Category: News

Upcoming workshop: External versus internal variability on decadal and longer time scales

On Wednesday 14th September, the CLIVAR Climate Dynamics Panel (CDP) will launch the first of an intended series of annual CDP workshops. This year’s workshop will target our understanding of internal and externally forced variability in the climate system, their interaction on decadal timescales and longer, and the effects of variability on extreme events. To foster discussion that will stimulate focused research on this important topic, the workshop aims to tackle the following overarching questions:

  • How to isolate the relative contributions of external and internal variability to observed decadal and longer variability?
  • How do the various external forcings modulate internal variability?
  • How to progress in narrowing observational and modeling uncertainties in external and internal variability?
  • What are the effects of external and internal variability on extreme events?

The workshop will be online, and consist of six, weekly 2-hour sessions, from September 14th to October 19th, 2022. The sessions will be on Wednesdays with the timings varying to accommodate participation from different time zones.

Workshop program and further event information:


Predicting Arctic sea ice for the marine transport sector

Image credit: Copernicus Marine Service

Check out this nice article by Dr. Ellen Viste at the Bjerknes Centre for Climate Research, on the evaluation of sea ice models and how far we are to being able to provide reliable, near-term sea-ice predictions:

In it, we hear from Tarkan Bilge, our BCPU data manager, and his recent paper on sea ice thickness forecasts to support Arctic marine transport, together with other collaborating scientists at our partner, NERSC, among others.

Hva gjør La Niña med været? (How does la Niña affect the weather?)

Værfenomenet El Niño forbinder mange med intens varme, men nå er dens kaldere lillesøster La Niña her. Hva betyr det? Vår forsker og førsteamanuensis, Dr. Lea Svendsen, skriver om dette hos Enegi og Klima: Hva gjør La Niña med været?.

(Most are all quite familiar with the El Niño phenomenon and its link with periods of intense heat. But now, El Niño’s colder little sister is here. What does this mean for the weather? Our researcher, Dr. Lea Svendsen, writes about this in her recent article in the Norwegian popular science journal Energi og Klima (link above. Article in Norwegian).

Scientific breakthrough: Winter climate in Norway now more predictable

Scientists from the Bjerknes Climate Prediction Unit, affiliated with the Nansen Environmental and Remote Sensing Center, the Bjerknes Centre for Climate Research, and the University of Bergen, contributed to a recent publication in Nature. The results indicate that it is possible to predict how the atmospheric circulation above the North Atlantic will evolve during the next decade. This is crucial for better predicting the winters in Europe and Eastern North America.

Figure 1: Rainfall variation over Northern Europe between 1960 and 2005. e) shows observations (black) and modelled predictions (red) with uncertainty range (shaded red) without adjustments, f) shows the improved and adjusted modelled predictions and uncertainty range.
Figure 1: Rainfall variation over Northern Europe between 1960 and 2005. e) shows observations (black) and modelled predictions (red) with uncertainty range (shaded red) without adjustments, f) shows the improved and adjusted modelled predictions and uncertainty range.

Investigating the climate of the past

In order to look forward in time, looking at the past is helpful. This is true in many cases, and the researchers behind this study led by the UK Met Office made use of this principle. They used climate models for investigating how accurately climate can be predicted on a decadal scale over the past sixty years.

Sea level pressure above the North Atlantic influences Norwegian winters

The main pattern of changes in sea level pressure above the North Atlantic, called the North Atlantic Oscillation (NAO), influences the wind and storms over the North Atlantic, which in turn influences the winter weather in Europe and Eastern North America. Two extremes are possible for winters in these regions: stormy, warm, and wet, or calm, cold, and dry. Which extreme the winter weather will tend towards is now shown to be very predictable on a decadal scale, according to the new study.

The researchers investigated the North Atlantic Oscillation and its influence by producing retrospective forecasts of the past climate (called hindcasts) and comparing them to observations made in the past. That way they quantified how accurate the model predictions are.

One of the most important predictions for Europe and especially Norway is the amount of rainfall. The comparison between hindcasts produced by models (Figure f, red line) and the observation (Figure f, black line) shows that the rainfall over Northern Europe can be predicted with high certainty. The model results match the previous observations nicely.

Contribution from the Bjerknes Climate Prediction Unit

Many hindcasts were produced by different research groups worldwide. The different climate models from these groups are part of t experiments performed for the last and upcoming Intergovernmental Panel on Climate Change (IPCC) reports. Bergen researchers involved in the study are the following: Noel Keenlyside (UiB/NERSC), François Counillon (NERSC), Ingo Bethke (UiB), and Yiguo Wang (NERSC). The four are part of the Bjerknes Climate Prediction Unit at the Bjerknes Centre for Climate Research. They used their climate model, the Norwegian Climate Prediction Model (NorCPM), which is part of CMIP6, to contribute to this study.

Climate models need to be improved

Apart from the high predictability of the North Atlantic climate indicated by the hindcasts, the study also shows that current climate models are underestimating this exact fact (Figure e). The researchers identified this deficiency and show that climate models need to be and can be adjusted (Figure f) to better predict the behaviour of the pressure above the North Atlantic and in turn the future winter conditions in Europe and Eastern North America.

To sum it up, confidently predicting the winters of the next years for Norway is now a reality, but climate models need to be improved.

Significance of this study: Climate can now be better predicted on short time scales

Noel Keenlyside, leader of the BCPU, commented “This is a major breakthrough for climate research and for the development of climate services in our region. Now we have solid evidence that we can provide to our stakeholders, like BKK and Agder Energi, that we can really say something useful about how the coming winters will be. It will also lead to improved models for providing better long-term projections of climate change.

The newly established Centre for Research-Based Innovation (SFI) called Climate Futures led by NORCE, with the Bjerknes Centre and Nansen Center as partners, among others, will benefit from this work in the future. The Centre’s objective is to improve climate prediction on short time scales of days to decades, and to improve the management of climate risks. By improving the predictability of Norwegian winters on a decadal scale, as indicated by this recent study, decadal climate prediction will become better and better. Erik Kolstad with NORCE and Bjerknes Centre leads this project:

“These results show that the models now can predict the climate in a useful way for planning in a number of sectors, like renewable energy, agriculture, and finance/insurance. With predictions like these both the business world and the public sector will be better prepared for extreme weather events and potentially gain more from periods of favorable weather and climate.”

Tarjei Breiteig (Head of Hydroglogy and Meterology at Agder Energi AS) represents one of the stakeholders this study directly impacts.

“This study shows that there is stilled untapped potential in saying something about possible weather and climate the next decade. To save hydropower in years of little demand, and have stored hydropower in years where demand will be high, it is essential for us to have sufficient information on what fluctuations to be expected in weather and climate the next decade. The climate research groups in Bergen show that they take this effort seriously, and that they are ahead when it comes to analyse and use climate models in the real world.”

Climate Futures: New Centre for Research-based Innovation

Press release from NORCE (in Norwegian)

The Norwegian Research Council has given Climate Futures the prestigious status as a Centre for Research-based Innovation (SFI).

Climate Futures is a new and ambitious action to generate long-term cooperation between companies, public organizations and research groups across sectors and disciplines to tackle one of the most urgent challenges of our time.

The changing nature of weather and climate poses a severe threat to the prosperity and well-being of our economy and society as a whole, but climate risk is inadequately managed due to knowledge gaps and deficiencies in the decision-making processes of businesses and public authorities.

– These are fantastic news. We knew that the theme of Climate Futures was relevant, and we are pleased that the Research Council also sees that climate risk is an area that requires great effort on the research front. We at NORCE and the Bjerknes Centre have a brilliant group of research partners, business world stakeholders and public sector partners. We are now looking forward to helping these deal with the great risk associated with weather and climate, whether for direct phenomena such as floods and droughts, or more transferred risk related to investments in other parts of the world, says centre manager and climate scientist Erik Kolstad in NORCE and the Bjerknes Centre.

Climate Futures is led by NORCE, and is comprised of seven other research partners and close to 30 stakeholder partners, representing agriculture, renewable energy, disaster mitigation, shipping, insurance, finance, risk management, and the public sector.

They will work together to create new solutions to predict and manage climate risk from 10 days to 10 years into the future.

Erik Kolstad, centre leader Climate Futures, NORCE and the Bjerknes Centre. +47 411 22 457
Trond Martin Dokken, Executive Vice President climate, NORCE   +47 975 64 402

Research partners in Climate Futures
NHH / SNF, Universitetet i Bergen, Norsk regnesentral, Meteorologisk institutt og Nansensenteret.
NORCE, UiB og Nansensenteret er alle samarbeidspartnere i Bjerknessenteret for klimaforskning.

Stakeholder partners
BKK, Golden Ocean, Gartnerhallen, Graminor, MOWI, StormGeo, Agder Energi, Tryg Forsikring, Norges Bondelag, Western Bulk, KLP, G2 Ocean, Safetec, Statkraft, Norsk Landbrukrådgiving, Vestland Fylkeskommune, Viken Fylkeskommune, Rogaland Fylkeskommune, Alle fylkesmennene i Norge, representert ved Fylkesmannen i Vestland og Direktoratet for Samfunnssikkerhet og Beredskap (DSB).