Variability and mechanisms of trade-wind cumuli : from the diurnal timescale to global warming

Séminaire de Jessica VIAL (LMD/IPSL - EMC3), mercredi 13 nov. à 13h, salle 105 OSUG-B

Abstract :
Oceanic shallow convective clouds, such as those prevailing in the trade-wind regions, have long been of great interest, because they strongly impact climate on a wide range of scales and they are critical in the estimation of the magnitude and pace of global warming. But surprisingly, the most fundamental mode variability, that is the daily cycle, has received very little attention for this cloud category, so that our knowledge of the diurnal processes in this oceanic shallow cumulus regime and their influence on climate at broader scales remains extremely limited. I recently relaunched the exploration of this topic, which today is subject to a growing interest in the community.
New investigating tools have been used, including large-eddy simulations run over large domains in realistic configurations and in-situ observations, which have helped study this daily cycle with a lot more details than was possible 40 years ago when it was first documented. Important features of this daily cycle have been found, which can have farreaching implications for climate change studies. My hypothesis is that understanding the processes that control trade-wind cumuli on the diurnal timescale will benefit to our understanding of the mechanisms that are involved in the tropical marine low-level cloud feedbacks.
In this seminar, I will present the major outcomes of my research activities on tradewind cumuli, including both the daily cycle and the mechanisms of cloud feedbacks.

Par Jessica Vial
(LMD/IPSL, CNRS, Sorbonne Université, Campus Pierre et Marie Curie, Paris 5e)

Séminaire animé par Sandra Rome