The effect of soil moisture and atmospheric conditions on the development of shallow cumulus convection: A coupled large-eddy simulation-land surface model study

Many processes and feedback mechanisms are involved in land-atmosphere interactions that play an important role in determining the boundary layer structure throughout the diurnal cycle. Here, the effect of soil moisture on the development of shallow cumulus convection is investigated using a coupled large-eddy simulation (LES)-land surface model (LSM) framework. First, the coupled model is run for an idealised case based on measurements at the ARM Southern Great Plain site on 21 June 1997 to demonstrate that many characteristics of the subcloud layer turbulence and of the cumulus layer can be modelled successfully. Moreover, an extensive sensitivity study is performed with different amounts of soil moisture and varying atmospheric conditions. Our results support the hypothesis that the response of shallow cumulus clouds due to a change of soil moisture severely depends on the thermal stability conditions. Furthermore, they also point out that the atmospheric moisture content is as important as the static stability in determining the boundary layer characteristics and in particular the fractional cloud cover. The results demonstrate that the soil moisture-cloud cover coupling is positive in most of the cases. However, we show that under specific conditions (a less stably stratified moist atmosphere) convective activity and cloud formation is stronger over dry soils, where the principle driving mechanism for cloud development is the boundary layer growth that tends to increase relative humidity by adiabatic cooling of the air at the top of the boundary layer. This leads to a soil moisture cloud cover relationship in which the cloud cover fraction decreases with an increase of soil moisture. Moreover, our findings suggest that in the limiting case of a water saturated soil the mean cloud cover is independent of static stability, but only depends on the vertical integrated atmospheric moisture content

Rain erosivity map for Germany derived from contiguous radar rain data

Erosive rainfall varies pronouncedly in time and space. Severe events are often restricted to a few square kilometers. Radar rain data with high spatiotemporal resolution enable this pattern of erosivity to be portrayed with high detail. We used radar data with a spatial resolution of 1 km"span class="inline-formula"""sup"2"/sup""/span" over 452 503 km"span class="inline-formula"""sup"2"/sup""/span" to derive a new erosivity map for Germany and to analyze the seasonal distribution of erosivity. The expected long-term regional pattern was extracted from the scattered pattern of events by several steps of smoothing. This included averaging erosivity from 2001 to 2017 and smoothing in time and space. The pattern of the resulting map was predominantly shaped by orography. It generally agrees well with the erosivity map currently used in Germany (Sauerborn map), which is based on regressions using rain gauge data (mainly from the 1960s to 1980s). In some regions the patterns of both maps deviate because the regressions of the Sauerborn map were weak. Most importantly, the new map shows that erosivity is about 66 % larger than in the Sauerborn map. This increase in erosivity was confirmed by long-term data from rain gauge stations that were used for the Sauerborn map and which are still in operation. The change was thus not caused by using a different methodology but by climate change since the 1970s. Furthermore, the seasonal distribution of erosivity shows a slight shift towards the winter period when soil cover by plants is usually poor. This shift in addition to the increase in erosivity may have caused an increase in erosion for many crops. For example, predicted soil erosion for winter wheat is now about 4 times larger than in the 1970s. These highly resolved topical erosivity data will thus have definite consequences for agricultural advisory services, landscape planning and even political decisions. Document type: Articl

Supramolecular organization of the human N-BAR domain in shaping the sarcolemma membrane

This is the final version of the article. Available from Elsevier via the DOI in this record.The 30 kDa N-BAR domain of the human Bin1 protein is essential for the generation of skeletal muscle T-tubules. By electron cryo-microscopy and electron cryo-tomography with a direct electron detector, we found that Bin1-N-BAR domains assemble into scaffolds of low long-range order that form flexible membrane tubules. The diameter of the tubules closely matches the curved shape of the N-BAR domain, which depends on the composition of the target membrane. These insights are fundamental to our understanding of T-tubule formation and function in human skeletal muscle.This work was supported by grants from the Deutsche Forschungsgemeinschaft (GRK 1026, SFB610) (A.A., T.G., J.B.), the BMBF ZIK program (A.M., J.B.), the European Regional Development Fund of the European Commission (A.M., T.G.: EFRE 1241 12 0001), and the state Sachsen-Anhalt (A.M., T.G., J.B.)

Temporary inhibition of papain by hairpin loop mutants of chicken cystatin Distorted binding of the loops results in cleavage of the Gly9-Ala10 bond

AbstractTemporary inhibition of the cysteine proteinases papain and cathepsin L was observed with several hairpin loop mutants of recombinant chicken cystatin at enzyme concentrations above nanomolar. Kinetic modelling of inhibition data, gel electrophoresis and amino acid sequencing revealed that reappearance of papain activity is due to selective cleavage of the Gly9-Ala10 bond in the N-terminal binding area of the chicken cystatin variants, resulting in truncated inhibitors of lower affinity. Cleavage of the same bond by contaminating papaya proteinase IV was ruled out by previous purification of papain and suitable control experiments. According to the proposed kinetic model, cleavage occurs within the enzyme-inhibitor complex with first order rate constants ktemp of 2.3 × 10−3 up to 5 × 10−1 s−1. A similar ktempKm ratio was found for all mutants (0.7 × 106–2.1 × 106 s−1·M−1); it is almost identical with the kcatKm ratio of the peptide substrate Z-Phe-Arg-NHMec. These results suggest that distorted contacts of one of the hairpin loops affect binding of the N-terminal contact area in a way that covalent interaction of the Gly9-Ala10 bond with the active-site Cys residue of papain can occur and the bond is cleaved in a substrate-like manner

Enhanced attraction between drops carrying fluctuating charge distributions

The electrostatic force between conductive spheres is always attractive at small separations, irrespective of their mean charge, when the charge on the spheres is constant. In many situations, the charge may not be fixed, such as for water drops in the natural atmosphere which vary in size and charge. We show that the attractive force between charged conductive spheres increases with increasing charge variance. The importance of this unrecognized electrostatic effect between water drops is evaluated for its potential to enhance rain formation

Temporal- and spatial-scale and positional effects on rain erosivity derived from point-scale and contiguous rain data

Up until now, erosivity required for soil loss predictions has been mainly estimated from rain gauge data at point scale and then spatially interpolated to erosivity maps. Contiguous rain data from weather radar measurements, satellites, cellular communication networks and other sources are now available, but they differ in measurement method and temporal and spatial scale from data at point scale. We determined how the intensity threshold of erosive rains has to be modified and which scaling factors have to be applied to account for the differences in method and scales. Furthermore, a positional effect quantifies heterogeneity of erosivity within 1&thinsp;km2, which presently is the highest resolution of freely available gauge-adjusted radar rain data. These effects were analysed using several large data sets with a total of approximately 2×106 erosive events (e.g. records of 115 rain gauges for 16 years distributed across Germany and radar rain data for the same locations and events). With decreasing temporal resolution, peak intensities decreased and the intensity threshold was met less often. This became especially pronounced when time increments became larger than 30&thinsp;min. With decreasing spatial resolution, intensity peaks were also reduced because additionally large areas without erosive rain were included within one pixel. This was due to the steep spatial gradients in erosivity. Erosivity of single events could be zero or more than twice the mean annual sum within a distance of less than 1&thinsp;km. We conclude that the resulting large positional effect requires use of contiguous rain data, even over distances of less than 1&thinsp;km, but at the same time contiguously measured radar data cannot be resolved to point scale. The temporal scale is easier to consider, but with time increments larger than 30&thinsp;min the loss of information increases considerably. We provide functions to account for temporal scale (from 1 to 120&thinsp;min) and spatial scale (from rain gauge to pixels of 18&thinsp;km width) that can be applied to rain gauge data of low temporal resolution and to contiguous rain data.</p

Rain erosivity map for Germany derived from contiguous radar rain data

Erosive rainfall varies pronouncedly in time and space. Severe events are often restricted to a few square kilometers. Radar rain data with high spatiotemporal resolution enable this pattern of erosivity to be portrayed with high detail. We used radar data with a spatial resolution of 1&thinsp;km2 over 452&thinsp;503&thinsp;km2 to derive a new erosivity map for Germany and to analyze the seasonal distribution of erosivity. The expected long-term regional pattern was extracted from the scattered pattern of events by several steps of smoothing. This included averaging erosivity from 2001 to 2017 and smoothing in time and space. The pattern of the resulting map was predominantly shaped by orography. It generally agrees well with the erosivity map currently used in Germany (Sauerborn map), which is based on regressions using rain gauge data (mainly from the 1960s to 1980s). In some regions the patterns of both maps deviate because the regressions of the Sauerborn map were weak. Most importantly, the new map shows that erosivity is about 66&thinsp;% larger than in the Sauerborn map. This increase in erosivity was confirmed by long-term data from rain gauge stations that were used for the Sauerborn map and which are still in operation. The change was thus not caused by using a different methodology but by climate change since the 1970s. Furthermore, the seasonal distribution of erosivity shows a slight shift towards the winter period when soil cover by plants is usually poor. This shift in addition to the increase in erosivity may have caused an increase in erosion for many crops. For example, predicted soil erosion for winter wheat is now about 4 times larger than in the 1970s. These highly resolved topical erosivity data will thus have definite consequences for agricultural advisory services, landscape planning and even political decisions.</p

Decreased Type I Interferon Production by Plasmacytoid Dendritic Cells Contributes to Severe Dengue

The clinical presentation of dengue virus (DENV) infection is variable. Severe complications mainly result from exacerbated immune responses. Type I interferons (IFN-I) are important in antiviral responses and form a crucial link between innate and adaptive immunity. Their contribution to host defense during DENV infection remains under-studied, as direct quantification of IFN-I is challenging. We combined ultra-sensitive single-molecule array (Simoa) digital ELISA with IFN-I gene expression to elucidate the role of IFN-I in a well-characterized cohort of hospitalized Cambodian children undergoing acute DENV infection. Higher concentrations of type I IFN proteins were observed in blood of DENV patients, compared to healthy donors, and correlated with viral load. Stratifying patients for disease severity, we found a decreased expression of IFN-I in patients with a more severe clinical outcome, such as dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). This was seen in parallel to a correlation between low IFNα protein concentrations and decreased platelet counts. Type I IFNs concentrations were correlated to frequencies of plasmacytoid DCs, not DENV-infected myloid DCs and correlated inversely with neutralizing anti-DENV antibody titers. Hence, type I IFN produced in the acute phase of infection is associated with less severe outcome of dengue disease