Journal
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
Volume 6, Issue 1, Pages 59-74Publisher
AMER GEOPHYSICAL UNION
DOI: 10.1002/2013MS000269
Keywords
self-aggregation; convection
Categories
Funding
- National Science Foundation
- NSF [1032244, 1136480, 0850639]
- MIT Joint Program on the Science and Policy of Global Change
- Directorate For Geosciences
- Div Atmospheric & Geospace Sciences [1136480, 0850639] Funding Source: National Science Foundation
- Div Atmospheric & Geospace Sciences
- Directorate For Geosciences [1032244] Funding Source: National Science Foundation
Ask authors/readers for more resources
We elucidate the physics of self-aggregation by applying a new diagnostic technique to the output of a cloud resolving model. Specifically, the System for Atmospheric Modeling is used to perform 3- D cloud system resolving simulations of radiative-convective equilibrium in a nonrotating framework, with interactive radiation and surface fluxes and fixed sea surface temperature (SST). We note that self-aggregation begins as a dry patch that expands, eventually forcing all the convection into a single clump. Thus, when examining the initiation of self-aggregation, we focus on processes that can amplify this initial dry patch. We introduce a novel method to quantify the magnitudes of the various feedbacks that control self-aggregation within the framework of the budget for the spatial variance of column-integrated frozen moist static energy. The absorption of shortwave radiation by atmospheric water vapor is found to be a key positive feedback in the evolution of aggregation. In addition, we find a positive wind speed-surface flux feedback whose role is to counteract a negative feedback due to the effect of air-sea enthalpy disequilibrium on surface fluxes. The longwave radiation feedback can be either positive or negative in the early and intermediate stages of aggregation; however, it is the dominant positive feedback that maintains the aggregated state once it develops. Importantly, the mechanisms that maintain the aggregate state are distinct from those that instigate the evolution of self-aggregation.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available