Seminar Speaker: CliMAS Graduate Student, Kevin Boyd
- Event Type
- Seminar/Symposium
- Sponsor
- Professor Steve Nesbitt
- Location
- 2079 NHB
- Date
- Dec 9, 2025 3:30 pm
- Views
- 22
Multi-Scale Perspectives on Polar Low Development and Forecasting
Polar lows (PLs) are intense mesoscale cyclones that form over high-latitude oceanic regions, posing hazards to coastal communities, maritime operations, and aviation. This talk examines PL development and forecasting across multiple spatial and temporal scales.
At the largest scales, we investigate relationships between PL activity and large-scale climate variability to improve our understanding of subseasonal PL predictability. We demonstrate that sources of subseasonal predictability—namely weather regimes and the Madden-Julian Oscillation—influence PL activity by modulating key environmental conditions. These relationships are captured by the PL genesis potential index (PGI), an empirical model linking variations in PL activity to large-scale climate predictors. The PGI skillfully predicts subseasonal PL activity up to a month in advance, with modes of large-scale climate variability both enhancing forecast skill and enabling forecasts of opportunity during specific phases and over certain regions.
At shorter time scales, we examine how precursor disturbances influence PL development by analyzing the early stages of a PL that evolved from a shear line in March 2024 during the CAESAR field campaign. We quantify the dynamical forcing mechanisms driving early PL intensification using an eddy kinetic energy (EKE) budget. Our analysis reveals a two-stage intensification process: barotropic and convective processes drive initial growth, followed by baroclinic and convective forcing after the system separates from the shear line. Sensitivity experiments further highlight the critical role of multi-scale interactions in polar low development. This case study provides the foundation for a broader investigation into the influence of precursors on PL frequency using seasonal downscaling simulations.
ZOOM:
https://illinois.zoom.us/j/82767407475?pwd=7ca6OfzVOPneyOwAULFkntXaYWaBvo.1
Meeting ID: 827 6740 7475
Pass Code: 809774