News Archive


Near-surface ozone: Will climate change jeopardize current success?

Despite large and successful efforts to reduce emissions of precursor gases, air quality standards for ozone in Switzerland are still exceeded on a regular basis. The frequency of extreme peaks has decreased, but not that of moderately high values. The causes are not fully clear, but large-scale emissions of precursors and climate change might have contributed. An increasing number of heat waves will lead to more frequent ozone exceedances. Furthermore, plants emit hydrocarbons in response to high temperatures, which contributed to ozone production. These two mechanisms counteract the success due to decreasing precursor emissions. This is stated in a new fact sheet of the Swiss Academy of Sciences, to which the climatology group has contributed.

Read more (in German)


New SNF Project started

In June, the new SNF project "RE-USE" (Reconstructing Climate Using Ensemble Kalman Fitting) started in the climatology group. The goal of this 3-year project is to provide global, monthly, three-dimensional climate reconstructions with a new method that combines climate model simulations, instrumental observations, and proxies. The new approach, which has been successfully tested, will provide new insights on interannual-to-decadal variability of climate and atmospheric circulation over the past 400 years, which encompasses the transition from the "Little Ice Age" climate to the present. The project will be conducted by Dr. Jörg Franke and PhD student Veronika Valler.


New book of Heinz Wanner on Holocene climate and human history

During the Holocene, climate has repeatedly interfered with human history. Societies in various parts of the world - the Pueblos, the Vikings, the Mayas, and many others - were faced with extreme climatic conditions, which did not remain without consequences. The book covers the relation between climate and societies over the past 12'000 years in an accessible way.

More information


Tambora and the “Year Without a Summer” of 1816. A Perspective on Earth and Human Systems Science.

The 1815 Tambora eruption devastated the island of Sumbawa, led to a global cooling and contributed to the last famine in Switzerland. A booklet by Stefan Brönnimann und Daniel Krämer pubished by Geographica Bernensia now provides a synthesis of this event (free online under, German and English versions):

Brönnimann S, Krämer D. 2016. Tambora and the “Year Without a Summer” of 1816. A Perspective on Earth and Human Systems Science. Geographica Bernensia G90, 48 pp., doi:10.4480/GB2016.G90.01.


Tambora and the „Year Without a Summer“ of 1816

Two hundred years ago, a cold and rainy summer led to the last famine in Switzerland, triggered by a volcanic eruption in Indonesia. In an article in "NZZ am Sonntag", Stefan Brönnimann explains what societies today can learn from the Tambora eruption with respect to dealing with climate risks.

NZZ article (in German)


Faculty Award for Martín Jacques Coper

Martín Jacques Coper receives this year’s University of Bern Faculty Award for Geosciences for his PhD thesis „A multiscale analysis of summer temperature variability in Southern South America during the 20th century“. In his thesis, Martín Jacques Coper analyses temperature variability in Patagonia during austral summer on various time scales, ranging from intraseasonal to interdecadal. The analysis of intraseasonal summer heat waves reveals a characteristic wave pattern of anomalous atmospheric circulation that can be tracked backward across the South Pacific to its origin over Oceania. A link is also found to convection over the western tropical Pacific Ocean. Interestingly, similar patterns are also found for the temperature variability on interannual-to-decadal scales. The work is thus not only relevant with respect to predictability, but also for the interpretation of past climatic changes.

download thesis (PDF, 17.2 MB)


Summer temperature in the eastern part of southern South America: its variability in the twentieth century and a teleconnection with Oceania

Summer heat waves in Southeastern Patagonia: an analysis of the intraseasonal timescale

Evidence for a modulation of the intraseasonal summer temperature in Eastern Patagonia by the Madden-Julian Oscillation


CLIMANDES e-learning course published

The CLIMANDES climate science e-learning course, developed by Stefan Brönnimann, Alena Giesche, Stefan Hunziker, and Martín Jacques-Coper at the Institute of Geography at the University of Bern, was recently published by Geographica Bernensia. This course was developed over the past three years for the CLIMANDES project, which is a collaboration between Peruvian and Swiss government, research, and education institutions. The course is available online: , DOI number: 10.4480/GB2015.U27


Book launch “Climatic Changes since 1700”

Understanding past climatic changes is the key to assessing present and future climate change. In his book “Climatic Changes since 1700”, Stefan Brönnimann provides a new, dynamical perspective of past climatic changes based on novel techniques and data sets of past climate. The book just appeared in Springer’s series “Advances in Global Change Research”. The book also is a tribute to the book with the same title published by Eduard Brückner, then professor at the Institute of Geography, University of Bern, 125 years ago.

Summary (EN (pdf, 120KB), DE (pdf, 118KB))

More information


Droughts and shifts in tropical circulation

A number of dry summers in central and southern Europe between 1945 and 1954 led to poor harvests. About 30 years later, the Sahel region suffered from deadly drought. Both events were related to a shift of the tropical belt. This is shown in the latest paper of the climatology group published in „Nature Geoscience“. The shift was caused by a strong interhemispheric gradient in sea-surface temperatures, as could be shown with climate model simulations. From the 1940s to the 1970s, the southern hemisphere warmed rapidly, drawing the tropical belt towards it, while the northern hemisphere cooled. Anthropogenic aerosols or oceanic variability modes both might have contributed. Since the 1970s the trend has changed. The tropical belt expands and the arid zones migrate poleward; a process that will continue with anthropogenic climate change.

Read more (in German)

Read article


CLIMANDES E-Learning course

Alena Giesche and Stefan Hunziker led a training workshop for the CLIMANDES E-Learning course at the SENAMHI in Lima, Peru from August 4-7, 2015. The workshop was attended by students and professors from the Universidad Nacional Agraria La Molina, meteorologists from SENAMHI (Peruvian National Service for Meteorology and Hydrology), as well as aviation meteorologists from the Peruvian military. Alena and Stefan were each awarded a medal from the Fuerza Aérea del Perú (Peruvian Air Force) for their contribution to the training of aviation meteorologists in Peru.



The GIUB and Foundation Science et Cité are presenting 8 «Jahreszeiten-Expeditionen» as part of SNCATs anniversary tour „Forschung live“. During guided tours at Swiss-German anniversary locations, experts will introduce the participants to natural phenomena and signs of the seasons and their simple, scientific recording. The tours are accompanied by improvisation actors, who will present the scenes in yet another entirely different way. The participants will not only listen but will also do their own research on urban nature and will feed their observations by iPad oder Smartphone into

Upcomign tours are in Aarau (August 30), Bern (Sep 5) and Basel (Sep 19).


Reduced activity of the sun by 60%?

Group Member Mikhaël Schwander commented a new study in the newspaper «Tages-Anzeiger» that said that the activity of the sun will be reduced by 60% in the period 2030–2040 on a level similar to the Maunder Minimum. «Im Maunder-Minimum war auch der Einfluss von Vulkanausbrüchen massgebend», Schwander said. The young climate scientist analysis the number of sunspots – an indicator of the sun’s activity – back to 1765 in comparison to weather patterns over Europe.

Read article


"The Great Climate Poker" went online

A computer game called “The Great Climate Poker” is accessible online ( The game provides information about some of the most important factors influencing the climate, it demonstrates the difference between variability and trend, and shows the spatial impacts of climate factors. The game is based on the “Climate Poker” game (created by the Oeschger Center for Climate Change Research), where physical dice are rolled to get yearly temperature anomalies.


Group excursion

This year's excursion of the groups of climatology, climate risks, and remote sensing brought us to Solothurn and from there via Balmberg to the Röti peak (1400 m), from where we had an impressive view of the Swiss Plateau and the Jura. Though rainy in the early morning, the weather improved and we enjoyed a sunny day and a pleasant hike to the Weissenstein.


Field course in micrometeorology

Last week students of the Institute of Geography participated in the micrometeorology field course at Chamau, ZG. The course takes place every two years in collaboration with Prof. Werner Eugster, ETH Zurich. The students performed eddy covariance measurements and conventional meteorological measurements, determined the light absorption within the canopy, launched radiosondes and cycled transects measuring the spatial variability of carbon dioxide. After a hard day's work, a swim in Lake Zug was the perfect refreshment.


Less sea ice, more Siberian snow

This week's issue of Nature features the paper published last week by Martin Wegmann et al. on links between Arctic sea ice and Siberian snow accumulation in autumn (Environ. Res. Lett. 10, 054015 (2015)). The research team investigated Eurasian snow conditions in years with decreased Arctic sea ice cover using more than 800 snow depth measuring weather stations. They could compute that the surplus of moisture responsible for the increased Siberian snow cover in late autumn is indeed originating from the anomalously open Arctic waters in the months before. This moisture is transported to Central Siberia via storm tracks, driven by the overall circulation and fueled by the relatively warm surface of the ice free sea.


Students Analyse Historical Flood Events

This spring, students of the "Proseminar Klimatologie" have analysed ten historical flood events in Switzerland in the new "Twentieth Century Reanalysis" v2c dataset. The students found that the data set quite accurately reproduces the large scale flow for strong, historical events such as the June 1876 heavy precipitation and flood (photo). It also provides a realistic depiction for less well documented events such as the 1852 or 1868 floods. However, the precipitation distribution and timing is not always well reproduced and details of the weather events may not be captured. This Proseminar continues a series of Seminars in which students have analysed extreme weather events in new historical weather data sets. Selected papers have been published in Geographica Bernensia.


Interview: Citizen Science

Is Citizen Science an alternative to the elitist world of science? On the occasion of the new citizen science project of the climatology group, This Rutishauser's "OpenNature", the university magazine "unipress" has interviewed climatologist Stefan Brönnimann and philosopher Claus Beisbart to find out what citizen science is, whether it can be theme-setting and what the value of a deeper dialog between scientists and lay people might be.

Read article

Podcast: interview with Stefan Brönnimann

Project: OpenNature


Successful Tambora Meeting

The international conference on "Volcanoes, Climate and Society", which took place last week in Bern, was a great success. The conference at the occasion of the bicentenary of the 1815 Tambora eruption attracted ca. 140 scientists from a wide range of disciplines. Volcanologists, atmospheric chemists and physicists, paleoclimatologists, climatologists, climate modellers and historians discussed the current knowledge on the Tambora eruption and its impact on climate and society. One of the highlights was the presentation of a a dynamical reanalysis of the years 1815-1817. The bicentenary was also reported in the media: "Einstein" and Radio SRF2.


Bicentenary of the great Tambora eruption of 1815

In early April 1815, the volcano Tambora in Indonesia erupted vigorously and caused one of the major climatic catastrophes of the last 400 years. Hemispheric and global temperatures dropped, Switzerland was particularly severely affected. The following cold and rainy summer of 1816 is known as a "Year Without a Summer". On the occasion of the bicentenary of the eruption, the Climatology Group and the Oeschger Centre for Climate Change Research are organising an international conference, which will take place next week in Bern (conference website, press release). On Wednesday, 8 April, a public panel discussion (in German) will address the question whether today's society would be able to cope with the climatic effects of a major tropical volcanic eruption.
Read the article be Renate Auchmann on the Tambora eruption in "Physik in unserer Zeit".


Climate Impact Science with Citizens:

On March 1st, the Swiss citizen science website was launched. The website aims at building awareness for science-based climate impact knowledge, collecting scientifically sound phenology and seasonality observations and understanding environmental change. The project features climate change impacts on plants, animals, mushrooms, landscapes, and climate extremes. includes a news section presenting new scientific findings and shares the results on social media network such as Facebook ( The project is lead by Stefan Brönnimann, Werner Eugster (ETHZ), Martine Rebetez (UniNE) and managed by This Rutishauser. It is mainly supported by the Swiss National Science Foundation through its AGORA program. Contact: This Rutishauser.

Read article in Unilink (in German, pdf, 147KB)


«Multiple independent Lines of Evidence»

The latest issue of the magazine «environment» («Umwelt») by the Federal Office for the Environment FOEN is dedicated to environmental observations. One contribution – «Beweiskraft dank Quellenvielfalt: Unzweifelhaft belegter Klimawandel» – covers meteorological measurements, data control and scientific analyses as done e.g. by the IPCC. Stefan Brönnimann describes the different independet lines of evidence that underline the warming of the globe to the general audience of the magazine.

Read more


2014 the warmest year on record

According to NASA, NOAA, and WMO 2014 was the warmest year on record, slightly warmer than the two previous record years 2005 and 2010. Is this the end of the "hiatus" in global warming? Read interview with Stefan Brönnimann in "Uniaktuell".


Pacemakers of warming and hiatus periods

Westerly winds over the equatorial Pacific may have played a pivotal role in the global warming episode of the early twentieth century. A new paper in "Nature Geoscience" presents a coral-based wind proxy and relates westerly wind strength over the Pacific to warming. In the accompanying News & Views, Stefan Brönnimann from the climatology group tries to fit the new piece of evidence to the puzzle of explanations surrounding episodes of accelerated or slowed warming, including the ongoing hiatus. Fitting together the pieces also means fitting together two communities with very different science cultures - palaeoclimatology and dynamical climatology.

Read more


Merry Christmas

The Climatology Group wishes you a merry Christmas and a happy 2015.


Maps of wind storm risk in Switzerland

Together with Meteotest and the Climate Impacts group of the Institute of Geography, Peter Stucki from the climatology group has contributed to generating maps of wind storm risk in Switzerland. The maps are based on downscaling of 83 wind storms since 1871. They provide wind gust speeds with return periods of 30, 50, 100 and 300 years.

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Mountains and Climate Change

Today (11 Dec 2014) is the International Mountain Day. At this occasion, the publication "Mountains and Climate Change" is launched at a side event in the Mountain Pavilion at COP 20 Lima. The publication was coordinated by Thomas Kohler from the University of Bern and encompasses several chapters authored by scientists from the Institute of Geography, including the opening chapter on climate.

Download Publication (pdf, 18.6 MB)


New HORIZON2020 project funded

The climatology group of the Institute of Geography participates in the HORIZON2020 project "EUSTACE", led by the UK Met Office. The project, which starts in January 2015 and last for 3.5 years, aims at producing global gridded data products of daily surface air temperature from combining satellite-derived skin temperatures with conventional meterological stations. At the climatology group, Yuri Brugnara and Renate Auchmann will carry out the work.


Projects in the Tropical Andes

Last week Stefan Hunziker, Martìn Jacques Coper und Stefan Brönnimann attended the project meetings of CLIMANDES in Lima and of DECADE in La Paz. The goal of the two projects, funded by the Swiss Agency for Development and Cooperation (SDC), is to improve climate services in the tropical Andes and to build up research capabilities in the region through links with the Universidad Nacional Agraria La Molina (Lima), the Universidad Mayor de San Andrés (La Paz), and the weather services of the two countries. The CLIMANDES project is led by MeteoSwiss ( under the umbrella of WMO. The DECADE project was funded under an SDC/SNF "Research for Development" project. The goal is to compile meteorological data and metadata for the Altiplano region, to perform quality assessment (and, if possible, homogenisation), and to produce climatological maps of extreme indices. The DECADE meeting ended with a visit at of the high-altitude research station Chacaltaya (Photo: S. Hunziker).


Synergies, not conflicts between air quality and climate policy

Air quality in Switzerland has improved over the past decade. This success should not be jeopardized by climate policy measures. Wood burning in small installations, for instance, has a positive effect on greenhouse gases, but leads to emissions of particulate matter. However, synergies between air quality and climate policy are obvious as many sources of pollutants and greenhouse gases are the same, writes the commission of Atmospheric Chemistry and Physics (ACP) of the Swiss Academy of Sciences (SCNAT). The fact sheet «Energiepolitik und Klimaschutz mit Luftreinhaltung verbinden» can be downloaded here:


Homogenisation expert visits Climatology Group

The Oeschger Centre regularly hosts visiting scientists. Victor Venema from the University of Bonn, Germany, is visiting us in August and September. He works on the removal of non-climatic changes from the raw climate station records, typically called data homogenisation.

Improvements in our understanding of measurement errors and economic, societal and technological changes over the centuries have produced non-climatic changes in the climate record. For example, an important change for temperature observations was the transition to double-Louvre Stevenson screens that protect the thermometer well against influences of solar and heat radiation. Before the time, observations were often performed at the window of North facing walls or half-open screens, such as the French screen or the Wild screen. These half-open screens provide more ventilation, but were found to be affected too much by radiation errors.

Past work on homogenisation was often focussed on the removal of mean shifts from monthly climate data (especially temperature and precipitation). The next important step is the homogenisation of the probability distribution of daily climate data. This is important for research on climatic changes in weather variability and extremes. The inherent reduction in the amount of data when considering extremes and the concurrent stochastic and deterministic nature of the non-climatic changes make this problem much more challenging.

Thus the current trend is to study the nature of these non-climatic changes using parallel measurements, where classical measurements are performed alongside modern ones. With such parallel measurements the statistical changes and their physical causes can be studied directly.

Read more

The group of Stefan Brönnimann at the Oeschger Centre has two beautiful datasets with parallel measurements with a frequently used Wild screen and a Stevenson screen (see photo), which Venema together with Renate Auchmann will analyse during this visit.


40 years of BernClim pheno data available

More than 40 years ago, the Institute of Geography started a network with phenological observations in the canton of Bern. Some of the observes are still actively reporting their observations, contributing to a long time series of climatically relevant data. Part of the data set, which offers a unique archive of seasonal climatic proxy data, is now available from the "Amt für Geoinformation" of the Canton of Bern. The data set includes the data of four standard plants (hazel, dandelion, apple, beech), snow and fog. Decadally aggregated maps of the phenophases complete the unique seasonal and regional information.


Downscaled historical wind storms for Switzerland

Wind storms are among the most costly natural disasters. However, good statistics of the wind storm hazard on a local scale are usually not available. In a collaborative project of the groups of Climatology and Climate Risks of the Institute of Geography and Meteotest, Bern, supported by the Bafu, MeteoSwiss and the Bretscher Fonds, approximately 100 historical storms have been downscaled to a 3 km resolution. The downscaling is based on the Twentieth Century Reanalysis.

Read article in 'Physik in unserer Zeit'


Northern and Southern Hemisphere Climate Change

Over the last 1000 years, temperature differences between the Northern and Southern Hemispheres were larger than previously thought. Using new data from the Southern Hemisphere, Raphael Neukom, Heinz Wanner and co- authors have shown that climate model simulations overestimate the links between the climate variations across the Earth with implications for regional predictions.

Read article


"Years Without a Summer" caused by weakening monsoon?

Historical records provide evidence that strong volcanic eruptions in the tropics are often followed by a cold and rainy summer in Central Europe. These «years without a summer» often lead to catastrophic famines; the last time in 1816 after the eruption of the Tambora volcano in Indonesia. Martin Wegmann and collaborators from the climatology group now found a possible cause for the rainy summers: the volcano-induced weakening of the African monsoon.

Read article


Climate Change 2013: The Physical Science Basis

The contribution of Working Group I of the IPCC to the Fifth Assessment Report is published in full today. It was jointly written by 259 authors over a period of almost 4 years. The authors had to reply to 54,677 review comments. The climatology group contributed to this report: Stefan Brönnimann was Lead Author, Heinz Wanner was Review Editor, and former group member and guest professor Jürg Luterbacher was also Lead Author. The full report can be donwloaded here:


Weather Extremes in the Twentieth Century Reanalysis

Winterstorms, floodings, heatwave, hurricanes - extreme weather events may cause tremendous damage. The "Twentieth Century Reanalysis", which provides six-hourly, global data back to 1871, allows studying more extreme events than hitherto possible. However, is this data set suitable for that purpose? In the framework of a seminar, students of the University of Bern analysed extreme weather events in the "Twentieth Century Reanalysis". Eleven papers are now published open access in "Geographica Bernensia".


Merry Christmas

The Climatology Group wishes you a merry Christmas and a happy 2014.


One hundred fifty years of Swiss climate monitoring

This weekend the Swiss meteorological network celebrates its 150th anniversary. On 1 December 1863, 88 stations started standardised measurements. Parts of these data were digitised by the climatology group in the DIGIHOM project.


Kick-off of DECADE project

The climatology group is leading the project "DECADE" (Data on climate and Extreme weather for the Central AnDEs), funded by the Swiss National Science Foundation. Together with MeteoSwiss and partners in Peru (SENAMHI-Peru) and Bolivia (SENAMHI-Bolivia, Universidad Mayor de San Andrés, La Paz), the project aims to produce climate data products for stakeholders in the region. Last week, a Pre-Kick-Off meeting took place in Lima, Peru. Official project start is February 2014.


IPCC-AR5: Summary for Policymakers of WG1 published

Today, the 12th Session of the Intergovernmental Panel on Climate Change Working Group I formally approved the Summary for Policymakers of the WG1 contribution to the Fifth Assessment Report of the IPCC. Over the last three years, several hundred scientists have worked on this report, including climatology group members Stefan Brönnimann (lead author), Jürg Luterbacher (lead author) and Heinz Wanner (review editor). The full text of the Summary for Policymakers can be downloaded from


Data Assimilation in Paleoclimatology

The field of paleoclimatology is undergoing profound changes of its methodological toolbox. Numerical models are increasingly used, and scientists think about methods to combine models with proxy data in order to obtain reconstructions of past climate or to estimate parameters. These methods are termed data assimilation. The climatology group is contributing actively to this process. A series of short papers in the latest PAGES newsletter now summarizes the state of research on data assimilation methods in paleoclimatology.


Climate Column of Heinz Wanner

The climate column of Heinz Wanner appeared in the latest issue of 'klimafreundlich', the annual for sustainability, ecology and lifestyle.

Read column (pdf, 168KB, in German)


Sunspot cycle affects atmospheric circulation over Europe

A study by Yuri Brugnara and colleagues from the Climatology Group finds a significant effect of solar variability changes during the sunspot cycle on atmospheric circulation over Europe. This study confirms earlier studies, which however were relying only on few sunspot cycles. Using the recently published Twentieth Century Reanalysis, circulation reconstructions based on historical upper-air data, and reconstructions of sea-level pressure, the study shows that circulation over Europe was more zonal during solar maxima winters, but more meridional (northerly over central Europe) during solar minimum winters. Recent solar minimum winters (which were not included in the study) exhibited a similar circulation anomaly.

Read article


Group excursion to Fribourg

Last Thursday, the climatology, climate risks and remote sensing groups went for a hike in the Gottéron Canyon near Fribourg (photo), followed by a geological city tour. We discovered amber on the pavement, shark teeth on the stairs to the city hall and heard many other fascinating stories.


Meteorology Field Course

Last week 15 highly motivated students attended a field course on micrometeorology and boundary layer meteorology led by Werner Eugster (ETH) and Stefan Brönnimann. The course took place at the farm Chamau near the Lake of Zug; an ETH research station. In small groups, the students had the tasks to compare parallel meteorological measurements, perform a radiosonde ascent, perform carbon dioxide flux measurements with eddy covariance and with flux chambers, build a psychrometer, and measure methane along a transect with a specially equipped car. The generally fair weather allowed efficient work and kept the spirits high. One of the highlights was an ascent with a helium-filled balloon reaching an altitude of 28 km.


First 2000-year-long temperature reconstructions for individual continents

Past climate change varied remarkably between regions. This is demonstrated in a new study coordinated by the international Past Global Changes (PAGES) project, which reconstructed temperature over the past 1000 to 2000 years. It is the first comprehensive temperature reconstruction on a continental scale. One of its main findings is that a general cooling trend, caused by different factors (e.g. orbital-driven insolation and changes in solar and volcanic activity), was ubiquitous across all continental-scale regions and was reversed by a distinct warm trend beginning at the end of the 19th century. Some 80 researchers from all over the world, including former climatology group leader Heinz Wanner, collaborated on the study, which has just been published in the scientific journal "Nature Geoscience".

Read more (pdf, 95KB)


Physics-based homogenisation of temperature records

Most temperature series are affected by inhomogeneities such as artificial breaks. Statistical methods are mostly used to correct such breaks, but the error may well have physical causes such as the change of the shelter. A new project in the climatology group (in collaboration with MeteoSwiss) aims at finding a physics-based correction for one, frequent cause of breaks: The change from a Wild Screen to a Stevenson screen. The project is funded by the Swiss National Science Foundation.


Limitations of tree-rings and other proxies

Information on climate variability during the past millennium comes to a considerable extent from tree rings. Tree growth is sensitive to temperature and moisture (i.e., precipitation), among other things, and climate scientists usually try to isolate these effects for reconstructing temperature or precipitation. Writing in "Nature Climate Change", Joerg Franke from the climatology group and his co-authors find significant limitations in the way tree rings and other climate proxies capture the variability spectrum of climate. Tree ring proxies are deficient in high frequency variability (year-to-year changes) relative to low frequency variability (multidecadal or centennial changes). This is specifically true for precipitation-sensitive tree rings. Compared to long instrumental observations of precipitation and model simulations, they overemphasize centennial changes and suppress interannual variability. This spectral bias seems to translate into climate field reconstructions, highlighting that particular care must be taken when working with climate proxies.

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IPCC WG1 Fourth Lead Author Meeting

The Fourth Lead Author Meeting of IPCC's Working Group I contribution to the Fifth Assessment Report (AR5) took place this month in Hobart, Tasmania. The climatology group is well represented in AR5 with Stefan Brönnimann and former group member Jürg Luterbacher as lead authors and Heinz Wanner as review editor. The picture shows Tasmanian's minister of Climate Change Cassy O’Connor addressing the scientists.


Merry Christmas

The Climatology Group wishes you a merry Christmas and a happy 2013.


Tree rings and volcanic cooling

A few months ago, a paper by Mann et al. triggered a discussion on whether or not tree rings are able to adequately capture the effects of volcanic eruptions on climate. Writing in "Nature Geoscience", Anchukaitis an co-authors, including Petra Breitenmoser from the Climatology Group, challenge the study and demonstrate that volcanic eruptions are well imprinted in tree ring records, in agreement with growth models.

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Swiss Geoscience Meeting 2012

The University of Bern hosted the 10th Swiss Geoscience Meeting on 16 and 17 November 2012. The meeting of attracted around 700 scientists from various fields within geosciences. The 18 topical sessions on Saturday were preceded by a plenary session on Friday afternoon on "Mountains - up and down", followed by the traditional "Geo party" on Friday night. Céline Dizerens of the Climatology Group was a key person behind the organisation of this large event.

Swiss Geoscience Meeting Homepage



The project CLIMANDES (Servicios climáticos con énfasis en los Andes en apoyo a las decisiones) is a pilot project under the umbrella of the WMO-led Global Framework for Climate Services (GFCS). The GFCS Twinning activities between Switzerland and Peru seek to improve climate services for the Peruvian region. In addition, the project aims at increasing the number of professionals and students trained in meteorology and climatology in support of the newly established WMO Regional Training Center in Lima hosted by the National Agrarian University La Molina (UNALM).
The project coordinated by WMO and implemented by the Peruvian National Service for Meteorology and Hydrology (SENAMHI) and the Federal Office of Meteorology and Climatology MeteoSwiss in collaboration with UNALM (Peru), the University of Bern (Switzerland), and Meteodat GmbH (Switzerland). CLIMANDES is financed by the Swiss Agency for Development and Cooperation (SDC) and runs from August 2012 to July 2015. The climatology group develops e-learning modules for the Regional Training Center.


Record sea ice minimum in the Arctic

The area of the Arctic Sea covered by ice has reached a record minimum this September. Only 25% of the area is ice covered. The reduced sea ice has consequences for the Arctic climate and water cycle. Read Blog by Stefan Brönnimann on ETH Klimablog.


Interview with Stefan Brönnimann in the "Berner Zeitung"

Are the recent droughts and other extremes due to climate change? What do we know about solar effects on climate? Will climate change also lead to a change of our preception of climate? In an interview with the "Berner Zeitung", Stefan Brönnimann answers these and other questions...

BZ article (pdf, 590KB)


New PhD project funded by the Bretscher Fonds

In the framework of a PhD project funded by the Bretscher Fonds, Peter Stucki will analyse wind storms in Switzerland during the past 140 years. The goals of the project are to compile a catalogoue of past wind storms events in Switzerland, to analyse each storm using the newly available "Twentieth Century Reanalysis" data set together with historical observations, and to explore relations between wind storm occurrence and synoptic weather types (including trends). Dynamical downscaling (in collaboration with Meteotest) will allow spatio-temporally detailed studies of the development of the storms; information that can be used for impact modeling and it will contribute towards the CH2014 Climate Impacts initiative.


Climate Blog of Heinz Wanner

Heinz Wanner has written a Blog on the influence of the sun on climate for the "ProClim Klimaportal". You can download the text and the figures via the Klimaportal.


New Arctic Climate project funded

The climatology group is leading a consortium of five partners in a new European research project "Arctic Climate Processes Linked Through the Circulation of the Atmosphere".

The project is one of the successful proposals in the "ERAnet.RUS" programme within FP7, which aims at intensifying and strengthening science and technology cooperation between Russia and Europe. The project will deal with decadal variability and trends in Arctic and subarctic climate.

The climate of the Arctic is the product of a range of processes, involving not only the atmosphere but also the ocean, sea ice, land-surface conditions, and snow cover. These processes are linked through the atmospheric circulation. The circulation moves weather systems across the Arctic and controls surface climate and snow cover. It transports heat, water vapour, and aerosol particles from the midlatitudes into the Arctic, it distributes these quantities within the Arctic, and it affects sea ice through wind stress. At the same time, atmospheric circulation is affected by the energy balance of the Arctic surface and thus by sea-ice and snow cover as well as by factors outside the Arctic. The goal of the project is to study the role of these interactions for decadal variability and trends in Arctic climate. The five partners University of Bern (Switzerland), RIHMI (Russia), University of Vigo (Spain), Alfred Wegener Institute, Potsdam (Germany) and NILU (Norway) will use newly available observation based data sets, long reanalyses, numerical techniques such as trajectory modeling or nudging, and different climate models that allow addressing effects of sea-ice and snow cover. The knowledge gained from better understanding the processes governing decadal climate variability in the Arctic may eventually lead to a better assessment of climate models, supporting an increased accuracy of seasonal predictions, projections, and adaptation plans.


Phenological observations are underestimated

Climatology group member This Rutishauser commented the plant phenology study «Warming experiments underpredict plant phenological responses to climate change» for BBC Science and Environment News. The study lead by Elizabeth Wolkovich found that experiments with electrict heaters or open top chambers cannot replicate advances in the timing of flowering and leafing by 8.5-fold and 4.0-fold, respectively, compared with long-term observations. The comment was written together with Reto Stöckli, MeteoSwiss, and published in the «News & Views» forum of the journal «Nature».

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BernClim : Seasonality-Monitoring – Jura, Plateau, Alps - Vernissage of a report on a topoclimatic long-term project

On 5 May, five leading personalities of the research project BernClim - This Rutishauser, Bruno Messerli, Heinz Wanner, Stefan Brönnimann and François Jeanneret - presented the newly published report on the activities from 1970 to 2011 of an original observing programme. Observations on plant phenology in summer and on snow cover duration and fog frequency in winter were designed for a mapping of tococlimatic conditions in a cross-section through Switzerland and ended up as a long-time survey of regional variations on topoclimate change in different landscape settings. The programme will carry on with both new methods and traditional observations, results will be presented in a the on-line atlas of geo-information of the Canton of Berne.

Details G 87


Science communication project funded

The climatology group will lead a «citizen science» project focusing on phenology and seasonality observations. The project aims to create a stage for interaction between scientists and citizens in order to raise awareness and understanding of the impacts of climate and environmental change. Under the auspices of the SCNAT, the project presently has 11 collaborating partner institutions and three communication expert teams. The project is lead by Stefan Brönnimann, Werner Eugster (ETHZ), Martine Rebetez (UniNE) and managed by This Rutishauser and runs from 2012–2015. It is mainly supported by the Swiss National Science Foundation through its AGORA program.


Happy Holidays

The Climatology Group wishes you a merry Christmas and a happy 2012.


Researchers' Night

Jörg Franke and Stefan Brönnimann from the climatology group participated in the Oeschger Centre project the Great Climate Poker at this year's "Researchers' Night". In a Casino ambiance with a large dice table the audience was invited to dice global climate, each of the five dices representing one climate factor. But the anthropogenic influence was a loaded dice, so that the temperature got hotter and hotter.....


Skeptische Forscher bestätigen globale Temperaturkurve

Vor zwei Jahren wurde führenden Klimawissenschaftlern die Manipulation von Daten vorgeworfen. Gefördert von Organisationen, die den Klimaskeptikern nahe stehen, erstellten Wissenschaftler der Universität Berkeley inzwischen eine neue, unabhängige globale Temperaturkurve. Von den mit Spannung erwarteten Ergebnissen berichtet Stefan Brönnimann, Professor für Klimatologie an der Universität Bern.

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17.8. 2011

Data-Rescue-at-Home in the News

Read articles by Antoinette Schwab on Open Science projects in the „Berner Zeitung (pdf, 1.2 MB)” and on the digitisation of ship log books and historical data in the “Coop Zeitung”.


“Mensch Klima!”: New Illustrated Book on Climate Change

Lars Müller publishers have released a new illustrated book on climate change in collaboration with the Department of Environmental Sciences (ETH). Stefan Brönnimann was part of the scientific support team.
The book „Mensch Klima!“ intends to discover the complex climate system, to illustrate findings of climate research understandingly and to analyse the background of climate politics. The book gives an overview of the Earth’s climate history and explains which factors are responsible for climate change. “Mensch Klima!” raises questions and gives answers: Why do we have global warming? What are the consequences? What can be done against it? Who determines the future?

The book will come out on 31.May 2011.

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Back to the past

An article in the March issue of the Swiss National Science Foundation magazine "Horizonte" describes the work in the climatology group (in German).

Horizonte, No 88, March 2011 (pdf, 95KB)


New Evidence for Climate Impacts on Ancient Societies

Annual-resolved European summer climate has, for the first time ever, been reconstructed over the past 2,500 years. Tree rings reveal possible links between past climate variability and changes in human history. Climate change coincided with periods of socioeconomic, cultural and political turmoil associated with the Barbarian Migrations, the Black Death and Thirty Years’ War.

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Workshops on Climate Change and Food security

The "Forum für Universität und Gesellschaft" of the University of Bern has carried out four workshops on climate change and food security from September to November 2010.
The presentations/podcasts (in German) can be downloaded here (including presentations by Martin Grosjean, Rolf Weingartner, Hans Hurni, Thomas Cottier, Pier Calanca, Urs Wiesmann, Gunther Stephan etc. and an interview with Stefan Brönnimann).


Stefan Brönnimann on Radio DRS 1

Are the recently experienced autumn storms, the high temperatures in regions with foen and the abrupt temperature drop with snowfall outcomes of climate warming? The radio programme "Treffpunkt" on DRS1 raises the question whether these extreme weather events are new or if they have happened in earlier times. Prof. Brönnimann was interviewed as a climate research expert. The talk was broadcasted on 22.11.2010 at 09.05.

Radio DRS 1 Treffpunkt (in German)


Good bye Apéro for Heinz Wanner

Former Klimet members organised an apéro for Heinz Wanner on 16. November 2010. As a small acknowledgement of our gratitude for all his work, his great team spirit and his cheerful anecdotes about a researcher's life he was given a young apple tree. Thank you very much Heinz!


Prof. Dr. Stefan Brönnimann is the New Chair of Climatology Research Group

During the summer of 2010, a new group of climatology has formed in the Institute of Geography. As of 1 October 2010, Prof. Dr. Stefan Brönnimann has officially taken on the position of chair of climatology from Prof. Dr. Heinz Wanner. Please visit our main page and the pages of the individual group members to get to know the new group.


Stefan Brönnimann on SF 1

Stefan Brönnimann speaks about the monsoon and the extreme weather events in Pakistan. The TV programme "Einstein" was broadcasted on 26.08.2010 at 21:00.

SF 1 Einstein (in german)


Stefan Brönnimann on Radio DRS 1

Prof. Brönnimann was interviewed regarding the latest natural disasters, extreme weather events and his new professorship at the university of Bern. The talk was broadcasted on 17.08.2010 at 13:00 as a DRS 1 "Tagesgespräch".

Radio DRS1 Tagesgespräch (in german)