EGU2020-9721
https://doi.org/10.5194/egusphere-egu2020-9721
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

A novel masking technique to investigate atmosphere-ocean interaction over Western Boundary Currents

Fumi Hayashi1, Arnaud Czaja2, and Benoit Vanniere3
Fumi Hayashi et al.
  • 1Atmospheric Physics Group, Imperial College London, United Kingdom of Great Britain and Northern Ireland (fh911@ic.ac.uk)
  • 2Imperial College London, United Kingdom of Great Britain and Northern Ireland
  • 3University of Reading, United Kingdom of Great Britain and Northern Ireland

Western Boundary Currents (WBC), such as the Gulf Stream, leave a strong imprint on the ocean-atmosphere boundary in the form of strong gradients and high variability of Sea Surface Temperature (SST). Recent studies have shown that midlatitude oceanic fronts have an influence throughout the depth of the troposphere by means of synoptic systems such as weather fronts. An understanding of how the midlatitude ocean influences the synoptic system is crucial for better climate projection, however, this has been challenging. For example, in model simulations the sensitivity of the atmosphere to SST anomalies are dependent on its resolution, with low resolution models unable to capture the air-sea interactions occurring over warm sectors of midlatitude cyclones, possibly leading to underestimations of the oceanic influence on the atmosphere. A novel modelling technique is developed in which an interactive “mask” is used to systematically isolate and study the air-sea interaction over different synoptic regimes (warm and cold sector). Here, simulations using an idealised aqua-planet atmospheric general circulation model (AGCM) are used to study the atmospheric response to a tightening of SST gradient (comparable to that of the Gulf Stream) over the cold sector (“cold path”) and the warm sector (“warm path”) separately. Same experiments will also be performed on models with higher resolution to investigate the difference in atmospheric response between the high and low resolution models and what physical processes are responsible for such change in response.

How to cite: Hayashi, F., Czaja, A., and Vanniere, B.: A novel masking technique to investigate atmosphere-ocean interaction over Western Boundary Currents, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-9721, https://doi.org/10.5194/egusphere-egu2020-9721, 2020

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