Shallow Cumuli at the SGP Site: Macro- and Microphysical Properties

 
Poster PDF

Authors

Jessica M Kleiss — Lewis and Clark College
Erin Allegra Riley — Lewis and Clark College
Evgueni Kassianov — Pacific Northwest National Laboratory
Laura Dian Riihimaki — CIRES | NOAA ESRL GML
Larry Berg — Pacific Northwest National Laboratory

Category

Warm low clouds, including aerosol interactions

Description

Shallow cumuli (ShCu) play an important role in cloud-atmosphere-land interactions, including reflection of incoming radiation, vertical transport of moisture and momentum, and reduction of the surface heating by cloud shadows. Evaluation of model outputs requires integrated observations of both macro- and microphysical properties of ShCu on spatial and temporal scales comparable to those used in model simulations. Ground-based lidar-radar observations provide rich vertical profiling of the ShCu properties. However, the narrow field-of-view (FOV) of these observations results in relatively small samples (approximately 10 clouds/hr), which may not adequately represent the areal-averaged properties of ShCu at short (~ 1h) temporal scales. Recently we have developed a new cloud area product that combines wide-FOV observations from the Total Sky Imager and narrow-FOV data from the lidar-radar measurements to provide horizontal ShCu size distributions over a wide range of cloud sizes (about 0.04-3.5 km) with high temporal resolution (30 s). We have also produced a quick-look visualization tool to discern differences in wide- and narrow-FOV observations of cloud amount. These macrophysical ShCu properties are combined with microphysical properties of ShCu, such as liquid water path (LWP) and effective droplet radius (DER) to explore the potential impact of several environmental factors such as atmospheric stability, surface fluxes and turbulence.