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Projected West Antarctic ocean warming caused by an expansion of the Ross Gyre
Felipe Gomez-Valdivia
Paul Holland

Felipe Gomez-Valdivia

and 4 more

June 27, 2022
We use the United Kingdom Earth System Model simulations from the Coupled Model Intercomparison Project 6 to analyse the dynamics of the Ross Gyre, West Antarctica, under historical and projected climate-change scenarios. During the historical period, the modelled Ross Gyre is relatively stable, with an extent and strength that are in reasonable agreement with observations. The projections exhibit an eastward gyre expansion into the Amundsen and Bellingshausen seas that starts during the 2040s. The associated cyclonic ocean circulation enhances the onshore transport of warm Circumpolar Deep Water into the eastern Amundsen Sea, a regime change that increases the subsurface shelf temperatures by up to 1.2◦C and is independent of future forcing scenario. The Ross Gyre expansion is generated by a regional surface stress curl intensification associated with anthropogenic forcing. If realised in reality, such a warming would strongly influence the future stability of the West Antarctic Ice Sheet.
Seismic evidence for a weakened thick crust at the Beaufort Sea continental margin
Clément Estève
Yajing Liu

Clément Estève

and 4 more

June 27, 2022
The Canadian Beaufort Sea continental margin of northwestern Canada is a Cenozoic convergent margin, potentially representing a rare case of incipient subduction. Here, we produce P- and S-wave seismic velocity models of the crust and the uppermost mantle using recordings from regional earthquakes. Our models reveal a northwest-dipping very low-velocity anomaly within the crust (δV up to -15%) beneath the Romanzof Uplift. We interpret this low-velocity feature to correspond to a weaker and thicker crust due to shortening and stacking of igneous and sedimentary rocks. The co-location of the thickened crust and lack of present-day seismicity indicates that north-south compression is accommodated by slow, aseismic deformation in the narrow margin beneath the Romanzof Uplift or more broadly offshore. Neither interpretation requires a subduction initiation process.
A Cautionary Tale: small earthquakes that might have changed our understanding of Tib...
Tim Craig
Jackson James

Timothy James Craig

and 3 more

June 27, 2022
Earthquake moment tensors and centroid locations in the catalogue of the Global CMT (gCMT) project, formerly the Harvard CMT project, have become an essential and extraordinarily valuable resource for studying active global tectonics, used by many solid-Earth researchers. The catalogue’s quality, long duration (1976–present), ease of access and global coverage of earthquakes larger than about Mw~5.5 has transformed our ability to study regional patterns of earthquake locations and focal mechanisms. It also allows researchers to easily identify earthquakes with anomalous mechanisms and depths that stand out from the global or regional patterns, some of which require us to look more closely at accepted interpretations of geodynamics, tectonics or rheology. But, as in all catalogues that are, to some extent and necessarily, produced in a semi-routine fashion, the catalogue may contain anomalies that are in fact errors. Thus, before re-assessing geodynamic, tectonic or rheological understanding on the basis of anomalous earthquake locations or mechanisms in the gCMT catalogue, it is first prudent to check those anomalies are real. The purpose of this paper is to illustrate that necessity in the eastern Himalayas and SE Tibet, where two earthquakes that would otherwise require a radical revision of current geodynamic understanding are shown, in fact, to have gCMT depths (and, in one case, also focal mechanism) that are incorrect — in spite of the overwhelming majority of gCMT solutions in that region being unremarkable and likely to be approximately correct.
Management of a iatrogenic cecal perforation after abdominal drain placement on a hor...
Ulrika MAIRE
Martin Genton

Ulrika MAIRE

and 2 more

January 20, 2023
Summary: A 16-year-old, French Saddlebred was referred for colic signs, diagnosed with incarceration of the jejunum in a mesoduodenic rent and subsequently treated surgically (with an end-to-end anastomosis of the jejunum and an enterotomy of the pelvic flexure). The horse recovered uneventfully, but the next day developed moderate signs of endotoxemia and severe sero-sanguineous discharge from the abdominal wound. Substantial peritoneal effusion was assessed on abdominal ultrasound and required an abdominal drain placement. The site was at first checked with ultrasound, and insertion of a redon drain was performed. Immediately, a brown smelly liquid drained in large quantities (figure 1), and examination of this liquid revealed it to be enteral fluid. The drain was pushed in the viscera and the horse brought to surgery. Placement of an embolectomy catheter was performed before induction and as the horse was induced the balloon catheter was inflated. The drain was pulled out of the viscera and traction on the embolectomy catheter was kept until a repeat laparotomy was performed (figure s2). Moderate contamination of the abdominal cavity occurred during the iatrogenic perforation of the cecum. The balloon catheter effectively occluded the breach in the cecum and revealed to be strong enough to pull on the viscera without tearing it. The abdominal cavity was then lavaged with 80 L of ringer lactates and another abdominal drain was placed. The horse recovered uneventfully and did not display any further complication during the rest of his hospitalization. The horse returned within 6 months to its intended use. KEY POINTS Abdominal drain placement carries risks of complication, one of them being enteric placement of the drain Temporary occlusion of the defect is feasible using an embolectomy catheter pending surgery If swift action is taken, contamination of the abdominal cavity can stay moderate.
Beyond carbon, nitrogen and phosphorus: Exploring the relationship between elemental...
Pu Yan
Nianpeng He

Pu Yan

and 3 more

January 20, 2023
The elemental composition of plants (i.e., the elementome) relates to their functional traits which has important implications for understanding nutrient cycles and energy flows within ecosystems. Theoretically, elemental diversity (ED) captures functional diversity by comparing the n-dimensional elementome of the present species in a community. However, empirical evidence linking ED with ecosystem functioning is still lacking. We collated an unprecedented volume of data (> 2500 species and 14 analyzed elements from leaves, stems, trunks, and fine roots) across eight biomes from 72 sites to explore the spatial patterns and drivers of ED and its relationship with ecosystem productivity and stability. Our results revealed that interannual variability in temperature is the main factor explaining ED spatial patterns. We provide strong empirical evidence indicating that ecosystems with higher ED show higher productivity and stability. The results provide important insights into how elementome differences among organisms affect ecosystem function across ecosystems and biomes.
Variability Assessment of Soil Water Balance Components in an Almond Field using Dist...
Tiago Ramos
Ana R. Oliveira

Tiago Ramos

and 3 more

May 15, 2022
Accurate estimates of the soil water balance components are critical for optimizing irrigation water use in agricultural fields. Estimates are normally obtained using simple water balance models and for representative areas, not taking into consideration the within variability of soil properties. In this study, we used the MOHID-Land distributed process-based model to compute the variability of the soil water balance components in a 23ha almond field located in southern Portugal, at a resolution of 5m. The main objective was the possible assessment of management zones for improving water productivity in that water-scarce region. An electromagnetic induction survey was carried out first to obtain electromagnetic conductivity images which provided the spatial distribution of the real soil electrical conductivity (ff) with depth. The spatial distribution of ff was then correlated to soil particle size distribution using an in-situ calibration. Afterward, pedotransfer functions were applied to define the soil hydraulic parameters necessary to run the distributed model and map the within soil variability at the field scale. Irrigation data was monitored on-site, at two locations, while weather data was extracted from a local meteorological station. The distributed modeling approach included the definition of potential evapotranspiration fluxes computed from the product of the reference evapotranspiration obtained according to the FAO56 Penman-Monteith equation and a crop coefficient for each stage of almond’s growing season, the variable-saturated flow using the Richards equation, and root zone water stress following a macroscopic approach. Modeling results were used to present the maps of the variability of the seasonal actual crop transpiration and soil evaporation, the mean soil moisture, seasonal runoff, and seasonal percolation. Then, management zones for improving irrigation water use in the studied almond field were proposed.
Magnetic field conditions upstream of Ganymede
Marissa F. Vogt
Fran Bagenal

Marissa F. Vogt

and 2 more

September 23, 2022
Jupiter’ magnetic field is tilted by ~10º; with respect to the planet’s spin axis, and as a result the Jovian plasma sheet passes over the Galilean satellites at the jovigraphic equator twice per planetary rotation period. The plasma and magnetic field conditions near Ganymede’s magnetosphere therefore change dramatically every ~5 hours, creating a unique magnetosphere-magnetosphere interaction, and on longer time scales as evidenced by orbit-to-orbit variations. In this paper we summarize the typical magnetic field conditions and their variability near Ganymede’s orbit as observed by the Galileo and Juno spacecraft. We fit Juno data from orbit 34, which included the spacecraft’s close Ganymede flyby in June 2021, to a current sheet model and show that the magnetospheric conditions during orbit 34 were very close to the historical average. Our results allow us to infer the upstream conditions at the time of the Juno Ganymede flyby.
Biocultural calendars in southwestern South America
Ricardo Rozzi
Ricardo Álvarez

Ricardo Rozzi

and 5 more

March 25, 2022
To integrate temporal and spatial dimensions of seasonal cycles, we combine two conceptual frameworks: ecological calendars and the “3Hs” model of the biocultural ethic. The latter values the vital links between human and other-than-human co-inhabitants, their life habits (e.g., cultural practices of human communities or life cycles of other-than-human species) and the structure, patterns and processes of their shared habitats. This integration enhances an understanding of core links between cultural practices and the life cycles of biocultural keystone species. As a synthesis, we use the term biocultural calendars to emphasize the co-constitutive nature of calendars that result from continuous interactions between dynamic biophysical and cultural processes. We apply biocultural calendars to examine cultural practices and socio-environmental changes in southwestern South America, specifically in Chile, spanning from (1) Cape Horn at the southern of the Americas in sub-Antarctic habitats inhabited by the Yagan indigenous community, (2) artisanal fisher communities in Chiloe; archipelagoes, (3) coastal regions of central-southern Chile inhabited by Lafkenche and Williche indigenous communities, to (4) high Andean habitats in northern Chile co-inhabited by Aymara communities along with domesticated camelids and a rich biodiversity. To illustrate biocultural calendars, we designed analemma diagrams that show the position of the Sun in the sky as seen from a fixed time and location, and linked to continuous renewal of astronomical, biological and cultural, seasonal cycles that sustain life. These biocultural calendars enhance the integration of indigenous and scientific knowledge to confront complex challenges of climate change faced by local communities and global society.
Quantifying complex microstructures of earth materials: Reconstructing higher-order s...
Hamed Amiri
Ivan Vasconcelos

Hamed Amiri

and 4 more

March 26, 2022
Key to most subsurface processes is to determine how structural and topological features at small length scales, i.e., the microstructure, control the effective and macroscopic properties of earth materials. Recent progress in imaging technology has enabled us to visualise and characterise microstructures at different length scales and dimensions. An approach to characterisation is the sampling of n-point correlation functions - known as statistical microstructural descriptors (SMDs) - from images. SMDs can then be used to generate statistically equivalent structures having larger sizes and additional dimensions – this process is known as $reconstruction$. We show that a deep-convolutional generative adversarial network trained with Wasserstein-loss and gradient penalty (WGAN-GP) results in a stable training and high-quality reconstructions of two-dimensional electron microscopy images of complex rock samples. To evaluate reconstruction performance, n-point polytope functions are calculated in both reconstructed and original microstructures and mean square error between them is used as a quality metric. These n-point polytope functions provide statistical information about symmetric, user-oriented higher-order geometrical patterns in microstructures. Our results show that GANs can naturally capture these higher-order statistics at short and long ranges. Furthermore, we compare our model with a benchmark stochastic reconstruction method based solely on two-point correlation. Our findings indicate that although yielding the same two-point statistics, two microstructures can be morphologically and structurally different, emphasising the need for coupling higher-order correlation functions with reconstruction methods. This is a critical step for future schemes that aim to reconstruct complex heterogeneous systems and couple microstructures to macroscopic phenomena.
A Non-linear Optimization Model to Minimize Flood Risks on Urban Roadways Due to Stor...
James Ekeh
Manoj K Jha

James Ekeh

and 1 more

March 25, 2022
Urban flooding is caused due to poor drainage design, extreme weather, and excessive rain. Such flooding severely affects the road infrastructure. While there are a number of hydrologic software (e.g., TR-55, HydroCAD, TR-20, HEC-RAS, StreamStats, L-THIA, SWMM, WMOST, MAST, HY-8) available to examine extent of urban flooding, the softwares primarily require walking through a series of manual steps and address each study area individually preventing a collective view of an urban area in an efficient manner for hydrologic analysis. Furthermore, the softwares have no ability to recommend optimal culver pipe sizes to minimize flooding. In this paper, we develop a non-linear optimization formulation to minimize urban flooding using underdrain pipe size as a decision variable. We propose a solution algorithm in an integrated GIS and Python environment. Monte Carlo Simulation is used to simulate rainfall intensity by using empirical data on extreme weather from the National Oceanic and Atmospheric Administration. An example using the storm-drain system for the Baltimore County is performed. The results show that the model is effective in identifying storm-drain deficiencies and correcting them by choosing appropriate storm-drain inlet types to minimize flooding. The proposed method eliminates the need to examine each study area manually using existing hydrologic tools. Future works may include expanding the methodology for large datasets. They may also include a more sophisticated modeling approach for estimating rainfall intensity based on extreme weather patterns.
Transcriptomics to unravel regulation of nutrient uptake rates upon synthetic CEP1 pe...
Divya Jain

Divya Jain

February 06, 2022
Plant roots are responsible for essential functions like nutrient uptake, anchorage, and storage. Study of root uptake mechanisms for macro nutrients like nitrogen, phosphorus, potassium, and sulphur is vital to our understanding of their role in plant growth and development. Small signaling peptides (SSPs), are hormones which regulate diverse plant developmental processes including root growth. However, their involvement in regulation of nutrient uptake by roots is poorly understood. We recently developed a hydroponics- based plant growth system which combines ion chromatography with synthetic peptide application, to analyze the depletion rates of nutrients by Medicago truncatula roots. Application of the synthetic SSP MtCEP1 and AtCEP1 led to enhanced uptake of nitrates, sulphates, and phosphates. To further elucidate the molecular mechanism of nutrient uptake mediated by these peptides, we conducted an RNAseq of M. truncatula roots treated with the peptides. A differential gene expression analysis revealed thousands of peptide responsive genes. Several known nitrate transporters and a sulphate transporter AtSULTR3:5-like gene showed enhanced expression under both, MtCEP1 and AtCEP1 peptide application. Multiple, as of yet uncharacterized, CEP peptide responsive pathway regulatory genes such as kinases and transcription factors were also identified through this transcriptomic analysis. This study highlights the potential of phenomics enabled biology to uncover target genes for improving agriculturally important traits such as nutrient uptake.
The Impact of Seasonal Phenology on Photosynthetic Water Use Efficiency: an Evaluatio...
Kenneth J Davidson
Julien LAMOUR

Kenneth Davidson

and 4 more

December 15, 2021
Vegetation acts as a critical link between the geosphere, biosphere, and atmosphere, regulating the flux of water to the atmosphere via transpiration (E) and the input of carbon from the atmosphere to plants and soil via photosynthetic carbon assimilation (A). The rate of A is known to be seasonally dynamic, however, few studies have investigated how the ratio between E and A, known as the water use efficiency (WUE), changes with phenology. WUE directly impacts regional to global carbon and water cycles and lack of knowledge regarding the dynamics of WUE remains among the largest uncertainties in current earth system model (ESM) projections of carbon and water exchange in temperate forests. Here we attempt to reduce this knowledge gap by studying these dynamics across a range of eight deciduous tree species common to temperate forests of North America. Using gas exchange and spectroscopic measurements, we investigated seasonal patterns in leaf level physiological, biochemical, and anatomical properties, including the seasonal progress of WUE and foliar capacity for carbon assimilation, which corollate with seasonal leaf phenology. We incorporate these findings into a modeling framework that contains the same representation of A, E, and canopy scaling found in ESMs to explore the impact of parameterization, which tracks phenological status, on model forecasts. Our results indicate that both photosynthetic capacity and WUE are seasonally dynamic processes which are not synchronized. WUE increased from a minimum at leaf out toward a more conservative behavior at the mid-summer growth peak. This pattern was explained by a decreased stomatal aperture and a decrease in cuticular leakage with leaf aging. We also observed a seasonal increase in maximum carboxylation capacity, with maximum rates of A and modeled tree net primary productivity (NPP) occurring later toward the end of the summer. This change was primarily driven by an increase in foliar nitrogen content, and a shift in the ratio of Vcmax to Jmax between expanding and mature leaves. By applying our revised parameterization, which captures seasonal dynamics of gas exchange, into our model framework we aim to improve the process representation of leaf function in a temperate forest, and more faithfully represent dynamics of NPP and E in the early and late growth season.
The Effect of Equatorial noise on the Proton Density Structure of the Inner Van Allen...
Jayasri Joseph
Allison N Jaynes

Jayasri Joseph

and 4 more

January 10, 2022
We present evidence of damping of equatorial noise due to Finite-Larmor-radius (FLR) effect in the inner Van Allen belt. Detail observation of the FLR phenomenon in the inner belt region has not been reported until now. Waves primarily damped by the FLR mechanism can influence the energy dependent proton density structure. We analyze a typical case recorded by the Van Allen probe that involves FLR damping of equatorial noise, which was propagating radially towards the Earth, at L-shell ~1.7. As a result of this damping, protons in the energy range of ~18 – 21 MeV at L-shell ~1.7 – 2 get energized. This kind of wave-particle interaction should be included in the future models of the inner Van Allen belt. This phenomenon may also account for the unknown proton loss mechanism reported in Selesnick and Albert (2019).
Clouds in the Vicinity of the Stratopause Observed with Lidars at Mid-latitudes (40.5...
Shaohua Gong
Guotao Yang

Shaohua Gong

and 4 more

December 24, 2021
A cloud event in the altitude range of 53-65 km was observed with lidars over Yanqing (40.5°N, 116°E) and Pingquan (41°N, 118.7°E) on 30 October 2018. Clouds with a multilayer structure first occurred within the line view of lidar at dawn (03:40-06:00LT). They were faint and tenuous, and the maximum volume backscatter coefficient (VBSC) was 1.4×10-10m-1sr-1. At twilight, clouds with multilayer structures were reobserved via lidars, but they became much thicker, with a maximum VBSC of 11.2×10-10m-1sr-1. The structure of the cloud layers varied with time, and they faded completely at approximately ~00:30 LT (+1 day). Measurements from SABER/TIMED were utilized for analysis, and it was found that before the onset of cloud event, a temperature anomaly occurred in the mesosphere over Beijing, and water vapor was also very abundant. The frost point temperature profile of water vapor was estimated, and lidar measurements showed that the atmospheric temperature was close to the frost point of water vapor in the vicinity of the stratopause when the mesosphere was undergoing a low-temperature phase. It was a rare mesospheric cloud event observed with lidars at rather low latitudes, and the clouds probably resulted from the nucleation of saturated water vapor due to the occurrence of a temperature anomaly in the mesosphere.
Effects of differences in aboveground dead organic matter types on the stand-scale ne...
Hayato Abe

Hayato Abe

May 04, 2022
[This presentation is published at https://doi.org/10.1111/1440-1703.12317] Dead organic matter (DOM), which consists of leaf litter, fine woody debris (FWD; < 3 cm diameter), downed coarse woody debris (CWDlog), and standing or suspended coarse woody debris (CWDsnag), plays a crucial role in forest carbon cycling. However, the contributions of each DOM type on stand-scale carbon storage (necromass) and stand-scale CO2 efflux (Rstand) estimates are not well understood. In addition, there is little knowledge of the effect of each DOM type on the accuracy of stand-scale estimates of total necromass and Rstand. This study investigated characteristics of necromass and Rstand from DOM in a subtropical forest in Okinawa island, Japan, to quantify the effect of each DOM type on total necromass, total Rstand, and estimate error of total necromass and Rstand. The CWDsnag accounted for the highest proportion (54%) of total necromass (1499.7 g C m–2), followed by CWDlog (24%), FWD (11%), and leaf litter (11%). Leaf litter accounted for the highest proportion (37%) of total Rstand (340.6 g C m–2 yr–1), followed by CWDsnag (25%), CWDlog (20%), and FWD (17%). The CWDsnag was distributed locally with 173% of the coefficient of variation for necromass, which was approximately two times higher than those of leaf litter and FWD (72–73%). Our spatial analysis revealed, for accurate estimates of CWDsnag and CWDlog necromass, sampling areas of ≥ 28750 m2 and ≥ 2058‒42875 m2 were required, respectively, under the condition of 95% confidence level and 0.1 of accepted error. In summary, CWD considerably contributed to stand-scale carbon storage and efflux in this subtropical forest, resulting in a major source of errors in the stand-scale estimates. In forests where frequent tree death is likely to occur, necromass and Rstand of CWD are not negligible in considering the carbon cycling as in this study, and therefore need to be estimated accurately.
Watershed Model Parameter Estimation in Low Data Environments
Roja Garna
Daniel Fuka

Roja Garna

and 9 more

December 13, 2021
Watershed scale models are essential for determining best management practices (BMPs), but they contain many parameters that modelers cannot directly measure. Modelers commonly estimate these parameters through a calibration process based on observed streamflow and nutrient data. However, a lack of long-term streamflow records makes watershed model parameter estimation in low data environments (LDE) challenging for hydrologists. To reliably estimate parameters in LDE, a new calibration technique, simultaneous multi-basin calibration (SMC), was developed to estimate the parameters of several SWAT model initializations for newly instrumented USGS gages in the Lake Champlain Basin of Vermont, USA (Little Otter Creek-Monkton, West Branch Dead Creek, and East Branch Dead Creek). In SMC, SWAT models of each watershed were initialized following standard methods. Then, in order to increase information content, the simulated flow from each model and the corresponding measured flow were combined, and calibrated as one model using a differential evolution algorithm DEoptim. We compared the results obtained from the new technique with one of the most commonly used approaches for calibration in LDE: the similarity-based regionalization (SBR) based on a calibration of a nearby watershed with similar characteristics. In the SBR method, the calibrated parameters from a watershed with a more extended period of recorded data (donor watershed, Little Otter Creek-Ferrisburg) transfer to the LDE watersheds (receptor watersheds). We show that in SBR the uncertainty of the donor watershed model propagates through the receptor watershed model, this propagation does not occur in SMC. We demonstrated that the agreement between simulated and observed streamflow, via the Nash-Sutcliffe efficiency (NSE) improved model performance from 1-20% using the SMC technique. Moreover, the calibrated soil storage parameters, including soil depth, available water capacity, and soil saturated hydraulic conductivity obtained from individual SMC and SBR models, were compared to the SSURGO soil database, where the SMC method provided parameter estimates that more closely matched SSURGO. This study demonstrated that a SMC method can outperform SBR in low data environments.
Identifying Southern Ocean fronts using unsupervised classification and edge detectio...
Simon Thomas
Daniel C Jones

Simon Thomas

and 4 more

May 22, 2021
Fronts are ubiquitous in the climate system. In the Southern Ocean, fronts delineate water masses, which correspond to upwelling and downwelling branches of the overturning circulation. A robust understanding of Southern Ocean fronts is key to projecting future changes in overturning and the associated air-sea partitioning of heat and carbon. Classically, oceanographers define Southern Ocean fronts as a small number of continuous linear features that encircle Antarctica. However, modern observational and theoretical developments are challenging this traditional framework to accommodate more localized views of fronts [Chapman et al. 2020]. In this work, we present two related methods for calculating fronts from oceanographic data. The first method uses unsupervised classification (specifically, Gaussian Mixture Modeling or GMM) and an interclass metric to define fronts. This approach produces a discontinuous, probabilistic view of front location, emphasising the fact that the boundaries between water masses are not uniformly sharp across the entire Southern Ocean. The second method uses Sobel edge detection to highlight rapid changes [Hjelmervik & Hjelmervik, 2019]. This approach produces a more local view of fronts, with the advantage that it can highlight the movement of individual eddy-like features (such as the Agulhas rings). The fronts detected using the Sobel method are moderately correlated with the magnitude of the velocity field, which is consistent with the theoretically expected spatial coincidence of fronts and jets. We will present our python GitHub repository, which will allow researchers to easily apply these methods to their own datasets. Figure caption Two methods for interpretable front detection. Solid lines represent classical fronts. (a) The “inter-class” metric, which indicates the probability that a grid cell is a boundary between two classes. The classes are defined by GMM of principal component values (PCs) derived from both temperature and salinity. The different colors indicate different class boundaries. (b) Sobel edge detection: approximately the magnitude of the spatial gradient of the PCs divided by each field’s standard deviation, which highlights locations of rapid change.
Study and analysis of Irrigation furrow measurement, Flow rate Soil moisture distribu...
Kishor Kolhe
Duba Chena

Kishor Kolhe

and 1 more

May 10, 2021
Abstract Techniques of furrow preparation on a field are mostly traditional; farmers provide furrow shape and direction based on their experience without the concept of scientific information. The measurement, evaluation and optimization of furrow irrigation are restricted to the single furrow or small number of adjacent furrows. The measurement process is too intensive to be applied at the full field scale. Consequently; it is necessary to assume that the infiltration characteristics and inflow rates of the measured furrow(s) represent the remainder of the field. The field inflow and outflow rates of five irrigation events in experimental plots were planned. The gross applied and estimated depth of irrigation was determined for a scheme based on the available data of inflow rate, which was measured through the graduated bucket and CROPWAT 8 model, respectively. Soil specific calibration was made for the soil moisture reading and its error result is presented. Furrow parameters including; furrow slope, width, length, and shape were measured and presented. The results of soil moisture measurements showed that crops are water stressed during the experiment period. Application efficiency decreases with increasing steep slope and cutoff time, large applied depth, and high inflow rate in the study area. The Melka Hida small scale irrigation scheme was granted to farmers and empowered them occasionally to harvest twice in a year. With increased population growth and the erratic rainfall, competition of water users in this area is reported increasing from time to time. This limits water usage, crop production and overall living standard of farmers of this region.
S-wave velocity structure of the Sichuan-Yunnan region, China: implications for extru...
Chuansong He
Haoyu Tian

Chuansong He

and 3 more

January 17, 2021
The Sichuan-Yunnan region is located at the intersection between the South China Block, the Indian plate and the Tibet Plateau and is crisscrossed with deep and large faults and is characterized by strong seismic activities. Here we employ one-year continuous waveforms of the vertical component of 89 broadband seismic stations in this region to evaluate the velocity structure and its implications. Through single station data preprocessing, cross-correlation calculation, stacking, group velocity dispersion measurement and quality evaluation, the group velocity dispersion curves of Rayleigh waves for the different periods were obtained. We then use the surface wave tomography method to obtain the Rayleigh wave group velocity distribution of 9-40s in this area. Finally, the S-wave velocity structure in the depth range of 0-60 km in the study area is obtained by pure path dispersion inversion. The results show that the surface layer or the top of the upper crust in the Sichuan Basin is characterized by low velocity due to the influence of the sedimentary strata, whereas the middle and lower crust of the Sichuan Basin shows high velocity structure. The Sichuan-Yunnan diamond-shaped block (SYDB) in the middle curst shows high-velocity structure, whereas in the lower crust show low-velocity structure. The seismic activities are mainly concentrated at the western part of the region, with the earthquakes distributed at the boundary between the low- and high-velocity structures, as well as the adjacent region, which we correlate with the extrusion of the Tibet Plateau.
Ecthyma Gangrenosum in Three Unrelated  Patients with Combined Immunodeficiency      ...
Arefeh Zahmatkesh
Mahnaz Jamee

Arefeh Zahmatkesh

and 3 more

January 23, 2023
Case reportEcthyma Gangrenosum in Three Unrelated Patients with Combined Immunodeficiency Arefeh zahmatkesh1, Amirhossein Hajialigoli2, Mahnaz Jamee3, Zahra Chavoshzadeh4 1Pediatric Nephrology Research Center, Research Institute for Children’s Health, Shahid Beheshti     University of Medical Sciences, Tehran, Iran2Alborz Office of Universal Scientific Education and Research Network (USERN), Alborz University of      Medical Sciences, Karaj, Iran3Pediatric Nephrology Research Center, Research Institute for Children’s Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran4Immunology and Allergy Department, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Correspondence should be addressed to Arefeh Zahmatkesh: arefeh.zhmtksh@gmail.com.  AbstractBackground:Ecthyma Gangrenosum(EG) is a necrotizing vasculitis characterized by cutaneous manifestation ranging from a nodule or papule to necrotic ulceration with surrounding erythema, especially with black eschar or central crust. The most common pathogen that causes EG is Pseudomonas aeruginosa(PA). PA is an opportunistic pathogen with predominance incidence among patients with primary immunodeficiency with hypo or agammaglobulinemia, malignancies, and acquired immune deficiency.Case presentation:In this case study, we present three unrelated patients (three male toddlers, mean age: 0.75 years) with the primary manifestation of EG, who underwent immunological assessment and were diagnosed with combined immunodeficiency. all patients were alive although EG has a high mortality rate, the prognosis depends on the host and the degree of immunosuppression.  A history of Persistent fever followed by skin lesions was common in our cases. Surprisingly, the initial immunological assessment reported different cellular and humoral immune deficiencies with the overall diagnosis of combined immunodeficiency based on the ESID criteria. For patients suspected of EG, early diagnosis and administration of appropriate systemic antibiotic therapy can considerably reduce morbidity and potential mortality.Conclusions:This case report illustrates the importance of immunodeficiency evaluation in patients with a skin lesion and considers pseudomonas aeruginosa culture for initiating appropriate antipseudomonal antibiotic therapy. Although recent studies show high EG-related mortality with predisposing factors, hopefully, due to appropriate intravenous antibiotics and immunoglobulin therapy, all patients remained alive.Key-words:Ecthyma Gangrenosum, combined immunodeficiency, Immunoglobulins I. Introduction Ecthyma gangrenous (EG) is a rare skin disorder, that usually starts as an erythematous macule, which developed into a vesicle. These Lesions can rapidly indurate and develop pustules or bullae, which slough and leave an eschar. (1) The first case of EG was reported by L. Borker. Hitschman and Kreibichin 1897, which accompany Pseudomonas septicemia. (2) although several studies show more pathogens associated with EG, Pseudomonas aeruginosa(Pa) is the most reported cause. (3). Pa as an opportunistic bacterium can detect from the skin, nose, throat, and stool. (4) The most common site for superinfection of the skin with Pa includes the gluteal and anogenital region, the extremities, the trunk, and the face. (5). The pathogenesis of skin lesions due to Pa is mainly dependent on the vessel walls invasion interfering with the toxin followed by ischemic necrosis resulting in necrotic ulcer with a black/gray eschar surrounded by an erythematous halo. (6) Since the first report of EG, several studies show the EG incidence among patients with predisposing risk factors like pre-existent viral infections, weak mechanical skin barriers, especially immunocompromised individuals, and even previously healthy patients. Also, malignancies like leukemia (7) and primary immunodeficiency disorders like leukocyte adhesion deficiency-1(LAD) (8), and X-linked agammaglobulinemia(XLA) are reported related to EG. (9) However, skin necrosis is a symptom of a broad range of pathologies, (1) the diagnoses of EG are based on clinical findings, that are confirmed by the skin and blood culture. (2) Besides, early appropriate treatment e.g., antibiotics, and surgical debride reduce EG-related mortality rates, also understanding the patient’s immunological status and underlying disease affect the prognosis, and initiation of appropriate treatment can reduce mortality rates. (3)This manuscript summarizes three cases of EG who were admitted to a tertiary hospital with pursuing chief complaints, initial evaluation, and treatment.II.   Case reportsA. Case 1A 16-month-old male was admitted to the hospital with a one-week history of fever and lesions on his left groin, neck, and left axilla. his fever started 3 days after influenza vaccine and didn’t respond to initial treatment(Acetaminophen). He hospitalized due to persistent fever and then Bullae lesions began 2 days after admission and progressed to a necrotic lesion with infectious secretion with a positive lesions culture which showed pseudomonas aeruginosa, he received appropriate antibiotics (Amikacin and Imipenem) based on the culture and G-CSF due to leukopenia with no response. He had a diarrhea history due to milk powder allergy when he was 2 months. His vaccination was upon the routine plan.  His parents were relative and did not report any recent travel and allergic reaction. The physical examination showed vesicular dark lesions on his left leg, axillary region, and neck. His lower extremities were swollen and tender, especially on left foot. The left foot was warmer than the right and had more lesions compared to other sites. The liver was enlarged up to 3 cm below the right costal margin, and the spleen was impalpable. In chest examination, coarse crackles at both lungs and the right lung consolidation on the chest X-ray (CXR) were found. The laboratory findings are summarized in Table 1. In the first days of admission, neutropenia and thrombocytopenia was detected, which improving during hospitalization.On the second day of administration, he was admitted to the intensive care unit (ICU) due to his unstable condition. He suffered extensive ulcerative lesion with necrotic center on his left foot which was more tender and warmer than the opposite site. Following surgery consultation, Doppler sonography and X-ray of lower extremities were performed, which showed subcutaneous and intermuscular adenoma, which suspected to myositis and necrotizing fasciitis was ruled out.In this center bacterial blood culture was negative. we started antibiotics therapy with Meropenem, Vancomycin, and Clindamycin, then changed the regimen to Ceftazidime and Clindamycin after 22 days of administration. In addition, human serum albumin and calcium with heart monitoring, were prescribed and because of low hemoglobin, packed red blood cells was infused. He received Ribavirin suspected for Crimean Congo Hemorrhagic Fever. On hospital day 3, the necrotic lesion was debrided and drained surgically. Finally, based on immunology consultation, he started receiving 5-gram intravenous immunoglobulin (IVIG). He was continued on antibiotics and finally discharged from the hospital in a stable condition with receiving monthly IVIG. B. Case 2A 5 month years old male was admitted to this center with four days’ history of fever and chilling, which did not respond to medical treatment with cephalexin. The fever was complicated with several lesions on the face after one day. Erythematous plaques without pus were seen on the cheek, under the right eye, and genitalia Picture 1. His vaccination was upon the routine plan. His parent were not relatives and did not report any recent travel or contact with the ill person. His sibling was healthy. In his physical examination, multiple hemorrhagic plaques were observed on the right leg and left thigh. Lower extremities and scalp were swallowed. He did not have organomegaly on the abdominal examination. The chest examination was normal. He was under observation in the pediatric intensive care unit and received 2 gr intravenous immunoglobulin (IVIG) because of his severe edema (suspicious of Kawasaki disease) on the first day of admission. He was also started on abroad-spectrum systematic antibiotic regimen (Meropenem, Vancomycin, and Amikacin) after admission. On hospital day 5, his fever was reduced and skin lesions improved, while his wound culture grew Pseudomonas aeruginosa. Because of the immunodeficiency suspicion, bone marrow aspiration(BMA) was performed, which reported maturation arrest in the myeloid series. For agammaglobulinemia assessment, immunologic workup was performed which yielded in Table 1. and compare with other cases.With Ecthyma Gangrenosum impression, he received intravenous methylprednisolone 1 mg/kg/BD and Mometasone ointment twice a day. He continued on antibiotics and underwent surgical debridement of the necrotic lesion and skin graft. His temperature gradually returned to normal after surgical and medical treatment on hospital day 15, he was discharged from the hospital in stable condition with prophylactic antibiotic (Cotrimoxazole) and repeating complete blood count every 2 weeks.C. Case 3:A 6months old male was admitted to this center with a history of a two-week fever. The fever was accompanied by erythematous papule which transformed into necrotic, bullous, and gangrene lesions and spread through his thigh, posterior conjunctiva, and left flunk Picture 2. One week before referral to this center, he was hospitalized and received antibiotics (Meropenem, Vancomycin, and Ciprofloxacin) upon a positive pseudomonas wound culture and positive Klebsiella cerebrospinal fluid (CSF) culture. He had a history of acholic defecation two days before hospitalization. His parents were not relatives and his older siblings were healthy. He did not have a history of recent travel or contact with a contiguous disease. In the physical examination, a few gangrenous 2*3 mm lesions with surrounding blisters were scattered on his left flank, thigh, and posterior conjunctiva. The right testis was larger than normal and bilateral hydroceles were noted. The sclera was icteric. Pulmonary and heart examinations were normal. The abdomen was distended with a bilateral erythematous lesion, without tenderness, rebound, or guarding. The liver was enlarged to 3 Cm below the right costal margin and the spleen was impalpable.The broad-spectrum antibiotic (Amikacin, Meropenem, and Vancomycin) were administrated as well as two doses of IVIG to provide passive antimicrobial coverage. In addition, abdominal sonography and surgical debridement were performed. Sonography showed mild pulmonary edema, cellulitis, myositis, and hydrocele. On hospital day 2 regarding the abnormal liver function test (LFT), he received Ursobil, and LFT was checked two times every week. Vitamins and fresh frozen plasma (FFP) were also prescribed to correct international normalized ratio(INR). The immunologic function was tested. the lymphocyte subtypes detail notice in the Table 1 and compared with others. The T CD8+ cells were reduced and the lymphocyte transformation test (LTT) was dysfunctional Table, further confirming the diagnosis of combined Immunodeficiency. He was discharged with 5 mg IVIG, antibiotics, and antifungal prophylaxis.The first step of Biochemical diagnosis of CID suspected patients is complete blood count which gives clues of immunological alteration. despite, the assessment of absolute neutrophil and lymphocyte count of our cases was influenced by Pa toxin, after human immunodeficiency virus (HIV) ruled out the specific evaluation of immunological parameters was performed. this evaluation included: i. Measurement of immunoglobulins (IgA/IgG/IgM/IgE) which is summarized in Table 1-D. Except for generalized hypogammaglobinemia in case 1, reduced IgE and IgA were seen in cases 2&3. ii. Vaccinal response which done when maternal antibodies transferred via placenta decrease (6 month years old) Table 1-E. based on our data we detected less than 1 Iu/mL Anti-Diphtheria IgG in case 2. iii. Measurement of leukocyte subtypes by flow cytometry (Immunophenotyping of CD3/CD4/CD8/CD19 and NK) summarized at Table 1-C. CD3+ as a general lymphocyte and CD19+ as a B lymphocyte marker reduced in case1&3.  Reduced CD3+/CD4+  in case 2&3 shows lymphocyte impairment, and high CD3+/CD8+ indicate low CD8+ in all cases. More CD information provide in Table 1-F. iv. Lymphocyte function assessment by Lymphocyte Transformation Test (LTT) can be measured by lymph proliferation after stimulation with phytohemagglutinin(PHA). Table 1-B. In our study all patients had normal PHA level, however cell proliferation against BCG in case 1 was slightly low and also cell proliferation against Candida in case 2&3 were reduced. II.  Discussion and conclusion:  Ecthyma Gangrenosum is a rare skin disorder, which is an ulcerative variant of septic vasculitis. EG is characterized by sharply circumscribed “pinched out” deep ulceration. These lesions usually start as an erythematous macule, which subsequently forms a vesicle, pustules, bullae with debris, and necrotic material within the ulcer. (1) since the first case report of EG, several studies show different causative pathogens. (2) In a study of 164 patients diagnosed with EG  between 1974 to 2014, PA was detected in 73.65% of cases, whereas other bacteria and even Candida albicans, were detected in only 17.35% and 9% of cases respectively. (3) Although in case 3 we isolated Klebsiella from CSF culture , Pa was detected from all lesions culture. However, Klebsiella can cause EG.(4) A case report from Isezuo K.O in 2018, shows different isolated organisms from CSF(S.aureus) and lesions(E.coli) culture in the concept of co-infection at EG pathogenesis. (5) Pa species are a normal part of the skin flora and usually found in the anogenital, axillae, and external ear canal. (6) clinical manifestations related to PA  are mainly due to the vessels walls invasion mediated by the toxin, (7) and usually affects the lower extremities, especially gluteal and genital areas. fever, diarrhea, pneumonia, shock are the most relevant associated symptoms especially in PA sepsis. (5) As CCHF was suspected in case 2, several studies show infections that can mimic EG, like mycobacterial ulcer, cutaneous leishmaniasis cutaneous tuberculosis, and even deep fungal infections thus, EG must be considered in any necrotic lesions that are unresponsive to prolonged antibiotics. (8) Another important differential diagnosis is necrotizing fasciitis which was ruled out by MRI in case3. (9)Despite, EG usually being described in immunocompromised patients, it also has been seen in patients suffering from malnutrition, underlying (hematological) malignancy, and even previously healthy individuals. (10)A literature review by Danel J Lewis et al in 2019, shows cutaneous manifestations of primary immune deficiency disorders (PID). (11) several studies show EG in patients who suffer from X-linked agammaglobulinemia (XLA) (Burton hypogammaglobinemia), which is characterized by the complete absence of circulating B-cells and plasma cells, with decreased(IgG) or absent (IgA and IgM) levels of immunoglobulins. (12) Leukocyte Adhesion Deficiency (LAD) is also reported with EG. these disorders involve an absence of ß2-integrin subunit(CD18), which prevents neutrophils aggregation. (11)  neutrophils are a vital part of the cellular host defense against bacterial infections, whereby neutrophil count bellow 500/mm3 cause the greatest risk of bacterial infections. (13) two cases of our study (Case1&2) had neutropenia on the first days of admission which resolved after treatment. In addition to several case reports of neutropenia with EG, PA toxins can produce neutropenia through bone marrow suppression and inhibition of granulocyte migration. (2). In 2003 Maria Baro et all reported X-linked agammaglobulinemia with EG, that neutropenia with bone marrow granulocyte arrest resolved when infection was treated. They also postulated that neutropenia could result from a neutrophil-altered response to stress due to mutations in the Btk gene that is expressed in myeloid series. (14) unlike other cases, case 3 had neutrophil predominance. in a case report at a tertiary hospital in Sokoto, the index patients also had neutrophil predominance as usual neutropenia associated with PA. However, our patient’s immunological comparison didn’t show obvious differences, this may be explained by their relatively good immunity. (8) another primary immune disease that leads to neutrophil dysfunctions is chronic granulomatous disease(CGD), it is caused by gene mutations encoding essential subunits of NADPH oxidase complex subsequently neutrophils fail to increase oxygen consumption for the destruction of phagocytes bacteria (e.g.; Klebsiella, Pseudomonas, Candida) and fungi. (15)  Nitro blue tetrazolium Blood Test(NBT) was normal (100%) in all our cases, thus we rollout CGDs. Besides underlying immunodeficiency diseases, some studies suggest that the immunoglobulin level and B cell percentage were decreased in the disease process and are transient.(10) However hypogammaglobinemia and reduced B cell were observed in our cases, CID was applied based on other flow cytometry data and ESID criteria. However it should be considered molecular diagnosis such as next-generation sequencing(NGS) is the exact diagnostic modality.(16)Combined immunodeficiency (CID) is an Inborn Error of Immunities(IEIs) characterized by defects in both humoral and cellular limbs of the immune system. the main clinical manifestations of IEIs are susceptible to unusual or recurrent infections that are difficult to treat. (17)  Previous studies show variable skin manifestations in CID patients with syndromic features (e.g.: atopic dermatitis in Wiskott-Aldrich syndrome (18), bulbar telangiectasia and ataxia in Ataxia-telangiectasia (19), Café au lait macules and telangiectasia in sun-exposed are in Bloom syndrome (20), dermatitis, prominent papulopustular eruption and recurrent staphylococcal infections with abscess formation in Hyper-IgE syndrome (Job syndrome) (21).The first step of Biochemical diagnosis of CID-suspected patients is a complete blood count which gives clues of immunological alteration. (22) despite, the assessment of absolute neutrophil and lymphocyte count of our cases being influenced by Pa toxin after HIV was ruled out the specific evaluation of immunological parameters was performed. this evaluation included (23, 24):In our study all patients were alive. although EG has a high mortality rate, prognosis depends on the host and the degree of immunosuppression. in patients with EG and septicemia secondary to pseudomonas it ranged from 38%-77%, and in patients without sepsis is about 15%. (25) Notably, neutropenia below 500 cells can predispose a patient to severe PA infection and this seems to be associated with a higher mortality rate even in a previously healthy child. (13) EG’s high mortality rate emphasizes the importance of early suspicion and proper treatment even when the diagnosis has not been confirmed. While awaiting culture results, empirical antimicrobial therapy with anti-pseudomonas penicillin and aminoglycoside should be started, and adjusted based on culture results. Administration of GCSF along with antibiotics should be considered to shorten the duration of neutropenia, to help resolve the EG, and to minimize the risk of septicemia in immunocompromised patients.  In conclusion, EG is a rare skin disorder, usually caused by PA, and commonly occurs in immunocompromised individuals. despite, the previously healthy and immunocompetent individuals, may become affected, we must consider an immune assessment for all patients, especially in early childhood. furthermore, early diagnosis of an underlying illness, notably primary immunodeficiency, leads to using the appropriate treatment and preventing EG-related mortality.Data Availability: Not applicable.Ethical Approval: Informed consent was obtained from the patient and parents of the patient prior to being included in the study.Consent: Written informed consent for publication was obtained from the parents of the patients prior to being included in the study.Conflicts of Interest: The authors have no conflicts of interest.Acknowledgments The authors thank the patients and their families for their participation in this study.    Ⅳ. Table 1Laboratory data: A.       Complete blood count:                           CBC1 Case number WBC 1000/ul Neutrophils 1000/µl Lymphocyte 1000/µl HB g/dl Platlet cell/ul 1 2700 1215 1405 10.7 306000 2 7980 1516 5426 9 381000 3 7900 5925 1422 11.9 219000 1.CBC: Complete Blood Count B.       Lymphocyte transformation test:                 LTT1    Case PHA2 (normal range≥3) BCG (normal range≥2.5) Candidia (normal range≥2.5) 1 4 2.2 4.4 2 3.2 3.1 2.2 3 4.3 3.1 1 1.LTT: Lymphocyte Transformation Test, 2.PHA: Phytohemagglutinin, C.       Flow cytometry:             CD markers1   Case   CD3+    CD4+   CD3+/CD4+    CD8+      CD3+/CD8+      CD16     CD19     CD56         1     88% Absolut=1236×103/µl (range=1400-8000)               58%        1.51 (range=0.9-5.5)                31%                2.84 (range=0.4-2.3)             4%      7% Absolut=98×103/µl (range=600-3100)         4%         2         70.1% Absolut=3798 (range=2400-6900)      55.2%       1.27 (range=1.4-5.1)      18.2%          3.84 (range=0.6-2.2)        -           14.2% Absolut=770 (range=700-2500)       -          3     68% Absolut=967 (range=2400-6900)      62%        1.09 (range=1.4-5.1)      6%           11.37 (range=0.6-2.2)       1.5%          14% Absolut=199 (range=700-2500)                3%  1.CD3: T-cells(general), CD4: T helper, CD8: T cytotoxic, CD16: Granulocytes/natural killer cells(NK), CD19: B-cells, CD56: NK D.       Immunoglobulins             Igs Case       IgG mg/dl        IgM mg/dl        IgA mg/dl            IgE mg/dl             1         110 Normal range for age:(666-1340)            18 Normal range for age:(76-233)          <3 Normal range for age:(24-116)           1 Normal range for age:()             2         820 Normal range for age:(377-774)           65  Normal range for age:(40-141)          <37 Normal range for age:(13-56)           3 Normal range for age:()             3         698   Normal range for age:(363-1690)           86 Normal range for age:(48-249)          7 Normal range for age:(7-78)           0.7 Normal range: 70-400)   E.        Immunoglobulin response:  Case Anti-Tetanus IgG Anti-Diphtheria IgG                 1                 1.5                0.26                 2                 2.12                >1                 3                 -                 -  1.NBT: Nitroblue Tetrazolium Test F.         Further flow cytometry information: Case2: flow cytometry lymph phenotyping analysis, Gate: Lymph (21.0%), Viability:>90% CD1 0.1 CD34 2.3 CD2 69.6 CD11 2.5 CD3 70.1 CD9 0.3 CD4 55.2 CD10 0.1 CD5 68.2 CD19 14.2 CD7 69.2 CD20 13.5 CD8 18.2 CD22 12.9 CD13 0.1 CD45 95.1 CD33 2.5 CD18 90  rang(60-90) CD14 1.3 CD11a 99 rang(Total=50-90,Lymph=50-90) CD15 97 rang(60-90) CD11b 90 rang(Total=40-85,Lymph=5-20)   CD11c 97 rang(Total=10-30%,Lymph=2-8%)    Case3: flow cytometry lymph phenotyping analysis, Gate: Lymph (39%), Viability:90%, Specimen: PB   CD2 77.4 CD20 21.3 CD56 0.3 CD3 84.3 CD38 0.1     CD4 67.2 CD4/CD8(dual) 0.4     CD8 7.9 CD2/CD19(dual) 0.2     CD10 1 CD3/HLADR(dual) 2.1     CD19 19.1 CD16 1.5        V. PicturesPictures-1:Case B:·         Initial lesions
Winter Equatorial Warming in Martian Upper Atmosphere from MAVEN Densities
Jiandong Liu
Yawen Li

Jiandong Liu

and 5 more

December 23, 2020
Martian upper atmosphere warming reflects the energy-materials interactions from the lower atmosphere layers. In this paper, we show a new phenomenon that enhances Mars upper atmosphere density in the equatorial region during the winter periods. First, both accelerometer-derived density and NGIMS-measured species from MAVEN show that the winter equatorial region has a secondary warming peak compared with that of the high-latitude polar warming area. Second, the major neutrals (CO2, Ar, CO, N2, and O) indicate that the phenomenon extends at least up to 240 km during both day and night sides. Furthermore, the topographic-related longitudinal structure emerged in the equatorial sector indicates that the variations are more dynamical than we expected. The warming found in this study suggest to be dust-related and influenced by the evolution of the seasonal solar insolation. Both local factors, upward small-scale gravity waves and CO2 IR-thermal effect transfer, may play key roles in shaping the warming structure.
The Climate Literacy and Energy Awareness Network (CLEAN)
Kathryn Boyd
Anne Gold

Kathryn Boyd

and 9 more

November 20, 2020
It is important that we prepare tomorrow’s scientists, decision makers, and communities to address the societal impacts of a changing climate. In order to respond to, manage, and adapt to those changes, citizens of all ages need accurate, up-to-date information, knowledge of the sciences, and analytical skills to make responsible decisions and long-term resiliency plans regarding these challenging topics. The Climate Literacy and Energy Awareness Network (CLEAN, http://cleanet.org) is 1) providing teaching resources for educators through the CLEAN Collection and pedagogical support for teaching climate and energy science; and 2) facilitating a professionally diverse community of climate and energy literacy stakeholders, called the CLEAN Network, to share and leverage efforts to extend the reach and effectiveness of climate and energy education. This presentation will provide an overview of the CLEAN web portal and techniques we have used to market it. We will showcase the CLEAN Collection, which is comprised of 700+ resources (curricula, activities, videos, visualizations, and demonstrations/experiments) that have been reviewed for scientific accuracy, pedagogical effectiveness, and technical quality. Recent activities of the CLEAN Network will be highlighted. We will present findings from our web analytics work, which monitors visitor use of the CLEAN web portal. Through analytics data, we will show evidence of successful CLEAN marketing efforts. The results of our recent pop-up survey, which has been completed by CLEAN visitors from six continents, will also be discussed. Survey results will provide detailed information about how our audiences use the web portal. We anticipate that our insights from the CLEAN network can aid other climate and energy education programs in effectively increasing the visibility of their vital work.
Effect of Porosity and Permeability Evolution on Injection-Induced Aseismic Slip
Yuyun Yang
Eric M Dunham

Yuyun Yang

and 1 more

October 30, 2020
It is widely recognized that fluid injection can trigger fault slip. However, the processes by which the fluid-rock interactions facilitate or inhibit slip are poorly understood and some are neglected or oversimplified in most models of injection-induced slip. In this study, we perform a 2D antiplane shear investigation of aseismic slip that occurs in response to fluid injection into a permeable fault governed by rate-and-state friction. We account for pore dilatancy and permeability changes that accompany slip, and quantify how these processes affect pore pressure diffusion, which couples to aseismic slip. The fault response to injection has two phases. In the first phase, slip is negligible and pore pressure closely follows the standard linear diffusion model. Pressurization of the fault eventually triggers aseismic slip in the immediate vicinity of the injection site. In the second phase, the aseismic slip front expands outward and dilatancy causes pore pressure to depart from the linear diffusion model. Aseismic slip front overtakes pore pressure contours, with both subsequently advancing at constant rate along fault. We quantify how prestress, initial state variable, injection rate, and frictional properties affect the migration rate of the aseismic slip front, finding values ranging from less than 50 to 1000 m/day for typical parameters. Additionally, we compare to the case when porosity and permeability evolution are neglected. In this case, the aseismic slip front migration rate and total slip are much higher. Our modeling demonstrates that porosity and permeability evolution, especially dilatancy, fundamentally alters how faults respond to fluid injection.
Magma mixing during conduit flow is reflected in melt-inclusion data from persistentl...
Zihan Wei
Zhipeng Qin

Zihan Wei

and 2 more

September 04, 2020
While emitting most magmatic gas passively, persistently degassing volcanoes commonly erupt with varied explosivity. To understand the eruptive behavior without the ability to observe volatile transport at depth, we rely on indirect constraints such as CO2-H2O concentration profiles in melt inclusions trapped at different depth, but this data is rarely straight-forward to interpret. Here, we use a multiscale model, which resolves individual bubbles within the larger context of conduit flow, to establish a closer link between conduit flow and surface measurements. We quantify when and why magma mixing happens in bidirectional conduit flow. We then test the joint effect of magma mixing and CO2 influx on volatile concentrations profiles against melt-inclusion and surface-gas-flux data for Stromboli and Mount Erebus. The finding that the two processes have distinct observational signatures suggests that tracking them jointly could help identify changes in the conduit flow and advance our understanding of the eruptive regimes.
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