5–7 May 2021
virtual
Europe/Copenhagen timezone

The diurnal path to persistent convective self-aggregation

5 May 2021, 16:00
1h 45m
virtual

virtual

Interactive presentation Modelling and Parameterising Deep Convective Organisation Modelling and Parameterising Deep Convective Organisation

Speaker

Gorm Gruner Jensen (Atmospheric Complexity, NBI, Uni. Copenhagen)

Description

Convective self-aggregation (CSA) has attracted a lot of attention as a possible explanation for large scale tropiccal weather phenomena such as the Madden-Julian oscillation and cyclo-genesis. However, CSA is hampered in the realistic limit of fine model resolution when cold pools---dense air masses beneath thunderstorm clouds---are well-resolved.

Here we mimic the diurnal cycle in cloud-resolving numerical experiments by prescribing a surface temperature oscillation. Our simulations show that the diurnal cycle enables the formation of persistent dry patches closely resembling the early onset of CSA. In fact, the dry-patch formation is accelerated by finer resolutions. We attribute these findings to the highly non-linear dynamics of large ‘combined cold pools’ emerging in symbiosis with mesoscale convective systems. Our results may help connecting CSA paradigm in favor of more realistic simulations.

A preprint of the findings are available at: arXiv:2104.01132

Primary authors

Gorm Gruner Jensen (Atmospheric Complexity, NBI, Uni. Copenhagen) Dr Jan O. Härter (Atmospheric Complexity, NBI, Uni. Copenhagen) Romain Fiévet (Niels Bohr Institute)

Presentation materials