SNOWGLACE: The Changing Arctic Cryosphere: Snow and Sea Ice Impact On Prediction and Climate Over Europe and Asia
Climate impact of Arctic sea ice and snow cover
Objectives
The primary objective of SNOWGLACE is to improve our understanding of the complex interconnections between the shrinking Arctic cryosphere, and the weather and climate in middle latitudes. More specifically, it is aimed at determining how rapid changes in both the snow and sea ice extent observed in the northern regions affect the atmospheric circulation and extreme weather events (such as cold air outbreaks in mid- to high-latitudes), with a special focus on Europe and Asia. In particular, a key objective is to determine the interplay between the decline in summer Arctic sea ice and the build-up of the Eurasian snowpack in the following autumn, and their impacts on the winter circulation both in current and in future climates. A secondary objective is to quantitatively estimate actual predictability at the sub-seasonal to seasonal scale gained from initialisation of forecast models with accurate snow and sea ice conditions, thereby potentially improving ong-range forecasting.
Project Summary
Arctic summer sea-ice extent exhibits a sharp declining trend, and the induced atmospheric warming at high latitudes in autumn has potentially important consequences for the climate of Europe and Asia. On the other hand, North America, Europe, and East Asia have experienced anomalously cold winters with record high snowfalls during some recent winters. The autumn snow cover over Eurasia is increasing, while in spring, the snow decline at high northern latitudes is the largest cryospheric change in terms of spatial extent.
To examine the impact of the changing Arctic cryosphere, both land and sea ice, as a predictor of Eurasian climate at the seasonal time scale using advanced dynamical prediction systems is the central theme of this proposal. A key geographical focus will be Europe and Asia, with a strong involvement of partners in Japan, Korea and China. We will focus on the sea ice retreat influence onto the Eurasian snowpack in autumn as a link to winter weather anomalies, and address the cryospheric influence on mid-latitude extreme weather events, such as cold air outbreaks, blockings or heat waves. To this end, we will carry out ensemble seasonal simulations with NorCPM and coordinate an international initiative to investigate the effect of snow on sub-seasonal to seasonal forecasts, and other simulations with realistically initialised sea ice and snow. The results will be examined in the context of a multi-model framework.
The implications of projected accelerating Arctic sea ice cover disappearance in a warming world are wide ranging and we will assess the snow impact and its potential link to retreating sea ice in climate model simulations with the Norwegian climate model (NorESM).
Hence, a secondary objective is to allow Norwegian scientists to participate and play a leading role in international programmes on cryosphere-climate interactions, for example by promoting the use of the Norwegian prediction and climate models in multi-model assessments.
