Investigation of the Nocturnal Boundary Layer during the Land Atmosphere Feedback Experiment (LAFE) during August 2017

The Land Atmosphere Feedback Experiment (LAFE) conducted at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site during the month of August 2017 provides a unique opportunity to observe Low Level Jets (LLJs) using the large suite of additional instrumentation that was added to the existing ARM-SGP measurement suite. LAFE was an international collaborative effort that brought together several state of the art remote-sensing and in-situ instruments to study the summer time land atmospheric feedbacks. In addition to the measurements of wind speed and temperature, LAFE provided continuous measurements of turbulent kinetic energy (TKE) and momentum flux. These additional observations along with the routinely available measurements from the ARM extended facilities will be used to study the structure and evolution of the nocturnal LLJs.

In this presentation, measurements from LAFE (at the ARM central facility) and from the ARM extended facilities are used to study the dynamic and thermodynamic processes occurring around the formation and evolution of the LLJs. The impact of LLJs on the temperature, TKE, and momentum-flux profiles as well as possible feedback mechanisms will be investigated. Ability of the operational HRRR to simulate the LLJ formation and its properties will be evaluated.