Abstract:
Mesoscale Convective Systems (MCSs) are understood to produce a variety of gravity waves throughout their convective lifecycle. These waves can range from high to low frequencies depending on the properties of their generating mechanism. A wave’s frequency subsequently determines its angle of propagation away from the MCS, impacting its effect on the surrounding environment or the MCS itself. Low-frequency waves can spend the largest amount of time in the troposphere and thus are able to have a significant impact on the MCS and its environment. A review of convective wave generation mechanisms will identify likely potential sources of low-frequency gravity waves among the terms of the thermodynamic equation. These terms’ typical properties among idealized simulations will be discussed, along with some subsequent impacts of these waves on the environment in advance of the MCS.
Following this overview of waves in an idealized space, these concepts will then be applied to two real-data Weather Research and Forecasting – Large Eddy Simulations (WRF-LESs), one each from the Midlatitude Continental Convective Clouds Experiment (MC3E) and from the Plains Elevated Convective at Night (PECAN) field campaigns. Spectral analysis is used to identify the primary wave types generated by these systems and how they evolve over their lifecycle. Particular focus is paid to variations in the strength of the rear inflow jet, with the potential gravity wave contributions compared to the flow induced by line-end vortices. Finally, field campaign observations themselves are queried for confirmation of the existence of these low-frequency wave structures.
This colloquia will be on Zoom webinar: https://psu.zoom.us/j/98738756683?pwd=YKGai8K8aw347U0hTrhjr8LVtqhctX.1
| Attachment | Size |
|---|---|
| Becky Adams-Selin | 338.07 KB |