What is the role of the model in socio-hydrology? Discussion of “Prediction in a socio-hydrological world”*

Srinivasan et al. provide an interesting overview of the challenges for long-term socio-hydrological predictions. Although agreeing with most of the statements made, we argue for the need to take socio-hydrological analysis a step further and add some fundamental considerations, especially concerning the crucial importance of many (conscious and unconscious) assumptions made upfront of the modelling exercise. Eventual assumptions of technological determinism need correction: Models are not “value-free”, but uncertain, subjective and a product of the society in which they were shaped. It is important to acknowledge this uncertainty and bias when making decisions based on socio-hydrological models, considering also that these models are “social and political actors” in and by themselves. Furthermore, socio-hydrological models require a transdisciplinary approach, since physical water availability is only one of the boundary conditions for society. Last but not least, interaction with stakeholders remains important to enable understanding of what the variable of interest is.     

Reporting negative results to stimulate experimental hydrology: discussion of “The role of experimental work in hydrological sciences – insights from a community survey”*

Experimental work in hydrology is in decline. Based on a community survey, Blume et al. showed that the hydrological community associates experimental work with greater risks. One of the main issues with experimental work is the higher chance of negative results (defined here as when the expected or wanted result was not observed despite careful experimental design, planning and execution), resulting in a longer and more difficult publishing process. Reporting on negative results would avoid putting time and resources into repeating experiments that lead to negative results, and give experimental hydrologists the scientific recognition they deserve. With this commentary, we propose four potential solutions to encourage reporting on negative results, which might contribute to a stimulation of experimental hydrology.     

Application of electrical resistivity imaging (ERI) for the assessment of peat properties: a case study of the Całowanie Fen,Central Poland

Complex studies were carried out to recognize the fen structure and peat properties in the Ca?owanie Fen area, belonging to the Natura 2000 network. The studies were conducted in two study areas that differ significantly in terms of peat thickness. Electrical resistivity imaging (ERI) was used to identify the properties of the peat and its substrate, such as thickness and electrical resistivity. Comparison of the field studies with the laboratory tests has shown that the ash content rises electrical resistivity in peat. In addition, the study has shown that the application of non-invasive geophysical methods in protected areas is justified. The fen, as a medium containing mostly water, was a proper test area for the ERI measurements.     

Processes affecting dissolved iron across the Subtropical North Atlantic: a model study

Ocean Dynamics - Trace metal measurements in recent years have revealed a complex distribution of dissolved iron (dFe) in the ocean that models still struggle to reproduce. The GEOTRACES section...     

Physical mechanisms of submesoscale eddies generation: evidences from laboratory modeling and satellite data in the Black Sea

Ocean Dynamics - The observed evidence of the implementation of three different mechanisms of the submesoscale eddies generation in the Black Sea previously studied by the field research and...     

The first samples from Almahata Sitta showing contacts between ureilitic and chondritic lithologies: Implications for the structure and composition of asteroid 2008 TC3

Almahata Sitta (AhS), an anomalous polymict ureilite, is the first meteorite observed to originate from a spectrally classified asteroid (2008 TC₃). However, correlating properties of the meteorite with those of the asteroid is not straightforward because the AhS stones are diverse types. Of those studied prior to this work, 70–80% are ureilites (achondrites) and 20–30% are various types of chondrites. Asteroid 2008 TC₃ was a heterogeneous breccia that disintegrated in the atmosphere, with its clasts landing on Earth as individual stones and most of its mass lost. We describe AhS 91A and AhS 671, which are the first AhS stones to show contacts between ureilitic and chondritic materials and provide direct information about the structure and composition of asteroid 2008 TC₃. AhS 91A and AhS 671 are friable breccias, consisting of a C1 lithology that encloses rounded to angular clasts (<10 μm to 3 mm) of olivine, pyroxenes, plagioclase, graphite, and metal‐sulfide, as well as chondrules (~130–600 μm) and chondrule fragments. The C1 material consists of fine‐grained phyllosilicates (serpentine and saponite) and amorphous material, magnetite, breunnerite, dolomite, fayalitic olivine (Fo 28‐42), an unidentified Ca‐rich silicate phase, Fe,Ni sulfides, and minor Ca‐phosphate and ilmenite. It has similarities to CI1 but shows evidence of heterogeneous thermal metamorphism. Its bulk oxygen isotope composition (δ¹⁸O = 13.53‰, δ¹⁷O = 8.93‰) is unlike that of any known chondrite, but similar to compositions of several CC‐like clasts in typical polymict ureilites. Its Cr isotope composition is unlike that of any known meteorite. The enclosed clasts and chondrules do not belong to the C1 lithology. The olivine (Fo 75‐88), pyroxenes (pigeonite of Wo ~10 and orthopyroxene of Wo ~4.6), plagioclase, graphite, and some metal‐sulfide are ureilitic, based on mineral compositions, textures, and oxygen isotope compositions, and represent at least six distinct ureilitic lithologies. The chondrules are probably derived from type 3 OC and/or CC, based on mineral and oxygen isotope compositions. Some of the metal‐sulfide clasts are derived from EC. AhS 91A and AhS 671 are plausible representatives of the bulk of the asteroid that was lost. Reflectance spectra of AhS 91A are dark (reflectance ~0.04–0.05) and relatively featureless in VNIR, and have an ~2.7 μm absorption band due to OH^? in phyllosilicates. Spectral modeling, using mixtures of laboratory VNIR reflectance spectra of AhS stones to fit the F‐type spectrum of the asteroid, suggests that 2008 TC₃ consisted mainly of ureilitic and AhS 91A‐like materials, with as much as 40–70% of the latter, and <10% of OC, EC, and other meteorite types. The bulk density of AhS 91A (2.35 ± 0.05 g cm^?3) is lower than bulk densities of other AhS stones, and closer to estimates for the asteroid (~1.7–2.2 g cm^?3). Its porosity (36%) is near the low end of estimates for the asteroid (33–50%), suggesting significant macroporosity. The textures of AhS 91A and AhS 671 (finely comminuted clasts of disparate materials intimately mixed) support formation of 2008 TC₃ in a regolith environment. AhS 91A and AhS 671 could represent a volume of regolith formed when a CC‐like body impacted into already well‐gardened ureilitic + impactor‐derived debris. AhS 91A bulk samples do not show a solar wind component, so they represent subsurface layers. AhS 91A has a lower cosmic ray exposure (CRE) age (~5–9 Ma) than previously studied AhS stones (11–22 Ma). The spread in CRE ages argues for irradiation in a regolith environment. AhS 91A and AhS 671 show that ureilitic asteroids could have detectable ~2.7 μm absorption bands.     

Divergent growth trends and climatic response of <Emphasis Type="Italic">Picea obovata</Emphasis> along elevational gradient in Western Sayan mountains,Siberia

In mountain ecosystems, plants are sensitive to climate changes, and an entire range of species distribution can be observed in a small area. Therefore, mountains are of great interest for climate-growth relationship analysis. In this study, the Siberian spruce’s (Picea obovata Ledeb.) radial growth and its climatic response were investigated in the Western Sayan Mountains, near the Sayano-Shushenskoe Reservoir. Sampling was performed at three sites along an elevational gradient: at the lower border of the species range, in the middle, and at the treeline. Divergence of growth trends between individual trees was observed at each site, with microsite landscape-soil conditions as the most probable driver of this phenomenon. Cluster analysis of individual tree-ring width series based on inter-serial correlation was carried out, resulting in two sub-set chronologies being developed for each site. These chronologies appear to have substantial differences in their climatic responses, mainly during the cold season. This response was not constant due to regional climatic change and the local influence of the nearby Sayano-Shushenskoe Reservoir. The main response of spruce to growing season conditions has a typical elevational pattern expected in mountains: impact of temperature shifts with elevation from positive to negative, and impact of precipitation shifts in the opposite direction. Chronologies of trees, growing under more severe micro-conditions, are very sensitive to temperature during September-April and to precipitation during October-December, and they record both inter-annual and long-term climatic variation. Consequently, it would be interesting to test if they indicate the Siberian High anticyclone, which is the main driver of these climatic factors.     

Epipalaeolithic occupations in Nahal Neqarot Rockshelter,Negev, Israel: Radiocarbon dating and identification of charred wood remains

Recent excavations at Nahal Neqarot Rockshelter in the Central Negev, Israel, revealed 60 cm of in situ sediments. The associated lithic industry is mostly attributable to the Middle Epipalaeolithic Ramonian industry, though there is also evidence for sporadic earlier and later Epipalaeolithic use of the site. This is confirmed by three accelerator ¹⁴C dates, which contribute to a better understanding of the chronological framework for the Epipalaeolithic in the region. Microscopic examination of charred wood remains uncovered with the lithics, revealed the dominance of juniper, which is presently extinct in the nearby contemporaneous vegetation, otherwise composed of still extant taxa. © 1998 John Wiley & Sons, Inc.     

Using sedimentology to address the marine or continental origin of the Permian Hutchinson Salt Member of Kansas

The Permian Hutchinson Salt Member of the Wellington Formation of the Sumner Group of Kansas (USA) has multiple scientific and industrial uses. Although this member is highly utilized, there has not been a sedimentological study on these rocks in over 50 years, and no study has investigated the full thickness of this member. Past publications have inferred a marine origin as the depositional environment. Here, this marine interpretation is challenged. The goals of this study are to fully document sedimentological and stratigraphic characteristics of the Permian Hutchinson Salt Member in the Atomic Energy Commission Test Hole 2 core from Rice County, Kansas. This study documents colour, mineralogy, sedimentary textures, sedimentary structures, diagenetic features and stratigraphic contacts in core slab and thin sections. The Hutchinson Salt Member is composed of five lithologies: bedded halite, siliciclastic mudstone, displacive halite, bedded gypsum/anhydrite and displacive gypsum/anhydrite. These lithologies formed in shallow surface brines and mudflats that underwent periods of flooding, evapoconcentration and desiccation. Of note are the paucity of carbonates, lack of marine-diagnostic fossils, absence of characteristic marine minerals and lithofacies, and the stratigraphic context of the Hutchinson with associated continental deposits. The Hutchinson Salt Member was most likely deposited in an arid continental setting. This new interpretation offers a refined view of Pangaea during the middle Permian time.