SSMRS

The technical goal was to support the campaign "Enhanced soundings for local coupling studies" of Dr. Craig Ferguson by providing (1) temporally continuous sensible heat flux measurements over homogeneous scintillometer transects (± 500 m) at five minute intervals and (2) spatially continuous ET and root zone soil moisture distributions with a spatial resolution of 30 m on days that a clear Landsat image is available.

We installed four scintilometer transects over relatively homogeneous areas. The homogeneity of the areas was evaluated using Landsat imagery. Two transects were placed in relatively moist areas and two in relatively dry areas. One transect was over Dr. Gentine’s site where Distributed Temperature Sensors (DTS) were installed at 20‐centimeter spatial resolution to measure at 1‐Hertz temporal frequency. Three novel MkII Kipp & Zonen LAS’s (large aperture scintillometer) were installed in the second week of June; one calibrated MkI Kipp & Zonen LAS was installed later over the DTS site.

On days with clear Landsat images we used the algorithm Mapping EvapoTranspiration at High Resolution and Internalized Calbiration (METRIC) to map actual ET and root zone soil moisture (degree of saturation over the entire root zone) with a spatial resolution of 30 m. We compared the root zone soil moisture maps with NASA’s SMAP root zone soil moisture products as they become available during the summer of 2015. A long-term goal was to develop procedures to use LAS sensible heat flux measurements for the automatic calibration of METRIC so that actual ET and root zone soil moisture maps could be derived from Landsat and MODIS imagery in nearly real-time. Jan Hendrickx of New Mexico Tech is a long time scintillometer user with a focus on hydrology remote sensing using optical/thermal imagery; Jan Kleissl of UC San Diego works on environmental fluid mechanics and solar radiation in the atmosphere through field experimental (scintillometry, sky cameras, sensor networks) and computational techniques.

Timeline