bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation of Biogenic Aerosols in the Boreal Region and their Climatic Impact
Authors: Mielonen Tero , Tonttila Juha , Romakkaniemi Sami , Kühn Thomas , Kokkola Harri
Published: March 2022

Biogenic secondary organic aerosol (BSOA) constitutes a major fraction of aerosol over boreal forests. As the emissions of BSOA precursors are temperature dependent, changes in temperature are likely to have substantial implications on regional aerosol radiative forcing. In this work, we have used a century long aerosol-climate model simulation to investigate the effect of increasing temperature on organic aerosol mass loadings, and further on aerosol-cloud interaction. The analysis was based on a nudged simulation done with ECHAM6-SALSA covering the period from 1905 to 2010. We limited the analysis to summer months to isolate the temperature dependence of biogenic emissions from the seasonal cycle of vegetation growth. We concentrated on three regions in Russia and three in Canada to analyze the spatial variability of the climatic impacts of BSOA. Our analysis showed that BSOA loadings increased with surface temperature and higher BSOA loads were connected to higher cloud condensation nuclei concentrations in all the regions. However, the relationship between BSOA and cloud optical thickness or cloud droplet size was not that clear in all the regions. These regional differences highlight the need to have accurate aerosol and cloud observations from various locations in the boreal region in order to estimate the climatic significance of biogenic aerosols.
A global assessment of spatiotemporal uncertainties in Land Cover – a key indicator for monitoring sustainable development
Authors: barrasso caterina , remelgado ruben , meyer carsten
Published: March 2022

Land cover (LC) is an important indicator to reach several of the targets under the Global Goals. Accurate global LC time-series are thus vital to monitor sustainable development. Although the number and quality of open-access, remotely sensed LC products is increasing, all products have uncertainties due to widespread classification errors. However, the relative magnitude of uncertainties among exiting LC products is largely unknown, which hampers their confident selection and robust use for sustainable development evaluation and planning. To close this gap, we quantified region-, time-period-, and coarse-LC class-specific data uncertainties for the 10 most widely used global LC time-series. To this end, we developed a novel multi-scale validation framework that accounts for differences in mapping resolutions and scale mismatches between the spatial extent of map grid cells and validation samples. We aimed for a fair validation assessment by carefully evaluating the quality of our validation samples with respect to landscape heterogeneity that LC products often fail to classify accurately. To address the issue, we supported the validation assessment with Landsat-based measures of cross-scale spectra similarity. The metric was computed by taking advantage of the full Landsat archive in Google Earth Engine. We base our assessment on more than 1.8 million globally integrated LC validation sites, where we mobilized around 2.8 million samples during the period 1980-2020 composed by hundreds of sampling effort of varied nature, from field surveys to crowdsourcing campaigns. Here, we will present the results of the assessment, providing insights on global and regional patterns of LC uncertainties. We found that no single product is more accurate over the others in mapping all LC classes, regions and time-periods. We will provide recommendations on the selection of fit-for-purpose LC time-series, and discuss future strategies for addressing their uncertainties in sustainable development evaluation and planning.
Probabilistic forecasting and scenario generation of pumped discharge in polder systems
Authors: van der Heijden Ties , van de Giesen Nick , Palensky Peter , Abraham Edo
Published: March 2022

The Netherlands is a low-lying country in the Rhine-Meuse delta. Because a large part of the Netherlands is situated below sea level, proper management of local and national waterways is a necessity. Polders are used to manage groundwater levels, drain excess rainwater and store water for droughts. Typically, pumping stations in local Dutch polders pump water up to a drainage canal (in Dutch: ‘boezem’).

The Noordzeekanaal—Amsterdam-Rijnkanaal (NZK-ARK) is one such drainage canal, receiving discharge from the Rhine and four local water authorities. The canal connects with the North Sea in IJmuiden, through a pumping station and a set of undershot gates. The combination of pump and gate discharge allow the canal to discharge excess water to the North Sea when the sea water level is both higher and lower than the water level in the canal.

Pump and gate discharge is scheduled through Model Predictive Control (MPC), where reliable forecasts are necessary to reliably schedule discharge. The objectives for the control system of the gates and pumps are likely to become more complex in the future. For example, the availability of renewable energy, or electricity prices are to be taken into account when scheduling pump discharge. Research has shown that regular MPC can lead to suboptimal schedules when uncertainty is introduced, for example leading to high energy costs. Stochastic MPC allows for the consideration of uncertainty in decision making, optimising control actions over a set of possible scenario’s.

One way of generating these scenarios is by using a probabilistic forecasts. A Quantile Regression Deep Neural Network (QR-DNN) can be used to forecast quantiles of a forecast variable. When enough quantiles are considered, a Cumulative Distribution Function (CDF) can be constructed. A Bayesian Network (BN) is a graph-structured network that can estimate multi-dimensional Probability Density Functions by conditionalizing random variables according to a user defined structure and observed data. The BN can be applied to sample from the marginal CDF’s generated by the QR-DNN, while respecting autocorrelation or considering exogenous variables that are not yet considered by the QR-DNN.

In this research, we apply probabilistic forecasting methods to generate pump discharge scenarios that can be used in a stochastic MPC for the NZK-ARK. We use actual data from the four local water authorities discharging into the NZK-ARK, and apply a QR-DNN to generate marginal CDF’s of the expected pump discharge into the NZK-ARK. A BN is then applied to generate scenarios by conditionalizing the marginal CDF’s and take multidimensional samples with autocorrelation.
Land-use change impacts on ecosystem services: an overview
Authors: Pereira Paulo , Inacio Miguel , Kalinauskas Marius , Bogdzevič Katažyna , Bogunovic Igor , Zhao Wenwu
Published: March 2022

Land-use changes are one of the most critical drivers of change. Territorial dynamics such as urbanization, agriculture intensification and land abandonment have important implications for ecosystems and the services supplied. This work aims to overview the impacts of land-use changes on ecosystem services supply (ES). Urbanization and agriculture intensification have detrimental impacts in all regulating ES (e.g., air quality, microclimate regulation, flood regulation, carbon storage). On the other hand, the afforestation process positively impacts all the ES abovementioned. Urbanization and land consumption reduce agriculture and natural areas, key for food supply. Therefore, provisioning ES (e.g., food, fodder, water, timber) are drastically affected. Agriculture intensification may short term positive impacts on food production. However, it occurs at the expense of high soil degradation, reducing the ecosystem capacity to supply wild food, water, fodder and medicinal plants. The land abandonment process implies a decrease in the cultivable area. Therefore, it reduces the capacity of food production. Also, water supply is reduced since the afforestation process increases water consumption and evapotranspiration. However, other benefits for provisioning ES occur from soil degradation, such as increasing wild food, medicinal plants, and timber. Finally, urbanization negatively impacts most cultural ES (e.g., natural heritage, cultural heritage, landscape aesthetics). Some benefits can be positive for recreation or knowledge systems. Except for knowledge systems, agriculture intensification negatively impacts all cultural ES (e.g., recreation, natural heritage, cultural heritage, landscape aesthetics). Land abandonment has detrimental impacts on cultural heritage (e.g., loss of traditional landscapes). However, it positively impacts all other cultural ES (e.g., recreation, landscape aesthetics, knowledge systems).

Keywords: Land use, ecosystem services, afforestation, soil degradation     

Acknowledgements

This work is supported by the project A09.3.3-LMT-K-712-01-0104 Lithuanian National Ecosystem Services Assessment and Mapping (LINESAM) funded by the European Social Fund according to the activity “Improvement of researchers” qualification by implementing world-class R&D projects.
The representation of the summer Southern African rainfall and its relationship with the Angolan Low and ENSO in the CORDEX models
Authors: Abba-Omar Sabina , Raffaele Francesca , Coppola Erika , Jacob Daniela , Teichmann Claas , Remedio Armelle
Published: March 2022

Models tend to show strong rainfall biases over Southern Africa, especially during the Summer (DJF) months. This study aims to explore and understand why these biases occur. The Angolan Low (AL) and ENSO are two important sources of Summer rainfall variability. Thus, the study explores whether the relationship between the AL, ENSO and rainfall is represented correctly in three different ensembles; the CORDEX-CORE ensemble (CCORE, 0.22 degrees resolution), the lower resolution (0.44 degrees) CORDEX-phase 1 ensemble (C44) and the driving CMIP5 models. From regression analysis and a self organizing map the results show that wetter (drier) than normal DJF seasons usually occur during a strong (weak) AL and a La Nina (El Nino) event. While the models show this to an extent, they also show some differences in these relationships compared to the observed. The study examines some key dynamical features to understand why these differences occur. These results can further the understanding and improvement of the simulated Southern African rainfall in models. 
Latest developments in research on mineral reactions: Accessibility of results and progress versus convenience
Authors: Lüttge Andreas
Published: March 2022

How do we connect the results generated at the molecular scale with meso- and large scale processes?  Or, in other words how do we make frontier research results accessible for the multitude of applications that our daily work demands?

During the last couple of decades the combined effort of field and experimental studies, sophisticated analytical methods and computational models has generated fast and important progress in our fundamental understanding of mineral reactions. Here, we will briefly present and highlight some of these exciting results. Results that are highly appreciated in light of the ever increasing number of applications that demand a better in-depth and quantitative understanding of mineral reactions and their often critical role in large scale processes such as the prediction of long-term behavior of geo-reservoir rocks, ocean acidification, hazardous (nuclear) waste safety, and – of course – global climate change.

Surprisingly enough, our main challenge is often to make the cutting-edge achievements of mineralogical and (geo)chemical research accessible to a broad audience in sedimentology, geochemistry, and geobiology. To highlight just one example, we recognize that crystal dissolution, corrosion and weathering rates are not correctly described by a rate constant but by a multitude of rates, a rate spectrum. However, this insight is difficult to implement in reactive-transport models and is met with significant skepticism.

We will have to focus on new strategies that will not only provide better (and easier) accessibility of cutting-edge research results but address also the even greater challenge of up-scaling our results, i.e., how do we utilize the fast increasing results at the molecular scale with the meso- and large scale problems. It looks like that we need the interfaces that connect the results both in length scale as well as in time. 
Surface faulting and liquefaction hazard assessment in the central Apennines for land use practices: a case study from the L’Aquila urban area (central Italy)
Authors: Spadi Marco , Maceroni Deborah , Dixit Dominus Girolamo , Tallini Marco , Falcucci Emanuela , Galadini Fabrizio , Gori Stefano , Moro Marco , Saroli Michele
Published: March 2022

The Seismic Microzonation, as practiced in Italy, consists in defining microzones of the territory affected by homogeneous response to seismic ground shaking, defined as stable zones, vulnerable seismic amplification zones, and unstable zones. In detail, the unstable zones are affected by landslides, soil liquefaction, ground subsidence and surface faulting. In this framework, we conducted a study in the administrative district of L’Aquila (central Italy) aimed at the construction of a new school building, in an area indicated as prone to surface faulting (an active and capable fault was hypothesised in the area) and liquefaction.

We dug two trenches (named as A and B) perpendicular to the presumed active fault trace. The excavation walls exposed several different continental units mainly characterized by colluvial, organic-rich and “cultural” sediments, as well as paleosols. In trench A, some units, made of sandy-gravelly colluvial deposits, contained abundant pottery fragments, being intensely reworked by very recent human activity. These units were mainly composed of silt and sand sparse with carbonate clasts and directly overlying Middle Pleistocene alluvial deposits. Trench B only exposed units containing pottery fragments and hence pertaining to historical times. Several radiocarbon dating made on charcoal found within these units confirmed the recent age of the deposits, spanning from 25000 to 1800 years before the present. The analysis of the trench walls, the analysis of two boreholes, and field geological investigations revealed the absence of any surface faulting events affecting the stratigraphic sequence of the area, at least since the Middle Pleistocene, likely since the Early Pleistocene. Furthermore, trench B exposed several sedimentary dikes reaching up close to the ground surface, crossing the historical colluvial units, as well as other deformation features typical of liquefaction phenomena. The radiocarbon age determination and the sedimentological characteristics of the units indicate that the most recent liquefaction event occurred after 180 A.D.

Ultimately, this work represents a “best-practice” case study to investigate the occurrence of geological surface criticalities (such as surface faulting and liquefaction) at specific sites of interest.
Interannual-to-decadal variability of the Southern Ocean carbon uptake in a high-resolution ocean biogeochemistry model 
Authors: Patara Lavinia , Rieck Jan Klaus , Tanhua Toste , Ödalen Malin , Oschlies Andreas
Published: March 2022

Recent studies point to pronounced decadal variability in the Southern Ocean carbon sink over the past decades, but the mechanisms are still not fully understood. In this study, the regional patterns and bio-physical drivers of the interannual-to-decadal variability of the air-sea CO2 fluxes in the Antarctic Circumpolar Current (ACC) are investigated. A suite of global ocean biogeochemistry configurations (based on the NEMO-MOPS model) is used to perform hindcast experiments covering the period 1958-2018. The configurations include a non-eddying 0.5° model, an eddy-permitting 0.25° model, and a global 0.5° model featuring an eddy-rich 0.1° nest between 30°S and 68°S. The 0.25° model is also used to perform additional sensitivity experiments, where the variability of the wind stress or of the buoyancy forcing is suppressed on interannual time scales. All simulations show a positive trend in the air-sea CO2 fluxes over ACC, with a weaker rate of increase in the 1970s and in the 1990s, and a stronger rate of increase in the 1980s and 2000s. The interannual and decadal variability of air-sea CO2 fluxes is highest in frontal regions of the ACC, especially in the Southeast Pacific basin. Wind stress emerges as the dominant driver of the large interannual and decadal variability of air-sea CO2 fluxes at subpolar latitudes. On the other hand, air-sea buoyancy fluxes gain more relevance at middle latitudes. The simulations highlight the relevant role of explicitly simulating ocean mesoscale eddies for the Southern Ocean carbon uptake. Indeed, the 0.1º model shows a steeper trend of the Southern Ocean carbon uptake with respect to the lower-resolution models, driven to a large extent by a higher uptake of anthropogenic carbon.
Assessment of climate change impacts on precipitation and temperature over Subtropical Chile based on South America CORDEX-CORE regional simulations
Authors: Torrez Rodriguez Limbert , Goubanova Katerina
Published: March 2022

In this study, we analyze the projected changes in mean and extreme precipitation and temperature over subtropical Chile, based on simulations of 3 Regional Climate Models (RCMs) (RegCM4-7, REMO2015, and ETA) from South-America CORDEX-CORE, each one driven by three different CMIP5 GCMs. The RCM’s performance for the present climate is evaluated against the CR2MET (~5km) dataset.

The changes for the end (2070-2099) of the century for the RCP8.5 scenario are assessed with respect to the historical period (1976-2005). Extreme events are expressed in terms of 30-yrs return values, estimated from the GEV distribution fitted to seasonal extremes for extended austral winter and summer.

Accordingly, to GCMs projections, robust mean drying conditions are found among RCMs between 35ºS-40ºS in winter and 35ºS-45ºS in summer over the continental Chile and adjacent ocean. North of 30ºS REMO2015 and ETA show a statistically significant increase of mean winter precipitation over mountain regions. Another robust signal among the RCMs consists in an increase of extreme winter precipitation north of 35ºS over the mountain area. Increases in the maximum and minimum temperatures are significant over all domain for the 3 RCMs, but it is prominent to the north of 35°S (30°S) for REMO2015 and RegCM4-7 for winter (summer), especially over the mountain leeward, while ETA depicts the higher heating in the south of 30°S. The changes are mainly associated with a positive displacement of distribution (changes in location parameter) for temperatures and the amplification of interannual variability (positive changes in scale parameter) for precipitation. The physical processes responsible for these changes are discussed.
OSDYN: a new python tool for the analysis of high-volume ocean outputs.
Authors: Garnier Valerie , Le Roux Jean-Francois , Magin Justus , Odaka Tina , Garreau Pierre , Boutet Martial , Raynaud Stephane , Estournel Claude , Beuvier Jonathan
Published: March 2022

OSDYN (Observations and Simulations of the DYNamics) is a Python library that proposes diagnostics to explore the dynamics of the ocean and its interactions with the atmosphere and waves. Its main strengths are its genericity concerning the different types of netCDF files and its ability to handle large volumes of data.

Dedicated to large data sets such as in-situ, satellite, and numerical model observations, OSDYN is particularly powerful to manage different types of Arakawa-C grids and vertical coordinates (Nemo, Croco, Mars, Symphonie, WW3, MesoNH). Based on common Pangeo stack (xarray, dask, xgcm), OSDYN provides data readers that standardize the dimensions, coordinates, and variables names and properties of the datasets. Thus, all python diagnostics can be shared regardless of the model outputs.

Thanks to progress made using kerchunk and efforts on transforming metadata of Ifremer’s HPC center (auto-kerchunk), the reading of a large amount of netCDF files is fast and the selection of sub-domains or specific variables is almost immediate.

Jupyter notebooks will detail the implementation of three kinds of analyses. The first one focuses on climatologic issues. In order to compare modeled and satellite sea surface temperatures, the second one addresses spatial interpolation and comparison of data when some may be missing. Lastly, the third analysis provides an overview of how diagnostics describing the formation of deep water masses can be used from different data sets.
The effects of reduced Atlantic and Pacific land-sea thermal contrast on the extratropical circulation
Authors: Portal Alice , Pasquero Claudia , D'Andrea Fabio , Davini Paolo , Hamouda Mostafa , Rivière Gwendal
Published: March 2022

In the Northern-Hemisphere mid latitudes the winter land-sea thermal contrast is expected to decrease with increasing CO2 in the atmosphere, due to a faster warming of the continents with respect to the oceans. Moreover, the reduction of the winter thermal contrast is basin dependent, as it is influenced by regional warming patterns specific of the Atlantic and Pacific sectors, e.g. by the North-Atlantic Warming Hole.
In this work we run a set of idealised perpetual-winter numerical experiments made with the simplified atmospheric circulation model SPEEDY where the extratropical land-sea thermal contrast is reduced by means of warm temperature anomalies over the continents. The reduction of the thermal contrast is performed first over the whole Northern Hemisphere, then over individual basins - Atlantic and Pacific - by warming, in turn, the land temperature of East Asia and North America. The impact of the reduced winter contrast on the mid-latitude tropospheric circulation is analysed with a focus on stationary planetary waves, the jet streams and the associated storm tracks. From the individual-basin approach we find that the Pacific land-sea thermal contrast is particularly important for the shape and amplitude of the stationary planetary waves and that it affects the whole Northern-Hemisphere circulation, reaching the North Atlantic storm track and jet. The role of the stratospheric pathway in the tropospheric response to reduced thermal contrast is also investigated, and shows nearly opposite features with respect to reduced Atlantic or reduced Pacific thermal contrast.
Helium partitioning between mantle and the core at the early Earth
Authors: Ozgurel Ozge , Caracas Razvan
Published: March 2022

Noble gases are geochemical tracers, providing information about the formation of our planet and serving as a record of conditions in Earth history. Each noble gas has at least one stable non-radiogenic isotope, which is residue either of Big Bang or supernovas, and at least one stable radiogenic isotope, product of nuclear decay reactions from unstable heavier isotope of another element. The ratio of non-radiogenic and radiogenic isotopes of the noble gases arriving at the surface are essential to understand processes occurring on various timescale in the Earth interior.

The isotopic signature of the noble gases in the mid-ocean ridge basalts (MORBs) are different than in the ocean island basalts (OIB) such as in Iceland, Hawaii, Galapagos, Réunion, or Samoa. One such example is the high 3He/4He ratio observed in OIB, which are explained as a signature of the core, which in this case becomes a hidden geochemical reservoir. Here, we study the Helium partitioning between molten pyrolite and liquid iron, which represent proxies for the crystallizing magma ocean and the growing core, respectively. We employ molecular dynamics simulations based on the density functional theory as implemented in the VASP package. We perform the simulations at several temperatures and pressures that sample the magma ocean adiabat.

These calculations will allow to derive some trends on the preference of Helium on the silicate or iron melts. In the long term, they will confirm or inform the existence of a hidden reservoir deep inside the Earth, to position it in space, and to determine its formation in time.

We acknowledge support from the Research Council of Norway, project number 223272. RC acknowledges support from the European Research Council under EU Horizon 2020 research and innovation program (grant agreement 681818 – IMPACT) and access to supercomputing facilities via the eDARI gen6368 grants, the PRACE RA4947 grant, and the Uninet2 NN9697K grant.
Composition and accumulation conditions of the Belokatay Formation of the Lower Permian (Middle Urals)
Authors: Volodina Ekaterina , Tevelev Alexandr , Borisenko Alexandra , Koptev Egor
Published: March 2022

Introduction. Deposits of the Belokatay Formation were studied in four quarries in Belyanka region and Kirikeevo region (Belokataisky District, Bashkortostan). All of these careers are quite similar to each other. The Belokatay Formation is represented by polymictic conglomerates with rare layers of fine-medium-grained polymictic sandstones. The composition of the pebbles is extremely diverse - there are fragments of all types of rocks - sedimentary (70%), magmatic (20%), metamorphic (10%). Sedimentary rocks: pelitomorphic limestones, fragments of coral reefs and organogenic-detrital limestones. Igneous rocks - basaltoids and granitoids. Metamorphic rocks - shales, gneisses, quartzites. The roundness of all the pebbles is very good, there are no angular fragments. The size: more than 70% of fragments – 5-10 cm, which accords to a medium-grained conglomerate (although rare boulders, as well as smaller pebbles, are also sometimes found).

Materials and methods. We analyzed thinsections of matrix rocks and individual fragments in the amount of 60 pieces, identified foraminifera from pebbles of organogenic limestones, and also examined some samples for the presence of conodonts and other fauna.

Results and discussion. The diversity of the composition of the fragments, their consistent size and good roundness, as well as their high thickness (more than 700 meters) indicate that the formation accumulated in a very active hydrodynamic environment. In literary sources, faults are reported - but they were not found on our territory. On the other hand, in the conglomerates vertically layers of sandstones were found. Perhaps these are not layers, but olistoplaks from older formations. However, olistoplaks, as well as faults, only confirms a very active environment. The main source of material for this formation was the Ural Orogen located to the east of the trough. When the mountains were uplifting, fragments of rocks of different formations were demolished into this basin. And not only the rocks of the orogen could be eroded, but also the sediments, which filled the trough earlier (Late Carboniferous-Permian). The formation of sediments of the Ural foredeep has certain patterns: from the bottom up the section, there is an alternation of coarse-grained rocks (including the Belokatay Formation) and fine-rhythmic flysch strata. The formation of Ural foredeep occurs simultaneously with the collision. There are several stages in this process. The accumulation of the Belokaty Formation characterizes the beginning of one of the stages of collision, as the rocks change – from flysch to conglomerates.

Financial support. The research has been funded by RFBR and CNF as a part of the research project № 19-55-26009 Czechia_a
Morphological and paleoseismic evidence of surface faulting in the coastal Zagros, southwestern Iran
Authors: Fathian Aram , Nazari Hamid , Shokri Mohammad Ali , Talebian Morteza , Ghorashi Manouchehr , Reicherter Klaus
Published: March 2022

The Zagros Mountains accommodate intense seismicity due to the ongoing deformation; however, surface faulting has been rarely observed and/or documented. The earthquakes of Furg (November 6th, 1990) and Qir-Karzin (April 10th, 1972) are unique events in the Zagros associated with a surface rupture. We use tectonic geomorphology and paleoseismology to document a previously unknown outcropped fault within the Zagros. This ~ 20 km fault zone lies between the Khormuj and Khaki anticlines, where the Simply Folded Belt (SFB) of the Zagros is physiographically known as the coastal Zagros as well. The Khormuj anticline, located in the northeast of the city of Khormuj, was previously linked to the Main Front Fault (MFF) on the southern limb of the anticline. Further to the south, the oblique-slip Khormuj fault zone with a strike of N120°–N125° cut the Quaternary sediments and displaced the streams and ridges laterally and vertically. Opposite to the dip of the MFF, the Khormuj fault dip is inclined to the southwest—approximately 75°—where the southern block is uplifted and marks an obvious trace on the ground. We carried out a kinematic GPS survey along the deflected ridges to measure the horizontal and vertical components. Our observations indicate significant dextral strike-slip displacements compared to the dip-slip offset. We observed a sequence of fluvial risers in three different levels along the Khormuj fault. We additionally studied a paleoseismological trench perpendicular to the Khormuj fault scarp evidencing at least two paleoearthquakes. The OSL age of the bottom of the colluvium wedge correlated with the older event indicates the latest event is younger than 25±8 ka considering the fault cuts these deposits up to the ground surface.
Mitigation scenarios for methane and nitrous oxide emissions from Indian agriculture sector
Authors: Patange Omkar , Purohit Pallav , Klimont Zbigniew , Garg Amit , Avashia Vidhee
Published: March 2022

India is now the fourth largest emitter of greenhouse gases (GHG) in the world with one of the highest growth-rate of emissions. As a fast-growing major economy, its future emissions trajectory is important for the long-term global goal of restricting the temperature rise to “well below 2 ℃”, compared to pre-industrial levels. In India, emissions from methane (CH4) and nitrous oxide (N2O) account for about a quarter of all greenhouse gas emissions. The agriculture sector contributes to over 70% of these non-CO2 emissions through activities like rice cultivation, livestock rearing (enteric fermentation and manure management) and application of nitrogen fertilizers. On the other hand, the agriculture sector employs two-third of Indian work force. Around 86% farmers fall in the marginal and small (less than 2 hectares) land-holding category and collectively own about 45% of the total agricultural area and around 80% of total cattle. Considering the socio-economic context, reducing emissions from Indian agricultural sector would be a challenge. The subsistence farming, fragmented production and political economy constraints make it difficult to implement the technological and structural interventions to mitigate the non-CO2 emissions. If India is to achieve net-zero GHG emissions in the latter half of the century, mitigation strategies for the agriculture sector need to balance the climate and sustainable development goals.

In this research, we focus on methane and nitrous oxide emissions from the Indian agricultural activities. Our analysis uses the GAINS model which has been widely applied for assessing the mitigation strategies for non-CO2 emissions and multiple air pollutants at regional and global scales. We analyse four mitigation scenarios using different combinations of activities and control measures. For the reference and sustainable policy scenarios, we compare the current policies (often lacking any controls) versus maximum feasible reductions through technological and management control measures to inform the Indian and global climate policy debates. The preliminary results suggest that a combination of sustainable agricultural practices and control measures could reduce the CH4 and N2O emissions by about 30% by 2050 as compared to the reference scenario. This would also contribute to the reduction of ammonia emissions with considerable co-benefits for local air quality and health.
Evolution of the wintertime salt budget of the Arctic Ocean mixed layer observed during MOSAIC
Authors: Kanzow Torsten , Rabe Benjamin , Schaffer Janin , Kuznetsov Ivan , Hoppmann Mario , Tippenhauer Sandra , Li Tao , Mohrholz Volker , Janout Markus , von Albedyll Luisa , Stanton Timothy , Kaleschke Lars , Haas Christian , Schulz Kirstin , Lei Ruibo
Published: March 2022

In wintertime, the Arctic Ocean mixed layer (ML) regulates the transport of oceanic heat to the sea ice, and transfers both momentum and salt between the ice and the stratified ocean below. Between October, 2019, and May, 2020, we recorded time series of wintertime ML-relevant properties at unprecedented resolution during the MOSAIC expedition. Vertical and horizontal salt and temperature gradients, vertical profiles of horizontal velocity, turbulent dissipation of kinetic energy, growth of both level and lead ice, and ice deformation were obtained from both the Central Observatory and the Distributed Network around it.  

We find that the ML deepened from 20 m at the onset of the MOSAIC drift to 120 m at the end of the winter. The ML salinity showed a decrease between early November 2019 and mid-January 2020 followed by a pronounced increase during February and March 2020 - marking the coldest period of the observations. Applying the equation of salt conservation to the ML as a guiding framework, we combine the abovementioned observations, to intercompare the temporal evolutions of the different processes affecting salinity. Overall, brine rejection associated with thermodynamic ice growth turns out to be the largest salt flux term in the ML salt budget. Thereby the observed amplitudes of upward ocean heat fluxes into the mixed layer are too small for them to have a relevant impact on limiting ice growth. Horizontal salt advection in the ML is the second-most important flux term, actually representing a net sink of salt, thus counteracting brine release. It displays considerably larger temporal variability than brine release, though, due to the variable of ocean currents and horizontal salt gradients. Vertical ocean salt fluxes across the mixed layer base represent the third-most important salt flux term, showing particularly elevated values during storm events, when small-scale turbulence in the ML is triggered by the winds. The results presented will be interpreted in the context of the changes in the regional and temporal ocean, atmosphere and sea ice properties encountered during the MOSAIC drift.
Perturbations of volcanic CO2 emission to orbital paced climate-carbon cycle
Authors: Liu Fenghao , Huang Enqing , Du Jinlong , Ma Wentao , Ma Xiaolin , Lourens Lucas , Tian Jun
Published: March 2022

How the global carbon cycle and climate changes interact on orbital timescales under different boundary conditions remains elusive. Previous studies have found that changes in global ice-sheet volume and marine carbon cycle are synchronized at the eccentricity time scales with a slight lead of climate-cryosphere relative to carbon cycle throughout Oligo-Miocene (~34-6 Ma). Here, we analyze the evolutive phase relationship between benthic foraminiferal oxygen (δ18O) and carbon isotope (δ13C) to reveal an unnoticed phenomenon that variations of oceanic carbon cycle could lead those of global ice-sheet volume on 405-kyr cycle during Miocene Climate Optimum (MCO, ~17-14 Ma), which was a profound warming interval partly ascribed to the carbon emission from the eruption of the Columbia River Basalts Group (CRBG). Eccentricity sensitivity analysis indicate a relatively constant response of ice sheet to orbital forcing during MCO. Combined the results of box model, we propose that volcanic CO2 input accelerates the response of marine carbon cycle to orbital forcing. The enhanced greenhouses effect probably had strengthened the low-latitude hydrological cycle and chemical weathering and ultimately generated the δ13C-lead-δ18O scenario.
Preliminary analysis of high-resolution precipitation in Friuli Venezia Giulia region, Italy
Authors: Arnone Elisa , Treppiedi Dario , Noto Leonardo
Published: March 2022

The northeastern area of Italy, and specifically of Friuli Venezia Giulia region (FVG), is characterized by the heaviest precipitation annual totals in the country. Effects of both prolonged and extreme precipitation can be particularly damaging in this area, causing debris flow, flash floods, avalanches. Due to the very short times of concentration and hydrological response of the mountain watersheds of the analyzed area, extreme and short events are of particular interest. The region has a dense ground-station network which is managed by the regional Civil Protection Agency, constituted by 2 main rain-gauges networks, based on CAE and Micros-SIAP technology, respectively; this last is co-managed by the OSMER-ARPA (OSservatorio MEteorologico Regionale-Agenzia Regionale per la Protezione dell’Ambiente) FVG. The networks count a total of about 200 rain-gauges; for some stations, data at 5-minute resolution are available since the 1996 (CAE network), whereas Micros-SIAP works continuously and at high resolution since the early 2000s. Over the last two decades, the temporal resolution of stations has been progressively increased up to 1-minute step.

This work presents a comprehensive analysis of the available dataset at high temporal resolution (i.e. 30 min, 5 min and 1 min) to verify whether trends in very short rainfall duration are underway. The continuous time series of data recorded by a sample of rain-gauges by the two networks are first analyzed. A preliminary analysis aims at verifying the consistency of the dataset at the higher resolutions. Statistical trends are then assessed by comparing two methods, i.e., the classical Mann-Kendall and the quantile regression at different thresholds and durations. Differently than the traditional methods that require a subset of data (e.g., the rainfall annual maxima), the quantile regression method allows to detect changes in the tails of the rainfall distributions and to screen the whole rainfall time series.
Characteristics of wildfires in the Eastern Alps
Authors: Melzner Sandra , Shtober-Zisu Nurit , Katz Oded , Wittenberg Lea
Published: March 2022

The Eastern Alps are an important tourist destination and attract many visitors every year for their scenic beauty, sports attractions and rich cultural heritage. Tourism is an important source of income and contributes to the revival or maintenance of local traditions. However, tourism also has potential negative impacts on the regions, for example Austria's largest forest fire in Hirschwang near Reichenau an der Rax (district of Neunkirchen) in the period 25.10.2021 to 6.11.2021 was anthropogenically triggered by tourists.

In addition to the anthropogenic factors, the increase in extreme weather events caused by climate change and its scale dependent variations are a major challenge in the preparation of wildfire risk maps.

Wildfires in steep Alpine valleys behave differently than those on flat or moderate inclined slopes. The present work describes a wildfire that occurred in August 2018 in a famous world-heritage site in Austria (Melzner et al. 2019), which was presumably initiated by a carelessly discarded cigarette or the reflection of a broken glass bottle at the foot of the rockwall. Indicators of fire severity and rockfall occurrence during and after the fire are described.

The vertical rockwalls, the anabatic winds and patchy vegetation pattern, caused an upward jumping of the fire resulting in a spotty fire pattern. This most probably resulted in spatially varying fire intensities, and consequently highly heterogenic changes in soil and rockmass structure. The wildfire clearly showed that wildfires can have a significant impact on ecosystems and pose a high risk to settlements in the Alpine area. The rockfall hazard and risk assessment conducted in 2014 (Melzner 2015) enabled a fast decision making as part of an emergency response during and after the wildfire catastrophe in terms of identification of possibly endangered houses and planning of preliminary rockfall preventive measures.
Evidence of cryptic methane cycling in sulfate-reducing sediments of the Santa Barbara Basin
Authors: Krause Sebastian J. E. , Liu Jiarui , Yousavich David J. , Robinson DeMarcus , Hoyt David W. , Valentine David L. , Treude Tina
Published: March 2022

             Methane in anoxic marine sediments comes primarily from microbial methanogenesis. Methanogenesis is facilitated by groups of obligate anaerobic archaea and is the last step in carbon remineralization according to the redox cascade. Before the methane is emitted into the water column and ultimately the atmosphere, where is acts as a potent greenhouse gas, a large portion (~90%) of the methane is consumed by anaerobic oxidation of methane (AOM). In anoxic marine sediments AOM is typically mediated by a consortium of methanotrophic archaea and sulfate-reducing bacteria to oxidize methane to inorganic carbon within a sediment layer classically known as the sulfate-methane transition zone (SMTZ). Organic matter in sediments above the SMTZ is consumed by organoclastic sulfate reduction, which thermodynamically outcompetes methanogenesis for hydrogen and acetate. However, methanogenesis can persist in sulfate-reducing environments with non-competitive substrates such as methylamines, which are produced from the microbial degradation of glycine betaine and dimethylsulfoniopropionate. Methanogenesis from methylamine can directly fuel AOM, now known as the “cryptic methane cycle”, in sulfate-reducing sediments. The cryptic methane cycle above the SMTZ is still poorly understood. Here we will present our preliminary research that shows evidence of cryptic methane cycling in sulfate-reducing sediments of the organic-rich Santa Barbara Basin (SBB).

            We sampled the top 10-15cm of sediments at 5 stations along a depth transect across the basin. Sediment samples were subjected to radioisotope incubations with 14C-methane, 14C-mono-methylamine, and 35S-sulfate, gas chromatography, and porewater geochemical and metabolomic analysis. Porewater methane concentrations ranged from 3 to 13 µM. Metabolomic analysis of porewater using nuclear magnetic resonance for mono-methylamine concentrations found evidence of mono-methylamine presence below the quantification limit (< 3 µM). Results from the radiotracer incubations with 14C-methane detected ex-situ AOM rates at all 5 stations, where the highest rates were found within the top 1 cm. Integrated AOM (0-11cm) activity decreased with station water depth. 14C-mono-methylamine incubations revealed concurrent methanogenesis and AOM from mono-methylamine in the presence of sulfate reduction at all 5 stations. These results indicate evidence of potential cryptic methane cycling near the sediment-water interface in the Santa Barbara Basin.
Can we afford fracture pressure uncertainty? Limit tests as a key calibration for geomechanical models
Authors: Kępiński Michał , Wiprut David , Basu Pramit
Published: March 2022

The Leak-Off Test (LOT) is one of the most common fracture pressure/Shmin calibration measurements conducted in wellbores. Well engineers rely on readings from LOTs to design safe drilling plans. The LOT results indicate the maximum mud weight or equivalent circulating density that can be used to drill the next hole section without causing fluid losses to the formation. Losses are one of the most expensive issues to mitigate in drilling operations. In more severe cases, losses may lead to subsequent drilling challenges such as hole collapse or kicks. Oftentimes, drillers choose not to pressurize the well up to the leak-off pressure due to the risk of weakening the rock beneath the casing shoe by creating a fracture. In these cases, a formation integrity test (FIT) is conducted. However, the FIT is inadequate for properly constraining the fracture gradient or for input to geomechanical models because it is possible for the FIT to terminate at pressures that are either above or below the far-field minimum stress.

Geomechanical modelling from several projects in Poland shows that insufficient LOT measurements introduce a wide range of fracture gradient uncertainty, complicating the analysis of optimal ECD values in narrow margin drilling sections. This leads to difficulty in determining the proper mud weight when a loss event occurs. Additionally, without reliable calibration of the minimum horizontal stress, the geomechanical model used to determine the lower bound of the mud window becomes more uncertain. An inadequately constrained mud window can result in further drilling complications such as tight hole, stuck pipe, poor hole condition, and compromised log quality.
A global gridded monthly water withdrawal dataset for multiple sectors from 2015 to 2100 at 0.5° resolution under a range of socioeconomic and climate scenarios
Authors: Khan Zarrar , Thompson Isaac , Vernon Chris , Graham Neal , Wild Tom , Chen Min
Published: March 2022

Future sectoral-specific water withdrawals at a temporal resolution capable of representing patterns in seasonality and a commonly used spatial resolution are an important factor to consider for energy, water, land and environmental research.  Projected water withdrawals that are harmonized with assumptions for alternate futures that capture socioeconomic and climatic variation are critical for many modeling studies on future global and regional dynamics. Here we generate a novel global gridded water withdrawals dataset by coupling Global Change Analysis Model (GCAM) with a land use spatial downscaling model (Demeter), a global hydrologic framework (Xanthos) and a water withdrawal downscaling model (Tethys) for the five Shared Socioeconomic Pathways (SSPs) and four Representative Concentration Pathways (RCPs) scenarios. The dataset provides sectoral monthly data at 0.5° resolution for years 2015 to 2100. The presented dataset will be useful for both global and regional analysis looking at the impacts of socioeconomic, climate and technological futures as well as in characterizing the uncertainties associated with these impacts.
Influence of sediment depth and groundwater underflow on residence time distributions in dune-shaped streambeds
Authors: Boano Fulvio , Monofy Ahmed , Grant Stanley
Published: March 2022

Stream dunes have been widely recognized among the major morphological features driving water exchange between a stream and its sediments, and many modeling studies have been performed to characterize hyporheic exchange induced by this type of bedforms. Despite of these efforts, the high number of factors that affect hyporheic exchange has not been completely addressed yet, mainly because of the simplifying assumptions that are unavoidably required to reduce the complexity of the problem. For instance, the effect of the limited extent of the thickness of the sediment layer on the Residence Time Distribution (RTDs) of hyporheic exchange has not been fully explored. This incomplete knowledge is particularly relevant due to the paramount role of RTDs in controlling biogeochemical reactions in microbiologically active sediments.

In this context, this study presents a modeling analysis of RTDs in dune-shaped streambeds of finite depth in the presence of groundwater flow. Numerical simulations of particle tracking have been performed to determine the combined influence of sediment depth and horizontal underflow on the shape of RTDs. Moreover, different analytical distributions (Exponential, Gamma, LogNormal, Fréchet) have been fitted to the numerical RTDs, and the best distribution for each range of dimensionless sediment depth and underflow velocity have been identified on the basis of Anderson-Darling tests.