POSTER: New seasonal climate field reconstruction for the North Atlantic region covering CE 1241-1970 - expanded proxy dataset and new isotope enabled climate model simulation for assimilation

Description

Climate field reconstructions covering the past millennium usually target the annual mean or the summer season in terms of temporal resolution. While several reconstructions of the winter North Atlantic Oscillation (NAO) have been done, the variability of other weather patterns are often ignored despite having significant regional impact. Compare to our previous reconstructions we have expanded the proxy dataset, and use a new isotope enabled climate model simulation. While the assimilation method for the proxy data is still based on a relatively simple analogue-type approach, we now weigh the contribution of model analogues to the final reconstruction according to the goodness-of-fit to the proxy data. Furthermore, we have introduced a variance correction which to a large extent eliminates the problem of underestimated reconstructed variance, especially in regions far away from the proxy sites. While the skill for circulation modes is still best for winter NAO, the reconstruction has significant skill for the three first modes for both summer and winter. This can also be seen in the increase in spatial coverage of skill for temperature and sea level pressure for both seasons. Our new reconstruction provides an improved dataset for attribution studies and provides a baseline for climate model evaluation.

Period	2024 Apr 15 → 2024 Apr 16
Event title	Swedish Climate Symposium 2024
Event type	Conference
Location	Norrköping, SwedenShow on map