bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of surface volatile exchanges in evolving climate conditions on terrestrial planets
Authors: Gillmann Cédric , Golabek Gregor
Published: March 2022

The habitability of a terrestrial planet depends on its surface conditions, which can vary greatly during its evolution. Volatile exchanges between the interior, the surface and the atmosphere - the cycles of volatile species or their absence - are largely responsible for these variations and the resulting complex feedback mechanisms between the processes involved. The differences between Earth and Venus climate conditions highlight how similar processes and base characteristics can lead to divergent states after billions of years of evolution. While Venus exhibits hostile conditions and its atmosphere appears mostly desiccated, some hypothetical evolution scenarios suggest it was not always so, and that it could have sustained liquid water oceans for an undefined period of time during its past history. We investigate what mechanisms are likely to be responsible for this type of catastrophic change on Venus and possibly on terrestrial planets, using coupled numerical evolution simulations of planetary evolution, involving mantle dynamics, volcanism, atmospheric greenhouse, escape mechanisms, meteoritic impacts and surface solid-gas exchanges. Increasing solar luminosity (the faint young sun paradox) only marginally affects surface temperature changes. Atmospheric escape could only hide the results of a runaway greenhouse phase by removing water rather than cause the observed climate change. Moreover, it is shown, especially in light of recent measurements interpretation, to be unlikely to be responsible for massive water loss. Large impacts, capable of releasing large amounts of volatiles in the atmosphere, are infrequent and unlikely to occur during late evolution. The smaller impactors do not have enough mass to affect the mantle or atmosphere substantially.  The cause of catastrophic transitions and the means to dessicate the atmosphere of Venus post-runaway greenhouse may be internal. We investigate volcanic gas release based on mantle composition and mantle dynamics over time, as well as oxidation mechanisms of fresh material that can trap volatiles into the surface. Solid surface oxidation is inefficient and appears to be roughly as efficient (within 0.1-1 order of magnitude) as recent atmospheric escape, when considering O removal during the last few billion years. Ashes oxidation could be more efficient but requires explosive volcanism that is not widespread on Venus, given the few traces detected from surface observation. We compare its effects to that on Earth. However, large variations in atmospheric composition and vertical structure resulting from runaway greenhouse could affect all the mechanisms involved in the evolution of terrestrial planets and, under some circumstances lead to a late molten surface phase. Surface exchanges and atmospheric loss would therefore be affected in turn.
Geomagnetically Induced Currents over Kazakhstan during Large Geomagnetic Storms
Authors: Mukasheva Saule , Andreyev Alexey , Kapytin Vitaliy , Sokolova Olga
Published: March 2022

The paper shows that during very large magnetic storms (VLMS), the energy systems of Kazakhstan are exposed to geomagnetically induced currents for quite a long time (from tens of minutes to several hours). The minute values of the magnetic field vector B or its components Bx, By, Bz during four very large geomagnetic storms with a local geomagnetic activity K-index≥7 were used to calculate the values of geomagnetically induced currents:

- September 26-28, 2011, VLMS, Sc, duration 54 h 00 min, K-index =7;

- June 22-25, 2015, VLMS, Sc, duration 78 h 30 min, K-index =8;

- October 24-28, 2016, VLMS, duration 93 h 00 min, K-index =7;

- May 12-17, 2021, VLMS, Sc, duration 17 h 25 min, K-index =7.

Sc – a sudden commencement of strong storms.

The data of four magnetic observatories of the INTERMAGNET network, whose geomagnetic latitudes are close to the geomagnetic latitudes of the southern and northern borders of Kazakhstan were considered: Alma-Ata Observatory, Kazakhstan (code AAA, 43.25°N, 76.92°E); Novosibirsk Observatory, Russia (code NVS, 54.85N, 83.23E); Irkutsk Observatory, Russia (code IRT, 52.17°N, 104.45°E) and the Beijing Ming Tombs Observatory, Beijing, China (code BMT, 40.3°N, 116.2°E).

Variations of the Bx component of the geomagnetic field during the four considered very large magnetic storms according to the observatories AAA, NVS, IRT, BMT showed variability from 50 nT to 150 nT for several hours.

Also, based on measurements of geomagnetic observatories AAA, NVS, IRT, BMT, the analysis of variations of the horizontal component H of the magnetic field vector and its time derivative (dH/dt) was carried out. Histograms of the distribution dH/dt and histograms of the distribution of the directions H and dH/dt are constructed.

It is shown that the energy systems of Kazakhstan are exposed to geomagnetically induced currents when dH/dt/ varies from 17 nT/min and more. The geomagnetic-induced current is estimated based on the calculation that the electromotive force of self-induction is proportional to the rate of change in the magnetic field strength. According to preliminary calculations, the values of geomagnetic-induced currents are fractions of mA. For more accurate calculations, it is necessary to take into account the topology of the electrical system, the composition of the underlying surface and other factors that determine the degree of susceptibility of individual elements of the power system.

This research has been/was/is funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. AP09259554).
Factors controlling the dissolved 137Cs seasonal fluctuations in the Abukuma River under the influence of the Fukushima Nuclear Power Plant accident 
Authors: Igarashi Yasunori , Kenji Nanb , Wada Toshihiro , Wakiyama Yoshifumi , Onda Yuichi , Moritaka Shota
Published: March 2022

The 2011 Fukushima Daiichi Nuclear Power Plant (FDNPP) accident released large amounts of radioactive materials into the environment. River systems play an important role in the terrestrial redistribution of FDNPP-derived 137Cs in association with water and sediment movement. We examined the seasonal fluctuations in dissolved and particulate 137Cs activity concentrations and clarified the biological and physicochemical factors controlling 137Cs in the Abukuma River’s middle course in the region affected by the FDNPP accident. The results showed the water temperature and K+ concentration dominated the seasonality of the dissolved 137Cs activity concentration. We concluded that the 137Cs in organic matter is not a source of dissolved 137Cs in river water. The study also revealed the temperature dependence of Kd in riverine environments from a Van ’t Hoff equation. The standard reaction enthalpy of 137Cs in the Abukuma River was calculated to be approximately −19.3 kJ/mol. This was the first study to clearly reveal the mechanisms by which the dissolved 137Cs activity concentration and Kd are influenced by chemical and thermodynamic processes in the middle course of a large river, and it is expected to lead to an improved model of 137Cs dynamics in rivers.
Complex strain accommodation mechanisms during rift linkage: an example from the central Afar, East Africa
Authors: Muluneh Ameha , Brune Sascha , Kidane Tesfaye , Pagli Carolina , Keir Derek , Corti Giacomo
Published: March 2022

The Afar rift, at the northern part of the East African Rift System (EARS), is a classic natural laboratory to study the formation of sea-floor spreading centers. Several geo-physical monitoring studies have been conducted mainly following the 2005 Dabbahu-Manda Harraro (DMH) and the 1978 Asal segments volcano-seismic crises. The two segments are located at the tips of the Red Sea and the Gulf of Aden rifts, respectively, hence how the two segments propagate towards each other is crucial to our understanding on deformation during rift linkage. To this end, we use GPS data from central Afar to model the strain and rotation rates in the region. Our results show that both the DMH and Asal segments are characterized by high shear strain and rotation rates, in agreement with independent geophysical and geological observations. No significant strain concentration occurs between the two rift propagators. By combining our results with previous geophysical observations, we suggest that linkage between the DMH and Asal segments occurs via ∼E-W oriented strike-slip fault at the tip of DMH and a broad region of NW-SE oriented normal fault bounded en echelon grabens, which are almost parallel to the Asal segment. Our preliminary results show that the style of deformation in the central Afar region is more complex and distributed than at ocean ridges where rift segments connect with localized transform faults. However, our results may inform on how transform faults initiate. 
Inter-plant C Transfer and Associations between Plant-assimilated C Inputs and Soil Pores
Authors: Kravchenko Alexandra , Zheng Hongbing , Kuzyakov Yakov , Guber Andrey
Published: March 2022

Greater plant diversity facilitates soil C gains, yet the exact mechanisms of this effect are still under intensive discussion. Whether a plant grows in monoculture or in an inter-cropped mixture can affect allocation of plant assimilates, belowground exudation, and microbial stimulation. The goal of this study was to examine the effects of inter-cropping on a previously overlooked aspect of plant-soil interactions, namely, on locations where plant assimilated C is allocated within the soil pore system and its subsequent fate in relation to soil pores. The soil for the study originated from a greenhouse experiment with switchgrass (Panicum virgatum L.) (var. Cave'n'Rock) (SW), big bluestem (Andropogon gerardii Vitman) (BB), and wild  bergamot (Monarda fistulosa L.) (WB) grown in monocultures and in inter-cropped pairs and subjected to species specific C pulse labeling (Kravchenko et al., 2021). Intact soil cores (8 mm Ø) were collected from the experimental pots, subjected to a short-term (10 day) incubation, X-ray computed micro-tomography (μCT) scanning, and soil C micro-sampling "geo-referenced" to μCT images. Results indicated that in the plant systems with demonstrated interplant C transfer soil C was positively correlated with <10 μm Ø pores immediately after plant termination and with 20-80 μmØ pores after the incubation. In the systems without marked interplant C transfer, soil C was positively correlated with 20-30 μm Ø pores, however, the correlations disappeared after the incubation. Soils from the systems with demonstrated belowground C transfer displayed lower losses of root-derived C during incubation than the systems where interplant C transfer was negligible. These differences suggest dissimilarities in the possible mechanisms of adding photoassimilated C to the soil: via mycorrhizal hyphae into small sized pores vs. via roots into mediumsized pores. In the latter case the plant-derived C was quickly lost during subsequent incubation. Our findings indicate that greater losses of plant assimilated C from the soil often reported during comparisons of monocultures with inter-cropped plant mixtures are related not only to monoculture vs. polyculture dichotomy, but to the route of plant C additions to the soil and its localization within the soil pores.
The role of forest vegetation seasonality on the dynamics of nitrate-nitrogen export during rainfall events
Authors: Lebar Klaudija , Rusjan Simon
Published: March 2022

Afforestation is recognized as one of the commonly used nature-based solutions for flood risk mitigation as well as for reduction of anthropogenic impacts on sediment and nutrient flushing. Processes of nutrient cycles (e.g., nitrogen cycle) are directly dependent on the amount of precipitation and its temporal and spatial distribution as water is the main transport medium and the driving force for many ecosystem processes. To understand the natural background of biogeochemical processes and transport of their products, it is therefore necessary to improve understanding of the hydrological control mechanisms, especially the formation of rainfall-runoff. Forest ecosystems without any or with negligible anthropogenic influences represent such kind of a reference, i.e. natural state in the field of nutrient flushing research. For this reason, we established an experimental monitoring system in the small, almost completely afforested Kuzlovec river catchment, Slovenia. Most of the hydrometeorological variables were measured continuously at a 20-min time step accompanied with measurements of concentrations of nitrate-nitrogen in the stream and leaf area index, which was used as an indicator of seasonal growth periods. Based on a two-year data set of various variables, we identified rainfall events for which we investigated: i) the influences of rainfall characteristics on the nitrate-nitrogen flushing, ii) the rainfall-runoff formation processes taking into account nitrate-nitrogen concentration changes during rainfall events, and iii) the role of the forest on the dynamics of the nitrate-nitrogen flushing (i.e., are there differences between the seasons). The focus of this contribution will be on the latter. We will present the most important findings obtained by using statistical analyses, such as hierarchical clustering, k-means, and principal component analysis. We believe that information obtained from such research is extremely important for improving the understanding of the processes’ controlling factors in areas with anthropogenic activities that affect the circulation and amount of nutrients exported to water bodies. 
A novel method to predict hydraulic fracturing breakdown pressure.
Authors: Powlay Ben , Karakus Murat , Amrouch Khalid , Chester Chris
Published: March 2022

Hydraulic fracturing is increasingly becoming utilized within Underground hard rock mines such as block caves and Sub Level Caves as a way to promote controlled cave propagation, increase resource recovery, and seismic hazard through the manipulation of rock mass properties through fracture surface creation and limiting of stress concentration.
While hydraulic fracturing is not a new application, it is still in its infancy in mining projects such as cave mining. It is used on entirely different scales, under different stress regimes and with varying motives. Therefore, more research needs to be carried out in understanding the fundamentals of fracture growths that can help improve hydraulic fracturing applied in mining projects.  

Predicting breakdown pressure is an important part of the designing of hydraulic fracturing with accurate prediction being the baseline of designing and implementing a successful preconditioning campaign in all industries, but especially so in block cave mining.
The most commonly used breakdown pressure theoretical model is the conventional breakdown model and is based on tensile strength and confining stresses acting upon the borehole. This might be imprecise within hard rock mining environments and increasingly so at depth of higher stresses. 

This work compares indirect tensile strength results and their fracture toughness, from both conventional Brazilian Disc Testing and the recently developed Adelaide University Snapback Indirect Tensile Testing (AUSBIT).
By using lateral strain control to stabilise the brittle material responses, AUSBIT allows for the capture of true post-peak behaviour, i.e. controlled fracture propagation can be achieved.

The captured post-peak behaviour allows practitioners to measure a more reflective tensile strength and fracture toughness from just one testing method, Alongside this are laboratory hydraulic fracture experiements on the same rock unit, which in turn is used to propose a new Hard Rock Breakdown Pressure prediction based on the conventional method which incorporates fracture toughness when checked against the results of the lab fracture experiments, and other lab studies. 

The results of this work factors in a progressive toughness of a rock at depths, and creates a more accurate predictor of breakdown pressure in underground hard rock mines under varying stress conditions.  
Urban Morphometrics and Microclimate Responses in a Typical Residential Neighborhood of a Hot Urban Desert City
Authors: AlKhaled Saud
Published: March 2022

Urban morphological attributes and surface properties can largely influence near-surface air temperatures. Unpacking such morpho-thermal relationships are of particular importance in hot urban desert (HUDs) cities given the already extreme thermal bioclimatic dynamics, urban-induced heating with rapid urbanization processes, and vulnerability of residents. Satellite-derived investigations may underestimate critical system dynamics of urban thermal stimuli found within sub-diurnal phenomena and sub-meter classifications. High resolution spatiotemporal measurements are therefore required to objectively assess latent magnitudes of heat mitigation and amelioration strategies. This study utilized the natural heterogeneity of morphometric predictors with fixed ground-based measurements in a representative neighborhood unit typology within Kuwait’s residential landscape to build a composite dataset of sub-hourly air temperature measurements with sub-meter morphological attributes. The presentation will share initial findings of the study and preliminary analysis of the drivers of heating/cooling rate’s association to defined morphological factors.
Larger Foraminiferal Extinction and Origination Event during the Paleocene-Eocene Thermal Maximum in the Potwar Basin (Eastern Neotethys) 
Authors: Muhammad kamran , Fabrizio Frontalini , Dangpeng Xi , Cesare Andrea Papazzoni , Kamran Mirza , Ghulam Akbar , Tian Jiang , Xiaoqiao Wan
Published: March 2022

In the Potwar Basin (Pakistan, Eastern Neotethys), the Paleocene-Eocene transition has been investigated and the changes in larger benthic foraminiferal (LBF) assemblages have been compared with the carbon isotope excursion (CIE). The ~5‰ negative CIE is here used to place the exact position of the Paleocene-Eocene boundary that falls in the base of the Shallow Benthic Zone (SBZ) 5. The boundary between the SBZ 5 and 6 corresponds to the early stages of the CIE recovery phase, which is characterized by the disappearance of the some typical Paleocene lamellar-perforate LBF genera such as Miscellanea, Kathina, and possibly Ranikothalia. In the Potwar Basin, some species of Daviesina and Glomalveolina also disappeared at the base of SBZ 6. At the same time, the genus Orbitolites and some species of Alveolina, Nummulites, miliolids, and Assilina appeared and led to the larger foraminiferal extinction and origination (LFEO) event.

The LFEO event represents the late response of the LBF to the abrupt environmental perturbation induced by the Paleocene-Eocene Thermal Maximum (PETM). At the Duleram section (Potwar Basin), the pre-PETM phase is characterized by highly stable and oligotrophic conditions, as revealed by the dominance of large, K-strategists LBF genera (e.g., Miscellanea, Ranikothalia, and Daviesina). At the onset of the PETM, an increased nutrient supply led to establishment of more eutrophic conditions and a collapse of the oligotrophic LBF with the rise of more nutrient-tolerant, small-sized LBF (e.g., glomalveolinids). At the post-PETM phase, stable oligotrophic conditions were re-established, as revealed by the dominance of new K-strategists LBF genera (Alveolina, Nummulites, and Assilina).

As the changes in the LBF assemblages match well with the CIE changes, we can use them as proxies to infer the variations from stable oligotrophic to eutrophic marine conditions during the PETM event in the Eastern Neotethys.
Observational study of time-varying climate feedback parameter
Authors: Chenal Jonathan , Meyssignac Benoît , Guillaume-Castel Robin
Published: March 2022

The climate sensitivity is the central metric for evaluating the amplitude of climate change. It is inversionally proportional to the climate feedback parameter which can be estimated with observations of surface temperature (T), radiative forcing (F) and Earth energy imbalance (EEI). Since EEI is proportional to the time derivative of the ocean heat content, EEI can be derived from in situ temperature/salinity measurements or, equivalently, from the thermosteric component of sea level rise.  Here we use a regression method applied to T, F and in situ temperature as well as thermosteric sea level to estimate the climate feedback parameter over the 20th century. Several recent climate studies have shown that the feedback parameter changes with time, because of the spatial pattern of warming. We evaluate the time variations of the climate feedback parameter over 1900- 2020 by applying the regression method to different periods within the 20th century. For the first time, we confirm with observations that the climate feedback parameter does change with time, and responds to external forcings such as major volcanic eruptions, as well as to climate internal variability. We also demonstrate that we need a consistent and reliable observing systems across time to derive a credible climate feedback parameter time series.
Quiet‐Time Day‐to‐Day Variability of Equatorial Vertical E × B Drift From Atmosphere Perturbations at Dawn
Authors: Zhou Xu
Published: March 2022

Ionospheric day‐to‐day variability is ubiquitous, even under undisturbed geomagnetic and solar conditions. In this paper, quiet‐time day‐to‐day variability of equatorial vertical E × B drift is investigated using observations from ROCSAT‐1 satellite and the Whole Atmosphere Community Climate Model with thermosphere and ionosphere eXtension (WACCM‐X) v2.1 simulations. Both observations and model simulations illustrate that the day‐to‐day variability reaches the maximum at dawn, and the variability of dawn drift is largest around June solstice at ~90–180°W. However, there are signifificant challenges to reproduce the observed magnitude of the variability and the longitude distributions at other seasons. Using a standalone electro‐dynamo model, we fifind that the day‐to‐day variability of neutral winds in the E‐region (≤~130 km) is the primary driver of the day‐to‐day variability of dawn drift. Ionospheric conductivity modulates the drift variability responses to the E‐region wind variability, thereby determining its strength as well as its seasonal and longitudinal variations. Further, the day‐to‐day variability of dawn drift induced by individual tidal components of winds in June are examined: DW1, SW2, D0, and SW1 are the most important contributors.
Land-atmospheric coupling amplify the flash drought intensity in India
Authors: Mahto Shanti Shwarup , Mishra Vimal
Published: March 2022

Concurrent high temperature and low soil moisture during flash drought (FD) can become significantly hazardous, posing a devastating impact on human health, agriculture, and the ecosystem. Strong land-atmospheric coupling influences the intensity of flash drought events. Despite flash drought having detrimental impacts, the soil moisture (SM)-temperature (T) relationship and their characteristics are poorly understood in a coupled land-atmospheric scenario. Using variables from ERA5 reanalysis, we identify the major flash drought events and evaluate the SM-T coupling in India for the 1980-2019 period. We find that the summer monsoon season experiences most flash drought events during the monsoon breaks. Temperature anomalies and FD intensities remained strongly correlated (r= 0.78 and r= 0.67, respectively) with the SM-T coupling. Central India and Indo-Gangetic Plain experienced higher FD intensity and SM-T coupling compared to other parts of the country. Moreover, the SM-T coupling during flash drought increased by three-fold against the normal condition with an increasing trend over India. The strengthening of SM-T coupling is attributed to the increasing temperature and potential of declining soil moisture to influence the partitioning of the heat budget in the warming climate. Overall, we find that SM-T coupling is a key factor in deciding the intensity of flash drought, which may further increase under the future warming climate. Exacerbated flash drought intensity can severely affect crop production, irrigation demand, and ecological health.
Deciphering the global onset of Oceanic Anoxic Event 2 (OAE2) in the mid-Cretaceous greenhouse world
Authors: Li Yong-Xiang , Liu Xinyu , Selby David , Liu Zhonghui , Montañez Isabel , Li Xianghui
Published: March 2022

The mid-Cretaceous (~120 Ma to ~90 Ma) is a well-known greenhouse period in the Earth’s history that was punctuated by multiple dramatic paleoceanographic changes known as oceanic anoxic events (OAEs). Among these OAEs, OAE2 occurred near the Cenomanian-Turonian boundary (CTB, ~93.9 Ma) and represents one of the most pronounced OAEs. OAE2 is widely believed to be triggered by submarine volcanism, primarily based on proxy records from the Northern Hemisphere in which a large osmium isotope excursion indicative of volcanism precedes the carbon isotope excursion (CIE) of OAE2. However, the timing and mechanism of the global initiation of OAE2 remain elusive in part due to the lack of detailed osmium-isotope proxy records across the OAE2 intervals in the Southern Hemisphere. Here we report a high-resolution initial osmium isotope (187Os/188Osi, Osi) and δ13Corg record from a highly expanded OAE2 interval in southern Tibet, China that was deposited in the northern margin of India Plate in eastern Tethys in the Southern Hemisphere. The Osi record documents three distinct Osi shifts toward unradiogenic compositions with increasing amplitudes at ~95.1 Ma, ~94.8 Ma, and ~94.5 Ma, respectively, indicating episodic, intensifying volcanism with the highest intensity episode at ∼94.5 Ma. In addition, the large Osi excursion at ~94.5 Ma is followed by an ∼200 kyr Osi minimum concomitant with a cooling interval as revealed by an overall broad minimum interval of the difference of the paired δ13Ccarb and δ13Corg. This cooling interval is broadly synchronous with the Plenus Cold Event (PCE) recorded in the Northern Hemisphere. Furthermore, the large Osi excursion paradoxically lags the onset of OAE2 by ∼50 kyr at the Tibetan section. Comparison with and re-examination of the expanded OAE2 record of the Yezo Group (Japan) and those from the western interior seaway (WIS) in North America reveal the regional difference in the phasing relationship between the large Osi excursions and the CIEs of OAE2. Intriguingly, the large Osi excursions occurred during a near synchronous global transgression at ~94.5 Ma that led to increased connectivity of global oceans. Taken together, these results suggest that enhanced ocean connectivity was essential in helping trigger the global onset of OAE2 at ~94.5 Ma.
Melting relations of carbonates and trace element partitioning between carbonates and carbonate liquid in the Earth's upper mantle
Authors: Sieber Melanie J. , Wilke Max , Oelze Marcus , Appelt Oona , Wilke Franziska D.H. , Koch-Müller Monika
Published: March 2022

We examined the supra-solidus phase relations of the CaCO3-MgCO3 system and established trace element partition coefficient between carbonates and carbonate melt by conducting high pressure (6 and 9 GPa) and temperature (1300-1800 oC) experiments with a rocking multi-anvil press. It is well known that the major element composition of initial melts derived from low-degree partial melting of the carbonated mantle strongly depends on the melting relations of carbonates (e.g. 1, 2 and reference therein). Understanding the melting relations in the CaCO3-MgCO3 system is thus fundamental in assessing low-degree partial melting of the carbonated mantle. We show here to which extent the trace element signature of a pure carbonate melt can be used as a proxy for the trace element signature of mantle-derived CO2-rich melts such as kimberlites.

Our results support that, in the absence of water, Ca-Mg-carbonates are thermally stable along geothermal gradients typical at subduction zones. Except for compositions close to the endmembers (~Mg0-0.1Ca1-0.9CO3; Ca0-0.1Mg1-0.9CO3), Ca-Mg-carbonates will partially (to completely) melt beneath mid‑ocean ridges and in plume settings. Ca-Mg-carbonates melt incongruently to dolomitic melt and periclase above 1450 oC and 9 GPa making the CaCO3-MgCO3 a (pseudo-) ternary system as the number of components increases. Further, our results show that the rare earth element signature of a dolomitic melt in equilibrium with magnesite is similar to those of Group I kimberlites, namely that HREE are depleted relative to primitive mantle signatures. This implies that dolomite-magnesite solid solutions might be useful to approximate melting relations and melt compositions of low-degree partial melting of the carbonated mantle.

References

1  Yaxley, Ghosh, Kiseeva, Mallik, Spandler, Thomson, and Walter, CO2-Rich Melts in Earth, in Deep Carbon: Past to Present, Orcutt, Daniel, and Dasgupta, Editors. 2019, Cambridge University Press: Cambridge. p. 129-162.

2  Dasgupta and Hirschmann, The deep carbon cycle and melting in Earth's interior. Earth and Planetary Science Letters, 2010. 298 (1-2): p. 1-13.
Scale issues in runoff and sediment delivery: a global review and statistical analysis
Authors: Ke Qihua , Zhang Keli
Published: March 2022

Scale issues in runoff and sediment delivery (SIRSD) is a hot and frontier topic in the fields pertinent to hydrology and soil erosion. This study combined bibliometric analysis and data mining to provide a systematic and holistic review of global SIRSD studies. The bibliometric results indicate that SIRSD is a comprehensive and multidisciplinary issue that has been extensively investigated with a wide variety of methods by scientists from 85 countries since the 1950s. The rapid growth of publications over the last three decades reveals that the discussions on SIRSD are attracting booming attention due to its great potentials for research and practice on various contemporary issues of environment and natural resources. Especially topics about hydrological and sediment connectivity, storm flood, nonpoint pollution, landslide and debris flow are drawing increasing concerns under the context of climate change. Thematic structure analysis indicates that SIRSD field centres the spatial scaling issues in the delivery of suspended sediment, including sediment budget analysis and sediment delivery ratio (SDR) estimation. Compared to studies dealing with erosion and sediment that mainly focus on the spatial scale, studies related to hydrological runoff and climate tend to discuss more temporal scale issues. Regarding the study distribution, most studies cluster on the time scale from an event to 10 years and the spatial scale from plot to meso-watershed (10 m2-1000 km2) and tend to appear in regions that feature free-flowing rivers with rapid agricultural development. Based on the mined 1039 pairs of data on the relationship between SDR and the watershed area, we built a global view of the spatial effect on SDR. The spatial scale effect on SDR is most prominent in Europe, followed by the USA, then the Global average, while most gentle in China due to its high topographic variability. On the contrary, the average SDR is highest in China (0.51), followed by the Global case (0.37), then the USA (0.34), while lowest in Europe (0.28) due to its low mean topographic slope. From this review, we identified several research gaps: 1) lack of multi-scale studies with nested across-scale design and studies on the spatial scale effect on runoff delivery; 2) considerable gaps among the results obtained from different regions, methods, and scales; 3) debatable and unclear questions on the spatio-temporal scale of underground water and soil loss in the karst region. Moreover, we emphasize three areas for future research: 1) scale issues of flood processes regarding extreme rainstorms under climate change; 2) scale transformation methodology and multi-scale modelling of hydrology, erosion, and sediment transport and their integrations with the climate models; 3) comparative study in different regions to bridge the regional gaps.
Antarctic ice shelf open ocean corridors with large swell available
Authors: Teder Nathan , Bennetts Luke , Massom Rob , Reid Phil
Published: March 2022

Over the last three decades there have been two catastrophic disintegrations events on the Antarctic peninsula, the Larsen A ice shelf in 1995 and the Larsen B in 2002, alongside the Wilkins ice shelf which underwent multiple partial disintegrations between 1998—2009.  Previous research into these events indicated that there had been prolonged periods where the Larsen and Wilkins Ice Shelves were without a sea-ice buffer to protect them from ocean swell in the leadup to their respective disintegrations. Swell potentially acted as a trigger mechanism to each shelf to disintegrated, as they had already been destabilised by surface flooding, fracturing, thinning and other glaciological factors.

This study will focus on the algorithm we developed which calculates the time where an ice shelf is without a local sea ice buffer (“exposure”), the size of the ocean which could directly propagate waves into the shelf (“corridor”) and the maximum wave height of swell which is directed towards the shelf in the corridor. An analysis of the last forty-one years showed that there was a large variation over individual ice shelves for both exposure and the available swell, due to the impact of polynyas, ice tongues and fast-ice growth which can protect the ice shelf. On a regional scale, the East Antarctic Ice Shelf and West Antarctic Ice Shelf had opposing trends, with the West Antarctic Ice Shelf recording a weak increasing trend of exposure and available swell.
Variation in soil erosion rate under typical land uses and vertical zones in an agricultural catchment of the Daliangshan region, Southwest China
Authors: Wu Han , Xiong Donghong , Yuan Yong
Published: March 2022

Identification the effects of land use and vertical zone on soil erosion is vital to optimize land management in mountainous areas. In this study, the variation in soil erosion rate under typical land uses and vertical zones in a small agricultural catchment of the Daliangshan region (DLS), Southwest China, were evaluated using the cesium-137 tracer technique. Ten plots representing five land uses with four typical vertical zones (valley, low mountain, middle mountain and subalpine) were selected herein. Two parallel downslope transects were built in each plot, and soil samples were collected at 3-7 m intervals along these transects. The results showed that the sloping farmland (4.82 kg·m-2·y-1) and grassland (4.09 kg·m-2·y-1) soil erosion rates were significantly higher than those in abandoned farmlands (0.91 kg·m-2·y-1) and forest lands (0.80 kg·m-2·y-1), and horizontal terraces were dominated by net deposition (with erosion rate of -0.62 kg·m-2·y-1). The low mountain zone yielded the highest erosion rate (5.65 kg·m-2·y-1), followed by the middle mountain (2.96 kg·m-2·y-1) and subalpine (1.46 kg·m-2·y-1) zones, and the lowest erosion rate (1.28 kg·m-2·y-1) was observed in the valley zone. In addition, the soil erosion rate showed significant correlations (P<0.05) with sloping farmland proportion. The results indicate that land use controls soil erosion, and the vertical zone associated with land use patterns, topography, and human activities impact soil erosion variation. The low mountain zone near the catchment lower reaches has the highest erosion rate, largely because it is dominated by steep sloping farmlands and affected by immigration from high-altitude areas. Our findings highlight the importance of agricultural activities in sloping farmlands regarding soil erosion acceleration and the role of vertical zone in soil erosion rate impact. Appropriate management measures must be implemented to prevent soil erosion in the low mountain zone with increasing anthropogenic activities.
Atmospheric rivers drive exceptional Saharan dust transport towards Europe and subsequent snow melt in the Alps.
Authors: Francis Diana , Fonseca Ricardo , Nelli Narendra , Bozkurt Deniz , Picard Ghislain , Guan Bin
Published: March 2022

This study highlights the occurrence of atmospheric rivers (ARs) over northwest Africa towards Europe, which were accompanied by intense episodes of Saharan dust transport all the way to Scandinavia, in the winter season. Using a combination of observational and reanalysis data, we investigate two extreme dusty AR events in February 2021 and assess their impact on snow melt in the Alps. The warm, moist, and dusty air mass (spatially-averaged 2-meter temperature and water vapour mixing ratio anomalies of up to 8 K and 3 g kg−1, and aerosol optical depths and dust loadings of up to 0.85 and 11 g m−2, respectively) led to a 50% and 40% decrease in snow depth and surface albedo, respectively, in less than one month during the winter season. ARs over northwest Africa show increasing trends over the past 4 decades, with 78% of AR events associated with severe dust episodes over Europe. 
This study was published recently in Atmospheric Research (https://doi.org/10.1016/j.atmosres.2021.105959).
Magnetic Field Line Path Length Variations and Effects on Solar Energetic Particle Transport
Authors: Sonsrettee Wirin , Chuychai Piyanate , Seripienlert Achara , Tooprakai Paisan , Sáiz Alejandro , Ruffolo David , Matthaeus William Henry , Chhiber Rohit
Published: March 2022

Modeling of time profiles of solar energetic particle (SEP) observations typically considers transport along a large-scale magnetic field with a fixed path length from the source to the observer.  Chhiber et al. (2021) pointed out that the path length along a turbulent magnetic field line is longer than that along the large scale field, and that the path along the particle gyro-orbit can be substantially longer again; they also considered the global variation in these quantities.  Here we point out that variability in the turbulent field line path length can affect the fits to SEP data and the inferred mean free path and injection profile.  To explore such variability, we perform Monte Carlo simulations in representations of homogeneous 2D MHD + slab turbulence in spherical geometry and trace trajectories of field lines, particle guiding centers, and full particle orbits, considering ion injection from a narrow or wide angular region near the Sun, corresponding to an impulsive or gradual solar event, respectively. We analyze our simulation results in terms of path length statistics within and among square-degree pixels in heliolatitude and heliolongitude at 0.35 and 1 AU from the Sun.  For a given representation of turbulence, there are systematic effects on the path lengths vs. heliolatitude and heliolongitude.  Field line path lengths relate to the fluctuation amplitudes experienced by the field lines, which in turn partly relate to the local topology of 2D turbulence.  Particles from an impulsive event that arrive at a distant angular separation (up to ~25 degrees from the mean field connection) generally have longer path lengths, not because of the angular distance per se but because of strong magnetic fluctuations experienced to drive the guiding field lines to such angular distances and because of the associated scattering of the particles.  We describe the effects of such path length variations on observed time profiles of solar energetic particles, both in terms of path length variability at specific locations and motion of the observer with respect to turbulence topology during the course of the observations.  This research was partially supported by Thailand Science Research and Innovation grant RTA6280002 and the Parker Solar Probe mission under the ISOIS project (contract NNN06AA01C) and a subcontract to University of Delaware from Princeton University (SUB0000165).  Additional support is acknowledged from the NASA LWS program (NNX17AB79G) and HSR program (80NSSC18K1210 & 80NSSC18K1648).
Searching for fibrous erionite in air and dust samples across an urban Southern Hemisphere airshed 
Authors: Talbot Nick` , Dirks Kim , Davy Perry , Patel Hamesh , Fan Wendy , Brook Martin , Salmond Jennifer
Published: March 2022

Erionite is a fibrous zeolite found in the rock beneath parts of Auckland, New Zealand. As a known carcinogen that can be easily inhaled. it has been linked to the development of mesothelioma. It has a high degree of carcinogenicity due to the specific physical dimensions of the fibres, with certain sizes able to easily deposit deep in the lung tissue once inhaled. This project seeks to understand the extent to which erionite, once exposed, propagates in the ambient air in the form of dust and airborne fibres. The research is made challenging by the lack of standard methodological approaches to detect and quantify such fibres in airborne samples. Initial monitoring has been targeted on areas that have the combined attributes of rapid urban development (and thus excavation) and a confirmed presence of erionite in the rock strata beneath. The key sampling periods will be during the New Zealand summertime when warm temperatures and drier conditions prevail, increasing the potential for dust and fibre generation and buoyancy. The research findings from this project aim to develop a standard method for investigating erionite fibres in ambient air, including recommendations for the use and application of suitable screening methods, instrumentation and field site choice and instrument network density for given scenarios.
Identifying the geographic distribution of seawater desalination plants globally using species distribution models
Authors: Ai Zhipin , Ishihama Fumiko , Hanasaki Naota
Published: March 2022

Desalination water is a vital source of freshwater for regions with coastal water scarcity. Identifying the geographic distribution of global seawater desalination plants enables a spatially detailed water sources assessment. In this study, which is the first of its kind, we investigated the potential application of species distribution models (SDMs), which are widely used in ecology, to predict the global spatial distribution of seawater desalination plants. Two regression SDMs, a generalized linear model (GLM) and a generalized additive model (GAM), along with two machine learning SDMs, a random forest (RF) model and a generalized boosted regression model (GBM), were trained and tested using the cross-validation method at 0.5 degrees. For each SDM, we considered four explanatory variables: aridity, distance to seashore, gross domestic product (GDP) per capita, and the sum of annual domestic and industrial water withdrawal. Our results showed that the four SDMs have good accuracy according to three different evaluation metrics. An ensemble presence map was then created from the four individual SDM predictions. Finally, we mapped the future distribution of seawater desalination plants. Due to the increases in aridity, GDP per capita, and domestic and industrial water withdrawal, the total number of presence grid cells is predicted to increase from 2014 figures by 37%, 47%, 35%, and 30% in 2030, 2050, 2070, and 2090, respectively. Using future predictions such as these, our study can contribute to integrated global water resources assessments. Our findings also provide insight into how SDMs can be used for predicting the geographic locations of water management facilities.
The evolution of tidal hydrodynamics and its underlying mechanism in “Bay-Outlet-Tidal Channel” system of the Pearl River Delta, China
Authors: Zhang Ping , Yang Qingshu , Cai Huayang
Published: March 2022

Due to the intensive human activities, the tidal hydrodynamics of “Bay-Outlet-Tidal Channel” system experienced considerable spatiotemporal change owing to the morphological alterations. The outlets in the Pearl River delta (PRD), especially the connecting outlet between Lingdingyang Bay and Shiziyang Channel, are small-scale dynamic structures that have a special morphodynamic feature, playing an essential role in energy transport and transformation. In this study, bathymetric maps of the “Bay-Outlet-Tidal Channel” system in 1965, 1974, 1989, 2009, and 2015 were collected to investigate the geomorphologic structure by means of a digital elevation model (DEM). It was shown that the water depth increased with the decreasing convergence width, indicating the channel deepening and narrowing. The tidal hydrodynamics, especially focusing on the tidal amplitude and velocity amplitude, were explored using a 2D numerical model in the system of “Lingdingyang Bay-Humen outlet-Tidal Channel” considering dramatic anthropogenic effects. In addition, the 1D analytical model was used to reproduce the historical development of tidal hydrodynamics and its underlying mechanism. The results show that the relationship of tidal amplitude and velocity amplitude was dramatically affected by the morphological alterations, with the deepening playing a much more important role. It was shown that the tidal amplitude was increased by 0.0393 m, while a decrease by 0.0432 m/s for the velocity amplitude. Owing to the Outlet in the “Bay-Outlet-Tidal Channel” system, the channel networks and outer bay in the PRD were kept relatively stable, with the tidal energy decay rate of tidal channel remaining approximately constant (70%). These results quantifying the impacts of estuarine morphology on tidal hydrodynamics can provide scientific guidelines for sustainable water resources management in the PRD and other estuaries that are subject to intensive human interventions, especially regarding morphological alterations.
Short-wavelength Bouguer anomaly and folding with disclination in the northeastern Japan
Authors: Hirano Mitsuhiro , Nagahama Hiroyuki
Published: March 2022

In the northeastern Japan arc with the active compressive stress field since ~3 Ma, it is reported that a characteristic relationship between crustal deformation including faulting and short-wavelength (< 160 km) Bouguer anomalies. According to previous studies, active faults tend to be located in negative regions, which are caused by cracks and volumetric strain due to accumulated fault dislocation. Especially, it is shown that in strain concentration zones with active faults and muti folding, the effect of accumulated fault dislocation forms the negative zones of gravity anomaly along the northeastern Japan arc, impacting the pattern of short-wavelength Bouguer anomalies throughout the entire arc. In this presentation, we extend this concept further and discuss the positive and negative zones of gravity zones along the entire northeastern Japan arc from the geometrical viewpoint of folding with one of the defect, disclination. Folding is described by Euler-Schouten curvature tensor, which defines the protrusion of included space (e.g., two-dimensional Riemannian space) from enveloping space (e.g., three-dimensional Euclid space). Based on previous studies, the density of earthquake occurrence is proportional to the curvature of the plastic folding deformation of the crust, which is related to Euler-Schouten curvature, and fault dislocation also accumulates at the regions with its high curvature. The row (accumulation) of fault dislocation can be replaced by the disclination, and Riemann-Christoffel curvature, derived from Euler-Schouten curvature tensor, also expresses disclination density. In particular, angular folding with local curvature accompanied by a pair of disclination is called Kink folding, forming the mass-loss or mass-excess regions around disclination. Since Kink folding can approximately be the same as the undulating region bounded by several faults (fault block) in strain concentration zones, it is expected that the northeastern Japan arc has not only negative zones of gravity anomaly but also positive zones along the arc due to the mass-loss or mass-excess regions around disclination. Therefore, we conclude that the positive and negative zones of gravity anomaly along the northeastern Japan arc reflect the geometric condition of the crust with disclination.