Energetics of Convectively Coupled Tropical Phenomena

Free tropospheric moisture strongly influences tropical convection through processes such as entrainment, resulting in an approximately exponential relationship between tropical precipitation and column relative humidity. This relationship was leveraged by Adames 2017 to directly relate precipitation associated with the Madden-Julian Oscillation (MJO) to various sources and sinks of column moisture, as well as provide new insights to the geographical distribution of MJO precipitation anomalies.

Here we expand this methodology to a much broader range of convectively coupled tropical phenomena, including easterly waves, mixed Rossby-gravity waves, Rossby waves, Kelvin waves, and the MJO. Such phenomena can modulate tropical precipitation by changing the large-scale thermodynamic structure of the atmosphere (e.g. CAPE or CIN), changing large-scale horizontal and vertical wind shear, and by changing the large-scale moisture content of the atmosphere. We identify which phenomena modulate tropical precipitation primarily through their modulation of large-scale free-tropospheric moisture, and which phenomena modulate tropical convection through other processes.

This methodology is then used to provide new insights to the energetics of this broad range of convectively coupled phenomena.