Group seminar on 9. May, 14:15 CET
The influence of the sea surface temperature gradient in the Gulf stream region on cyclone development and warm conveyor belt ascent during the European winter "heat wave" in February 2019
Svenja Christ
The European wintertime ‘heat wave’ in February 2019 provides an opportunity to investigate the impact of sea surface temperature (SST) gradients on air-sea interactions, cyclone formation, and warm conveyor belt (WCB) ascent in the North Atlantic. To this end, we conducted five global ICON simulations over a period of nine days, with different SST gradients in the Gulf stream region. Our results indicate that changing SST gradients influence air-sea interactions and cyclone formation. Specifically, we found that warmer air temperatures and higher specific humidity were observed in simulations with warmed SST. In comparison, lower air temperatures and less specific humidity were found in simulations with weakened SST gradients in the Gulf stream region. Despite no significant changes in synoptic dynamics, we observed lower deepening rates for weakened SST gradients. The diabatic heating within WCB associated with these extratropical cyclones was also altered. We found that the number of WCB trajectories was higher for simulations with warmed SST, while weakened SST gradients resulted in fewer WCB trajectories. Our findings provide insights into the processes connecting SST gradients, air-sea interactions, cyclone formation, and WCB characteristics in the North Atlantic.