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Please note that this session was withdrawn and is no longer available in the respective programme. This withdrawal might have been the result of a merge with another session.

CL4.01

The Dynamics of the Seasonal Cycle and its Signature Across All Timescales
Convener: Anne-Katrine Faber  | Co-Conveners: Katherine Hutchinson , Pragallva Barpanda , Ruth Geen , Mads Bruun Poulsen 

Seasonal changes are the largest observed perturbations to the climate system. They impact the ocean, atmosphere, land and ice with varying magnitudes, and are readily observed, for example, in sea ice formation, atmospheric moisture transports, the strength of ocean currents and in the life-cycle of biological components. Besides the first order effect of producing alternating seasons, these changes also interact nonlinearly with other climate phenomena like large-scale internal modes of variability (ENSO, Annular modes, MJO, and others) on an interannual timescale, as well as the orbital parameters on a glacial time scale.

Since the Earth’s formation, the seasonal cycle itself has been subjected to many adjustments, suggesting possible alterations in the future as well. A better understanding of the seasonal cycle and its feedback is therefore deemed important for understanding past climate records (proxy data), future climate changes and climate extremes.

This session brings together studies related to the seasonal cycle, from atmospheric science, oceanography, glaciology and paleoclimatology to examine the complementarity of ideas and approaches.

We welcome contributions from modeling and theoretical studies, modern and historical data, and proxies that provide insights into the dynamics of the seasonal cycle. Contributions including but not limited to the following questions are highly encouraged:
• What is the role of land and ocean in seasonal cycle?
• How do modes of internal variability, e.g. ENSO/ NAO /MJO couple with the seasonal cycle?
• What are the different responses of the biological or physical components of atmosphere/ocean in different seasons?
• Which role does the changes of the seasonal cycle play in climate changes on orbital timescales?
• How can we decode the past seasonal cycle from proxy records? What are the limitations?
• How can we detect shifts in the feedbacks to the seasonal cycle due to climate change?
• Understanding the seasonality of sea ice, past and present.
• Can we use the seasonal cycle as a tool to understand other aspects of climate change?

Invited speaker: Axel Timmermann

This session is convened by participants from the 2017 Advanced Climate Dynamics Course on The Dynamics of the seasonal cycle (http://www.uib.no/en/rs/acdc/).
This session is sponsored by the Advanced Climate Dynamics Summer School, through the Bjerknes Centre for Climate Research at the University of Bergen.