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Gift Dumedah and Jeffrey P. Walker

particular, the assessment of model parameter convergence across several assimilation time steps can provide the potential to retrieve variables that are not directly observed. This study examines the contributions of model parameter convergence to overall performance of the EnKF and the evolutionary data assimilation (EDA) approaches, through estimation of soil moisture using the Joint UK Land Environment Simulator (JULES) in the Yanco area located in southeast Australia. The EnKF and EDA methods were

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Gabriëlle J. M. De Lannoy, Rolf H. Reichle, and Valentijn R. N. Pauwels

1. Introduction Assimilating low-frequency (1–10 GHz) passive microwave observations into land surface models is expected to improve estimates of land surface conditions and, hence, weather and climate predictions. Global observations of brightness temperatures (Tb) are available from the (late) Advanced Microwave Scanning Radiometer–Earth Observing System (AMSR-E), the Soil Moisture Ocean Salinity (SMOS; Kerr et al. 2010 ) mission, and Aquarius ( Le Vine et al. 2007 ). Soil moisture has a

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Mustafa Gokmen, Zoltan Vekerdy, Maciek W. Lubczynski, Joris Timmermans, Okke Batelaan, and Wouter Verhoef

, surface meteorology, and surface and vegetation properties ( Su et al. 2005 ). Latent heat flux, or equivalently evapotranspiration, is estimated considering the surface energy balance and the evaporative fraction. Comparing three process-based models (i.e., SEBS, Penman–Monteith, and Priestley–Taylor) to ET at the global scale, Vinukollu et al. (2011) concluded that all of them appear to underrepresent the sensitivity to soil moisture over water-limited regions and because of that overestimate ET

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Chiara Corbari and Marco Mancini

is important, in the form of soil moisture and snow accumulation over the ground ( Castillo et al. 2003 ; Famiglietti and Wood 1994 ; Noilhan and Planton 1989 ). However, soil moisture, which is the key variable in the hydrologic water balance, is most of the time confined to an internal numerical model variable. Calibration and validation of distributed models at basin scale generally refer to external variables, which are integrated catchment model outputs, and usually depend on the

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Haolu Shang, Li Jia, and Massimo Menenti

moisture over large regions, but only from the topsoil down to a certain depth, which is determined by the wavelength. Because of the shallow soil layer sensed at 37 GHz (detected soil depth is around 0.8 mm), when this layer is water saturated, additional water will become vertical and horizontal water flow, or standing water after the deep soil layers are saturated. We could then consider the fractional area of water-saturated topsoil and standing water as an indicator of the residual water

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Donghai Zheng, Rogier van der Velde, Zhongbo Su, Martijn J. Booij, Arjen Y. Hoekstra, and Jun Wen

main components of land cover, and they have a height of 15 cm during summers and about 5 cm during winters. The Maqu station is equipped with a micrometeorological observation system and a combined soil moisture and soil temperature monitoring network. The data used in this study have been collected at the micrometeorological observation system from 20 May 2009 to 17 May 2010. The episodes with snow on the ground are excluded by using only the data records for which the observed albedo attains the

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