ISFF Project Report: CHATS

NCAR Integrated Surface Flux Facility for CHATS (1 Mar - 30 Apr 2007)

Investigators: Lenschow, Patton, Horst, Oncley, Sullivan

Facility: Integrated Surface Flux Facility (ISFF), Integrated Sounding System (ISS) with Sodar and RASS

Location: Stockton, CA, (Central Valley)

The objective of CHATS is to make spatial measurements of the velocity and scalar turbulence fields in a uniformly vegetated canopy using arrays of sonic anemometer/thermometers augmented with fast response water vapor and carbon dioxide sensors. With this spatial information, the three-dimensional fields of velocity and scalar fluctuations will be studied to quantify turbulence transport processes and coherent structures throughout the canopy layer. In addition, an ISS with a sodar and RASS are requested to monitor boundary layer top, winds, and temperature.


ISFF Resources: 26 sonic anemometers will be deployed in a two-level, horizontal array. The sonics will be augmented with Campbell KH2O and Li-Cor LI-7500 fast-response water vapor and carbon dioxide sensors. The numbers of those scalar sensors will be limited to those available from EOL and other collaborators. The dimensions of the array (height and sonic spacing) will be changed roughly once per week to obtain data within a range of those dimensions and canopy density. The main sonic array will be supplemented with a vertical profile of three sonic anemometers extending from near the surface to well above canopy top. Also requested are fast-response static pressure sensors and hot-wire/film anemometers to be collocated with the sonic anemometers in the horizontal array, as well as digital camera system to measure leaf area index (LAI).

This page was prepared by Greg Poulos NCAR Earth Observing Laboratory, In-situ Sensing Facility