrial chemicals. The investigations elucidate the combined effects of climate and substance properties on transport and distribution of pollutants and allow to quantify persistence and long-range transport potential. more

Impact of carbonaceous aerosoles

2005 Feichter, Johann
Chemistry Climate Research
Since begin of the industrial revolution levels of the greenhouse gases carbon dioxide, methane and nitrous oxide have risen dramatically. Fossil fuel combustion, increasingly intensive agriculture and an expanding global human population have been the primary causes for this rapid increase. The same increases in fossil fuel burning and biofuel use have also led to an increase in the emissions of sulphur dioxide, soot and particulate organic matter which form aerosol (=suspended particulate matter) in the atmosphere. Most aerosols cool the atmosphere by increasing Earth's reflectivity, but aerosols containing soot warm it by absorbing sunlight. Cleaner fuel technologies are today leading to a reduction in sulphate emissions. Unlike carbon dioxide and sulphur dioxide emissions, soot emissions are largest in developing countries and are still increasing. According to future emission scenarios, the most polluted regions in the first part of the 21th century will be found at lower latitudes whilst aerosol emissions have decreased in North America and Europe. The most notable climate response as calculated by the MPI Earth-System Model to this latitudinal shift in atmospheric aerosol load is a mitigated surface warming and a wetter soil in highly polluted regions and a pronounced warming and drying in regions where the aerosol load is decreasing. more

The simulation of glacial cycles with a complex Earth system model

2004 Mikolajewicz, Uwe; Gröger, Matthias; Marotzke, Jochem; Schurgers, Guillaume; Vizcaíno, Miren
Climate Research Earth Sciences
What causes the sequence of ice ages and interglacials is one of the big unsolved questions of Earth system science. Interactions between atmosphere, ocean, ice, and oceanic and terrestrial biosphere are likely to be crucial. Here, we describe the fundamentals and first results of the most complex extant Earth system model for the simulation of long timescales. Interactive land vegetation enhances the climate change caused by variations in the Earth’s orbital parameters, and thus constitutes a positive feedback even in a complex Earth system model. more
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