bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of soil erosion and nutrient loss characteristics using fallout 137Cs on the Loess Plateau
Authors: Zhang Ningning
Published: March 2022

The Grain for Green Project is one of the important projects implemented by the Chinese government to control soil erosion on the Loess Plateau, and its successful implementation has brought remarkable ecological benefits to relevant regions in China. The land use change is the most intuitive representation. Meanwhile, the soil erosion and soil nutrient distribution has also been influenced to produce significant changes. In this research, the characteristics of soil erosion and nutrient loss characteristics of soils from different land utilization types including apple, shrub, forest, grass and gully land, and their relationship were quantitative evaluated with 137Cs tracer technique in a typical watershed, which is located in Yan'an city of northern Shaanxi province in China. Results showed that soil erosion was observed in the all-land use types but shrub land, however, the degree of soil erosion was slight (the maximum value of soil erosion rate for 151.27 t/km²•a). The soil erosion of forest was significant differences with apple, shrub and gully but not with grassland. As will as there were significant differences in among shrub, apple orchard and gully. The soil nutrient loss, soil nutrient status and soil erosion degree showed a very similar pattern of spatial variation, with the difference that the correlation coefficients were different. In addition, there was highly signiﬁcantly positive correlation between three indicators. However, Soil total nitrogen, total phosphorus, organic matter, N/P and C/P significantly affected the total nitrogen loss, total phosphorus loss and organic matter loss, but C/N ratio and nutrient loss were not significant. Soil nutrient loss in small watershed was more closely related to the soil carbon and nitrogen and soil erosion. The basic contents of different nutrients affected their nutrients loss laws, by and large, soil erosion affected soil nutrient loss and results in differences in nutrient distribution in the small watershed. 
An improved laser-diffraction analysis-based approach on soil aggregate stability: a new factor governing soil methane uptake
Authors: van den Bergh Stijn , Chardon Iris , Korthals Gerard , de Boer Wietse , Bodelier Paul
Published: March 2022

Methane (CH4) is a potent greenhouse gas contributing to climate change, with a global warming potential of 24x of CO2 on a 100-year time-frame. More importantly, the atmospheric methane concentration has been rising rapidly in the last decade. Soils are as yet the only known biological sink for atmospheric methane, but the methane uptake capacity of agricultural soils is substantially reduced when compared to native soils. This may be due to a reduction of soil organic matter and soil aggregate stability as a result of agricultural management practices. In this study, we improved a laser-diffraction analysis-based modelling of soil aggregate stability. Using data from an extensive field study, we show new relationships between soil aggregate stability, atmospheric methane uptake, and soil organic matter. The use of organic amendments like compost increases soil organic matter content, which improves soil aggregate stability, and in this study, we show that an improved soil aggregate stability enhances atmospheric soil methane uptake. These results provide new insights on the use of organic amendments like compost on agricultural soils as an atmospheric methane mitigation strategy.
Mapping of complex soil properties at global scale 
Authors: Poggio Laura , Kempen Bas , Turek Maria-Eliza , Batjes Niels H. , Genova Giulio , de Sousa Luís M. , Rossiter David , Heuvelink Gerard
Published: March 2022

Relevant soil information at different scales would greatly help addressing many of the Sustainable Development Goals. Digital Soil Mapping is an established methodology to create maps of soil properties at different resolutions and extents.  Many projects across the globe have provided information on primary soil properties, such as soil textural fractions, soil organic carbon content, cation exchange capacity and soil pH. For environmental modelling and assessment, maps of complex soil properties are also important. These can be defined as properties that cannot be measured directly in the laboratory but are derived from primary soil properties, for instance by simple calculations,  pedotransfer functions or  more advanced spatial analyses. Examples are available water capacity, soil carbon density and stocks, as well as soil erodibility. There are two main approaches to map complex properties: 1) “model first, interpolate later”, where the complex property is first calculated at point locations where the primary properties are known and then mapped; and 2) “interpolate first, model later”, where the complex property is calculated from maps of the primary properties contributing to it. 

We present and discuss these two approaches for global applications using legacy data with a non-uniformspatial distribution of observations and the SoilGrids workflow. We compare the results for available water capacity of the 0 to 100 cm depth interval and soil carbon densities for six depth layers. Both properties were derived from a combination of simple calculations for point locations where the input soil properties were available and pedotransfer functions for other point locations where basic soil properties were available. There were substantial differences between the “model first, interpolate later” and “interpolate first, model later” approaches, both in point-wise evaluation metrics and in landscape patterns.  
Atmospheric dissolved iron from coal combustion particles
Authors: Baldo Clarissa , Ito Akinori , Krom Michael D. , Shi Zongbo
Published: March 2022

It is known that mineral dust is the largest source of aerosol iron (Fe) to the offshore global ocean, but acidic processing of coal fly ash (CFA) may result in a disproportionally higher contribution of dissolved Fe to the surface ocean. In this study, we determined the Fe speciation and dissolution kinetics of CFA from Aberthaw (United Kingdom), Krakow (Poland), and Shandong (China) in acidic aqueous solutions which simulate atmospheric acidic processing. The CFA bulk samples were re-suspended in a custom-made chamber to separate the PM10 fraction. The Fe speciation in the PM10 fractions was determined using sequential extraction methods. In the PM10 fractions, 8%-21.5% of the total Fe was as hematite and goethite (dithionite extracted Fe), 2%-6.5 % as amorphous Fe (ascorbate extracted Fe), while magnetite (oxalate extracted Fe) varied from 3%-22%. The remaining 50%-87 % of Fe was associated with aluminosilicates. At high concentrations of ammonium sulphate ((NH4)2SO4) and low pH (2-3) conditions, which are often found in wet aerosols, the Fe solubility of CFA increased up to 7 times. The oxalate effect on the Fe dissolution rates at pH 2 varied considerably, from no impact for Shandong ash to doubled dissolution for Krakow ash. However, high concentrations of (NH4)2SO4 suppressed this enhancement in Fe solubility. The modelled dissolution kinetics suggest that magnetite may also dissolve rapidly under acidic conditions, as the dissolution of highly reactive Fe alone could not explain the high Fe solubility at low pH observed in CFA. Overall, Fe in CFA dissolved up to 7 times faster than in Saharan dust samples at pH 2. These laboratory measurements were used to develop a new scheme for the proton- and oxalate- promoted Fe dissolution of CFA. The new scheme was then implemented into the global atmospheric chemical transport model IMPACT. The revised model showed a better agreement with observations of surface concentration of dissolved Fe in aerosol particles over the Bay of Bengal, due to the rapid Fe release at the initial stage at highly acidic conditions.
Attributing observed climate change impacts in agriculture using observationally-derived counterfactual climate data and statistical crop-yield modelling
Authors: Undorf Sabine , Schauberger Bernhard , Gornott Christoph
Published: March 2022

Statistically rigorous methods to attribute large-scale, long-term changes in observed climate to anthropogenic forcing are well established and the attribution of individual extreme events has advanced rapidly too. Further attributing climate impacts in society and ecosystems can be important for understanding and assessing loss and damage, for informing adaptation policies, and for motivating both adaptation and mitigation efforts. For this purpose, a counterfactual climate dataset was recently published within the Inter-Sectoral Impact Model Intercomparison Project (Mengel et al., 2021). Constructed by removing the long-term shifts in daily reanalysis data that are correlated to global-mean temperature change, the dataset does not address anthropogenic climate change, but its large spatial and temporal coverage and the range of variables covered as well as minimum requirements on computational tools and data make it a desirable resource for this interdisciplinary problem.

Here, we trial the use of that counterfactual dataset for the quantification of climate impacts on agricultural crop yields, which are of paramount importance to many of the regions most exposed and vulnerable to climate change, not least for food security. We present results from case studies that examine the impacts of selected drought events and are chosen based on reports of substantial food security impacts, on the availability of crop yield data, and on the existence of published scientific literature of a corresponding climate attribution study. The latter allows the comparison with results using methods that isolate the anthropogenic (combined, or by individual forcing) climate change signal. Together with more systematic discussion, this gives an idea of the degree to which our results on the contribution of any climate variations to the observed impacts may be a proxy for the anthropogenic climate change contribution specifically.

Impacts are explicitly simulated using statistical crop models that are established in the agricultural and agronomic literature, built and validated based on the observed record. The use of the single-realisation, weather-preserving factual and counterfactual dataset gives a deterministic rather than probabilistic estimate, but parametric and structural crop-model uncertainty is characterised, and the robustness of the results to different observational crop-yield datasets assessed. We collaborate with local stakeholders to ensure appropriate consideration of non-climatic factors and to improve data availability and quality. Our work combines perspectives of climate attribution, disaster risk reduction, and agricultural science to enhance attributing loss and damage in agriculture to climate change.
Effect of potato starch application on wood cell parameters of Scots pine (Pinus Sylvestris L.)
Authors: Waszak Nella , Campelo Filipe , Robertson Iain , Puchałka Radosław , Boularbach Ali , Koprowski Marcin
Published: March 2022

Koprowski et al. 2015 investigated the effect of N, P, K elements contained in wastes from the Forest Wastewater Treatment (FWT) zone, entering a forest area from a potato starch factory. It was found that the use of starch causes a reduction in the photosynthetic efficiency and growth of Scots pine. The study extends the tree ring analysis of Scots pine by cell wood anatomy. It was examined how cell parameters like cell wall thickness (CWT), lumen diameter (LD) and ring width (RW) responded to fertiliser supply in different years. Three sites were distinguished at the FWT zone. Site 1 and 2 were located in the FWT zone, whilst Site 3 was a control site situated outside this zone. Trees growing at Site 1 were fertilised, whilst trees growing at Site 2 were unfertilised despite being located within the FWT zone. The amount of water supplied and the concentration of elements varied over the years, which, in combination with the supply of fertiliser, clearly influenced the cellular structure of the growths, as was seen in the microscopic examination. For anatomical analyses, one of the most representative and highly correlated trees from each site was selected: site 1 - 0.78, site 2 - 0.74, site 3 - 0.77. The analysis was based on growth years 1961-2011. Preliminary climatic studies confirm a negligible effect of precipitation and temperature on observed variations in cell parameters at these sites. Thus the results obtained seem to depend mainly on fertilisation and water supply.
Multi-Hazard Risk Assessment of Schools in Lower Himalayas: Haridwar District, Uttarakhand, India
Authors: Chouhan Shivani , Narang Aishwarya , Mukherjee Mahua
Published: March 2022

The Indian Himalayan Region possesses a unique place among the world's mountain ecosystems. Being a geographic young region and tectonically active, it is subject to multiple hazards and has seen a significant loss of life and property each year. Historically, the Himalayas have been subject to various disasters (earthquakes, landslides, floods, etc.), resulting in devastating socio-economic effects on the country's population, further straining an already stressed economy.

Haridwar, the most populous city in Uttarakhand, attracts tourists from all over the world. It is a state in northern India with young mountains and is affected by multiple disasters every year. Many national and international organizations are doing disaster risk reduction research, studies, and initiatives in the Himalayas.

Educational institutions, such as schools, act as lifeline structures in the case of a crisis. As a result, it's critical to protect these structures for those who rely on the school as a disaster shelter and help center. Schools and hospitals, which are considered lifeline structures, play a critical role in the aftermath of disasters. The essential elements to recognize are coping capability, multi-hazard vulnerability, and their risk should be readily available for better planning and decision-making.

In Haridwar District, multi-hazard risk assessment assessments were undertaken at 50 schools (with 285 building blocks) with the same goal. The hazard assessment is divided into two types: building-level surveys that include Rapid Visual Screening (RVS), Non-Structural Risk Assessment (NSRA), and Fire Safety Audit, and campus-level surveys that include vulnerability analysis for earthquakes, floods, industrial hazards, landslides, and wind. The Rapid Visual Screening will highlight potential weaknesses in a building's wall, roof, site condition, block geometry, foundation, seismic band availability, and other components.

This research aims to find hazard vulnerabilities and overlooked behavioral patterns in the region that raise the multi-hazard risk of the schools and the community. The analysis findings should be utilized to prioritize hazard preparedness, retrofitting, prospective building activities, and decision-making to decrease risk and prepare the school for possible catastrophes.

Multiple surveys are employed in this study to identify deficiencies/gaps in building methods and development patterns in existing Haridwar district schools, and solutions for risk assessment and retrofitting are proposed based on the findings. The research findings can be utilized to prioritize disaster preparedness, retrofitting, future building practices, and decision-making to lower risk and better prepare the school for future calamities.
Measuring and modeling biocide entry from facades in urban swale sediment 
Authors: Linke Felicia , Schnarr Lena , Olsson Oliver , Kümmerer Klaus , Preusser Frank , Leistert Hannes , Bork Marcus , Lange Jens
Published: March 2022

Urban swales collect stormwater runoff containing micropollutants such as biocides washed off from facades during wind driven rain. Although swales retain contaminants, they might eventually reach groundwater through soil. However, there is little data available of biocide occurrence in urban swale sediment. In this study, we measured the biocide entry to an urban swale and its distribution in sediment. The selected swale in south-west Germany collects runoff from a 3 ha residential area with 46 houses. Two pipes lead into the swale, one collecting runoff from a 1 ha area (“East”) and one from a 2 ha area (“West”). We took sediment samples after dry and wet periods close to both pipes and additional water grab samples during wet periods. In total, we collected 19 stormwater samples during 7 events and 116 sediment samples during 8 days over a period of two years. Water samples were analyzed for three biocides (diuron, terbutryn, octylisothiazoline= OIT) and four transformation products (= TPs, diuron-desmethyl, terbuthylazine-2-hydroxy, terbutryn-desethyl, terbumeton) using LC-MS/MS. Sediment samples were analyzed for terbutryn, OIT and 3 TPs of terbutryn. Finally, we linked a water balance model to a leaching model and simulated longterm biocide input into the swale. This we compared with biocide concentration in the swale sediments using a mass balance approach. We found all biocides and all TPs in water samples at both pipes confirming biocide input to the swale. In the sediment, terbutryn concentrations were generally below 1 ng/g. Of three measured TPs of terbutryn we detected only one, terbutryn-desethyl (<1 ng/g dry weight). There were no significant differences of terbutryn concentration in the sediment before and after storm events. This suggests continuous input and long presence of biocides. Concentrations at pipe West were higher than at pipe East. This pointed to differences in the connected areas such as differences in paints used at individual houses. At the outlet of pipe West, we found maximum concentrations of terbutryn (26 ng/g) in saturated sediments below standing water, which suggests more sorption and less degradation at this location. We thus assume that dry condition in swales during dry weather promote degradation. Overall, our findings emphasize that not only the quantity of urban runoff should guide the design of urban swale systems but also potential biocide entry.
Climate conditions of coals and evaporates in the Earth history
Authors: Bao Xiujuan , Hu Yongyun
Published: March 2022

Coals and evaporates are the most commonly used paleoclimate indicators, regarded as representatives of humid and arid climate conditions in the geological record, respectively. However, the quantitative and systematic climate significance of coals and evaporates in the Earth history still unknown. Here, we perform a series of simulations to simulate global climate conditions of Phanerozoic, using an Earth system model CESM 1.2.2 and reconstructed paleotopographies (Scotese, 2018). Combining with a global-scale complication of coals and evaporate from the present back to Devonian (Boucot et al., 2013), climate variables of annual average surface temperature (AAST), annual average precipitation (AAP) and annual average net precipitation (AANP) of the area where coals and evaporates formed are extracted for analysing quantitative climate conditions of coals and evaporates. The preliminary results show that (1) AAST of evaporate areas vary with global mean temperature, while the variation of coals areas’ AAST reflect a stage change,which are consistent with the stage evolution of land plant and lignin-degrading fungi; (2) AAP and AANP of coals and evaporates areas are relatively stable through the Earth history. Coals areas have general more AAP and AANP than evaporates in 25%-75% quantiles but have similar range with evaporites areas in 5%-95% quantiles.

 

Key words: coals, evaporates, plant evolution, deep-time climate, numerical simulation

References

Scotese C R, 2018. PALEOMAP PaleoAtlas Rasters[J].

Boucot A J, Chen X, Scotese C R, 2013. Lithology Data Tables[J].
The new web application of the Phenological Network of Catalonia (Fenocat) 
Authors: Busto Montserrat , de Yzaguirre Xavier , Cunillera Jordi
Published: March 2022

The Phenological network of Catalonia (Fenocat) was established by the Meteorological Service of Catalonia (SMC) in 2013, due to the lack of phenological records in Catalonia and with the aim to preserve the former phenological information available to study the impact of climate change on natural ecosystems.

Based on citizen science, today the network consists of 60 volunteers around Catalonia that observe 25 different spices of wild and crop plants, 14 birds and 6 butterflies. The observation is done two or three times per week in order to record both the onset and the duration of the different phenophases. BBCH code is used for vegetal species, and the data is sent regularly to PEP725 database. 

Until 2021, observers submitted their observations by email on a monthly base, which had to be manually inserted into the database. This slowed down the quality control and exploitation of the database, which could never be done in real time. 

Since January 2022, an object-relational database is created with the open-source system PostgreSQL, permitting the storage and management of all the information from the Fenocat network, and conducting real-time inquiries to generate, visualize and download reports. In addition, observers are able to enter the information directly into the database via a web application. Fenocat web application makes data entry more flexible -the data can be introduced in situ at the same moment that is observed by any device with internet connection (mobile phone, tablet or PC computer)- and allows the observer to compare their observations with those produced by other observers.

Both, the new database and the web application, mean a significant step forward in the management of the Phenological Network of Catalonia, strengthening our relationship with the observers, enhancing the data analysis and opening the door to a network expansion. 
The Mansurov Effect: A new perspective on the correlation between By and polar pressure
Authors: Edvartsen Jone , Maliniemi Ville , Tyssøy Hilde , Asikainen Timo , Hatch Spencer
Published: March 2022

The Mansurov effect is related to the interplanetary magnetic field (IMF) and its ability to modulate the global electric circuit, which is further hypothesized to impact the polar troposphere through cloud generation processes. We investigate the connection between IMF By-component and polar surface pressure by using daily ERA5 reanalysis for geopotential height since 1966. Previous studies produce a 27-day cyclic response during solar cycle 23 which appears to be significant according to conventional statistical tests. However, we show here that when statistical tests appropriate for strongly autocorrelated variables are applied, there is a fairly high probability of obtaining the cyclic response and associated correlation merely by chance. Our results also show that data from three other solar cycles, produce similar cyclic responses as during solar cycle 23, but with seemingly random offset in respect to timing of the signal. By generating random normally distributed noise with different levels of temporal autocorrelation, and using the real IMF By-time series as forcing, we show that the methods applied to support the Mansurov hypothesis up to now, are highly susceptible to random chance, as cyclic patterns always arise as artefacts of the methods. Further analyses of the time period 1966-2018 in both polar hemispheres reveals highly significant correlations over large time scales between the 27-day smoothed gradient of the By, Bx and Bz-index, and the geopotential height at 700 hPa. The smoothed gradient can be understood as the movement of the sector structures of the Heliospheric Current Sheet (HCS). As the new results suggest another driver that is only partially related to By, this can explain why the correlations for the raw By is found to be insignificant. The full mechanism of the newly discovered driver is still unknown and under development. 
Modelling Solid-Fluid Phase Separation and Dewatering in Debris Flows
Authors: Meyrat Guillaume
Published: March 2022

The runout behaviour of debris flows is strongly governed by their solid-fluid composition.  In mitigation projects it is often necessary to predict when the solid phase deposits and if there exists the possibility of fluid washes.  The solid-fluid composition in the runout zone often controls the size and type of mitigation measures, as well as how land is zoned around a specific torrent.  This problem is extremely difficult to solve in general terrain because of the difficulty to establish initial conditions for both sediment and fluid, the inability to accurately account for torrent geometry and erosion, or the complexity of the muddy-granular flow rheology.  Here we present a dilatant, two-phase debris flow model that predicts the deposition of the solid phase with eventual dewatering.  Theoretically, the model exhibits a specific solid-fluid composition ratio for a debris flow in steady-state conditions.  In the runout zone, when the flow decelerates, the shear-work is no longer capable of sustaining this steady-state, leading to the deposition of solid material with decoupling of the fluid phase.  We apply the model to simulate several debris flow events where the stopping/dewatering behaviour of flow was captured using high-resolution drone scans.   Finally, we show that the wide range of empirical friction coefficients used in single phase debris flow models can be constrained by application of two-phase models, with varying solid-fluid compositions. 
Heat-death by volcano - how Venus went rogue?
Authors: Way Michael , Ernst Richard , Scargle Jeffrey
Published: March 2022

The idea of a habitable Venus epoch has gained traction in recent years via 1-D and 3-D General Circulation Modeling (GCM) efforts [1,2,3]. Although recent work has supported an alternative permanent hot and dry scenario [4].  However, the habitable scenario presents us with a conundrum - how does a terrestrial planet transform from temperate to hot-house? For decades it was proposed that the gradual brightening of the sun was the probable cause [5]. Yet 4 billion years ago Venus was receiving nearly 1.4 times the insolation that Earth receives today, and many studies have put Earth at the inner boundary of the habitable zone today [6].  The newer 3-D GCM efforts have demonstrated that if Venus had an early habitable period, that the cloud-albedo feedback responsible for maintaining temperate surface conditions [7] could still be in operation today. From this perspective increasing insolation through time cannot be an answer to the transition from habitable to hot-house. We propose that the 'Great Climate Transition' (GCT) was trigged by simultaneous large igneous provinces (LIPs) akin to those like the Siberian Traps responsible for the End Permian [8].  We have taken the most up to date LIP database for Earth [9] and characterized their distribution through time as random or nearly random. Next we initiate a large suite of Monte Carlo simulations based on this record and generate the likelihood for simultaneous, or environmentally overlapping events in this hypothetical setup. We find the probability of such events to be quite high, a probable cause for Venus' GCT, and a possible harbinger of things to come for Earth.

[1] Grinspoon, D.H. & Bullock, M.A. (2007) AGU https://doi.org/10.1029/176GM12
[2] Way, M. J. et al. (2016) GRL 43, 8376–8383
[3] Way, M. J. and Del Genio, A D.  (2020) JGR Planets 125, e2019JE006276
[4] Turbet et al. (2021) Nature,598,276 https://doi.org/10.1038/s41586-021-03873-w
[5] Kasting J. F., Pollack J. B. and Ackerman T. P. (1983) Icarus, 57, 335-355
[6] Kopparapu, R.K. et al. (2013) ApJ 765, 131
[7] Yang, J. et al. (2014) ApJ 707, L2
[8] Wignall, P. (2001) Earth Science Reviews, 53 (1-2), 1-33
[9] Ernst R. E. et al. (2021) AGU Geophys. Mon. 255, pp. 3-26
Low cost source apportionment of urban air pollution
Authors: Pope Francis , Bousiotis Dimitrios , Beddows David , Allison Gordon
Published: March 2022

Over the last 10 years, there has been a revolution in the use of low cost sensors to measure air pollution concentrations. These sensors are not without problems, but it is now possible to get high quality measurements of air pollutants. In particular, the use of low cost optical particle counters (OPCs) for the measurement of particulate matter (PM) in regulatory size ranges has been successfully achieved in many urban areas worldwide, with an associated cost that is far less than regulatory instruments.

Successful air quality management and control not only requires measurement of air pollution levels, but it also requires information on the sources and their relative importance. Without this critical, targeted information on pollution sources, it is difficult to plan and enact control measures with which to reduce air pollution.

This talk will present new work on using low cost PM sensors to achieve low cost source identification and apportionment. The measured PM size distribution obtained from OPCs is used to identify sources. Typically, source apportionment that uses particle size distributions as input relies on particle size information in the sub 300 nm size range to obtain information about sources. However, OPCs typically only provide size information above approximately 300 nm.  Initial work used k-means clustering to obtain source information (Bousiotis et al. 2021). Subsequent work has used other algorithms including positive matrix factorization (PMF). Comparison between source information obtained between low cost and regulatory grade instruments is remarkably promising.

This presentation will highlight the methodological approaches undertaken. It will then use a series of urban case studies showing how low cost source apportionment can be used to identify different sources of PM pollution in urban areas, both in the ambient air and indoor air. Finally, the presentation will discuss the prospects for low cost urban source apportionment and hyperlocal air pollution management.

Bousiotis, D., Singh, A., Haugen, M., Beddows, D., Diez, S., Murphy, K.L., Edwards, P.M., Boies, A., Harrison, R.M. and Pope, F.D., 2021. Assessing the sources of particles at an urban background site using both regulatory instruments and low-cost sensors–a comparative study. Atmospheric Measurement Techniques, 14(6), pp.4139-4155. https://doi.org/10.5194/amt-14-4139-2021
An analytical model for dust impact voltage signals, and its application to STEREO/WAVES data
Authors: Rackovic Babic Kristina , Zaslavsky Arnaud , Issautier Karine , Meyer-Vernet Nicole , Onic Dusan
Published: March 2022

Dust grains are a common constituent of the Solar system. Dust impacts have been observed using radio and wave instruments onboard spacecraft since the 1980s. Voltage waveforms show typical impulsive signals generated by dust grains. We aim at developing models of how signals are generated to be able to link observed electric signals to the physical properties of the impacting dust. To validate the model, we use the Time Domain Sampler (TDS) subsystem of the STEREO/WAVES instrument which generates high-cadence time series of voltage pulses for each monopole. A model that we propose takes into account impact-ionization-charge collection and electrostatic-influence effects. It is an analytical expression for the pulse and allows us to measure the of amount of the total ion charge, the fraction of escaping charge, the rise timescale, and the relaxation timescale. The model is simple and convenient for massive data fitting. To check our model’s accuracy, we collected all the dust events detected by STEREO/WAVES/TDS simultaneously on all three monopoles at 1AU since the beginning of the STEREO mission in 2007. Our study confirms that the rise time largely exceeds the spacecraft’s short timescale of electron collection. Our estimated rise time value allows us to determine the propagation speed of the ion cloud, which is the first time that this information has been derived from space data. Our model also makes it possible to determine properties associated with the electron dynamics, in particular the order of magnitude of the electron escape current. The obtained value gives us an estimate of the cloud’s electron temperature — a result that, as far as we know, has never been obtained before except in laboratory experiments. Furthermore, a strong correlation between the total cloud charge and the escaping charge allows us to estimate the escaping current from the amplitude of the precursor, a result that could be interesting for the study of the pulses recently observed in the magnetic waveforms of Solar Orbiter or Parker Solar Probe, for which the electric waveform is saturated.
Linking the measurement data of the substance flows of the SMEAR Estonia measuring station with the place of growth
Authors: Kollo Joonas , Padari Allar , Krasnova Alisa , Kangur Ahto , Noe Steffen
Published: March 2022

The SMEAR Estonia is an important step towards understanding how forest ecosystem and the atmosphere affect each other. The station provides long-term continuously measured eddy-covariance CO2 flux data. Parameters such as wind speed and direction are not controllable by human, but forest management methods are, thus the flux tower helps to assess how human activities affect forest ecosystem-atmosphere relationship as well as to assess natural processes. In this study, the footprint for years 2015–2020 was calculated with Kljun model according to wind speed and direction. Measurements were taken from 30 m and 70 m height. Data was obtained by continuous high frequency (10 Hz) measurements by the eddy-covariance method and averaged over half-hour intervals. Results showed that the footprint area measured from 30 m over six-year period differed only by 5%. From 70 m this difference was only 1.2% over the six-year period. Average area for both 30 m and 70 m FFP was 61,5 ha and 4029,7 ha respectively. The growing stock of the forest was affected by forest management, but in general it grew by 3,2% for 30 m FFP. The main tree species growing in the area of the footprint are Scots pine (Pinus sylvestris), Norway spruce (Picea abies) and Silver birch (Betula pendula) with some small amount of aspen and alder species. The dominant wind directions were ranging from west to south in 2015–2017 and in 2018–2020 from south-west to south-east. The footprint area is affected mainly by wind speed and direction, and by forest management activities like harvesting and clear-cutting. Such measurements help to understand how human activity and natural processes affect formation of the footprint.
Heat Field Deformation (HFD) vs Linear Heat Balance (LHB):  A critical comparison of two sap flow methods based on the same instrumentation
Authors: Zhao Junbin , Lange Holger , Meissner Helge , Bright Ryan
Published: March 2022

As a way to estimate evapotranspiration (ET), Heat Field Deformation (HFD) is a widely used method to measure sap flow of trees based on empirical relationships between heat transfer within tree stems and the sap flow rates. As an alternative, the Linear Heat Balance (LHB) method implements the same instrumental configuration as HFD but calculates the sap flow rates using analytical equations that are derived from fundamental conduction-convection heat transfer equations. In this study, we systematically compared the sap flow calculated using the two methods from four Norway spruce trees. We aimed to evaluate the discrepancies between the sap flow estimates from the two methods and determine the underlying causes. Diurnal and day-to-day patterns were consistent between the sap flow estimates from the two methods. However, the magnitudes of the estimated sap flow were different, where LHB resulted in much lower estimates in three trees and slightly higher estimates in one tree compared to HFD. We also observed larger discrepancies in negative (downward) than in positive (upward) sap flow, where the LHB resulted in lower reversed flow than HFD. Consequently, the seasonal budget estimated by LHB can be as low as ~20% of that estimated by HFD. The discrepancies can be mainly attributed to the low wood thermal conductivities for the studied trees that lead to substantial underestimations using the LHB method. In addition, the sap flow estimates were very sensitive to the value changes of the empirical parameters in the calculations and, thus, using a proper case-specific value is recommended, especially for the LHB method. Overall, we suggest that, despite the strong theoretical support, the correctness of LHB outputs depends largely on the tree individuals and should be carefully evaluated. 
Enhanced impacts of compound precipitation and wind extremes on residential buildings
Authors: Grieger Jens , Ulbrich Uwe
Published: March 2022

While it is known that severe winter wind storms are related with strong impacts, this study investigates the enhanced impact of compound precipitation and wind extremes. Therefore, we analyse the co-occurrence of extreme wind and precipitation using ERA5 reanalysis data for the European winter season. Co-occurring events are defined by simultaneous threshold exceedance of daily wind speed and precipitation in same or neighbouring areas.

For the quantification of impacts, we are using daily insurance records of damages for residential buildings over Germany provided by the German Insurance Association (GDV). Using the definition of co-occurring extremes, those damage records can be grouped into compound and non-compound events. Analysing insurance loss data between 1997-2016 allows comparisons of the distribution of both groups. There are much more events in the non-compound group. On the other hand, the distribution of the compound group is shifted towards higher damages with an increased median of a factor of ten.
From SDGs to IDGs: Translating global Sustainable Development Goals for water, food and energy to river basin specific Indus Development Goals
Authors: Lutz Arthur , Smolenaars Wouter , Dhaubanjar Sanita , Jamil Khalid , Biemans Hester , Ludwig Fulco , Immerzeel Walter
Published: March 2022

The UN Sustainable Development Goals (SDGs) are a powerful concept to drive action towards a more sustainable future. However, the SDGs are formulated in a qualitative and generic way whereas specific and quantitative definitions of targets are required to steer policy and practice.

The Indus river basin is a global hotspot for future climate change and socioeconomic development. The basin has the largest continuous irrigation scheme in the world, and hydropower is developing rapidly with a large hydropower potential still untapped. Therefore, water, food and energy are strongly interlinked in the basin’s water-food-energy nexus. The basin already faces insecurity of water, food and energy in the present situation, and with strong projected climate and socioeconomic change, achieving the SDGs for these three resources in the basin will be challenging.

Here we present a novel approach to translate the global SDGs for water, food and energy (SDGs 2, 6 and 7) to quantitative targets specified for the Indus river basin. Our approach is based on a resource accounting framework operating at sub-basin scale and monthly time step, combining models and geospatial data. The approach uses ensembles of downscaled projections for three climate change scenarios driving water availability and three sets of downscaled projections of socioeconomic drivers, including population and GDP, as main drivers for the demand for water, food and energy. The accounting framework considers dependencies between the three resources and represents scenario-specific exchange of resources between sub-basins in this transboundary river basin. The approach results in scenario-specific quantitative targets for water, food and energy to be realized to achieve the three related SDGs at the river basin scale.
Links between drought and atmospheric circulation types during 1950-2019
Authors: Bešťáková Zuzana , Kyselý Jan , Lhotka Ondřej
Published: March 2022

The study deals with links between drought and atmospheric circulation in different parts of Europe (Western Europe, Central Europe, Eastern Europe, Northern Europe, and Southern Europe) during 1950–2019. The links are evaluated using drought characteristics (based on a difference between potential evapotranspiration and precipitation) calculated from gridded EOBS data and atmospheric circulation types that were classified using daily sea level pressure patterns obtained from the NCEP-NCAR reanalysis. Circulation types supporting drought in warm half-year are identified, and we analyse changes in their occurrence in the period after 1950, seasonal changes, and the connection with drought trends in individual European regions.
Fate of the grain size gap material in river bed sediments
Authors: Dingle Elizabeth , Venditti Jeremy
Published: March 2022

There is a paucity of rivers beds with median surface grain sizes between ~1 and 5 mm, a range also referred to as the grain size gap. The grain size gap corresponds to the rapid reduction in grain size associated with the gravel-sand transition in river systems, where grain sizes reduce from >5 mm to 1 mm over a downstream distance equivalent to just a few channel widths. In existing models and experiments, these grain sizes must typically be omitted to generate the abrupt reduction in grain size across the transition. However, there is evidence that these grain sizes are present in river systems and hillslope sediment supplies. We present a series of new laboratory experiments in a narrow flume, examining the fate of grain size gap material in both sediment feed and bed distributions. Our observations indicate that where sand falls out of suspension at the upstream end of the gravel-sand transition, grain size gap material in gravel beds experiences enhanced mobility. We propose that this occurs through a geometric effect where medium sand is the exact size to bridge interstitial pockets in fine gravel bed surfaces. We hypothesize this effect could enhance grain protrusion of fine gravel and increases the likelihood of entrainment, or that sand deposition smooths the bed, generating fluid acceleration in the near-bed flow region. Grain size gap particles cannot form the dominant mode in river bed surface sediments because sand destabilizes particles of this size. 
Electron Kinetic Entropy Generation at Quasi-perpendicular Collisionless Shocks: Dependence on Shock Parameters
Authors: Lindberg Martin , Vaivads Andris , Raptis Savvas , Lindqvist Per-Arne , Giles Barbara , Gershman Daniel
Published: March 2022

We calculate the change in electron kinetic entropy, ΔSe, across 22 supercritical quasi-perpendicular Earth bow shock crossings observed by the Magnetospheric Multiscale (MMS) mission. The crossings cover a wide range of shock parameters. We calibrate the measured distribution functions measured by MMS to correct for spacecraft potential, secondary electron contamination, lack of measurements at the lowest energies and electron density measurements based on the plasma frequency measurements. The change in electron kinetic entropy displays a strong dependence on the change in electron temperature, ΔTe, and the upstream plasma beta. Shocks with a small upstream plasma beta have a large ΔSe while shocks with high upstream plasma beta have a small ΔSe.

The calculated changes in kinetic entropy, density and temperature are used to estimate the proxy adiabatic index, γe, for each shock crossing. The estimated adiabatic indices are all in the vicinity of 1.6, comparable to that of a monatomic gas with three degrees of freedom.
Effect of the relative humidity on the oxidation of arsenopyrite and löllingite
Authors: Drahota Petr , Ettler Vojtěch , Culka Adam , Rohovec Jan , Jedlička Radim
Published: March 2022

Humidity is an important factor in sulfide oxidation as it has been shown that sulfide minerals weather differently depending on the humidity. Arsenopyrite (FeAsS) and löllingite (FeAs2) concentrates were placed under six relative humidities (RH) between 75% and 100% for 40 months and then studied using XRD, EMPA, Raman microspectrometry, and chemical extractions. Results of our experiments showed that oxidative dissolution of arsenopyrite and löllingite concentrates led to formation of different mineral assemblages in different amounts. Oxidative dissolution of arsenopyrite concentrate led to formation of poorly crystalline ferric arsenate (PCFA) and minor elemental sulfur, while oxidation of löllingite concentrate resulted in formation of well crystalline scorodite (FeAsO4·2H2O) and arsenolite (As2O3). Our data indicated that high levels of sulfate in arsenopyrite concentrate (released from sulfide oxidation) triggered fast precipitation of PCFA and retarded its transformation to scorodite. Effect of the RH on the mineralogy of oxidation products was negligible; however, quantity of newly formed oxidation products was function of RH. The data indicated that oxidation kinetics of arsenopyrite and löllingite concentrates were relatively similar and low (corresponding up to 3.5 % of the sulfide/arsenide) at RH≤94%, but löllingite concentrate oxidized much faster (up to 10×) at RH levels close to 100%.
High-resolution climate ensemble reveals low confidence in projected changes in storm surges for the mid-century
Authors: Muis Sanne , Aerts Jeroen C.J.H. , A. Á. Antolínez José , Le Bars Dewi , Dullaart Job C. , Minh Dong Trang , Erikson Li , Haarsma Rein , Irazoqui Apecechea Maialen , O'Neill Andrea , Ranasinghe Roshanka , Roberts Malcolm , Yan Kun , Verlaan Martin , Ward Philip J.
Published: March 2022

In the coming decades, regions across the globe will be faced with increases in coastal flooding due to sea-level rise and changes in climate extremes. In a collective effort, we have produced new extreme sea level projections derived from an ensemble of high-resolution climate models. Our approach is based on the Global Tide and Surge Model forced with model outputs from the HighResMIP experiments. The HighResMIP models have a much higher spatial resolution than the previous generation of climate models, and can better resolve storms, including tropical cyclones. The dataset has global coverage and spans the period 1950-2050. The dataset provides: 1) timeseries of storm surges, astronomical tides, and total still water levels; and 2) water level statistics for different time slices, including percentiles and return periods.

In this contribution we focus on storm surges and have a first look at model performance for present-day climate conditions and at projected changes. Comparison of the 1 in 10-year surge levels against the ERA5 reanalysis reveals a large spatial bias for some of the HighResMIP models, highlighting the need for multi-model ensembles and bias correction. Comparison of the 1 in 10-year surge levels between the 1951-1980 and 2021-2050 period, shows that some regions, such as Northwest Europe, Alaska, China, and Patagonia, may be faced with an increase in storm surges (>0.1 m), while other regions, such as the Mediterranean and South Australia may see a decrease in storm surges. Overall, the projected changes are characterized by large intermodel variability due the uncertainties that arise from the climate models, internal variability, and extreme value statistics. Future research should aim to better constrain the uncertainties, which can be achieved by a more in-depth exploration of the changes in the meteorological conditions, enlarging the model ensemble, and the implementation of bias correction methods.

The full datasets will soon become openly available at the C3S Climate Data Store and can be used to inform climate impact assessments.