Society will feel the impacts of global warming most through regional changes in climate and weather extremes. Unfortunately uncertainties in future projections at these scales are large. They are dominated by both internal climate dynamics and model systematic errors. Initiating climate predictions from concurrent observations can reduce uncertainties due to internal climate dynamics on time scales shorter than a decade. Better simulating the atmosphere’s interaction with other parts of the climate system is a promising strategy to achieve more reliable long-term climate projections. For example, reducing uncertainties in the atmospheric response to arctic sea ice loss could help constrain regional climate change projections. This was GREENICE’s main objective, but our climate model experiments show that arctic sea ice has a rather limited impact on the northern hemisphere mid-latitudes.
TRACE aims to enhance Nordic-Russian cooperation in Higher Education and Research in GREENICE and the Nordic Centre of Excellence ARCPATH. It will achieve this through a joint study addressing an important scientific question that is not considered by either of these NordForsk projects: Can better resolving the sharp Gulf Stream sea surface temperature front help constrain future projections of climate and weather extremes over Eurasia? Addressing this requires the key expertise of the Nordic and Russian research teams, the mobility of junior and senior researchers, joint use of infrastructure, and the joint development of methods.
The main objective of TRACE is to assess the role of the Gulf Stream – North Atlantic SST front in future climate change over Eurasia. TRACE will achieve its main objective by performing and analysing climate model simulations for present day and future conditions. Stand-alone atmospheric model experiments forced by prescribed SST will isolate the effects of atmospheric and SST resolution in climate change projections over Eurasia. To assess the importance of ocean-atmosphere interaction we will also utilise a set of relatively high resolution coupled ocean-atmosphere model experiments being performed for the EU H2020 PRIMAVERA. Analysing these simulations will reveal the impact of resolving the North Atlantic SST front on atmospheric circulation, blocking, and weather extremes over Eurasia. We will assess model uncertainties by comparing these analysis in present day TRACE and multi-model, lower resolution GREENICE experiments. Thus, TRACE will provide the first mechanistic understanding of how resolving the sharp North Atlantic SST front may influence global warming projections.
Role of SMHI
In TRACE, SMHI will contribute with the analysis of standard and high resolution simulations from coupled and atmosphere models. SMHI will investigate if and how the position of the Gulf Stream and related sea surface temperature gradients in the North Atlantic change and how this affect the atmospheric circulation and weather and climate conditions over Europe.
TRACE is a partnership between three Nordic partners - the University of Bergen (Noel Keenlyside, coordinator), NERSC and SMHI - and three Russian partners – IORAS, IAPRAS and NIERSC.
TRACE is funded by NordForsk, Joint Nordic-Russian research activities (funding from the Nordic Council of Ministers and the Ministry of Education and Science of the Russian Federation), Project n. 81512.
TRACE will run from 2016 to 2017.