Unit:
Κατεύθυνση Φυσική ΠεριβάλλοντοςLibrary of the School of Science
Supervisors info:
Μαρία Τόμπρου-Τζέλλα, Καθηγήτρια, Τμήμα Φυσικής, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών
Γεωργία Σωτηροπούλου, Μεταδιδακτορική Ερευνήτρια, Τομέας Μετεωρολογίας, Πανεπιστήμιο της Στοκχόλμης
Ελισσάβετ Μποσιώλη, ΕΔΙΠ, Τμήμα ΦΥσικής, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών
Original Title:
A study of the evolution of clouds during a cold air outbreak with the use of numerical simulations
Translated title:
A study of the evolution of clouds during a cold air outbreak with the use of numerical simulations
Summary:
A stratocumulus-to-cumulus transition (SCT) is a change in the cloud morphology, typically observed in cold air outbreak (CAO) episodes and suggested, by recent studies, to be driven by microphysical and precipitation processes which are highly underrepresented in general circulation and climate models. Using the Weather Research Forecasting (WRF) model, a set of simulations is performed on an SCT case observed to the north of the UK on 24/11/2013 by Abel et al. (2017) in order to test the effect of secondary ice production (SIP) mechanisms on the initiation and evolution of the transition. Of the SIP mechanisms tested (collisional break-up, droplet-shattering, Hallett-Mossop), collisional break-up was found to be the most impactful in generating precipitation-sized particles and decreasing the liquid water path (LWP) in the convective region, to values comparable to measurements (Abel et al., 2017) while the results also showed a considerable dependency on the assumed rimed fraction of the colliding particles. The impact of the Hallett-Mossop mechanism, despite its vast implementation in weather prediction models, appeared to be insignificant.
Main subject category:
Science
Keywords:
cold-air outbreak, stratocumulus-to-cumulus transition, cloud microphysics, secondary ice production, atmospheric modeling
