bluuebunny/crossref_metadata_2025 huggingface dataset:
Microbial control on Anthropocene carbonates in slag drainage waters
Authors: van der Land Cees , Cowan Keziah , Sherry Angela , Bastianini Laura , Gray Neil , Rogerson Mike , Mercedes-Martin Ramon , Prior Timothy , Cesar Edgley , Mayes William
Published: March 2020

Over the last decennia, alkaline leachates from the weathering of legacy steel slag disposal sites have affected the surrounding soils and drainage streams. The hyperalkaline and hypersaline conditions around these sites are comparable to extreme paleo environments such as alkaline lakes in rift volcanic settings. Investigating the carbonate deposits forming in these man-made systems provides a unique opportunity to link the ongoing physical and microbial processes to their resultant carbonate morphologies.

Here we present data from 3 sites across Dene Burn, a slag drainage stream in Consett, County Durham, UK. After 100 years, iron and steel production ceased in 1980, leaving over 20 million tons of slag in the form of several large mounds. Analysis showed Dene Burn to be typical of slag drainage waters with an elevated pH (>9) and saturated with different secondary phase minerals- particularly calcite. However, the physical distribution of carbonates is more comparable with estimated local kinetic precipitation rate than it is to thermodynamic saturation, indicating that the fundamental control on carbonate formation arises from crystal surface processes. A microbial community comprising predominantly Proteobacteria (Alpha-, Gamma-, Beta- and Deltaproteobacteria), Cyanobacteria, Bacillariophyta (diatoms) and Bacteroidetes (Flavobacterium) was identified at the 3 sites. The microbial communities and an abundance of extracellular polymeric substances (EPS) were shown in close association with the mineral phases detected at the sites. The presence and composition of these biofilms appears to control local carbonate mineralisation rates and carbonate morphologies.

Drainage streams from steel slag provide a unique opportunity to study carbonate mineral formation under extreme environmental conditions. Furthermore, maximising carbonate formation at such sites could be utilised as a remediation and carbonate sequestration technique.
Numerical Study of the impact of Meteorological and Emission control on the decreasing of PM2.5 concentration in Beijing by WRF-SMOKE-CMAQ model system
Authors: Wu Qizhong , Xu Qi
Published: March 2020

In the past years, the PM2.5 concentration in Beijing decreases from 89 ug/m3 in 2013 to 42 ug/m3 in 2019, especially in the recent three years, that the PM2.5 concentration rapidly decreases from 73 ug/m3 in 2016 decreases to 42 ug/m3. An air quality modeling system, based on WRF-SMOKE-CMAQ model, was established before APEC 2014 to forecast daily air quality and assess future air quality improvement plans, which plan expects Beijing’s PM2.5 would reach to 53 ug/m3 in 2020, and reach to 35 ug/m3 in 2030. Actually, the PM2.5 concentration in Beijing has fallen faster than expected, that the annual PM2.5 concentration is 42 ug/m3 in 2019. So how much influence do meteorological factors and emission control have on the annual PM2.5 concentration? The WRF-SMOKE-CMAQ modeling system has been used to re-build the PM2.5 concentration characteristics of Beijing from 2013 to 2019 to distinguish these two factors. Preliminary results show that under the same emission scenarios, the annual average concentration of PM2.5 in Beijing in 2013 was 68.6 ug/m3, and the average annual concentration of PM2.5 in 2017 was 69.4 ug/m3. More detailed model results will be presented.
Numerical modelling based saturation conductivity estimation uncertainty – influence of the quality of the pore space geometry representation based on X-ray CT images
Authors: Lamorski Krzysztof , Gackiewicz Bartłomiej , Sławiński Cezary , Hsu Shao-Yiu , Chang Liang-Cheng
Published: March 2020

X-ray computational tomography (CT) is becoming more and more popular research tool in geosciences. Estimation of the saturated conductivity of the porous media based on X-ray CT images is an example of its application. In case of simulations for the pore media, which are approximated by the very complicated meshes, problems might arise when mesh does not follow the shape of pore-space ideally, which may happen due to limitations imposed (e.g. due to some technical constraints) on minimum mesh cell size which usually is bigger than CT scan resolution used for determination of the pore space. If this is the case, the mesh can’t be generated properly in the narrow regions of the pore-space.

The work tries to quantify the impact of the limited mesh quality on estimation of the saturated conductivity coefficient. Four mesh generation parameters, resulting in different sizes of the minimum mesh cell size, were compared. For comparison five different pore media (three sandpacks prepared from different sand fractions and two types of sandstones) were used, all of them were used in two repetitions which resulted in 10 studied samples in total. First samples were X-ray CT scanned with resolution 2um. Than images were thresholded to obtain information about pore-space. In the next step, for all of 10 3D images of pore-space, mesh was generated in four repetitions differing with minimum mesh cell size: 2.56, 3.41, 5.12 and 10.25 times greater than voxel size used for CT scanning.

Saturated conductivity was simulated based on prepared meshes using finite volume based solver of the Navier-Stokes equations. Estimated for each sample saturated conductivity differed from 12% for coarse media to 200% for fine grain media for different numerical meshes representing with different accuracy pore space geometry.

Based on samples studied, one may conclude that for optimal results of saturated conductivity numerical estimation, the smallest numerical mesh’s cell size should be of the level of pore media CT scan resolution.  

 

Acknowledgments:

This work was partially supported by a grant from the Polish National Centre for Research and Development within the contract no.: PL-TW/IV/5/2017.
The three-dimensional geometries of segmented normal faults
Authors: Walsh John , Roche Vincent , Camanni Giovanni , Childs Conrad , Manzocchi Tom , Conneally John , Saqab Muhammad Mudasar , Delogkos Efstratios
Published: March 2020

Normal faults are often complex three dimensional structures comprising multiple sub-parallel segments separated by intervening relay zones. In this study we outline geometrical characterisations capturing this 3D complexity and providing a semi-quantitative basis for the comparison of faults and for defining the factors controlling their geometrical evolution.

Individual relay zones can be assigned to one of four types according to their form (i.e. whether the bounding segments are unconnected in 3D or merge into a single surface) and their orientation (i.e. whether they are slip-parallel or slip-perpendicular). From the detailed analysis of 84 fault arrays mapped from 3D seismic reflection surveys (including 63 from our mapping of 8 different study areas and 21 derived from the literature), we show that the 3D geometry of fault arrays can be quantitatively defined on the basis of the relative numbers of these types of relay zones.

Detailed mapping of fault zones indicates that whilst they can individually contain all four types of relay zone, their relative proportions varies between different study areas. Differences in the proportions of relay zone types are attributed to two primary controls, the mechanical heterogeneity of the faulted sequence and the presence of basement structure. For example, relay zones with an upward bifurcating geometry are prevalent in faults that reactivate deeper structures, whereas the formation of laterally bifurcating relays is promoted by heterogeneous mechanical stratigraphy. 

Fault arrays in the literature generally do not contain the full range of possible relay zone type but tend to comprise either all bifurcating relay zones or all unconnected relay zones. These end-member fault geometries have led to contrasting conceptual models for the growth of faults. The mapping conducted here suggests that the proportion of bifurcating relay zones increases as data resolution increases and that fault surface bifurcation is ubiquitous. Models for the geometrical evolution of fault arrays must account for the full range of relay zone geometries that appears to be a characteristic of all faults.
The response of the Northern Hemisphere storm tracks and jetstreams to climate change in the CMIP3, CMIP5, and CMIP6 climate models
Authors: Harvey Ben , Cook Peter , Shaffrey Len , Schiemann Reinhard
Published: March 2020

Understanding and predicting how extratropical cyclones might respond to climate change is essential for assessing future weather risks and informing climate change adaptation strategies. Climate model simulations provide a vital component of this assessment, with the caveat that their representation of the present-day climate is adequate. In this study the representation of the NH storm tracks and jet streams and their responses to climate change are evaluated across the three major phases of the Coupled Model Intercomparison Project: CMIP3 (2007), CMIP5 (2012), and CMIP6 (2019). The aim is to quantity how present-day biases in the NH storm tracks and jet streams have evolved with model developments, and to further our understanding of their responses to climate change.

The spatial pattern of the present-day biases in CMIP3, CMIP5, and CMIP6 are similar. However, the magnitude of the biases in the CMIP6 models is substantially lower in the DJF North Atlantic storm track and jet stream than in the CMIP3 and CMIP5 models. In summer, the biases in the JJA North Atlantic and North Pacific storm tracks are also much reduced in the CMIP6 models. Despite this, the spatial pattern of the climate change response in the NH storm tracks and jet streams are similar across the CMIP3, CMIP5, and CMIP6 ensembles. The SSP2-4.5 scenario responses in the CMIP6 models are substantially larger than in the corresponding RCP4.5 CMIP5 models, consistent with the larger climate sensitivities of the CMIP6 models compared to CMIP5.
3D numerical modeling of sediment handling techniques in a hydro power reservoir
Authors: Lal Maskey Diwash , Nepal Dipesh , Herman Daniel , Gaiti Gabriele , Rüther Nils
Published: March 2020

Sedimentation of small as well as large water storage reservoir has become a major issue. Due to the fact that we observe a 1% decrease of reservoir volume every year due to sedimentation and that the largest part of the reservoirs have been built between 70 and 40 years ago, many HPPs are confronted with the threatening scenario that soon the active storage and therefore their lifetime is dramatically diminished. Due to the above mentioned combination, active and sustainable sediment management has become the last option to retain or preferable enlarge the left-over reservoir volume. There are several options for a sustainable sediment handling, each for a different boundary condition, which must be evaluated carefully in order to be successful. For a successful choice, design and conduction of a sediment handling technique, usually a physical scale model will be conducted. Physical scale model have the advantage that there is a lot of experience in conducting these models and that they are illustrative. The disadvantage of scale models is that there are restrictions in the use of certain sizes of sediments due to scaling issues and that they are rather expensive.

This study attempt to use a 3D numerical model to overcome the above mentioned disadvantages and to serve as an additional source of alternatives in finding the right sediment handling techniques in reservoirs with high discharges of suspended and bed load. The goal is to simulate several flood events in order to gain insights in the current situation as well as to have a better understanding of the physical processes in the reservoir. This will support and positive influence the sustainable design of sediment handling techniques. The numerical model will be verified with flow measurements a physical model study and with bathymetry measurements from field observations. Based on the actual deposition pattern and the given input data, different sediment handling techniques are planned and conducted by means of the numerical model. The results show that the 3D numerical model is able to simulate sediment transport deposition pattern, bed load guide vane structures, as well as bed load diversion structures.
Transport of Nanoplastic under groundwater aquifer flow and transport conditions
Authors: Müller Sascha , Balic-Zunic Tonci , Posth Nicole R.
Published: March 2020

In terrestrial environments soils are hypothesized sinks for plastic particles. Nonetheless, due to the existence of preferential flow paths as well as a variety of geochemical and microbiological processes, this sink may only be temporary. A vertical translocation from soils to groundwater aquifers eventually occurs along different pathways. In these conditions Nanoplastic transport characteristics are similar to colloidal transport behavior. Therby the magnitude of plastic transport is eventually governed by complex interplay between the particle with its surrounding media (particle-particle, particle-solvent, particle- porous media) masked by different hydro-geochemical and microbiological conditions. The physical entrapment of particles (straining) may be significant when the particle diameter exceeds 5% of the median grain size diameter. Below that size additional electrostatic, van der Waals or steric interaction become increasingly important.

We present a preliminary dataset on the interaction between Nano-sized Polystyrene (PS) with different surface coatings and a variety of common minerals occurring in groundwater aquifers under the presence of Natural Organic Matter (NOM). The reference aquifer material is based on the Danish subsurface structure of Quaternary and Miocene aquifer material, e.g. quartz, calcite and pyrite among others. In our study, batch scale interactions are up-scaled in column flow and transport experiments, simulating different groundwater aquifer flow conditions in the presence of selected minerals and NOM.

This aims to clarify transport behavior of plastic pollutant in the subsurface environment. Furthermore, it serves as guide in qualitatively assessing and quantifying the vulnerability of groundwater aquifers to Nanoplastic pollution.
Extremely Low Frequency laboratory investigation of moving sand and dust – a case of the Martian environment
Authors: Kozakiewicz Joanna , Kulak Andrzej , Sobucki Mateusz , Kubisz Jerzy
Published: March 2020

We present first results of laboratory experiments on extremely low frequency (ELF) electromagnetic (EM) field generation by moving sand and dust. This work is a part of our ongoing project to design and manufacture an autonomous ELF Mars Station that will enable studying electric properties of the Martian ionosphere as well as the subsurface of Mars.

ELF waves are very weakly attenuated in the planetary environments and propagate in a cavity made of two high-conductivity spherical boundaries: a planetary ionosphere and a planetary ground. On Mars, as there is no liquid water at the planetary surface, the high-conductivity layer of the ground is expected to be located at greater depths than on Earth, and therefore, ELF investigation on Mars can be used as a tool for studying the subsurface layers. It can be especially useful for groundwater detection. However, the main aim in ELF studies on Mars is related to investigating ELF sources.

ELF sources on Mars can be generated by frequently occurring phenomena: dust storms and dust devils. However, up till now, electromagnetic activity of these dust events on Mars has not been investigated in situ, and remote sensing measurements have been inconclusive. On Earth, many works indicate that dust storms and dust devils generate electromagnetic field, and some ELF fields in dust devils were detected. Also, some aeolian tunnel experiments showed that electric fields can be produced by moving sand.

Our laboratory experiments were performed in an aeolian environmental tunnel located at the Jagiellonian University in Krakow, designed to study aeolian transport. The measurements were carried out by dedicated ELF detectors and using a developed technique of signal processing and analysis. Several aeolian materials, different in mineralogical and granulometric composition, were tested.

This work has been supported by the National Science Center under grant 2015/19/B/ST9/01710.
Revisiting carbon budgets of IPCC 1.5-degree report by taking into account correlation with non-CO2 warming and TCRE
Authors: Partanen Antti-Ilari , Liu Jia , Smith Christopher J. , Korhonen Hannele
Published: March 2020

The discovery of a nearly linear relationship between cumulative CO2 emissions and global mean surface temperature increase has given rise to intensive scientific research to assess the maximum allowable CO2 emissions compatible with some temperature threshold such as the goals of the Paris Agreement. The recent IPCC Special Report on Global warming of 1.5 °C (SR15) used a novel method to calculate remaining carbon budget for the 1.5 °C warming. The first step was to estimate non-CO2 warming contribution based on a perturbed parameter ensemble of two simple models to get the allowable CO2-caused warming. The second step was to use a probability density distribution for Transient Climate Response to cumulative CO2 emissions (TCRE) to calculate the carbon budget from the CO2-caused warming. One shortcoming of this method is that it ignores potential correlation between non-CO2 warming contribution and TCRE. A significant part of the non-CO2 warming comes from decreasing aerosol forcing, and the present-day aerosol forcing linked with TCRE.

Here, we revisit the carbon budgets presented in SR15 by taking correlation into account. We analysed the FaIR model simulations used in SR15 individually and found a linear relationship between TCRE and non-CO2 warming for a given temperature increase. After a slight rescaling to get the revised carbon budget (for 0.5 °C additional warming)  match with SR15 budget (600 Gt CO2) for the 50th-percentile TCRE value of 0.45 K/1000 Gt CO2, the 33th-67th percentile revised range was 380-960 Gt CO2, whereas SR15 gave narrower range of 440-850 Gt CO2. The wider range was expected as high TCRE is likely associated with high present-day aerosol forcing and hence with high non-CO2 contribution in future warming when aerosol forcing is decreasing. We analysed only results of FaIR model, and final SR15 numbers are an average of results based on FaIR and MAGICC. Therefore, this analysis should be repeated also for the MAGICC runs. As a conclusion, our results show that TCRE and non-CO2 warming contribution should not be considered independent variables when assessing remaining carbon budgets.
C3S: current status and future plans
Authors: Buontempo Carlo
Published: March 2020

This years marks the end of the first delegation agreement between the Eurpean Commission and ECMWF for the implementation of the Copernicus Climate Change Service. In the last five years the service was first established, then opened the Climate Data Store and finally became operational attracting the attention of over 30.000 users from all over the world who access tens of global dataset and dowload data at a rate of 50 TB/day to develop climate services.

The paper presents the current status of the implementation of the programme and illustrate some of the options -including changes in the portfolio of the programme- that are currently being considered for the evolution of the service in the future.
Chinese emissions reductions deliver reduced PM2.5-caused mortality across China during 2015-2017
Authors: Silver Ben , Conibear Luke , Reddington Carly , Knote Christophe , Arnold Steve , Spracklen Dominick
Published: March 2020

Air pollution is a serious environmental issue and leading contributor to the disease burden in China. Following severe air pollution episodes during the 2012-2013 winter, the Chinese government has prioritised efforts to reduce PM2.5 emissions, and established a national monitoring network to record air quality trends. Rapid reductions in fine particulate matter (PM2.5) concentrations and increased ozone concentrations have occurred across China, during 2015 to 2017. We used measurements of particulate matter with a diameter < 2.5 µm (PM2.5) and Ozone (O3) from >1000 stations across China combined with similar datasets from Hong Kong and Taiwan to calculate trends in PM2.5, Nitrogen Dioxide, Sulphur Dioxide and O3 across the greater China region during 2015-2019. We then use the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) regional air quality simulations, to explore the drivers and impacts of observed trends. Using annually varying emissions from the Multi-resolution Emission Inventory for China, we simulate air quality across China during 2015-2017, and calculate a median PM2.5 trends of -3.9 µg m-3 year-1. The measured nationwide median PM2.5 trend of -3.4 µg m-3 year-. With anthropogenic emissions fixed at 2015-levels, the simulated trend was much weaker (-0.6 µg m-3 year-1), demonstrating interannual variability in meteorology played a minor role in the observed PM2.5 trend. The model simulated increased ozone concentrations in line with the measurements, but underestimated the magnitude of the observed absolute trend by a factor of 2. We combined simulated trends in PM2.5 concentrations with an exposure-response function to estimate that reductions in PM2.5 concentrations over this period have reduced PM2.5-attribrutable premature morality across China by 150 000 deaths year-1.
Biogeochemical effects of land cover and land management
Authors: Guo Suqi , Pongratz Julia , Havermann Felix , Alessandri Andrea , Coumou Dim , Davin Edouard L , Hertog Steven De , Lejeune Quentin , Manola Iris , Menke Inga , Schleussner Carl , Seneviratne Sonia I , Thiery Wim
Published: March 2020

Land cover and land management (LCLM) changes are important sources of anthropogenic CO2 emissions, constituting about 10% of current annual CO2 emissions, or about one third of cumulative emissions over the industrial era. However, simulations with Earth system models (ESMs) show a large range of CO2 emissions from LCLM. Several reasons for the divergence in estimates have been identified, in particular differences in simulated biomass and soil carbon stocks, and if and which land management practices are included in models. The divergence of model estimates is particularly worrisome since LCLM practices are discussed as key mitigation tools or “negative emission technologies” to reach the temperature goals of Paris Agreement. In the LAMACLIMA project (land management for climate mitigation and adaptation) we therefore conduct a detailed analysis of several LCLM practices across three ESMs to improve our understanding about model uncertainties. The present study aims to quantify the effects of forest cover changes and wood harvesting on the global carbon cycle, globally important LCLM practices with relevance also for physical climate and economic production.

We conduct idealized global experiments of deforestation, afforestation and wood harvesting over a 150-year simulation period under present climate. All forcings (solar, trace gases, aerosols) are held constant at present-day levels to isolate the climatic effects from different LCLM scenarios on the carbon cycle. All experiments are conducted by three different Earth system models (MPI-ESM, EC-EARTH and CESM) to quantify inter-model uncertainty and potentially uncover specific model biases. The analysis focuses on the transient response of carbon fluxes after the LCLM practice is in order to unravel model differences concerning temporal dynamics of LCLM effects and to show how quickly signals emerge that could potentially mitigate climate change.

With this research, we will provide a deeper understanding about simulated LCLM effects on the carbon cycle and also report model uncertainties. Together with parallel efforts to quantify biogeophysical effects of LCLM, our study will also lead to assess the overall potential of LCLM as a means for land-based climate mitigation.
Machine-learning emulation of a forest biogeochemistry model for efficient biosphere optimization
Authors: Strigul Nikolay , Erickson Adam
Published: March 2020

Management controls the spatial configuration of a number of landscapes globally, from forests to rangelands. The majority of landcover change and all land-use change is the result of human decision-making. As human populations and global temperatures continue to increase, an engineering approach is needed to ensure the persistence of biological diversity and natural capital critical to human well-being. Such an approach may be based on manipulating ecosystems to achieve desired future states, informed by the latest simulation models. Models of the land surface are now being used to inform policy in the form of planning and management practices. This often involves the application of models that include spatial dynamics and operate at a landscape scale. The strong correspondence between the resolution and extent of modeling and management activities at this scale, and ability to efficiently simulate the decadal-to-centennial time-scales of interest, provide managers with a credible scientific tool for anticipating future land states under different scenarios. The importance of such tools to managers has grown dramatically with the challenges posed by anthropogenic climate change. As ecosystem simulation models continually improve in precision, accuracy, and robustness, we posit that models may be mathematically optimized as a basis for optimizing the management of real-world systems. Since current ecosystem simulation models are coarse approximations of highly complex and dynamic real-world systems, such optimizations should ideally account for uncertainty and physical or biochemical constraints, thereby improving the tractability of the optimization problem. In this work, we demonstrate the emulation and optimization of a forest biogeochemistry model from the SORTIE-PPA family of models. In doing so, we provide the first demonstration of the concept of biosphere optimization (Erickson 2015), which may one day be extended to include computational genetic manipulation experiments. To perform this work, we utilize the open-source Earth-systems Research and Development Environment (ERDE) library, which contains built-in functions for performing these and other analyses with land models, with a particular focus on forests.
Effect of metal speciation on the oxidative potential and cytotoxicity of airborne particles
Authors: DAronco Sara , Giorio Chiara , Chiara Federica , Seraglia Roberta , Di Marco Valerio , Tapparo Andrea
Published: March 2020

Aerosol particle components can mix and interact with oxidants and organic compounds present in the atmosphere. How these chemical components interact and how the interactions affect the Earth’s climate, particle toxicity and human health is largely unknown. In the case of trace metals, the main focus so far has been the determination of the total amount while much less attention has been directed towards the metal speciation. Aqueous phase processing of aerosol can lead to substantial modifications of aerosol chemical and physical properties [1] by promoting the formation of metal-organic ligand complexes in atmospheric aqueous phases, like fog/cloud droplets and deliquescent aerosol. Such process can increase the solubility of metals, therefore their bioavailability [2], and affect their capability to generate reactive oxygen species.

We investigated the formation of metal-organic ligand complexes, especially those involving small dicarboxylic acids, in urban aerosol collected in the city centre of Padua (Italy), in the Po Valley. We assessed the effects of metal-ligand complexes formation on the solubility and solubilisation kinetic of metals from the particles to aqueous solutions simulating fog/cloud water. We found that solubilisation kinetics of many metals depended on the chemical form in which they were present in the aerosol and they were influenced by the environmental conditions during the campaign. Changes in oxidative potential (OP) and cytotoxicity of particles due to the formation of metal-ligand complexes were investigated by performing acellular and cellular in vitro tests, respectively. Preliminary results showed that metals and their complexed forms are both characterized by different OP and cellular toxicity.

 

References

[1] Decesari, S., Sowlat, M. H., Hasheminassab, S., Sandrini, S., Gilardoni, S., Facchini, M. C., Fuzzi, S., and Sioutas, C. Atmos. Chem. Phys., 17, 7721‑7731 (2017).

[2] Okochi, H., and Brimblecombe, P. Sci. World J., 2, 767–786(2002).
Independent a priori information for reduced intercomparison errors between TROPOMI and TCCON retrievals of methane and carbon monoxide
Authors: Lutzmann Johannes , Sussmann Ralf , Chen Huilin , Hase Frank , Kivi Rigel , Strong Kimberly , Tsurata Aki , Warneke Thorsten
Published: March 2020

Ground-based column measurements of trace gases by FTIR spectrometers within the Total Carbon Column Observing Network (TCCON) provide accurate ground reference for the validation of the nadir-viewing hyperspectral Tropospheric Monitoring Instrument (TROPOMI) on-board the ESA satellite Sentinel 5 Precursor (S-5P). In such intercomparisons of two independent remote soundings, errors can occur as the a priori profiles used in the respective retrievals are i) differing from each other, and ii) both different from the true atmospheric state at the moment of observation. In certain conditions of atmospheric dynamics, e.g. polar vortex subsidence or stratospheric intrusions, which strongly alter the shape of vertical concentration profiles, these intercomparison errors can become considerable (Ostler et al., 2014).

In our work funded by the German Space Agency DLR and performed as part of the ESA AO project TCCON4S5P, we search for potential sources of realistic common a priori profiles for S-5P and TCCON CH4 and CO measurements which reduce these large errors. We examine the performance of a number of chemical transport models and data assimilation systems in reproducing dynamical effects and in minimizing intercomparison errors. In-situ profiles measured by AirCores are used as validation where they are available. We present the status and results of our ongoing work.

Reference:

Ostler, A., Sussmann, R., Rettinger, M., Deutscher, N. M., Dohe, S., Hase, F., Jones, N., Palm, M., and Sinnhuber, B.-M.: Multistation intercomparison of column-averaged methane from NDACC and TCCON: impact of dynamical variability, Atmos. Meas. Tech., 7, 4081–4101, doi:10.5194/amt-7-4081-2014, 2014. Ostler, A., Sussmann, R., Rettinger, M., Deutscher, N. M., Dohe, S., Hase, F., Jones, N., Palm, M., and Sinnhuber, B.-M.: Multistation intercomparison of column-averaged methane from NDACC and TCCON: impact of dynamical variability, Atmos. Meas. Tech., 7, 4081–4101, doi:10.5194/amt-7-4081-2014, 2014.
Investigating hydrological and biogeochemical controls on Irish alkaline fen habitats
Authors: Bijkerk Elisabeth , Bhatnagar Saheba , Coxon Catherine , Johnston Paul , Regan Shane , Waldren Stephen , Gill Laurence
Published: March 2020

Alkaline fens are listed under Annex 1 of the European Union (EU) Habitats Directive (Council Directive 92/43/EEC, habitat code 7230) as habitats requiring special conservation measures, including the designation of suitable sites as Special Areas of Conservation (SACs). These fens are peat-forming wetlands predominantly fed by groundwater containing significant concentrations of calcium, magnesium and bicarbonate. The hydrogeological dynamics and hydrochemical signature supports small sedge and brown moss communities in a mosaic of different habitats. Despite fens being an important part of the natural landscape in Ireland as well as one of the most threatened wetland habitats in Europe, there is little information on the hydrology and hydrochemistry that support these habitats. As part of a three year research project (Ecometrics) on GWDTE’s (Groundwater Dependent Terrestrial Ecosystems) an intensive hydrochemical monitoring programme was established on four Irish fen sites, designated as SACs, covering an eco-hydrological gradient from intact to highly degraded conditions. Ground and surface waters monitoring started in July 2018 with spot measurements supplemented by a continuous water table time series collected every two months. Simultaneously ground and surface water samples were taken and analysed for nutrients, mayor ions and metals. Topographical surveys as well as vegetation surveys were carried out in 2019. The hydrological and hydro-chemical evidence from each fen were then collated to build conceptual eco-hydrological models to represent both temporal and spatial variability in each geological setting. In addition, remote sensing was used in order to investigate the relationship between vegetation and water levels. Utilising ground surveyed habitat map and Sentinel-2 (S2) imagery in a Random Forest model a remotely sensed vegetation map was created. This information was then correlated with water level data as follows: hydrological data were interpolated over the entire area of the fen, giving seasonal information for both surface and groundwater levels. Using K-means clustering, the data were divided into clusters which were then matched and correlated with the vegetation map produced through S2 imagery. The strength of the correlation between water level and fen vegetation can further aid the construction of conceptual models for the four research sites. These models will then be used to define appropriate metrics that characterise the environmental supporting conditions in fens, as required for the EU Water Framework Directive. Here, the preliminary conceptual models for fen functioning will be presented as they are continuously updated by the ongoing data collection.
Does acclimation of plant traits improve dynamic vegetation modelling of a tree species?
Authors: François Louis , Hambuckers Alain , Henrot Alexandra-Jane , Trolliet Franck , Pitance Jean-Luc , Cheddadi Rachid , Dury Marie
Published: March 2020

Dynamic vegetation modelling is intensively used with plant functional types which limits the range of interest of obtained outputs for other fields of knowledge like conservation science. An alternative approach is to simulate plant species. This however requires additional data, i.e. morphological and physiological traits values characterizing the species and determining their functional properties. However, not only many traits vary among the species belonging to the same plant functional type but also the traits vary broadly according to climate factors.

Since most of the traits are functional, their values may be critical for dynamic vegetation model outputs. We measured several traits (specific leaf area, leaf and sapwood C:N) of Cedrus atlantica in its native range, the Rif and Middle Atlas Mountains of Morocco, as well as in some plantations in western Europe. Trait values exhibit significant variations between the sampled sites. It is possible to predict these trait values using multiple regression with climate factors as explanatory variables. Using regression equations, we produced spatial- and time-varying traits over the study area. We implemented these equations in the CARAIB dynamic vegetation model and tested whether they improve the simulation of C. atlantica in the Rif and Middle Atlas Mountains, by comparing the net primary productivities and biomasses computed with and without trait variation, with those retrieved from measurements on the sampled sites. We then performed simulations of the future using climate projections of the regional climate model RCA4 nested in HadGEM2 general circulation model under the RCP8.5 scenario, in order to test the influence of trait acclimation on the predicted future changes in the range and productivity of the species.
Automatic hydrograph separation approach provides possibility to look at less-studied characteristics of water regime
Authors: Rets Ekaterina , Kireeva Maria , Samsonov Timophey
Published: March 2020

The study presents an approach to automatic river hydrograph separation and analysis implemented in GrWat open source package for R programming language. In the proposed scheme of hydrograph separation, river hydrograph is separated into base and quick flow. For plain rivers quick flow is further separated into seasonal snowmelt flood quick flow; rain quick flow and thaw quick flow. For mountainous rivers seasonal snowmelt flood quick flow component is divided into “basic snowmelt flood” component and overlapping rain floods. Base and quick runoff is separated by a critical gradient. Flash-floods are separated from the seasonal snowmelt wave by critical values of air temperature and precipitation on the event for the plain rivers and using a critical gradient concept for mountainous rivers. More than 30 characteristics of river runoff regime are calculated for each water resource year: characteristics of annual and seasonal runoff, contribution of each genetic component, characteristics of maximum runoff, n-day minimum discharges and dates when they are observed. Additionally, more than 50 characteristics of each flash-flood are calculated:  characteristics of shape, volume, timing of flash-floods, the values of meteorological parameters that bring about different types of floods. The presented approach to automatic river hydrograph separation and analysis was tested on 45 plain rivers in the European part of Russia in different climatic zones and on 10 mountainous rivers in the North Caucasus. The result of application provides a possibility for analyzing previously unstudied characteristics of river runoff regime and its climate-related transformation on the European part of Russia.

The study was supported by the Russian Science Foundation grant No. 19-77-10032
Contributing to world's largest encylopedia: my experiences as a Wikipedia science communicator
Authors: Nijsse Femke J. M. M.
Published: March 2020

Every month, millions of people read about climate change on Wikipedia. However, the information is often outdated and written by non-experts with strong opinions, such as climate activists and climate contrarians. Based on my six years of experience of writing on Wikipedia, I’ve come to the conclusion Wikipedia that is an undervalued piece of the science communication landscape.

Wikipedia as a medium enjoys high levels of trust compared to traditional news media, at least in the UK. It is built by a game of consensus building and negotiation between people with differing views. I will distill the experiences I have had on effective collaboration with non-experts who expose complexity in my explanations, dealing with those in denial of climate change and more recent examples of the presence of climate activism.

For me editing has also been useful for my research, and I believe the same will be true for other experts,. As writing for Wikipedia is very similar to carrying out a literature review, it is especially worthwhile for early career scientists or others venturing into new topic. It has often helped me to better put my own research into context. Rewording scientific literature for a broad public allows for a better appreciation of the material as well. A further validation can be obtained by submitting your Wikipedia article as a scientific paper to various WikiJournals.
Validation of ESA Aeolus wind observations using French ground-based Rayleigh Doppler lidars at midlatitude and tropical sites
Authors: Hauchecorne Alain , Khaykin Sergey , Wing Robin , Mariscal Jean-François , Porteneuve Jacques , Cammas Jean-Pierre , Marquestaut Nicolas , Payen Guillaume , Duflot Valentin
Published: March 2020

French ground-based Rayleigh Doppler lidars deployed at Observatoire de Haute Provence (OHP) in southern France (44° N, 6° E) and Observatoire du Maido (La Reunion island, tropical Indian Ocean, 21° S, 55° E) are among the primary instruments within ESA Aeolus Cal/Val programme.  The ground-based lidars are designed to measure vertical profiles of wind velocity in the altitude range 5 - 70 km with an accuracy better than 1 m/s up to 30 km. The horizontal wind components are obtained by measuring Doppler shift between emitted and backscattered light by means of double-edge Fabry-Perot interferometer. This technique, pioneered by French Service d’Aeronomie in 1989, is implemented in Aeolus ALADIN instrument.

We present the results of validation of Aeolus L2B horizontal line-of-sight wind profiles using the French Doppler lidars and regular radiosoundings. The point-by-point validation exercise relies on the dedicated validation campaigns at OHP in January and Maido in September-October 2019 involving simultaneous lidar acquisitions and collocated radiosonde ascents coincident with the nearest Aeolus overpasses. For evaluation of the long-term variation of the bias in Aeolus wind product, we use twice-daily routine radiosoundings performed by MeteoFrance and regular wind lidar observations at both sites.

The orbital configuration of Aeolus satellite enables 2 overpasses per week above OHP within 100 km range and 2 overpasses in the vicinity of Maido observatory, of which one being within 10 km range. Evaluation of Aeolus wind profiles is done in consideration of the expected mesoscale variability of wind field inferred from numerous lidar-radiosonde intercomparisons at both stations. In addition to the quantitative validation of Aeolus wind profiles, we attempt to evaluate the capacity of Aeolus observations in resolving fluctuations of stratospheric wind field induced by atmospheric gravity waves.
Climate Change and its impact on Poaceae and Fagaceae pollen season in Northern Sardinia, Italy
Authors: Canu Annalisa , Vargiu Arnoldo , Pellizzaro Grazia
Published: March 2020

Airborne pollen data are an important source of information on flowering phenology, because they record the response of plants surrounding the sampling station, rather than the responses of individual plants, as with direct phenological observation. Plant phenology represents a good indicator of vegetation responses to long-term variation to temperatures. Furthermore, several studies have evidenced that aerobiological data series and pollen season are often strongly correlated to climate change.

This research aims to analyze airborne pollen data of Poaceae and Fagaceae measured from 1986 to 2008 in a urban area of northern Sardinia (Italy) and to investigate the trends in these data and their relationship with meteorological parameters using time series analysis. The aerobiological monitoring station was located in the center of the city very close to a public garden, and it is part of both the Italian and the European - A.I.A. Aeroallergen monitoring Network. Meteorological data were recorded during the same period by an automatic weather station.

The following parameters were calculated for each pollen: start, end and duration of pollen season, date of peak pollen concentration, number of days from the beginning of the season to the peak, annual pollen index (API), percentage distribution of API and maximum daily concentration.

The correlation between meteorological variables and the different characteristics of pollen seasons was analyzed using Spearman’s correlation tests.

A linear regression model was used for the trend analysis of the API of airborne pollen spread of the two family from 1986 to 2008.
Evaporite controls on basin-inversion structures in the southern Danish Central Graben, North Sea – a 3D seismic-data study
Authors: Hundebøl Hansen Torsten , Rønø Clausen Ole
Published: March 2020

During Cretaceous and Paleogene times, tectonic shortening caused mild basin inversion of earlier rifting depocentres in the Danish Central Graben. This exerted an important control on the thickness variations and geometries of e.g. the Late-Cretaceous and Danian Chalk Group. Structural highs formed by inversion and especially Permian-salt movements, host important hydrocarbon reservoirs in the sector. Earlier researchers have linked basin inversion in the North-Sea area to Alpine deformational phases and the onset of seafloor spreading in the North Atlantic.

The objective of this 3D seismic-data study is an analysis of the relationships between basement (sub-salt) faults, salt movements, and salt-cover deformation, as well as fluid migration near and within inversion structures.

We find that the northeastern margin of the larger inverted area generally has a thick-skinned style. Here, reverse reactivation of the rift-bounding master fault is coupled between the strata above and below the salt. Oppositely, the southwestern margin has a thin-skinned style. Here, buttressed hangingwall folds sit above reverse faults detaching into even thin evaporite sequences. The strike of this cover-fault trend mimics that of the underlying basement faults, although they dip in opposite directions. A triangle-zone model explains how sub-salt shortening (reactivation of major basement faults) can be balanced to the shortening observed in the sedimentary cover. As the current thickness of Permian salt increases and mobile-salt structures become predominant towards the south, the effects of basin inversion grow difficult to distinguish from those of halokinesis.

Interestingly, the shallow crests of inversion folds, especially along the southwestern margin, host groups of smaller normal faults. These formed to some degree during inversion, indicating that local extensional tectonism (crestal collapse) took place during the overall shortening. We conclude that the shallow parts of the folds experienced forced bending rather than buckling during folding.

A significant number of hydrocarbon reservoirs sit within basin-inversion structures. Potentially, this work can increase our understanding of deformation within these and similar structures.

Acknowledgements: We thank the Centre for Oil and Gas – DTU (DHRTC) for funding and supporting this project and for providing data. We also thank Schlumberger and Eliis for providing seismic-interpretation software.