Patterns in Soil–Vegetation–Atmosphere Systems: Monitoring, Modeling, and Data Assimilation

Abstract

In this special issue, we present recent scien fi c work that analyzes the role of pa erns in soil-vegeta on-atmosphere (SVA) systems over a wide range of scales ranging from the pore scale up to mesoscale catchments. Specifi c a en on is given to the development of novel data assimila on methods, noninvasive measurement techniques that allow mapping spa al pa erns of state variables and fl uxes, and two-way coupling of models in a scale-consistent way. "Pa erns in Soil-Vegeta on-Atmosphere Systems" is also the research topic of a collabora ve research center (TR32) between the universi es of Aachen, Bonn, and Cologne and the Forschungszentrum Jülich. In this center, which is funded by the Deutsche Forschungsgemeinscha , on the basis of an interna onal evalua on, scien sts covering a broad range of earth science disciplines are working together. During June 11-12, 2010 the center organized its fi rst interna onal workshop in Aachen. The contribu ons presented in this special issue of Vadose Zone Journal include contribu ons from the collabora ve research center and external contribu ons, both from Germany and worldwide.Abbrevia ons: CLR, Community Landsurface Model; CR, capaci ve resis vity; DC, direct current resisvity; DTS, distributed temperature sensing; EC, eddy covariance; HHT, Hilbert-Huang transform; MRI, magne c resonance imaging; NMR, nuclear magne c resonance; SIP, spectral induced polariza on; SVA, soil-vegeta on-atmosphere.The system of soil, vegeta on, and the adjacent atmosphere is characterized by complex patterns, structures, and processes that act on a wide range of time and space scales. While the exchange of energy, water, and carbon is continuous between compartments, the pertinent fl uxes are strongly heterogeneous and variable in space and time. Th erefore, quantitatively predicting the systems' behavior constitutes a major challenge.Patterns and structures play an important role in controlling and determining the spatial and temporal variability of fl uxes of water and carbon dioxide within and between the compartments of the soil-plant-atmosphere system (Flury et al., 1994;Raich and Potter, 1995, Vereecken et al., 2007). Th ey may result from either deterministic processes or from processes causing spatial dependency and autocorrelative behavior or both (Levin, 1992;Borcard and Legendre, 2002). In addition, patterns occur at diff erent hierarchical scales, ranging from the pore scale to the global scale. Patterns and structures in soilplant-atmosphere systems are intimately linked to the notion of heterogeneity of state variables, parameters, and fl uxes. Improving our understanding of soil-plant-atmosphere systems therefore requires (i) the development of measurement techniques that enable us to characterize the spatial structure of key properties across scales, (ii) the development and improvement of coupled numerical models and data assimilation methods, and (iii) the long-term monitoring of key state variables and fl uxes for model evaluation. Characterizing Pa erns and Structures i...

Diurnal Dynamics of Wheat Evapotranspiration Derived from Ground-Based Thermal Imagery

“…The Merzenhausen research site was established by the Collaborative Research Center TR32 [22]. The site is located at 93 m a.s.l.…”

Evaluation of atmosphere–land interactions in an LES from the perspective of heterogeneity propagation

“…The airborne measurements used in this study consist of 13 flight legs flown over the German research collaborative SFB/TR 32 (TR32) (Vereecken et al, 2010) SelhausenMerken field site-an area of 7.5 × 6.0 km 2 , centered at (50 • 51 N, 6 • 25 E) and 120-200 m above ground-between 1300 and 1400 UTC5 August 2009. The weather conditions during this period were fair, with mainly easterly wind of about 3 m s −1 in the entire boundary layer and no cloud cover.…”

Impacts of grid resolution on surface energy fluxes simulated with an integrated surface-groundwater flow model

“…The model was set up for a sub-catchment of the Rur River (TR32 test bed site; Vereecken et al, 2010;Simmer et al, 2014), on the northern foothills of the lower Eifel mountain range with an approximated drainage area of 325 km 2 (Fig. 2a).…”