A comparison of vertical velocity PDFs in the cloudy and cloud-free atmosphere
Poster PDF
Authors
Jennifer M. Comstock — Pacific Northwest National Laboratory
Larry Berg — Pacific Northwest National Laboratory
Julia Flaherty — Pacific Northwest National Laboratory
Category
Dynamics/Vertical Motion
Description
The Routine Atmospheric Radiation Measurement (ARM) Aerial Facility (AAF) Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (collectively RACORO) study was conducted from January through June of 2009. During RACORO, 59 flights were conducted in the vicinity of the ARM Southern Great Plains (SGP) site, including flights in clear and cloud-topped boundary layers. Vertical velocity measurements made at 10Hz temporal resolution have been analyzed using wavelet analysis to determine the distribution of vertical velocity perturbations at time scales of 1–10 sec and 10–50 sec. Flights were conducted at a number of altitudes, including flights through shallow cumuli. Vertical velocity perturbation probability density functions are presented for the cloudy and cloud-free atmosphere. These in situ measurements of vertical velocity can be used to verify velocity statistics from a range of remote sensing instruments, as well as assumptions that are commonly applied in global and regional scale models of the atmosphere.
