Featured Research

from universities, journals, and other organizations

Predicting climate: Researchers test seasonal-to-decadal prediction

Date:
March 25, 2014
Source:
University of Bergen
Summary:
Researchers are exploring the potential for seasonal to decadal climate prediction. Seasonal-to-decadal prediction is now being tested with an advanced initialization method that has proven successful in weather forecasting and operational oceanography.

In a new study published in Tellus A, Francois Counillon and co-authors at the Bjerknes Centre are testing seasonal-to-decadal prediction.

Related Articles


At the Bjerknes Centre, researchers are exploring the potential for seasonal to decadal climate prediction. This is a field still in its infancy, and a first attempt was made public for the latest Intergovernmental Panel on Climate Change (IPCC) report.

Apart from a few isolated regions, prediction skill was moderate, leaving room for improvement. In a new study published in Tellus A, seasonal-to-decadal prediction is tested with an advanced initialisation method that has proven successful in weather forecasting and operational oceanography.

"Ordinary" climate projections are designed to represent the persistent change induced by external forcings. Such "projections" start from initial conditions that are distant from today's climate and thus fail to "predict" the year-to-year variability and most of the decadal variability -- such as the pause in the global temperature increase (hiatus) or the spate of harsh winter in the northern hemisphere. In contrast, weather predictions rely entirely on the accuracy of their initial state as the influence of the external forcing is almost imperceptible.

For seasonal-to-decadal time scales both the initial state and the external forcing influence the prediction. Starting a climate prediction from an initial state closer to the real climate is therefore necessary to yield better prediction than accounting only for external forcing. In our region of interest, decadal skill may be achieved by improving the representation of the heat content transiting into the Nordic Sea and in turn may influence the precipitation and temperature over Scandinavia.

The method employed to initialise/ correct a dynamical system is referred to as data assimilation. It estimates the initial state of a model knowing a set of sparse observations (much less than 1% of the ocean variables are observed). A relationship between the observations and the non-observed variables must be found to broaden the corrections.

Furthermore, the corrections must satisfy the model dynamics to avoid abrupt adjustments during the forecast. The Ensemble Kalman Filter uses statistics from an ensemble of predictions to estimate the relationship between the observations and all variables for their correction. This method is computationally intensive as it requires parallel integrations of the model but it ensures that the relationship evolve with the system, and that the corrections satisfy the dynamics of the model.

The Norwegian climate prediction model (NorCPM) combines the Norwegian Earth System model with the Ensemble Kalman Filter. In time, we intend to perform retrospective decadal predictions (hindcasts) over the last century, to test the skill of our system on disparate phases of the climate and shed light on the relative importance of internal and external influences on natural climate variability, including the significance of feedback mechanisms. Sea surface temperatures (SST) are the only observations available for such a long period of time and will be used for initialisation.

Our study investigates the potential skills of assimilating SST only, using an idealised framework, i.e. where the synthetic solution is taken from the same model at different times. This framework allows an extensive validation because the full solution is known and our system can be evaluated against the upper predictive skill (the case where observations would be available absolutely everywhere). NorCPM demonstrated decadal predictability for the Atlantic meridional overturning and heat content in the Nordic Seas that are close to the model's limit of predictability. Although these results are encouraging, the idealised framework assumes that the model is perfect and lower skill is expected in a real framework. This verification is currently ongoing.


Story Source:

The above story is based on materials provided by University of Bergen. Note: Materials may be edited for content and length.


Journal Reference:

  1. FRANCOIS Counillon, INGO Bethke, NOEL Keenlyside, MATS Bentsen, LAURENT Bertino, FEI Zheng. Seasonal-to-decadal predictions with the ensemble Kalman filter and the Norwegian Earth System Model: a twin experiment. Tellus A, 2014; 66 (0) DOI: 10.3402/tellusa.v66.21074

Cite This Page:

University of Bergen. "Predicting climate: Researchers test seasonal-to-decadal prediction." ScienceDaily. ScienceDaily, 25 March 2014. <www.sciencedaily.com/releases/2014/03/140325102007.htm>.
University of Bergen. (2014, March 25). Predicting climate: Researchers test seasonal-to-decadal prediction. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2014/03/140325102007.htm
University of Bergen. "Predicting climate: Researchers test seasonal-to-decadal prediction." ScienceDaily. www.sciencedaily.com/releases/2014/03/140325102007.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Reuters - Innovations Video Online (Nov. 26, 2014) — Innovative recycling project in La Paz separates city waste and converts plastic garbage into school furniture made from 'plastiwood'. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Antarctic Sea Ice Mystery Thickens... Literally

Antarctic Sea Ice Mystery Thickens... Literally

Newsy (Nov. 25, 2014) — Antarctic sea ice isn't only expanding, it's thicker than previously thought, and scientists aren't sure exactly why. Video provided by Newsy
Powered by NewsLook.com
3D Map of Antarctic Sea Ice to Shed Light on Climate Change

3D Map of Antarctic Sea Ice to Shed Light on Climate Change

Reuters - Innovations Video Online (Nov. 24, 2014) — A multinational group of scientists have released the first ever detailed, high-resolution 3-D maps of Antarctic sea ice. Using an underwater robot equipped with sonar, the researchers mapped the underside of a massive area of sea ice to gauge the impact of climate change. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Car Park Solution for Flexible Green Energy

Car Park Solution for Flexible Green Energy

Reuters - Innovations Video Online (Nov. 24, 2014) — A British solar power start-up says that by covering millions of existing car park spaces around the UK with flexible solar panels, the country's power problems could be solved. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins