AGS-PRF: Bridging the Gap between Idealized Simulations and Daytime Tower Observations of Forest-Atmosphere Interactions in Complex Terrain

Significant portions of Earth’s land surface are covered by complex terrain and vegetation. Simulating the air flow through these areas is key to predicting surface temperature, moisture, and air-quality related measures. While much research has studied how air flows across terrain or through forested canopies, less research has investigated the combination of these factors. Another complicating factor is the stability of the atmosphere, or how the structure of the temperature aloft affects whether air rises or falls. In this project, the researcher will investigate the intersection of these issues by conducting high-resolution numerical modeling runs and comparing the results to observed data. The results of this research can be used in weather models for improved forecasts in critical areas like agriculture and wildfires.

This Postdoctoral Research Fellowship is for the study of atmospheric boundary layer turbulence over complex, vegetated topography across a range of unstable convective conditions. The core of the project is the extension of the researcher’s prior Large Eddy Simulation (LES) database to include the effects of heat and moisture in unstable daytime conditions. Nearly 30 LES runs will be conducted in an idealized framework, to address the following two science questions: 1) How do ABL flow physics above forested periodic hills change as unstable stratification is introduced and what is the impact of these new physics on scalar transport, and 2) Can we use the new idealized topography framework to classify important turbulent and scalar transport terms across different topography types in unstable stratification. Additionally, the researcher will conduct a simulation of the area surrounding the Amazon Tall Tower Observatory, which will allow for the comparison between the model and a wide array of atmospheric measurements available at that site. This comparison will help to address the final question: 3) Can the idealized topography accurately represent real topography under realistic atmospheric conditions?

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Award Number: 2535750
Principal Investigator: Gregory Torkelson
Funds Obligated: $202,000
State: CA