Arctic weather and climate: from mechanisms to forecasts

• Main Author: Liu, Yang
• Other Authors: Hazeleger, W., Attema, J.J.
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Wageningen University 2021
• Subjects: Life Science; Arctic; Climate change; Sea ice
• Online Access: https://research.wur.nl/en/publications/arctic-weather-and-climate-from-mechanisms-to-forecasts; https://doi.org/10.18174/545045

Since the mid-20th Century, the Arctic is warming about two times faster than the rest of the world. This is widely known as Arctic Amplification (AA) and has drawn lots of attention recently. Apart from a dominant impact on the local weather and climate, its influence has been extended beyond the polar region through significant modification on the circulation in both the atmosphere and ocean. In order to identify the drivers of Arctic climate change and the connections between the Arctic and global climate system, it is important to understand the Arctic weather and climate.The Arctic weather and climate system is manifested by the cryosphere. Given the essential role of sea ice and the key factors that regulate the variability of sea ice, it is of vital importance to shed new light on the energy budget, as well as the atmosphere-ocean interaction in the perspective of the energy budget in the Northern Hemisphere. A better quantification of the Arctic sea ice variability and the Arctic energy budget will give us a better understanding of the mechanisms behind Arctic climate warming. This in turn would help improve the weather forecasts for the Northern Hemisphere.This thesis, I mainly focus on the variations and forecasting of the Arctic sea ice. Given the close relation between the Arctic energy budget and sea ice variability, an emphasis is placed on the meridional energy transport (MET). In chapter 2, I quantified meridional energy transport in the atmosphere (AMET) and ocean (OMET) at subpolar latitudes using the latest methods and six reanalysis data sets. An intercomparison of the results from the chosen reanalysis products indicates that although the mean transport in all data sets agrees well, the spatial distributions and temporal variations of AMET and OMET differ substantially among the reanalysis data sets. Our study confirms that the analyzed reanalysis products are useful for the diagnostics of energy transport. However, beyond interannual timescales, the results must be interpreted with caution, ...