A118-0002
Characterization and Evolution of Organized Shallow Convection
Characterization and Evolution of Organized Shallow Convection
Friday, 11 December 2020
Poster
Abstract:
Uncertainty in the response of clouds to warming is the leading source of uncertainty in projections of future warming. To a large fraction the frequently occurring shallow cumulus clouds in the trade wind region contribute to this uncertainty. In symbiosis with thin clouds of stratiform extent they often create various cloud patterns.
By combining the meso-scale organization identified in GOES16 and MODIS satellite imagery with ten years of ground-based measurements of the Barbados Cloud Observatory we are able to characterize the trade-wind cumuli in their meso-scale context.
While the cloudiness at cloudbase remains constant at 30% independent of the meso-scale organization, the stratiform cloudiness doubles the average cloud cover of the organization patterns with stratiform cloudiness: Flowers and Fish.
Despite a similar cloud fraction, the stratiform layers are dynamical distinct. While the stratiform layer of Fish are often intermittent by convective cells and permanently fueled, the cloud shields of Flowers are more decoupled from the surface moisture supply and only sporadically connected to cumulus convection.
Using back-trajectories we investigate the Lagrangian evolution of the environment and show that it is not only distinct at the time of pronounced mesoscale organization, but is already distinguishable days ahead in lower tropospheric stability, wind speed and sea surface temperature and often synoptically influenced.
By combining the meso-scale organization identified in GOES16 and MODIS satellite imagery with ten years of ground-based measurements of the Barbados Cloud Observatory we are able to characterize the trade-wind cumuli in their meso-scale context.
While the cloudiness at cloudbase remains constant at 30% independent of the meso-scale organization, the stratiform cloudiness doubles the average cloud cover of the organization patterns with stratiform cloudiness: Flowers and Fish.
Despite a similar cloud fraction, the stratiform layers are dynamical distinct. While the stratiform layer of Fish are often intermittent by convective cells and permanently fueled, the cloud shields of Flowers are more decoupled from the surface moisture supply and only sporadically connected to cumulus convection.
Using back-trajectories we investigate the Lagrangian evolution of the environment and show that it is not only distinct at the time of pronounced mesoscale organization, but is already distinguishable days ahead in lower tropospheric stability, wind speed and sea surface temperature and often synoptically influenced.