Investigating the impacts of Kelvin wave activity on convection in the Amazon through observations and model experiments
Poster PDF
Authors
Yolande Serra — University of Washington
Angela K Rowe — University of Wisconsin
Samson M Hagos — Pacific Northwest National Laboratory
Zhe Feng — Pacific Northwest National Laboratory
Category
Convective clouds, including aerosol interactions
Description
In our previous work, we linked GOAmazon derived cloud products with GPS-Met integrated column water vapor measurements to investigate the shallow-to-deep transition in the context of both local and large-scale moisture variability, including the observed role of Kelvin waves. Ground-based data were composited with respect to wave activity through use of space-time filtered geostationary satellite data for identifying active, suppressed, and neutral Kelvin and westward inertial gravity (WIG) wave periods. Our analysis showed that Kelvin and WIG waves significantly modulate surface rainfall, mid-level moisture, low- and upper-level divergence, MCS fraction, and precipitable water vapor at the GOAmazon ARM site and across the broader region captured by the SIPAM radar and GPS-Met network.
We found that Kelvin waves interrupt the moisture transport from the Amazon to mid-latitudes during their active phase through a weakening of the South American low-level jet. A weakening of the jet is reinforced through impacts on surface pressure via surface heat flux anomalies (Serra et al. 2019, in prep.). Regional model simulations at convective resolving scales offer the opportunity to further evaluate the importance of these waves on local convective development in this region.
