Two-Point Mixing, Buoyancy Sorting and Updraft Dilution Observed in the RACORO Campaign
Abstract
Aircraft measurements of shallow cumulus cases from the RACORO campaign are studied in a transformed Paluch diagram. Previous studies have interpreted samples in Paluch diagrams in terms of two-point mixing and buoyancy sorting. The two-point mixing behavior is frequently seen in the RACORO observations and can be unambiguously distinguished from buoyancy sorting. The latter is not found in the RACORO observations and is also rare in a large-eddy simulation (LES) of a RACORO case. As opposed to often assumed gradual dilution to updrafts, around half of the cases of two-point mixing show no clear evidence of updraft dilution. We also find substantial spread in the properties of parcels that have adjusted to their level of neutral buoyancy and that the inclusion of surface heterogeneity in a LES significantly improves the agreement of its horizonal moisture variations with the aircraft measurements.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMA085.0002W
- Keywords:
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- 3307 Boundary layer processes;
- ATMOSPHERIC PROCESSES;
- 3310 Clouds and cloud feedbacks;
- ATMOSPHERIC PROCESSES;
- 3314 Convective processes;
- ATMOSPHERIC PROCESSES;
- 3371 Tropical convection;
- ATMOSPHERIC PROCESSES