Synthesis and Evaluation of Meridional Heat Transport from Mid-latitudes towards the Arctic

• Main Authors: Liu, Yang, Attema, Jisk, Moat, Ben, Hazeleger, Wilco
• Format: Conference Object
• Language: English
• Published: Zenodo 2018
• Subjects: Meridional Energy Transport; Atmosphere and Ocean Reanalysis; Variation of Sea Ice Concentration; Arctic Climate Change; Arctic; Barents Sea; Greenland; Climate change; Greenland Sea; Orca; Sea ice
• Online Access: https://dx.doi.org/10.5281/zenodo.1492297; https://zenodo.org/record/1492297

Meridional Energy Transport (MET), both in the atmosphere (AMET) and ocean (OMET), has significant impact on the sea ice in the Arctic. We quantify the AMET & OMET from six reanalysis datasets and investigate their relations with sea ice variation at annual to interannual scales. The results indicate that, although the mean transport in all datasets agree well, the spatial distribution and temporal variation of AMET and OMET deviate substantially. This leads to large difference in the low frequency variability of AMET and OMET in subpolar regions. Only after 2010 the low frequency signals from ocean reanalysis products agree well. A comparison with the observation from RAPID ARRAY and a high resolution NEMO ORCA hindcast suggests the overall trend captured by all the ocean reanalysis products converge well. For the atmosphere, the deviations between data sets mainly originate from temperature transport. Presumably, the assimilated observations are not sufficient to constrain the MET. A more detailed analysis on the linkages between the Arctic sea ice concentration (SIC) and AMET & OMET identifies a strong anticorrelation between AMET/OMET and SIC at Greenland Sea and Barents Sea. However, with respect to AMET-SIC relationships there are large differences among the datasets. Only ERA-Interim data corroborates physical explanations hypothesized from climate models. With respect to the ocean data, ORAS4 and SODA3 agree well on the relation between OMET and SIC, while GLORYS2V3 differs from them. All the reanalysis products find strong links between AMET/OMET at subpolar latitudes and ENSO, which hints towards teleconnections between MET at high latitudes and climate variability at lower latitudes. As a result, our study suggests, since the reanalysis products are not designed for the quantification of energy transport, the AMET and OMET estimated from reanalysis should be used with great carefulness, especially when studying low frequency variability. : Presentation given at Earth Energy Imbalance workshop in Toulouse on November 14th, 2018 during the session "Regional Energy Budget and Energy Transports".