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Ronald D. Leeper, Jesse E. Bell, and Michael A. Palecki

1. Introduction Soil moisture is an important component of the hydrological cycle that describes the availability of water for vegetation and the capacity of the soil to retain/absorb incoming precipitation. As a result, observed (in situ and remotely sensed) or modeled soil moisture data can be readily applied to a variety of applications ( Ochsner et al. 2013 ): monitoring and/or forecasting droughts ( Otkin et al. 2016 ; Mo and Lettenmaier 2015 ; Hayes et al. 2012 ; Bell et al. 2015 ) and

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Ángel F. Adames and John M. Wallace

temperature and surface pressure and large variability in free-tropospheric moisture and precipitation ( Charney 1963 ; Sobel and Bretherton 2000 ). Held et al. (1993) noted that regions of precipitation are characterized by enhanced column-integrated water vapor and concluded that water vapor provides the “memory” necessary to ensure the development and maintenance of convection over an isolated region. Subsequent studies by Bretherton et al. (2004) , Holloway and Neelin (2009) , and Muller et al

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Ning Wang, Xin-Min Zeng, Yiqun Zheng, Jian Zhu, and Shanhu Jiang

1. Introduction The atmospheric moisture residence time, defined as the time between when moisture evaporates from and returns to the surface as precipitation, is a fundamental characteristic of the atmospheric hydrologic cycle ( Läderach and Sodemann 2016 ; van der Ent and Tuinenburg 2017 ). In addition to evaporation and precipitation rates, the residence time is an indicator of the atmospheric moisture-holding capacity and provides information about how climate change modifies dynamic

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Qingfang Jiang and James D. Doyle

1. Introduction Moist processes have been largely ignored in the majority of mountain-wave studies, partially because of the complexity associated with moisture and microphysical processes. Studies of the interaction between moist airflow and mesoscale topography can be broadly classified into two categories. The first category includes quasi-analytical studies with highly simplified representations of moist processes. For example, a set of two-dimensional steady-state linear wave solutions

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Yu-shu Zhou, Ze-ming Xie, and Xin Liu

through the Hexi Corridor ( Yang et al. 2012 ; Zhang et al. 2018 ). Previous studies on this subject have used Eulerian methods ( Shi and Sun 2008 ; Yang et al. 2012 , Cui 2013 ). In this study, the Lagrangian flexible particle dispersion model (FLEXPART) is used to study moisture sources of multiple torrential rainfall events in Xinjiang. FLEXPART, developed by the Norwegian Institute (NILU), was originally applied to the point source diffusion of pollutants and hazardous substances (such as

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Tiina Nygård, Tuomas Naakka, and Timo Vihma

1. Introduction During the recent decades, the Arctic has experienced drastic changes, the most recognized being the amplified warming and dramatic decline in sea ice concentration and thickness ( IPCC 2019 ). The horizontal moisture transport and especially the associated increase in downward longwave radiation have been recognized among factors contributing to these major changes ( Kapsch et al. 2013 ; Park et al. 2015 ; Graversen and Burtu 2016 ; Kapsch et al. 2016 ; Gong et al. 2017

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Wesley J. Rondinelli, Brian K. Hornbuckle, Jason C. Patton, Michael H. Cosh, Victoria A. Walker, Benjamin D. Carr, and Sally D. Logsdon

, and the color of the vegetation lightens, which increases the albedo of the canopy ( Jacobs and van Pul 1990 ). It is therefore not surprising that soil moisture has been found to play an important role in the weather and climate of Earth’s atmosphere (e.g., Findell and Eltahir 2003 ; Koster et al. 2003 ; Gutowski et al. 2004 ). Soil moisture also plays an important role in land surface hydrology, and specifically in the occurrence and severity of flooding (e.g., Hillel 2003 ). The soil

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Chi Zhang, Qiuhong Tang, Deliang Chen, Ruud J. van der Ent, Xingcai Liu, Wenhong Li, and Gebremedhin Gebremeskel Haile

and Vecchi 2010 ). Moreover, as Yao et al. (2013) pointed out, the NTP is mainly influenced by the westerlies, while the STP is controlled by the monsoons. Different circulations bring in different sources of moisture to the TP. The moisture sources for precipitation in the TP have been studied in the past. Chen et al. (2012) identified the primary moisture sources of precipitation over the TP, which include regions from the Indian subcontinent to the Southern Hemisphere, the Bay of Bengal

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Wade T. Crow

1. Introduction Despite significant advances in the development of remote sensing techniques for surface soil moisture, objective quantification of value for soil moisture retrievals remains an elusive goal. Traditional remote sensing product validation is based on the direct intercomparison of retrieved quantities with, presumably higher-accuracy, ground-based measurements. Significant progress has been made in the design of field experiments and operational networks that facilitate the

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Christopher M. Godfrey and David J. Stensrud

Planton 1989 ), which characterize the state of the land surface and forecast the evolution of the lowest layer of the model atmosphere. The surface energy balance relies strongly upon the soil and near-surface conditions and plays a critical role in determining the prognostic variables in land surface models. Vegetation coverage, atmospheric conditions, and the physical properties of the soil impact surface energy fluxes, which both influence and depend heavily upon soil temperature and soil moisture

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