1a.Objectives (from AD-416):
The overarching goal of the Airborne Microwave Observatory of Subcanopy and Subsurface (AirMOSS) project is to significantly reduce the current uncertainty in net ecosystem exchange (NEE) estimates of water and carbon over North America. AirMOSS will meet this challenge by providing high-resolution regional observations of Root Zone Soil Moisture (RZSM) over the major North American biomes. RZSM is defined here as the total moisture in the soil column from surface to the root zone. To measure RZSM, AirMOSS will build (from print) an ultra-high frequency (UHF) synthetic aperture radar (SAR) that has the capability to penetrate through substantial vegetation canopies and subsurface and retrieve information to the depths as large as 1.2m depending on the soil moisture content.
1b.Approach (from AD-416):
The project will build the AirMOSS sensor and deploy it during a serious of field experiments within the United States. Data sets derived from these experiments will then be assimilated into existing land surface models to improve our ability to track root-zone soil moisture and the net exchange of water carbon between agricultural landscapes and the atmosphere.
The ARS PI is tasked with generation of the Level 4 Root-Zone Soil Moisture (L4 RZSM) project for the Airborne Microwave Observatory of Subcanopy and Subsurface project (AirMOSS) aircraft mission. The L4 RZSM algorithm inputs non-continuous, 100-m Level 2/3 root-zone soil moisture (L2/3 RZSM) products and interpolates them into a continuous (hourly) 100-m root-zone soil moisture product using a distributed hydrologic model and model calibration techniques. The ARS PI’s year two primary objectives was to finish the construction of the L4 RZSM algorithm and processing L2/3 RZSM data acquired during AirMOSS airborne flights completed during Fall 2013. This objective has been met and project remains on target to meet future objectives.