Exploring the Secret Life of Low Clouds: A Proof-of-Principle for a Nocturnal Low-Cloud Mask during the PECAN Field Campaign
Authors
Daniel Feldman — Lawrence Berkeley National Laboratory
David Romps — Lawrence Berkeley National Laboratory
Category
Warm low clouds, including aerosol interactions
Description
We develop a nighttime low-cloud mask using a combination of ARM datasets including IRSI data to indicate the spatial distribution of clouds in general, and ARM active sounding instruments and nocturnal satellite imagery to differentiate low and high cloud tops. We develop a proof-of-principle for this mask by investigating the spatial and temporal distribution of nocturnal low clouds in the vicinity of the Southern Great Plains Central Facility during the PECAN campaign. With this nocturnal low-cloud mask, we may be able to characterize stratiform and transition regions of a mesoscale convective system, and, with the PECAN Integrated Sounding Array, determine the relationships between spatial and temporal variability in low-clouds and spatial and temporal variability in atmospheric thermodynamics. Given the large spatial domain of the PECAN campaign, we establish the regional representativeness of IRSI-derived low-cloud mask using a satellite-derived low-cloud mask built from a combination of nighttime reflected lunar radiation from the VIIRS Day-Night Band and thermal imagery from MODIS.
