The Response of Polar Cyclone Intensification to Changing Sea Ice and Sea Surface Temperature
Abstract
Global climate forcings and polar amplification significantly affect seasonal Arctic sea ice extent, concentration, and thickness. The changing Arctic landscape and climate has important implications for the development of polar low pressure systems. Retreating sea ice, increasing fetch, and increasing sea surface temperatures increase the potential for polar low development, intensification, and trajectory into higher latitudes. However, increasing polar low activity can exacerbate sea ice export from the region, generating a feedback effect. Therefore, understanding the mechanisms of polar low intensification and the interaction with the ice-ocean interface is critical for understanding the future of polar low activity and Arctic sea ice. However, given a lack of observational data, and the spatio-temporal scale of these systems, the dynamics of polar low intensification remain poorly understood.
This study uses numerical weather modeling techniques to provide insight into the life cycle of polar lows. We utilize the National Center for Atmospheric Research (NCAR) Weather Research and Forecasting (WRF) model in a three-domain configuration of 36/12/4 km horizontal grid spacing to simulate polar low events in the Norwegian and Barents Seas (polar low genesis hotspots) between 2011-2015. A Q-vector diagnostic is used to analyze the relative contribution of upper level divergence, in-storm convection, and surface level fluxes to the intensification of each simulated polar low. Initial results suggest that while many Barents Sea polar lows are baroclinic and intensify through in-storm convection, several cases demonstrate alternate intensification processes. Our analyses explore the sensitivity of these polar lows to changing sea surface temperatures and sea ice extent and concentration in the model boundary conditions. The analysis focuses on the relative change in the simulated polar low intensification mechanisms and storm characteristics such as pressure, wind speed, precipitation, size, trajectory, and translation speed with the changing environment. Regional, high resolution modeling studies such as these are essential for furthering the understanding of polar low intensification and their sensitivity to the changing climate, and, in turn, the future of Arctic sea ice.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.A53D..08P
- Keywords:
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- 3311 Clouds and aerosols;
- ATMOSPHERIC PROCESSESDE: 3339 Ocean/atmosphere interactions;
- ATMOSPHERIC PROCESSESDE: 0738 Ice;
- CRYOSPHEREDE: 0750 Sea ice;
- CRYOSPHERE