Ten years of passive microwaves derived SM products of the Pampas Plains, Argentina: Analysis of seasonality and anomalies

BRUSCANTINI C. A.; PANTANO V.; GRINGS F.; CARBALLO F.; PENALBA O.; KARSZENBAUM H.; RAHMOUNE R.; FERRAZZOLI P

Roma

Workshop; ESA-ESRIN; 2013

The Argentina’s Pampas region (aprox 50 million ha) is located in the center-east of Argentina where themain agricultural activities are cereal production and cattle-raising. It accounts for more than 90% of thenational grain production. Soybean, wheat, maize and sunflower are the main crops. Weather is among themost important and uncontrollable elements affecting agriculture in this region. The seasonal cycle ofprecipitation shows a maximum from October to April and a minimum from May to September.In this work, the objective is to assess the monthly behavior of soil moisture retrieval algorithms available forAMSR-E and SMOS and their corresponding optical depth product, and the Polarization Index (PI) in arelevant area of the rolling pampas. The analysis is performed for a time period from June, 2002 throughSeptember, 2012.In order to study the linkage between the soil moisture product and the climatology, an analysis of soilmoisture seasonality and anomalies is performed using as frame the precipitation, the Hydrological Situation(HS), the climatic Precipitation Deficit/Excess (PDE) and PDEs values for the period analyzed. The HS isrelated to the water balance. The PDE is the difference between precipitation and potential evapotranspiration.The PDE is used as an indicator of the climatic variability of the region and as a reference for the soil moistureproduct analysis. It is computed: (i) using daily precipitation and maximum and minimum temperatures data(National Weather Service and National Institute of Agricultural Technology) from 33 stations, located in therain fed agriculture production region of Argentina for the period 1970-2006, and (ii) monthly potentialevapotranspiration calculated following Thornthwaite, 1948, Camargo et al. 1999.The vegetation optical depth (OD) is simultaneously retrieved with soil moisture from SMOS and AMSR-Ebrightness temperature. Identifying errors on the retrieved OD can give valuable information on possibleerrors on the soil moisture retrieval. Therefore, the correlation between AMSR-E and SMOS OD product andOD obtained from MODIS NDVI was studied for the area of study and the period analyzed