Predictability of Arctic/North Atlantic climate”, research project of the Centre of Climate Dynamics: PRACTICE
The overall objective of PRACTICE is to establish a basis for interannual to decadal prediction of Arctic/North Atlantic climate.
Objectives
- To advance the mechanistic and observation-based understanding of anomalous ocean circulation and northern climate variability
- construct, test, and develop the Norwegian Climate Prediction Model (NorCPM)
- to extend the basis for interannual-to-decadal prediction of Arctic/North Atlantic climate, identify requirements – observational and model – of a prediction system, and coordinate its development
Project Summary
The Bergen community has key competence and infrastructure in
the observed and modelled circulation and dynamics of the North Atlantic/Nordic Seas/Arctic
Ocean climate system, including both an established Earth System Model and an advanced
operational ocean-ice forecasting system focused on the high northern latitudes and Arctic sea ice.
There have been several recent developments that corroborate the above and further
suggest that the Bergen community is well positioned to take on the challenge of climate
prediction. An internal Bjerknes project was undertaken in 2010 where an Ensemble Kalman
Filter (EnKF) assimilation module was successfully coupled to the ocean component of NorESM
(cf. WP2 below; Counillon et al. 2010). The NorESM is also at present in “operational mode” for
the IPCC AR5. The ensemble framework is both flexible and robust, and it does in particular
offer the perspective of stochastic parameterization, which was noted by Palmer et al. (2009) as a
way to reduce model biases in non-linear climate models. The latter would be most beneficial for
model analyses in general, and for IPCC-type assessments in particular. The suggested model
system can be foreseen to provide boundary conditions constrained by observations to regional
downscaling studies (Fig. 3).
There have also been major improvements with respect to human resources. Noel
Keenlyside, a leading expert and defining scientist in the emerging field of climate prediction
took up a professorship at UiB March 1 2011, and will be actively involved in the proposed
project (PI WP3). Maybe even more important is the fact that the Bjerknes Centre of Excellence
has given prioritized funding to syntheses – including all partner institutions – directly
contributing to the mechanistic knowledge base that must be developed in WP1, including a
synthesis of the Barents Sea’s role in the climate system. The latter is particularly relevant for
PRACTICE and northern climate prediction as the Barents Sea is where temperate Atlantic
surface waters meets the ice edge; the sea is thus a “hotspot” both for the regional climate system,
atmosphere-ocean feedback mechanisms included (e.g., Ikeda 1990; Ådlan
