AHATS: Advection Horizontal Array Turbulence Study

Summary

AHATS was the fourth in the series of Horizontal Array of Turbulence Studies (HATS). This series of experiments aims to improve large-eddy simulations (LES) of turbulence close to the Earth's surface, by collecting data that can be spatially filtered into scales that can be simulated by LES and those that must be parametrized.

The first was HATS, which was located in Kettlemen City, CA on fallow land with 19 anemometers. Then OHATS in Martha's Vineyard, MA on an over-ocean platform with 19 anemometers. The third project was CHATS which was done in Dixon, CA inside a walnut canopy with 30 anemometers. This project, AHATS is the most recent and was done in Kettlemen City, CA on fallow land with 33 anemometers.

AHATS returned to the original HATS site, but a third line was added upwind to provide spatial differences in the streamwise direction. In addition, two horizontal lines of turbulent pressure sensors were added to AHATS to investigate, for the first time, resolved and parameterized pressure correlation terms in the turbulence transport equations. Those capabilities were unavailable in previous field programs but are important for understanding the SGS turbulence and for testing SGS models that are based on the SGS physics.