0000000001216116

AUTHOR

Haydee Karszenbaum

Spatio-temporal soil drying in southeastern South America: the importance of effective sampling frequency and observational errors on drydown time scale estimates

The study of the spatio-temporal dynamics of surface soil moisture (SSM) drydowns integrates the soil response to climatic conditions, drainage and land cover and is key to advances in our knowledg...

research product

Radiometric correction effects in Landsat multi‐date/multi‐sensor change detection studies

Radiometric corrections serve to remove the effects that alter the spectral characteristics of land features, except for actual changes in ground target, becoming mandatory in multi‐sensor, multi‐date studies. In this paper, we evaluate the effects of two types of radiometric correction methods (absolute and relative) for the determination of land cover changes, using Landsat TM and Landsat ETM+ images. In addition, we present an improvement made to the relative correction method addressed. Absolute correction includes a cross‐calibration between TM and ETM+ images, and the application of an atmospheric correction protocol. Relative correction normalizes the images using pseudo‐invariant fe…

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Seasonal Analysis of Surface Soil Moisture Dry-Downs in a Land-Atmosphere Hotspot as Seen by LSM and Satellite Products

The soil drying process is a challenging framework to assess climatic, hydrologic and ecosystem processes. This work develops a seasonal analysis of temporal e-folding decay ( $\tau$ ) of surface soil moisture dry-downs using ORCHIDEE land surface model and SMOS observations over South Eastern South America (SESA). Results show that the soil drying process depends on both location and season, and that the modeled drying velocity is faster than the observed one, even when modeled data is sampled at the same frequency as the observations. Differences between observed and modeled data have been found both in the analysis of the regional overall $\tau$ and in the spatial patterns of $\tau$ esti…

research product

Spatio-temporal soil drying in southeastern South America: the importance of effective sampling frequency and observational errors on drydown time scale estimates

The study of the spatio-temporal dynamics of surface soil moisture (SSM) drydowns integrates the soil response to climatic conditions, drainage and land cover and is key to advances in our knowledge of the soil–atmosphere water exchange. SSM drydowns have also been employed to compare soil moisture spatio-temporal behaviour between different data sources such as satellite-derived data and land–surface models, difficult to compare with standard methodologies. However, the errors introduced by satellite effective sampling frequencies (SF) and by different methodologies employed to define a drydown period have until now not been properly addressed in the literature. Here, SSM from microwave re…

research product

Spatio-temporal soil drying in southeastern South America: the importance of effective sampling frequency and observational errors on drydown time scale estimates

The study of the spatio-temporal dynamics of surface soil moisture (SSM) drydowns integrates the soil response to climatic conditions, drainage and land cover and is key to advances in our knowledge of the soil–atmosphere water exchange. SSM drydowns have also been employed to compare soil moisture spatio-temporal behaviour between different data sources such as satellite-derived data and land–surface models, difficult to compare with standard methodologies. However, the errors introduced by satellite effective sampling frequencies (SF) and by different methodologies employed to define a drydown period have until now not been properly addressed in the literature. Here, SSM from microwave re…

research product