bluuebunny/crossref_metadata_2025_split huggingface dataset:
Potential caveats in land surface model evaluations using the US drought monitor: roles of base periods and drought indicators
Authors: Wang Hailan , Xu Li , Hughes Mimi , Chelliah Muthuvel , DeWitt David G , Fuchs Brian A , Jackson Darren L 
Published: December 2021

Abstract
The US drought monitor (USDM) has been widely used as an observational reference for evaluating land surface model (LSM) simulation of drought. This study investigates potential caveats in such evaluation when the USDM and LSMs use different base periods and drought indices to identify drought. The retrospective national water model (NWM) v2.0 simulation (1993–2018) was used to exemplify the evaluation, supplemented by North American land data assimilation system phase 2 (NLDAS-2). Over their common period (2000–2018), in distinct contrast with the USDM which shows high drought occurrence (>50%) in the western half of the continental US (CONUS) and the southeastern US with low occurrence (<30%) elsewhere, the NWM and NLDAS-2 based on soil moisture percentiles (SMPs) consistently show higher drought occurrence (30%–40%) in the central and southeastern US than the rest of the CONUS. Much of the differences between the LSMs and USDM, particularly the strong LSM underestimation of drought occurrence in the western and southeastern US, are not attributed to the LSM deficiencies, but rather the lack of long-term drought in the LSM simulations due to their relatively short lengths. Specifically, the USDM integrates drought indices with century-long periods of record, which enables it to capture both short-term (<6 months) drought and long-term (⩾6 months) drought, whereas the relatively short retrospective simulations of the LSMs allows them to adequately capture short-term drought but not long-term drought. In addition, the USDM integrates many drought indices whereas the NWM results are solely based on the SMP, further adding to the inconsistency. The high occurrence of long-term drought in the western and southeastern US in the USDM is further found to be driven collectively by the post-2000 long-term warm sea surface temperature (SST) trend, cold Pacific decadal oscillation and warm Atlantic multi-decadal oscillation, all of which are typical leading patterns of global SST variability that can induce drought conditions in the western, central, and southeastern US. Our findings highlight the effects of the above caveats and suggest that LSM evaluation should stay qualitative when the caveats are considerable.
Reforestation enhanced landscape connectivity for thermal buffering in China
Authors: Huang Anqi , Shen Runping , Jia Gensuo , Xu Xiyan 
Published: December 2021

Abstract
Deforestation-induced landscape fragmentation causes habitat loss and isolation, modifies local climate, and therefore threatens biodiversity. While, on the contrary, how large-scale reforestation may improve the connectivity and thermal buffers of habitats is not well understood. We show that decades long large-scale reforestation in China has effectively increased the size and connectivity of forest patches by gradually filling gaps among isolated patches and creating more core forests. The core forests have a stronger capacity to cool the land surface, leading to a daily mean cooling effect of −0.42 ± 0.23 °C relative to nearby marginal forests. Moreover, the core forests reduce diurnal range and seasonal variation of land surface temperature by 1.41 ± 0.23 °C and 0.42 ± 0.55 °C, respectively, relative to nearby marginal forests. The thermal buffering capacity of large size core forest (>100 km2) is more than twice that of small size (⩽10 km2). Despite their relatively low thermal buffering capacity, the marginal forests contribute about 73% to the increase of forest area in China during the last two decades and create buffer zones for the core forests to resist external disturbances, maintaining the internal stability of the forest ecosystem. We highlight that improving the integrity and connectivity of the forests with ecological restoration and succession can further enhance potential of forests to buffer local thermal environment under the current reforestation efforts, and thereby providing better connected thermal habitats for species to survive under climate change.
The changing carbon balance of tundra ecosystems: results from a vertically-resolved peatland biosphere model
Authors: Larson Erik J L , Schiferl Luke D , Commane Róisín , Munger J William , Trugman Anna T , Ise Takeshi , Euskirchen Eugénie S , Wofsy Steve , Moorcroft Paul M 
Published: December 2021

Abstract
An estimated 1700 Pg of carbon is frozen in the Arctic permafrost and the fate of this carbon is unclear because of the complex interaction of biophysical, ecological and biogeochemical processes that govern the Arctic carbon budget. Two key processes determining the region’s long-term carbon budget are: (a) carbon uptake through increased plant growth, and (b) carbon release through increased heterotrophic respiration (HR) due to warmer soils. Previous predictions for how these two opposing carbon fluxes may change in the future have varied greatly, indicating that improved understanding of these processes and their feedbacks is critical for advancing our predictive ability for the fate of Arctic peatlands. In this study, we implement and analyze a vertically-resolved model of peatland soil carbon into a cohort-based terrestrial biosphere model to improve our understanding of how on-going changes in climate are altering the Arctic carbon budget. A key feature of the formulation is that accumulation of peat within the soil column modifies its texture, hydraulic conductivity, and thermal conductivity, which, in turn influences resulting rates of HR within the soil column. Analysis of the model at three eddy covariance tower sites in the Alaskan tundra shows that the vertically-resolved soil column formulation accurately captures the zero-curtain phenomenon, in which the temperature of soil layers remain at or near 0 °C during fall freezeback due to the release of latent heat, is critical to capturing observed patterns of wintertime respiration. We find that significant declines in net ecosystem productivity (NEP) occur starting in 2013 and that these declines are driven by increased HR arising from increased precipitation and warming. Sensitivity analyses indicate that the cumulative NEP over the decade responds strongly to the estimated soil carbon stock and more weakly to vegetation abundance at the beginning of the simulation.
Extreme citizens science for climate justice: linking pixel to people for mapping gas flaring in Amazon rainforest
Authors: Facchinelli Francesco , Pappalardo Salvatore Eugenio , Della Fera Giuseppe , Crescini Edoardo , Codato Daniele , Diantini Alberto , Moncayo Jimenez Donald Rafael , Fajardo Mendoza Pablo Estenio , Bignante Elisa , De Marchi Massimo 
Published: December 2021

Abstract
In the Ecuadorian Amazon—one of Earth’s last high-biodiversity wilderness areas and home to uncontacted indigenous populations—50 years of widespread oil development is jeopardizing biodiversity and feeding environmental conflicts. In 2019, a campaign to eliminate oil-related gas flaring, led by Amazonian communities impacted by fossil fuel production, resulted in an injunction against the Ecuadoran Ministry of Energy and Non-Renewable Natural Resources and the Ministry of Environment and Water. On 26 January 2021 the Court of Nueva Loja issued a historical order to ban gas flaring in the Ecuadorian Amazon. The present citizen science project played an important role in this process, enabling the production of independent spatial information through participatory mapping with indigenous and farmer communities. Globally, lack of independent information about oil activities has led to the monitoring of gas flaring by satellite imagery, achieving remarkable results. However, apart from institutional and remotely sensed data, reliable spatial information on gas flaring in the Ecuadorian Amazon is not available. Therefore, we adopted the community-based participatory action research approach to develop a participatory GIS process, aiming both to provide reliable data and to support social campaigns for environmental and climate justice. This work presents the first participatory mapping initiative of gas flaring at a regional scale, carried out completely through open source data and software. Having identified 295 previously unmapped gas flaring sites through participatory mapping, we highlight that the extent of gas flaring activities is well beyond the official data provided by the Ecuadorian Ministry of Environment and National Oceanic and Atmospheric Administration Nightfire annual datasets, which map only 24% and 33% of the sites, respectively. Seventy five of the detected sites were in the Yasuní Biosphere Reserve. Moreover, 39 of the identified sites were venting instead of flaring, a phenomenon never before documented in the Ecuadorian Amazon. This study demonstrates that, because official datasets and satellite imagery underestimate the extent of gas flaring in the Ecuadorian Amazon, community-based mapping offers a promising alternative for producing trusted, community-based scientific data. This community-produced data can support campaigns for legal recognition of human rights and environmental justice in the Ecuadorian Amazon. Finally, this study shows how local environmental conflicts can foster policy transformations that promote climate justice.
Modelling potential range expansion of an underutilised food security crop in Sub-Saharan Africa
Authors: Koch O , Mengesha W A , Pironon S , Pagella T , Ondo I , Rosa I , Wilkin P , Borrell J S 
Published: December 2021

Abstract
Despite substantial growth in global agricultural production, food and nutritional insecurity is rising in Sub-Saharan Africa. Identification of underutilised indigenous crops with useful food security traits may provide part of the solution. Enset (Ensete ventricosum) is a perennial banana relative with cultivation restricted to southwestern Ethiopia, where high productivity and harvest flexibility enables it to provide a starch staple for ∼20 million people. An extensive wild distribution suggests that a much larger region may be climatically suitable for cultivation. Here we use ensemble ecological niche modelling to predict the potential range for enset cultivation within southern and eastern Africa. We find contemporary bioclimatic suitability for a 12-fold range expansion, equating to 21.9% of crop land and 28.4% of the population in the region. Integration of crop wild relative diversity, which has broader climate tolerance, could enable a 19-fold expansion, particularly to dryer and warmer regions. Whilst climate change may cause a 37%–52% reduction in potential range by 2070, large centres of suitability remain in the Ethiopian Highlands, Lake Victoria region and the Drakensberg Range. We combine our bioclimatic assessment with socioeconomic data to identify priority areas with high population density, seasonal food deficits and predominantly small-scale subsistence agriculture, where integrating enset may be particularly feasible and deliver climate resilience. When incorporating the genetic potential of wild populations, enset cultivation might prove feasible for an additional 87.2–111.5 million people, 27.7–33 million of which are in Ethiopia outside of enset’s current cultivation range. Finally, we consider explanations why enset cultivation has not expanded historically, and ethical implications of expanding previously underutilised species.
Lévy walk dynamics in non-static media
Authors: Zhou Tian , Xu Pengbo , Deng Weihua 
Published: December 2021

Abstract
Almost all the media the particles move in are non-static, one of which is the most common expanding or contracting (by a scale factor) non-static medium discussed in this paper. Depending on the expected resolution of the studied dynamics and the amplitude of the displacement caused by the non-static media, sometimes the non-static behaviors of the media can not be ignored. In this paper, we build the model describing Lévy walks in one-dimension uniformly non-static media, where the physical and comoving coordinates are connected by scale factor. We derive the equation governing the probability density function of the position of the particles in comoving coordinate. Using the Hermite orthogonal polynomial expansions, some statistical properties are obtained, such as mean squared displacements (MSDs) in both coordinates and kurtosis. For some representative non-static media and Lévy walks, the asymptotic behaviors of MSDs in both coordinates are analyzed in detail. The stationary distributions and mean first passage time for some cases are also discussed through numerical simulations.
Information geometry, trade-off relations, and generalized Glansdorff–Prigogine criterion for stability
Authors: Ito Sosuke 
Published: December 2021

Abstract
We discuss a relationship between information geometry and the Glansdorff–Prigogine criterion for stability. For the linear master equation, we found a relation between the line element and the excess entropy production rate. This relation leads to a new perspective of stability in a nonequilibrium steady-state. We also generalize the Glansdorff–Prigogine criterion for stability based on information geometry. Our information-geometric criterion for stability works well for the nonlinear master equation, where the Glansdorff–Prigogine criterion for stability does not work well. We derive a trade-off relation among the fluctuation of the observable, the mean change of the observable, and the intrinsic speed. We also derive a novel thermodynamic trade-off relation between the excess entropy production rate and the intrinsic speed. These trade-off relations provide a physical interpretation of our information-geometric criterion for stability. We illustrate our information-geometric criterion for stability by an autocatalytic reaction model, where dynamics are driven by a nonlinear master equation.
Requirements for the containment of COVID-19 disease outbreaks through periodic testing, isolation, and quarantine
Authors: Mukhamadiarov Ruslan I , Deng Shengfeng , Serrao Shannon R , Priyanka  , Childs Lauren M , Täuber Uwe C 
Published: December 2021

Abstract
We employ individual-based Monte Carlo computer simulations of a stochastic SEIR model variant on a two-dimensional Newman–Watts small-world network to investigate the control of epidemic outbreaks through periodic testing and isolation of infectious individuals, and subsequent quarantine of their immediate contacts. Using disease parameters informed by the COVID-19 pandemic, we investigate the effects of various crucial mitigation features on the epidemic spreading: fraction of the infectious population that is identifiable through the tests; testing frequency; time delay between testing and isolation of positively tested individuals; and the further time delay until quarantining their contacts as well as the quarantine duration. We thus determine the required ranges for these intervention parameters to yield effective control of the disease through both considerable delaying the epidemic peak and massively reducing the total number of sustained infections.
Confinement in bilayer graphene via intra- and inter-layer interactions
Authors: Castillo-Celeita Miguel , Jakubský Vít , Zelaya Kevin 
Published: December 2021

Abstract
We consider confinement of Dirac fermions in AB-stacked bilayer graphene by inhomogeneous on-site interactions, (pseudo-)magnetic field or inter-layer interaction. Working within the framework of four-band approximation, we focus on the systems where the stationary equation is reducible into two stationary equations with 2 × 2 Dirac-type Hamiltonians and auxiliary interactions. We show that the localized states are given in terms of solutions of an effective Schrödinger equation with energy-dependent potential. We consider several scenarios where bilayer graphene is subject to inhomogeneous (pseudo-)magnetic field, on-site interactions or inter-layer coupling. In explicit examples, we provide analytical solutions for the states localized by local fluctuations or periodicity defects of the interactions.
Monte Carlo simulations of the electron short-range quantum ordering in Coulomb systems and the ‘fermionic sign problem’
Authors: Filinov V , Levashov P , Larkin A 
Published: December 2021

Abstract
To account for the interference effects of the Coulomb and exchange interactions of electrons the new path integral representation of the density matrix has been developed in the canonical ensemble at finite temperatures. The developed representation allows to reduce the notorious ‘fermionic sign problem’ in the path integral Monte Carlo simulations of fermionic systems. The obtained results for pair distribution functions in plasma and uniform electron gas demonstrate the short-range quantum ordering of electrons associated in literature with exchange-correlation excitons. The charge estimations show the excitonic electric neutrality. Comparison of the internal energy with available ones in the literature demonstrates that the short range ordering does not give noticeable contributions to integral thermodynamic characteristics. This fine physical effect was not observed earlier in the standard path integral Monte Carlo simulations.
Structural and geological studies in the Naryn and Atbashi depressions (Tien Shan) and geological interpretation of magnetotelluric data
Authors: Przhiyalgovskii E S , Rybin A K , Morozov Yu A , Lavrushina E V , Leonov M G , Bataleva E A 
Published: December 2021

Abstract
The article presents the results of complex geological and geophysical studies in the Naryn depression and Atbashi depression in the Middle Tien Shan. They included the geological interpretation of new magnetotelluric data along the detailed profile crossing the key segment of the Tien Shan, and the study of the morphology and spatial position of the sedimentary cover and basement structures. The compilation of the results of structural-geological and geophysical studies makes it possible to create a 2D model of the upper-crust geological structure, consistent with the structure of the electrical conductivity to depths of about 10 km and to analyze the structural features of deeper horizons. Two types of structural patterns of the electric conductivity, corresponding to the sedimentary complexes of the cover and the folded-metamorphic complexes of the basement, have been identified. Sedimentary rock complexes in depressions have a high electrical conductivity and subhorizontal structure. The upper crust above the K2 density layer is characterized by an alternation of rocks volumes with contrasting conductivity, elongated vertically. The recorded structure of the field confirms the presence of steep zones of fluid permeability and fragmentation, noted earlier in seismic profiles and probably corresponding to the Paleozoic structures of fragmentation of the Earth’s crust, activated during Alpine orogeny. Comprehensive research allow to characterize the deformations of the Cenozoic sedimentary complex and the surface of the Paleozoic basement associated with the Alpine activation of the key segment of the Tien Shan.
Basin architecture and lithosphere structures of Western Central Asia – Uzbekistan: from geophysical studies
Authors: Sidorova I P 
Published: December 2021

Abstract
This paper presents an integrated geophysical study of the Western Central Asia (WCA) in the Uzbekistan area. It presents new interpretations of deep seismic sounding (DSS) data and new analyses of potential fields data. An integrated model of the physical properties and lithosphere structures displays distinct features that are related to tectonic history of the study WCA-Darius area. Task-oriented complex geological and geophysical research revealed in the lithosphere of western Uzbekistan series of crust blocks with abnormal petrophysical characteristics and established some correlation dependences between the distribution and placement of these objects (in plan) with deposits of minerals.
Features of the distribution of molecular hydrogen in groundwater in various geological and tectonic conditions of Uzbekistan
Authors: Umurzakov R K , Yusupov Sh S 
Published: December 2021

Abstract
As a result of generalization and analysis of previously performed work on the determination of hydrogen on the day surface, a picture of the distribution of hydrogen concentration in the aeration zone was obtained. The increased concentration of hydrogen on the day surface and in the aeration, zone is associated with the most favourable conditions for the transit of fluids from the folded Palaeozoic basement to the surface cover (upper part of the Earth’s crust). These zones are zones of active fluid conductivity, which leads to a high concentration of hydrogen on the day surface. Intense linear anomalies are confined to the zone of intersection of the Tuzkoy-Rometan transverse fault with the Bukhara-Gissar regional fault, with which seismic events are associated (epicentres Gazli earthquakes occurred 08.04.1976, 17.05.1976 and 19.03.1984). Analysis of long-term observations of gas composition on an example of molecular hydrogen in groundwater southwestern part Karzhantaus fault, covering the territory of Tashkent city and its surroundings, obtained hydrogen concentration distribution pattern area. A different concentration of hydrogen in the fault zone was revealed, associated with the heterogeneity of the geological and structural structure.
Geometric estimates of variations in space geodetic data
Authors: Kuzikov S I 
Published: December 2021

Abstract
Well-known statistical parameters have some disadvantages when analyzing space geodetic data. Geometric parameters are proposed here for estimating the variation properties of samples for various discrete datasets. The proposed parameters are logically related to each other and are based on the simplest well-known statistical parameters; they do not depend on the type of distribution of the sample under study. “Variation asymmetry” shows the shift of the arithmetic mean relative to the center of the variation interval in the units of the studied sample. “Density of variation” characterizes the level of average variability in sample units. This parameter has several times greater discriminatory sensitivity to extremely different types of variations than linear and standard deviations. The relative parameter “proportion of maximum density” shows the closeness of variation to a uniform distribution in the ranked sample and complements the indicator of variation density. An algorithm for separating different structural levels of the useful signal from emissions (noise) is proposed here based on the calculation of geometric characteristics. The iterations of dividing the sample into structurally homogeneous segments can be stopped at the level of the proportion of maximum density ≥0.9 when analyzing real GPS coordinates.