The Community Land Model version 3 (CLM3) is the land component of the Community Climate System Model (CCSM). CLM3 has energy and water biases resulting from deficiencies in some of its canopy and ...soil parameterizations related to hydrological processes. Recent research by the community that utilizes CLM3 and the family of CCSM models has indicated several promising approaches to alleviating these biases. This paper describes the implementation of a selected set of these parameterizations and their effects on the simulated hydrological cycle. The modifications consist of surface data sets based on Moderate Resolution Imaging Spectroradiometer products, new parameterizations for canopy integration, canopy interception, frozen soil, soil water availability, and soil evaporation, a TOPMODEL‐based model for surface and subsurface runoff, a groundwater model for determining water table depth, and the introduction of a factor to simulate nitrogen limitation on plant productivity. The results from a set of offline simulations were compared with observed data for runoff, river discharge, soil moisture, and total water storage to assess the performance of the new model (referred to as CLM3.5). CLM3.5 exhibits significant improvements in its partitioning of global evapotranspiration (ET) which result in wetter soils, less plant water stress, increased transpiration and photosynthesis, and an improved annual cycle of total water storage. Phase and amplitude of the runoff annual cycle is generally improved. Dramatic improvements in vegetation biogeography result when CLM3.5 is coupled to a dynamic global vegetation model. Lower than observed soil moisture variability in the rooting zone is noted as a remaining deficiency.
The Community Land Model version 3 (CLM3.0) simulates land‐atmosphere exchanges in response to climatic forcings. CLM3.0 has known biases in the surface energy partitioning as a result of ...deficiencies in its hydrological and biophysical parameterizations. Such models, however, need to be robust for multidecadal global climate simulations. FLUXNET now provides an extensive data source of carbon, water and energy exchanges for investigating land processes, and it encompasses a global range of ecosystem‐climate interactions. Data from 15 FLUXNET sites are used to identify and improve model deficiencies. Including a prognostic aquifer, a bare soil evaporation resistance formulation and numerous other changes in the model result in a significantly improved soil hydrology and energy partitioning. Terrestrial water storage increased by up to 300 mm in warm climates and decreased in cold climates. Nitrogen control of photosynthesis is revealed as another missing process in the model. These improvements increase the correlation coefficient of hourly and monthly latent heat fluxes from a range of 0.5–0.6 to the range of 0.7–0.9. RMSE of the simulated sensible heat fluxes decrease by 20–50%. Primary production is overestimated during the wet season in mediterranean and tropical ecosystems. This might be related to missing carbon‐nitrogen dynamics as well as to site‐specific parameters. The new model (CLM3.5) with an improved terrestrial water cycle should lead to more realistic land‐atmosphere exchanges in coupled simulations. FLUXNET is found to be a valuable tool to develop and validate land surface models prior to their application in computationally expensive global simulations.
Hillslope‐scale rainfall‐runoff processes leading to a fast catchment response are not explicitly included in land surface models (LSMs) for use in earth system models (ESMs) due to computational ...constraints. This study presents a hybrid‐3D hillslope hydrological model (h3D) that couples a 1‐D vertical soil column model with a lateral pseudo‐2D saturated zone and overland flow model for use in ESMs. By representing vertical and lateral responses separately at different spatial resolutions, h3D is computationally efficient. The h3D model was first tested for three different hillslope planforms (uniform, convergent and divergent). We then compared h3D (with single and multiple soil columns) with a complex physically based 3‐D model and a simple 1‐D soil moisture model coupled with an unconfined aquifer (as typically used in LSMs). It is found that simulations obtained by the simple 1‐D model vary considerably from the complex 3‐D model and are not able to represent hillslope‐scale variations in the lateral flow response. In contrast, the single soil column h3D model shows a much better performance and saves computational time by 2‐3 orders of magnitude compared with the complex 3‐D model. When multiple vertical soil columns are implemented, the resulting hydrological responses (soil moisture, water table depth, and base flow along the hillslope) from h3D are nearly identical to those predicted by the complex 3‐D model, but still saves computational time. As such, the computational efficiency of the h3D model provides a valuable and promising approach to incorporating hillslope‐scale hydrological processes into continental and global‐scale ESMs.
Key Points:
This study presents a hybrid‐3D model for the hillslope hydrological response
Hydrological simulations are similar to those predicted by a 3‐D Richards model
The hybrid‐3D model is computationally 2‐3 orders of magnitude more efficient
Satellite gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) provide new quantitative measures of the 2005 extreme drought event in the Amazon river basin, regarded as the ...worst in over a century. GRACE measures a significant decrease in terrestrial water storage (TWS) in the central Amazon basin in the summer of 2005, relative to the average of the 5 other summer periods in the GRACE era. In contrast, data‐assimilating climate and land surface models significantly underestimate the drought intensity. GRACE measurements are consistent with accumulated precipitation data from satellite remote sensing and are also supported by in situ water‐level data from river gauge stations. This study demonstrates the unique potential of satellite gravity measurements in monitoring large‐scale severe drought and flooding events and in evaluating advanced climate and land surface models.
Abstract
For the bridge tower with large inclination angle, the beam element in Midas finite element software is used to model and analyze the bridge tower structure, and its accuracy is difficult to ...guarantee. In this paper, taking the construction of a suspension bridge’s inward-inclined tower as the research background, the finite element simulation of the inward-inclined bridge tower is carried out by using the two modeling methods of the beam element and the solid element. The calculation accuracy of the beam element model, the specific position and the jacking force applied by the active transverse brace of the inward-inclined bridge tower are determined, and the field test of the tower bottom stress during the construction process is performed. The results show that: when the inclination angle of the bridge tower is small (5 °), the beam element element is used for modeling and analysis, which has fast calculation speed and high calculation accuracy; When the inclination angle is 15 °, the error of the beam element model exceeds 30%, and it is recommended to use the solid model for calculation; the active cross brace plays a key role in controlling the stress at the bottom of the tower column before the lower cross beam is applied. And after the construction of the cross beam, the active cross brace forms a closed frame structure with the lower tower column, and the subsequent cross brace has little impact on the stress at the bottom of the tower column; Compared with increasing the number of temporary cross braces, increasing the jacking force can improve the stress at the bottom of the tower. And by adjusting the position of the active cross brace and applying the appropriate active jacking force, the stress at the root of the tower column can be greatly improved.
Relativistic band theoretical calculations reveal that intrinsic spin Hall conductivity in hole-doped archetypical semiconductors Ge, GaAs, and AlAs is large approximately 100(planck/e)(Omega ...cm)(-1), showing the possibility of a spin Hall effect beyond the four-band Luttinger Hamiltonian. The calculated orbital-angular-momentum (orbital) Hall conductivity is one order of magnitude smaller, indicating no cancellation between the spin and orbital Hall effects in bulk semiconductors. Furthermore, it is found that the spin Hall effect can be strongly manipulated by strains, and that the ac spin Hall conductivity is large in pure as well as doped semiconductors.
Abstract Aims To investigate the relationships between integrin ανβ6 expression and the clinical–pathological features of gastric carcinoma and whether integrin ανβ6 can act as a prognostic indicator ...in gastric carcinoma. Materials and methods We generated the microarray of 300 human gastric carcinoma specimens, and used the method of immunohistochemistry to investigate the expression of ανβ6 in them and the relationships between the expression of ανβ6 and the clinical–pathological features of the tumours. Meanwhile, we retrospectively analysed the relationship between ανβ6 expression and the survival times of the patients. Results The expression of ανβ6 was detected in 36.7% of gastric carcinomas, and the expression was associated with Lauren type, differentiation, N stage and TNM stage of the tumours (the P values were 0.004, 0.035, 0.024 and 0.001, respectively). The Kaplan–Meier plot showed that patients who were ανβ6 negative had much longer survival times than those who were ανβ6 positive ( P < 0.0001). The survival estimates showed a striking difference in median survival between the negative and positive ανβ6 expression patients, especially in early stage tumours. Univariate analysis indicated that significant factors for prognosis included ανβ6 expression, differentiation, TNM stage, T stage, N stage, M stage and R classification (R0: potentially curative resection; R1: had residual microscopic disease after resection; R2: had residual macroscopic disease after resection), whereas in multivariate analysis using the Cox regression model, only ανβ6 expression, M stage, TNM stage and R classification retained significance for prognosis. Conclusions Positive ανβ6 expression in gastric carcinoma is linked to significantly reduced survival times and, even more important, is that its value as a prognostic marker is significant for early stage tumours.
Highlights • Intracerebroventricular injection of WT plus GFX activated GSK-3 in the striatum. • GSK-3 activation induced decline of ACh level in the striatum. • ACh decline in the striatum is due to ...inhibition of ChAT but not AChE activity. • ChAT was inhibited due to its maldistribution in interneurons rather than expression. • Cellular ChAT distribution is dependent on low phosphorylation status of NFs.
Hillslopes are important for converting rainfall into runoff, influencing the terrestrial dynamics of the Earth's climate system. Recently, we developed a hybrid‐3‐D (h3D) hillslope hydrological ...model that gives similar results as a full 3‐D hydrological model but is up to 2–3 orders of magnitude faster computationally. Here h3D is assessed using a number of recharge‐drainage experiments within the Landscape Evolution Observatory (LEO) with accurate and high‐resolution (both temporally and spatially) observations of the inputs, outputs, and storage dynamics of several hillslopes. Such detailed measurements are generally not available for real‐world hillslopes. Results show that the h3D model captures the observed storage, base flow, and overland flow dynamics of both the larger LEO and the smaller miniLEO hillslopes very well. Sensitivity tests are also performed to understand h3Ds difficulty in representing the height of the saturated zone close to the seepage face of the miniLEO hillslope. Results reveal that a temporally constant parameters set is able to simulate the response of the miniLEO for each individual event. However, when one focuses on the saturated zone dynamics at 0.15 m from the seepage face, a stepwise evolution of the optimal model parameter for the saturated lateral conductivity parameter of the gravel layer occurs. This evolution might be related to the migration of soil particles within the hillslope. However, it is currently unclear whether and where this takes place (in the seepage face or within the parts of the loamy sand soil).
Key Points:
In this study, the h3D hillslope model is tested using Biosphere 2 LEO observations
The h3D model captures observed hillslope flow and storage dynamics very well
Results reveal the possibility of migrating soil particles close to the seepage face
To evaluate the ability of inulin to enhance the immune response of a ptfA gene DNA vaccine for avian Pasteurella multocida, inulin was added as an adjuvant to the ptfA-DNA vaccine, obtaining an ...inulin-adjuvant DNA vaccine. The DNA vaccine was administered to chickens; a fimbria protein vaccine and an attenuated live vaccine were used as positive controls. The levels of the serum antibody and concentrations of interferon-γ (IFN-γ), interleukin-2 (IL-2), and interleukin-4 (IL-4) were determined, and a lymphocyte proliferation assay was performed. After being challenged with virulent P. multocida, the protective efficacy was evaluated. The results showed that the serum antibodies induced by the ptfA-DNA vaccine were not enhanced by inulin. The stimulation index values and the concentrations of IL-2 and IFN-γ in chickens vaccinated with inulin-adjuvant DNA vaccine were significantly higher than those in chickens vaccinated with the DNA vaccine, those with the fimbria protein vaccine, and the chickens gavaged with inulin. The concentrations of IL-4 in the inulin-adjuvant DNA vaccine group and the fimbria protein vaccine group were higher than those in the DNA vaccine group and the inulin-gavage group. The protective efficacy rates of the attenuated live vaccine group, the fimbria protein vaccine group, the DNA vaccine group, the inulin-adjuvant DNA vaccine group, and the inulin-gavage group were 90, 70, 55, 65, and 55%, respectively.
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