Soil respiration (Rs) is a major pathway by which fixed carbon in the biosphere is returned to the atmosphere, yet there are limits to our ability to predict respiration rates using environmental drivers at the global scale. While temperature, moisture, carbon supply, and other site characteristics are known to regulate soil respiration rates at plot scales within certain biomes, quantitative f...

An approach is proposed to estimate soil moisture and to monitor its change from AMSR-E 6.9 GHz passive microwave data acquired over a large northern basin. The lack of in situ direct measurements is a major issue to be resolved to reach the aim of this work. Therefore, “external” ancillary data were used as a surrogate for available measurements. The methodology is based on the inversion of a ...

Soil moisture is a vital parameter in various land surface processes, and microwave remote sensing is widely used to estimate regional soil moisture. However, the application of the retrieved soil moisture data is restricted by its coarse spatial resolution. To overcome this weakness, many methods were proposed to downscale microwave soil moisture data. The traditional method is the microwave-o...

The Soil Moisture and Ocean Salinity Mission (SMOS) acquires surface soil moisture data of global coverage every three days. Product validation for a range of climate and environmental conditions across continents is a crucial step. For this purpose, a soil moisture and soil temperature sensor network was established in the Skjern River Catchment, Denmark. The objectives of this article are to ...

A Land Surface Microwave Emission Model (LSMEM) is used to derive soil moisture estimates over Iowa during the Soil Moisture Experiment 2002 (SMEX02) field campaign, using brightness temperature data from the Advanced Microwave Sounding Radiometer (AMSR)-E satellite. Spatial distributions of the near-surface soil moisture are produced using the LSMEM, with data from the North American Land Data...

Passive microwave remote sensing by the Soil Moisture and Ocean Salinity (SMOS) satellite enables observations of surface soil moisture at global scale. This involves a retrieval process that uses a radiative transfer model to relate satellite-observed radiances to geophysical variables such as soil dielectric constant and soil moisture. The L-MEB (L-band Microwave Emission of the Biosphere) ba...

In this paper, a soil moisture estimation model was developed to calculate the nationwide soil moisture fields using on site soil moisture observation, precipitation, surface temperature, MODIS NDVI and a data mining technique, Classification And Regression Tree (CART) algorithm and neural networks. The model was applied to the Yong-dam dam basin since the soil moisture observations of the Yong...

This paper reports on the comparison of surface temperature and soil moisture observed by instruments onboard the Environmental Satellite (EnviSat) with simulations by an atmospheric circulation model over the period April 2005 to September 2007. The Naqu river basin has been selected as the study area, which is located on the eastern part of Tibetan Plateau. For the selected period, the PSU/NC...

The diurnal variations in soil-gas helium concentration have been monitored at depths of 0.5-2.0 m in three localities in Colorado, Wyoming, and C•lifornia.'Bar•metric p e•su TM, air temperature, wind speed, soil temperature and moisture, relative humidity, and precipitation were also measured. The helium variation below a 1-m sampling depth usually did not exceed the analytical sensitivity of ...

Important catchment-scale water and energy balance parameters are derived for a small catchment in southeastern Australia by assimilation in a catchment-scale soil-vegetation-atmosphere transfer (SVAT) model of subcatchment-scale soil water content observations and land surface temperature measurements. In order to incorporate the subcatchment-scale soil moisture variability and its time evolut...