SMOS validation sites: Goulburn & Murrumbidgee Cecilia Azcurra Supervisor: Jeff Walker

Background The SMOS satellite will be the first dedicated to the measurement of soil moisture Will measure soil moisture on a 50 x 50 km scale Ground-based measurements to be used for calibration and validation of soil moisture derived from SMOS SMOS validation sites are being identified world-wide Australian validation sites will cover a semi-arid climate

SMOS validation There is a discrepancy between the scale of SMOS measurements and that of the ground- based (point) measurements Heterogeneous land cover is an issue Other issues include urban areas and standing water Sampling needs to represent the soil moisture over SMOS-sized pixels How many point measurements are required to obtain the spatial average?

The study areas

Goulburn catchment

Goulburn catchment study area

Oct-31 Goulburn catchment data

Yanco region Soil moisture from air measurements Over 11 days 12 Monitoring stations

Kyeamba Creek Soil moisture from air measurements Over 3 days Regional sampling 14 Monitoring stations

General approach

Preliminary results – Goulburn catchment RMSE (regional) = v/v RMSE (monitoring stations) = v/v

Preliminary results – Yanco region RMSE = v/v

Next steps Regional sampling data For Goulburn catchment Re-sampling to determine the number of samples required to determine the spatial mean Monitoring stations Identify which stations are representative of the area

Bootstrap sampling - Goulburn catchment Oct-31 Nov-07 Nov-14 Nov-21

Preliminary results - Goulburn catchment Soil moisture measurement type From airRegional sampling Monitoring stations (6am to 10am average) Date Soil moisture (% v/v) Soil moisture (% v/v) Error (% v/v) Soil moisture (% v/v) Error (% v/v) 31-Oct Nov Nov Nov

Preliminary results - Yanco region AirMonitoring Stations SM (% v/v) Error (% v/v) 31-Oct Nov Nov Nov Nov Nov Nov Nov Nov Nov Nov