Atmospheric Modes of Drizzling Stratus at the ARM SGP Site
| Kollias, Pavlos | RSMAS/University of Miami |
| Albrecht, Bruce | University of Miami |
The representation of boundary layer clouds in GCMs remains a source of uncertainty in climate simulations. The cloud amount in the boundary layer is sensitive to the boundary layer scheme. Furthermore, little is known on the climatology of drizzling or precipitating boundary layer clouds, their seasonal variability and their dependency on atmospheric parameters and modes resolved by large-scale models and GCMs. A climatology of drizzling and non-drizzling boundary layer clouds is developed using long-term (6.5 years) observations of boundary layer clouds at the ARM SGP site. The analysis is limited to cold-season months (November-March) when continental stratus clouds are more pronounced and the effect of insects and bugs in the MMCR boundary layer observations is a minimum. Composite statistical distributions of drizzling and non-drizzling clouds are examined as a function of various atmospheric parameters, such as vertical velocity, stability and surface conditions. The observations illustrate that a significant portion of stratus clouds contain drizzle.
This poster will be displayed at the ARM Science Team Meeting.


