The Role of the Boundary Layer in Convective Self-Aggregation Illustrated by a New Diagnostic Framework of Moist Static Energy (VRMSE)
Abstract
Recent studies have shown that the planetary boundary layer (PBL, the lowest 2km) plays a key role in the development of convective self-aggregation using mechanism-denial experiments and available potential energy (APE) analyses (Muller and Bony 2015 GRL; Yang 2018 JAMES). However, the widely-used moist static energy (MSE) analysis is based on column-integrated MSE (CIMSE) budget, which does not have vertical resolutions so cannot explain why PBL is key. Here, we develop a vertically resolved MSE (VRMSE) framework and present the analysis result of self-aggregation simulations. The evolution of VRMSE has two dimensions: time and altitude (Fig. 1). We find that the development of self-aggregation is associated with increase of MSE variance in the lowest 2 km, consistent with earlier studies using the APE budget (Yang 2018). We then show that radiative feedbacks are primarily responsible for the generation of MSE variance in the PBL, which is further enhanced by atmospheric circulations. We will compare the CIMSE and VRMSE frameworks and suggest that the VRMSE framework could also help understand the development of tropical cyclones and the Madden-Julian Oscillation (MJO).
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A43H3103Y
- Keywords:
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- 3314 Convective processes;
- ATMOSPHERIC PROCESSES