EGU2020-11137
https://doi.org/10.5194/egusphere-egu2020-11137
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Tropical precipitation–buoyancy relationship in Convectively Coupled Waves over South America region

Victor Mayta and Angel Adames
Victor Mayta and Angel Adames
  • Department of Climate and Space Science and Engineering, University of Michigan, Ann Arbor, Michigan (vchavezmayta@gmail.com)

In this work, the tropical wave precipitation-buoyancy relationship is revisited by analyzing 4-times daily wave-filtered brightness temperature, reanalysis, and radiosonde datasets over tropical South America during the wet season. Prior studies demonstrated that an integrated measure of buoyancy well-diagnoses precipitation over land and ocean. However, it is an open question whether the buoyancy-based approach can yield a robust relation to precipitation for equatorial wave disturbances. To advance our understanding of this relationship, a comprehensive analysis of their vertical thermodynamic structure and potential interactions with the basic state is also presented. An emphasis is placed on understanding the convection coupling mechanism in convectively coupled Kelvin and inertia-gravity waves. It will be shown that buoyancy is a better predictor of convection for these disturbances than the often-used moist static energy (MSE). Examination of this discrepancy reveals that a cooling of the lower troposphere by gravity wave motions, which reduces MSE, is key to the production of precipitation in these disturbances.

How to cite: Mayta, V. and Adames, A.: Tropical precipitation–buoyancy relationship in Convectively Coupled Waves over South America region, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11137, https://doi.org/10.5194/egusphere-egu2020-11137, 2020