bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-scale anisotropy in NE China: Implications for intra-plate volcanism
Authors: Han Cunrui , Hammond James , Ballmer Maxim
Published: February 2023

Northeast China is a very typical area for studying intra-plate volcanism in the back-arc setting. It is commonly proposed that the subduction of the Pacific plate has been responsible for widespread Holocene volcanoes in NE China. Yet, how this process drives volcanism remains a topic of vigorous debate. Investigation of seismic anisotropy can provide important evidence for the cause-and-effect relationship between mantle flow, lithospheric deformation and shallow structures. In this study, using seismic data from four networks across NE China and north Korea, we analyze shear wave splitting in converted P- to S-waves at the Moho (Pms), S-waves from the subducted slab interface (local S), and SKS phases. The Pms phases show a relatively weak crustal anisotropy (~0.25 s), with fast polarization directions aligned sub-parallel to major tectonic features. For the local S and SKS phases, fast polarization directions show significant lateral variations. We further perform a quantitative inversion to show that the depth of the anisotropy is ~150 km, thus driven by flow within the asthenosphere associated with Pacific subduction. However, the presence of many null SKS splitting phases, together with scattered local S-wave anisotropy suggests a localized region of vertical flow directly beneath Changbaishan volcano. Such patterns correspond well to regional upper-mantle seismic velocity structure, and suggest that a localized upwelling with a relatively deep origin drives volcanism in the Changbaishan region. Furthermore, we infer that mantle upwelling is deflected to the SW beneath Changbaishan and spreads asymmetrically at the base of the lithosphere, possibly because of the long history of volcanism in the region.
Understanding Broadband Ocean Bottom Seismometer Noise: Fresh Insights and Future Directions
Authors: Janiszewski Helen , Eilon Zachary , Russell Joshua , Brunsvik Brennan , Gaherty James , Mosher Stephen , Hawley William , Coats Sloan
Published: February 2023

The proliferation of broadband ocean bottom seismometer (BBOBS) deployments over the last two decades has generated key datasets from diverse marine environments, improving our understanding of tectonics and earthquake processes. In turn, the community of scientists using this data has expanded. This growth in BBOBS data collection is likely to persist with the arrival of new seismic seafloor technologies, and continued scientific interest in marine and amphibious targets. However, the noise inherent in OBS data poses a challenge that is markedly different from that of terrestrial data. As a step towards improved understanding of the sources of variability in this noise, we present a new compilation and analysis of BBOBS noise properties from 15 years of US-led seismic deployments. We find evidence for similarity of noise properties when grouped across a variety of parameters, with groupings by seismometer type and deployment water depth yielding the most significant and interpretable results. Instrument design, that is the entire deployed package, also plays an important role, although it strongly covaries with seismometer and water depth. We find that the presence of tilt noise is primarily dependent on the type of seismometer used (covariant with a particular subset of instrument design), that compliance noise follows anticipated relationships with water depth, and that shallow, oceanic shelf environments have systematically different microseism noise properties (which are, in turn, different from instruments deployed in shallow lake environments). We discuss implications for the viability of commonly used seismic analysis techniques, and future directions for improvements in the efficiency of analysis of BBOBS data.
Digital Twin Water Management Platform - Innovative approach for optimal water management
Authors: Kim Jingon , Kim Kichul , Lee Junghwan , Kwon Mookhyunk , Kim Hyunjin , Jo Youngsik
Published: February 2023

Recently, digitalization has impacted drought and flood forecasting systems, and makes the application of technologies and advanced data processing techniques in the water management field possible. Especially, digital twin in the field of water management aims to effectively diminish unprecedented water-related issues such as floods and droughts using 3D objects and high-resolution spatial data. Climate change effects are expected to increase flood and drought risk through more frequent heavy precipitation and global temperature rise, and the water disaster sector is so complex, dynamic, and unpredictable that requires sophisticated management systems. The digital approaches showed effective prediction and decision-making support. This paper presents the state-of-the-art of digital twin concepts along with different digital technologies and techniques in water management contexts. The digital twin platform developed by K-water is a virtual representation of water management for dam operation and urban flood warning with water-related data. It presents a general framework of the digital twin in risk management, optimal operation, and decision-making in the water management and disaster forecasting field. This review also described the water data management, modeling including artificial intelligence, Radar, CCTV, rainfall-runoff module, analysis, prediction, and communication aspects of a digital twin. Digital twin platforms can support decision-makers as the next generation of digitalization paradigm by continuous and real-time water management of the cyber world and simulating the various events in the cyber world.Keywords: Digital Twin, Dam Operation, River, Spatial Data, AI, Urban Flood
Investigating the Hadley Cell and eddies with varying sea surface temperature gradients
Authors: Thakur Abu Bakar Siddiqui , Sukhatme Jai , Harnik Nili
Published: February 2023

We examine the tropical meridional overturning circulation in an aquaplanet GCM with fixed orbital parameters and uniform insolation angle. The atmosphere is forced by an imposed non-interactive sea surface temperature (SST) distribution which is varied between present-day Earth-like to a latitudinally uniform profile. A conventional Hadley Cell (HC) -like flow is observed in all experiments along with the poleward transport of energy and momentum. In simulations forced by a non-zero SST gradient, latent heat released from organized convection near the equator sets up a deep tropical cell. Rossby wave activity generated near the extratropical surface propagates upward and turns equatorward on reaching the tropopause. These waves break on the edge of the HC, fluxing heat and momentum poleward and reinforcing a thermally direct cell in the same sense as the HC. When the SST distribution becomes globally uniform, the traditional midlatitude Rossby waves are trapped near the surface as the mean flow inhibits their upward propagation. But, near the tropopause, baroclinicity generates waves that ride on a sharp upper tropospheric potential vorticity gradient. These waves propagate downwards towards the lower equatorial troposphere and transport angular momentum out of the tropics. Together with a dominant MJO-like mode, which facilitates near-equatorial convergence, this leads to a conventional tropical overturning circulation. As the SST gradient weakens, the HC moves from a regime intermediate to thermally and eddy-driven to one that's strongly influenced by eddies. Moreover, the thermal structure of the troposphere becomes uniform with weak gradients, and for flat SSTs, the tropopause in the midlatitudes is also set by convection. A Transformed Eulerian Mean perspective is consistent with this view and highlights the diabatic nature of the midlatitude circulation in the limit of flat sea surface temperatures.
Earth Radiation Budget Measurements on Chinese FY-3 Series Polar Orbit Satellites
Authors: Qiu Hong , Qi Jin
Published: February 2023

Earth Radiation Budget (ERB) measurement is one of the main missions of Chinese second generation of polar orbiting meteorological satellites ---FengYun-3 (FY-3) series. There are two instruments, the Solar Irradiance Monitor(SIM) and the Earth Radiation Budget (ERB), on board FY-3 satellite to observe the earth incoming and reflected solar radiance and the emitted radiance.  The ERMs on FY-3/A/B/C observe the Earth atmosphere within a narrow scanning field of view (NFOV）and a wide non-scanning field of view (WFOV). For each field of view, the measurements are made from two broadband channels: a total waveband channel covering 0.2 – 50 μm and a Short Wave (SW) band covering 0.2 - 4.3 μm. Because the sudden degradation happened that the SW channel of NFOV has stopped working after 20 months for FY-3A and 8 months for FY-3B in orbit. The observation from ERM on FY-3C has been in good condition for 9 years  In this presentation the performance of ERMs calibration in orbit is evaluated with CERES from EOS/Aqua and GERB-3 from Meteosat. The ERM LW and SW unfiltered radiance produced with spectral correction based on atmospheric transfer modelling has a good consistence with the other data. The new ERM instrument(ERM-II), which has a broadband LW channel covering 5-50 μm besides the Total and SW channels with a NFOV scanning mode, will be launch in the coming 2023 and provide 8 years global ERB observation from next FY-3 morning satellite.
Tracer-aided hydrological model in large mountainous catchments
Authors: Nan Yi , Tian Fuqiang
Published: February 2023

Issues related to large uncertainty and parameter equifinality have posed big challenges for hydrological modeling in cold regions where runoff generation processes are particularly complicated. Tracer-aided hydrological models that integrate the transportation and fractionation processes of water stable isotope are increasingly used to constrain parameter uncertainty and refine the parameterizations of specific hydrological processes in cold regions. However, the common unavailability of site sampling of spatially distributed precipitation isotopes hampers the practical applications of tracer-aided models in large-scale catchments. We explored the utility of precipitation isotope data derived from the isotopic general circulation models (iGCMs) in driving tracer-aided hydrological models in the typical large basins on the Tibetan Plateau (TP). Results indicate that the model driven by iGCM data can simulate the variation of isotope composition in stream water well. Integrating isotope simulation into the hydrological model helps reduce the modeling uncertainty, improve the parameter identifiability, and improve the quantification of the contributions of runoff components to streamflow.
Long-term Fluid Injection Can Expedite Fault Development: Riedel Shear Structures Illuminated by Induced Earthquakes in Alberta, Canada
Authors: Yu Hongyu , Kao Honn , Wang Bei , Visser Ryan
Published: February 2023

Riedel shear structures (RSS) are often observed in the embryonic stage of strike-slip fault development. Typical RSS often involve a set of conjugated fault segments that interact with each other prior to the growth of a through-going fault, that is, the principal deformation zone (PDZ), sub-structures R, R’ and P. Ideally, sub-structures R and P should be symmetric to the PDZ while structures R and R′ are conjugated to each other. It is a critical concept linking the geomechanical behavior of individual earthquakes to structural geology at both local and regional scales. The depiction of RSS can help understand the geomechanical behavior of individual earthquakes. In the meantime, the influence of long-term fluid injections on the developing process of RSS, as manifested by the common occurrences of injection-induced earthquakes, has been rarely addressed. Here we document a clear case in western Canada where the development of a local RSS system is expedited by 25 years of wastewater injection. RSS are manifested by an earthquake sequence consisting of 187 events (ML ranging 1.3–3.9) between 2018/01/01 and 2021/07/15 in an area without any previous seismic history. Focal mechanisms of these events exhibit various faulting types with the majority (87%) being compatible with the background stress regime. The orientation of derived nodal planes and six fault segments depicted from the refined earthquake distribution collectively define the overall geometrical characteristics of RSS, which consists of four primary strike-slip structures striking 19º (R’), 79º (R), 94º (PDZ) and 109º (P), respectively. Mohr-Coulomb failure analysis further suggests a cumulative stress perturbation of up to 10.0 MPa, probably bringing the local structures very close to the critically stressed state. Overall, our observations suggest that long-term fluid injection can expedite the development of local fault systems. Consequently, it is probably necessary to consider the full dimension of the local/regional RSS rather than the size of individual events in the assessment of the overall injection-induced seismic hazard. 
The role of afterslip in the stress interaction between repeating earthquakes and microseismicity in Parkfield
Authors: Chen Kate Huihsuan , Johnson Kaj , Burgmann Roland , Nadeau Robert
Published: February 2023

Earthquake can be triggered by small stress changes from local to distant earthquakes, seasonal forcing, and human activities. While the calculated magnitude and sign of stress change greatly varies with the assumption of source stress drop, receiver fault geometry, and consideration of aseismic slip, the near-field stress triggering can be easily misinterpreted. With a large number of repetitive occurrence times, small repeating earthquakes provides a unique opportunity to examine and model the extent to which fault interaction in the form of static stress changes and transient postseismic fault creep produces the observed aperiodicity in the occurrence of these events. Using the 655 repeating earthquakes (repeater) and M>1 4499 earthquakes during the period of 1984 – 2004 (before the M6 Parkfield event), the significant triggering between small earthquakes were previously documented as the increased rate of events producing(incurring) higher stress changes during the days preceding(following) a repeater. However, how to describe the stress in the vicinity of earthquakes has been a challenge especially that (1) the negative static shear stresses could be mistakenly resolved on the closely-located receiver and (2) the role of afterslip induced by very small earthquakes on the stress interactions could be largely underestimated. In this study, we propose the stress model that properly represents the relative three-dimensional location of the events and determine the instantaneous static stress fields associated with each event as well as the time-dependent contributions from afterslip. We hope to provide a better interpretation of the short-term triggering between the closely-spaced small earthquakes on the creeping strands of the SAF.
Coordinated Observations of Migrating Tides by Multiple Meteor Radars in the Equatorial Mesosphere and Lower Thermosphere
Authors: Yi Wen , Wang Jianyuan , Xue Xianghui , Vincent Robert , Batista Paulo , Tsuda Toshitaka , Mitchell Nicholas
Published: February 2023

We present the migrating tidal winds decomposed jointly from multiple meteor radars in four longitudinal sectors situated in the equatorial mesosphere and lower thermosphere. The radars are located in Cariri, Brazil (7.4°S, 36.5°W), Kototabang, Indonesia (0.2°S, 100.3°E), Ascension Island, United Kingdom (7.9° S, 14.4°W), and Darwin, Australia (12.3°S, 130.8°E). Harmonic analysis was used to obtain amplitudes and phases for diurnal and semidiurnal solar migrating tides between 82 and 98 km altitude during the period 2005–2008. To verify the reliability of the tidal components calculated by the four meteor radar wind measurements, we also present a similar analysis for the Whole Atmosphere Community Climate Model winds, which suggests that the migrating tides are well observed by the four different radars. The tides include the important tidal components of diurnal westward-propagating zonal wavenumber 1 and semidiurnal westward-propagating zonal wavenumber 2. In addition, the results based on observations were compared with the Climatological Tidal Model of the Thermosphere (CTMT). In general, in terms of climatic features, our results for the major components of migrating tides are qualitatively consistent with the CTMT models derived from satellite data. In addition, the tidal amplitudes are unusually stronger in January–February 2006. This result is probably because tides were enhanced by the 2006 Northern Hemisphere stratospheric sudden warming event.
Health co-benefits of green recovery in cities in China
Authors: Lu Chenxi
Published: February 2023

The compounding environmental, economic, societal and health crisis caused by the COVID-19 pandemic challenges the global endeavor to climate change and energy transition. The call for “green” recovery is unprecedently aiming to bring economies out of recession while also positively benefiting the environment. However, limited research has investigated the green recovery process during the post-COVID period.  This study explored the green recovery process defined by the increase of gross domestic product (GDP) and reduction of carbon emissions of 36 cities in China and the factors contributing to the green recovery in cities as well as potential health co-benefits of green recovery on cities during the post-COVID period (April1,2020-December 31, 2021) based on exposure-response function. We found that 8 (Beijing, Tianjin, Shenyang, Shanghai, Guangzhou, Haikou, Chengdu and Xian) out of 36 cities have achieved green recovery. During the post-COVID period, the mean Particular matter 2.5 (PM2.5) concentration has dropped 22.9%-26.7% relative to the pre-COVID period and avoided 49816 (95% CI: 29044- 88977) premature deaths attributable to PM2.5 exposure. The green recovery cities average avoid 2 persons per 1000 people during the post-COVID period. This research implies that the green recovery is happening in cities in China and could bring multi-benefits and the investment in green recovery can be offset by the health co-benefits. For cities that haven’t achieved green recovery, developing more green recovery policies is necessary. 
Quantifying soil microbial thermal adaptation
Authors: Alster Charlotte , van de Laar Allycia , Goodrich Jordan , Arcus Vickery , Deslippe Julie , Marshall Alexis , Schipper Louis
Published: February 2023

Thermal adaptation of soil microbial respiration has the potential to greatly alter carbon cycle-climate feedbacks through acceleration or reduction of soil microbial respiration as the climate warms. However despite its importance, the relationship between warming and soil microbial activity remains poorly constrained. Part of this uncertainty stems from persistent methodological issues and difficulties isolating the interacting effects of changes in microbial community responses from changes in soil carbon availability. To address these challenges, we sampled nearly 50 soils from around New Zealand, including from a long-term geothermal gradient, with mean annual temperatures ranging from 11-35°C. For each of these soils we constructed temperature response curves of microbial respiration given unlimited substrate and estimated a temperature optima (Topt) and inflection point (Tinf). We found that thermal adaptation of microbial respiration occurred at a rate of 0.29°C ± 0.04 1SE for Topt and 0.27°C ± 0.05 1SE for Tinf per degree of warming, demonstrating that thermal adaptation is considerably offset from warming. These relatively small changes occurred despite large structural shifts in microbial community composition and diversity. We also quantitatively assessed how thermal adaptation may alter potential respiration rates under future warming scenarios by consolidating all of the temperature response curves. Depending on the specific mean and instantaneous soil temperatures, we found that thermal adaptation of microbial respiration could both limit and accelerate soil carbon losses. This work highlights the importance of considering the entire temperature response curve when making predictions about how thermal adaptation of soil microbial respiration will influence soil carbon losses.
Reducing the computational cost of an iterative method for sediment yield minimization by afforestation
Authors: Castillo Reyes Grethell , Estrella René , Gabriels Karen , Van Orshoven Jos , Abrams Floris , Roose Dirk
Published: February 2023

Afforestation of certain areas of a river catchment can reduce the outflow of sediment from that catchment. We developed algorithms and software, called CAMF, to minimize the sediment outflow, based on a) a model for local sediment production, b) some parameters such as retention capacity and saturation threshold, c) a raster geo-database containing elevation data and land use. The software can also be adapted to model the effect of other actions than afforestation. We implemented both Single Flow Direction (SFD) and Multiple Flow Direction (MFD) methods to simulate flow transport. We analyze the differences between the two approaches. With the use of MFD methods the spatial interaction increases. As a consequence, the flow simulation with CAMF-MFD, executed in each iteration of the minimization procedure, has a substantially higher computational cost. The total execution time of CAMF can be prohibitively expensive for large geo-databases, since in each iteration only the cell(s) with the maximum sediment outflow reduction are selected.In each iteration of the minimization procedure, a sediment flow simulation is performed for each candidate cell. Since these simulations are independent of each other, we parallelized CAMF for multi-core processors using Open Multi-Processing (OpenMP) directives. Each thread executes the simulations for a subset of the candidate cells. To distribute the simulations over threads, dynamic scheduling is used to handle the imbalance due to the varying execution time of the simulations for each candidate cell. We also adapted the algorithm in two ways to accelerate the execution. First, in each iteration several cells, that produce nearly the same sediment yield reduction at the outlet, are selected. A threshold T determines the number of selected cells. Second, a complete ranking of all cells, with respect to their potential for sediment yield reduction by afforestation, is only computed every K iterations, while in intermediate iterations only N cells are ranked, namely those at the top of the previous complete ranking. The values for T, K and N substantially reduce the computational cost, while the solution quality is typically only slightly lower.We evaluated the performance of the accelerated variant for minimizing sediment outflow by afforestation using a raster geo-database of the Tabacay catchment (Ecuador), with a cell size of 30m × 30m. From a total of 73 471 non-null cells, 27 246 are candidate cells for afforestation.A high speedup is obtained for up to 28 cores (≈22), leading to a substantial reduction of the execution time. The accelerated variant produces nearly the same yield reduction at the outlet and selects almost the same cells than the original CAMF-MFD. The difference between the set of cells selected by both algorithms is measured by the relative spatial coincidence RSC. Results show that in all considered cases RSC > 99%.
Tectonostratigraphic evolution of the Hupo Basin in the western margin of the Ulleung back-arc basin, the East Sea
Authors: Park Yongjoon , Kang Nyeonkeon , Yi Boyeon , Lee Gwangsoo , Yoo Donggeun
Published: February 2023

The tectonostratigraphic evolution in the western margin of the Ulleung back-arc basin was reconstructed based on the seismic reflection data. According to our stratigraphic and structural analysis, the study area developed via four tectonostratigraphic stages, one extensional and two subsequent tectonic inversions. Together with the back-arc opening of the East Sea, most fault-controlled depocenters (e.g., half-grabens) were formed mainly in the western margin of the Ulleung Basin during the Early–early Late Miocene. This syn-extensional sedimentation occurred in non-marine to deep-marine environments analogous to typical rift-related linked depositional systems. During the early Late Miocene, the Ulleung back-arc basin had changed entirely into a compressive regime (NW–SE compression). Under the inversion tectonics, NNE–SSW and N–S trending extensional faults were mainly reactivated as reverse faults. The Hupo Basin was likely created by the regional flexural response to the crustal or thrust loading. As the formation of the Hupo Basin began, hemipelagic sedimentation accompanied by episodic gravity-controlled slope failures prevailed in the deep-water environment. Since the late Early Pliocene, the subsidence of the Hupo Basin was enhanced by the crustal shortening. The sedimentary condition became shallower gradually upward and coarse-grained terrigenous input into the Hupo Basin began, leading to deposition in shallow- to deep-marine environments. During the Quaternary, although the tectonic activity was subdued, the Hupo Fault was reactivated as a reverse fault, maintaining the uplift of the Hupo Bank and coeval flexural subsidence of the Hupo Basin. During this depositional period, shallow- to deep-marine deposition continued but a greater quantity of coarse-grained terrestrial sediments was transported into the Hupo Basin. The Quaternary depositional systems are likely the result of the interplay between tectonics and eustasy.
Evolution of the geological structure due to the collision of multiple basement topographic highs in a forearc accretionary wedge: insights from numerical simulations
Authors: Miyakawa Ayumu , Noda Atsushi , Koge Hiroaki
Published: February 2023

We propose a conceptual geological model for the collision of multiple basement topographic highs (BTHs; e.g., seamounts, ridges, and horsts) with a forearc accretionary wedge. Even though there are many BTHs on an oceanic plate, there are few examples of modeling the collision of multiple BTHs. We conducted numerical simulations using the discrete element method to examine the effects of three BTH collisions with forearcs. The typical geological structure associated with a BTH collision was reproduced during the collision of the first BTH, and multiple BTH collisions create a cycle of formation of BTH collisional structures. Each BTH forces the basal décollement to move up to the roof décollement, and the roof décollement becomes inactive after the passage of the BTH, and then the décollement moves down to the base. As the active décollement position changes, the sequences of underthrust sediments and uplifted imbricate thrusts are sandwiched between the décollements and incorporated into the wedge. The distinctive structural features observed in our model are comparable to the large faults in the Kumano transect of the Nankai Trough, Japan, where a splay fault branches from the plate boundary and there are old and active décollements. 
Responses of the middle and upper atmospheric wind to geomagnetic activities
Authors: Jiang Guoying , Liu Jinfang , Xu Jiyao , Zhu Yajun
Published: February 2023

Responses of the middle and upper atmospheric (80-100 km ) wind to geomagnetic activities have been investigated using neutral wind data from 2012 to 2018 years, which were observed by Mohe, Beijing and Wuhan Meteor radars. Daily averaged wind data for geomagnetic quiet condition (Kp<=2 ) and geomagnetic disturb condition (Kp>=4) were chosen for comparison, and the variation characteristics of wind during geomagnetic disturbances were obtained. The observations show that the influence of geomagnetic activity on zonal wind varied with seasons and latitudes. For zonal wind, the effect of geomagnetic activity at higher latitudes tended to be more westerly wind in the upper mesosphere and more easterly wind in the lower thermosphere, and the differences between disturbed and quiet conditions were on the order of 3 m/s; while for the lower latitudes, it tended to be more easterly wind in the 80-100 km region, and the influence were about 5 m/s. In spring, the three stations had similar tendencies, and had no latitude differences. But the easterly wind in the middle atmosphere became stronger with the decrease of latitude in summer/winter. The effect of geomagnetic activities on the meridional wind had seasonal differences. The influence of geomagnetic activities in spring and winter was stronger than that in summer and autumn. In winter, the effect of geomagnetic activity on the meridional wind in middle and low latitudes was stronger than that in higher latitudes. According to the calculation results, the influence on zonal wind was about 5 m/s to 10 m/s, and on meridional wind was about 3 m/s to 5 m/s. The impact of geomagnetic activities on MLT wind can penetrate down to about 80 km. At this height, the influence on zonal wind was the strongest in spring, reaching 8 m/s, and on meridional wind was the strongest in spring/winter, reaching 5 m/s.
Soil Zones of the Canadian Prairies: Creating Art to Visualize the Concept
Authors: van Rees Ken
Published: February 2023

Agriculture students, soil science faculty and farmers are familiar with the popular soil zone concept map for the Canadian Prairies. The map, first depicted by Professor AH Joel back in 1928 was based on organic matter contents as affected by climate and parent materials. Newer versions of the soil zone map have been created with colors associated with each soil zone (Brown, Dark Brown, Black, Gray and Dark Gray) that most people would be familiar with today. However, even though we have this mental picture of the color associated with the soil zones, what do the soils really look like if one were to visit sites in each of the different soil zones? Thus, the objective of the project was to collect surface soils samples from N-S transects along three highways in the province of Saskatchewan to convey the soil zones visually through art. Soil samples were collected every 25 km along the three highway transects: one in the east (Highway 9), one in the middle (Highway 2) and the west side of the province (Highway 21). Soil samples were dried, ground and sieved and then the samples used to create soil rubbings on watercolor paper for each of the transects. These transects would then be hung in the College of Agriculture building. A booklet would be developed with QR codes identifying where the samples were collected (GPS, nearest town, land management) and the organic matter content of the soils (measured in the soil science laboratory) that would be used for educational purposes whether in our soil science labs, lectures or summer children camps. This presentation will highlight the development of this project and how the information was used to visually communicate to students and the public the science behind the soil zones of the province.  
Relating Soil-Root Hydraulic Resistance Variation to Stomatal Regulation in Soil-Plant Water Transport Modeling
Authors: Lei Guoqing , Zeng Wenzhi , Ao Chang , Dong Liming , Liu Shenzhou , Ren Zhipeng
Published: February 2023

Soil-root hydraulic resistance variation and stomatal regulation are two critical hydrophysiological responses of plants to drought stress; however, few studies have been developed to quantify their interactions. To fill this gap, we developed a soil-plant hydraulic model (SR-HRV) that attempts to characterize the effects of stomatal regulation and three universal soil-root hydraulic resistance variations, i.e., root aquaporins promotion (AQU), apoplastic path damage (APD), and root-soil contact loosening (CONTACT). The sensitive parameters of the SR-HRV model were analyzed and optimized based on a field experiment with sunflower plants (Helianthus annuus L.). Several simulation scenarios were designed to clarify the individual and interactive effects of soil-root hydraulic resistance variations for plants with different stomatal sensitivities. Results show that the sensitivity of simulated stomatal conductance and soil water content response to stomatal regulation parameters, especially to abscisic acid-related parameters, are more active than to soil-root hydraulic resistance variation parameters. But as the soil dries, the sensitivities to APD and CONTACT parameters are rapidly increased. The simulation demonstrates that AQP alleviates the leaf water potential drop-down and maintains relatively high root water absorption of the plant when it is in mild drought conditions, while CONTACT and APD respectively restrict the water flux and drought signal responses with continuous soil dehydration. Moreover, the AQP effects are more pronounced but the effects of APD and CONTACT would be restricted for plants with higher stomatal sensitivity to drought signals. These simulation results imply the diverse response strategies of plants to drought, the collaborations between stomatal regulation and soil-root hydraulic resistance variations should be considered in soil-plant water transport modeling. 
Occurrence of Dissolved Organic Nitrogen (DON) in Low-relief Streams on the Eastern Shore of Virginia, USA
Authors: Herman Janet , Burruss Benjamin , Mills Aaron
Published: February 2023

The agricultural use of nitrogenous fertilizer in watersheds along the Atlantic Coast, USA, has fueled concerns and investigations into the upland-derived nitrate (NO3­-) discharging to coastal waters.  Past studies of low-relief, gaining streams in small watersheds on the Eastern Shore of Virginia, USA, have quantified the NO3-­-N flux to seaside lagoons and the Atlantic Ocean.  The contribution of dissolved organic nitrogen (DON) to the total nitrogen loading to coastal waters had not previously been evaluated.  This study quantified concentrations of DON, NO3­-, and total dissolved nitrogen (TDN) under baseflow conditions in 15 streams varying in watershed size and cropland use on the Eastern Shore of Virginia across a one-year period.  Mean concentrations of DON in streams ranged from 0.328 to 2.14 mg N L-1 and represented 12 to 70% of the TDN pool.  In 14 of the 15 streams, NO3- was the principal form of nitrogen ranging in mean concentrations from 0.094 to 6.06 mg N L­-1.  Instream DON concentrations were independent of NO3- concentrations, watershed area, and cropland use.  Unlike NO3-, DON varied seasonally with highest DON concentrations observed in spring.  DON ranged from 6 to 41% of the TDN in shallow groundwater with concentrations from 0.776 to 2.12 mg N L-1.  These concentrations were lower than the respective concentrations determined in overlying surface-water samples (0.001 to 0.773 mg N L-1) collected concurrently.  In a laboratory experiment, DON of 1.02 mg N L-1 was eluted in the effluent from an intact streambed sediment core using artificial groundwater influent containing NO3- only and represented nearly 60% of the TDN in the core effluent.  The results of this study establish DON as an important and dynamic constituent of the TDN pool in freshwater streams discharging from the Eastern Shore of Virginia, USA, to the coastal waters of the Atlantic Ocean.
Climate relevant processing of mineral dust by volatile organic compounds: first results on composition of complex dust/organic systems from the uptake of glyoxal
Authors: Battaglia Francesco , Formenti Paola , Cazaunau Mathieu , Michoud Vincent , Berge Antonin , Pangui Edouard , Noyalet Gael , Chevaillier Servanne , Giorio Chiara , D'Aronco Sara , Decorse Philippe , Doussin Jean-Francois
Published: February 2023

Mineral dust aerosols, which account for about 40% of global annual aerosol emissions, contribute to the persistent and large uncertainties on the global radiative budget and the oxidative capacity of the atmosphere.Indeed, the uptake of atmospheric volatile organic compounds (VOCs) on mineral dust particles can contribute to the formation of secondary organic aerosols (SOA), with consequent modification of the chemical and optical properties of the dust.Glyoxal, one of the most important VOC in the atmosphere, is a precursor of SOA, capable of interacting with mineral dust and forming SOA as a consequence of the interaction.In this experimental study we investigate the formation of SOA by the uptake of glyoxal on mineral dust particles. We present the results of the heterogeneous interaction obtained in the CESAM atmospheric simulation chamber (Chambre Expérimentale de Simulation Atmosphérique Multiphasique), used to conduct aging experiments in various controlled conditions in terms of relative humidity, irradiation, and gas phase composition. Prior entering the chamber, particles from a real soil sample (Gobi Desert) are size-selected using an aerodynamic aerosol classifier (AAC) in order to obtain a monodispersed size distribution centered at 300 nm in mobility diameter, narrow enough to be able to appreciate a dimensional variation from glyoxal condensation.In experiments conducted in humid conditions (RH=80%), a rapid uptake of glyoxal was observed on sub micrometric dust particles. 15 minutes after the injection of 1 ppm of glyoxal into the chamber, the mass of the particles increased by about 10%, with a variation of the modal diameter of the size distribution. As a consequence of glyoxal uptake in humid conditions, an increase of the aerosol organic mass concentration occurred immediately after the interaction, which was not observed in dry conditions. At the same time, the aerosol chemical speciation monitor (ACSM) mass spectra of the organic fraction show the increase in intensity of the glyoxal marker signals at m/z 58 and m/z 29. It is interesting to note also the drop of O/C ratio of the dust organic fraction after the injection of the glyoxal from 1.5 (the one of the dust itself) to a value close to 1, that is the one of the glyoxal.Hence, the first results of the study suggest the presence of a fast glyoxal uptake on submicronic mineral dust particles in high relative humidity conditions. This process modifies the mass and the size distribution of the aerosol, as well as the chemical composition of its organic fraction.
Observations of the vertical distributions of summertime atmospheric pollutants in Nam Co: OH production and source analysis
Authors: Xing Chengzhi , Liu Cheng , Hu Qihou
Published: February 2023

The Tibetan Plateau (TP) plays a key role in regional environment and global climate change, however, the lack of vertical observation hinders a deeper understanding of the atmospheric chemistry and atmospheric oxidation capacity (AOC) on the TP. In this study, we conducted MAX-DOAS measurements at Nam Co, central TP, to observe the vertical profiles of aerosol, water vapor, NO2, HONO and O3 from May to July 2019. In addition to NO2 mainly exhibiting a Gaussian shape with the maximum value appearing at 300-400 m, other four species all showed an exponential shape and decreased with the increase of height. The maximum values of monthly averaged aerosol (0.17 km-1) and O3 (66.71 ppb) occurred on May, water vapor (3.68×1017 molec cm-3) and HONO (0.13 ppb) appeared on July, while NO2 (0.39 ppb) occurred on June at 200-400 m layer. Water vapor, HONO and O3 all exhibited a multi-peak pattern, and aerosol appeared a bi-peak pattern for their averaged diurnal variation. Moreover, we found O3 and HONO were the main contributors to OH on the TP. The averaged vertical profiles of OH production rates from O3 and HONO all exhibited an exponential shape, and decreased with the increase of height with the maximum values of 2.61 ppb/h and 0.49 ppb/h at the bottom layer, respectively. In addition, source analysis for HONO and O3 were conducted based on vertical observations. The heterogeneous reaction of NO2 on wet surfaces was a significant source of HONO, which obviously associated with water vapor concentration and aerosol extinction. The maximum values of HONO/NO2 appeared around water vapor being 1.0×1017 molec cm-3 and aerosol being lager 0.15 km-1 under 1.0 km, and the maximum values usually accompanied with water vapor being 1.0-2.0×1017 molec cm-3 and aerosol being lager 0.02 km-1 at 1.0-2.0 km. O3 was potentially sourced from south Asian subcontinent and Himalayas through long-range transport. Our results enrich the new understanding of vertical distribution of atmospheric components and explained the strong AOC on the TP.
A particle filter based target observation method and its application to two types of El Niño events
Authors: Hou Meiyi , Tang Youmin
Published: February 2023

The optimal observational array for improving the El Niño-Southern Oscillation (ENSO) prediction is investigated by exploring sensitive areas for target observations of two types of El Niño events in the Pacific. A target observation method based on the particle filter and pre-industrial control runs from six coupled model outputs in Coupled Model Intercomparison Project Phase 5 (CMIP5) experiments are used to quantify the relative importance of the initial accuracy of sea surface temperature (SST) in different Pacific areas. The initial accuracy of the tropical Pacific, subtropical Pacific, and extratropical Pacific can influence both types of El Niño predictions. The relative importance of different areas changes along with different lead times of predictions. Tropical Pacific observations are crucial for decreasing the root mean square error of predictions of all lead times. Subtropical and extratropical observations play an important role in reducing the prediction uncertainty, especially when the prediction is made before and throughout the boreal spring. To consider different El Niño types and different start months for predictions, a quantitative frequency method based on frequency distribution is applied to determine the optimal observations of ENSO predictions. The final optimal observational array contains 31 grid points, including 21 grid points in the equatorial Pacific and 10 grid points in the North Pacific, suggesting the importance of the initial SST conditions for ENSO predictions in the tropical Pacific and also in the area outside the tropics. Furthermore, the predictions made by assimilating SST in sensitive areas have better prediction skills in the verification experiment, which can indicate the validity of the optimal observational array designed in this study. This result provided guidance on how to initialize models in predictions of El Niño types. 
Restoring Piping Plover Habitat and Building Coastal Resilience with Nature-based Solutions in Atlantic Canada
Authors: Graham Jennie , vanProosdij Danika , Ellis Kirsten , Bowron Tony , Thomas Jubin
Published: February 2023

Located in north-eastern Canada near Shippagan, New Brunswick, the Shippagan Gully Conservation Offsetting Project is leveraging salt marsh creation and sand motor techniques to create Piping Plover habitat while increasing resiliency of the Chaisson Office Spit and surrounding communities to climate change. The spit has been altered by more than a century of human activity and is increasingly impacted by climate change and sea-level rise. The project, which employs a holistic approach to improve marine navigation through the Gully and install nature-based solutions for coastal protection and habitat creation, is the first sand motor in Atlantic Canada and the most northern created marsh with sill to date. Extensive modeling was undertaken by NRC prior to the commencement of baseline data collection and design in 2017. Several monitoring and research initiatives are associated with the project, including a fifteen-year monitoring program (regulatory requirement), five-year post-graduate scientific research program, and a 3-year research project which will augment and build on the NRC-led Nature-Based Infrastructure for Coastal Resilience project. Construction began on the sand motor in 2020, with the marsh and marsh sill scheduled to be built in winter 2023 from on-site materials and planted in  spring 2023. The final stages of the implementation will include dune and wetland restoration following the removal of old infrastructure, returning nearly the entire spit to a more natural state and restoring natural processes. The first two years of monitoring following the sand motor implementation have shown a shift in conditions to those more closely matching a nearby control site, as well as the first successful nesting and fledging of Piping Plover (Federally Endangered Species) on the site in over 20 years. The project is the result of a collaborative effort that includes federal and provincial government departments, private industry, academia, and environmental NGOs.
Equilibrium and kinetic controls contribute to nitrogen and oxygen isotope effects during anammox in a wastewater treatment system
Authors: Magyar Paul , Hausherr Damian , Niederdorfer Robert , Huang Kun , Mohn Joachim , Bürgmann Helmut , Joss Adriano , Lehmann Moritz
Published: February 2023

Anammox plays a pivotal role in both natural and engineered systems as a process that simultaneously converts fixed nitrogen to N2 and regenerates NO3–. In aquatic and terrestrial ecosystems, isotopic measurements, especially of the NO3– pool, provide an essential constraint on the processes that regulate the supply and elimination of fixed nitrogen, but the isotope effects of anammox remain poorly constrained.We present measurements of the δ15N and δ18O of NO3–, NO2–, and NH4+ as processed by anammox in a mixed microbial community enriched for N removal from wastewater. We find that oxygen isotope effects expressed in NO2– include a substantial contribution from equilibration reactions with water superimposed on kinetic isotope effects. Equilibrium between water and NO2– during processing by anammoxis greatly accelerated above rates observed under abiotic conditions even during growth phases when NO2– is rapidly being consumed. In turn, δ18O of NO3– nearly completely reflects the incorporation of O atoms derived from water with little additional isotopic fractionation. The δ15N values of NO3– and NO2– also show evidence for an equilibrium isotope exchange reaction between these molecules, which raises the possibility that nitrite oxidation is partially reversible, while introducing a high degree of variability into the δ15N of NO3– generated by anammox. Finally, variation observed in the δ15N of NH4+ consumed by anammox can be connected to physiological limitations within the anammox cell.Despite this complexity, we were able to use NO2– and NO3– isotope measurements to diagnose changes in the activity of anammox and related processes within the wastewater treatment system during a low-temperature perturbation experiment. These results provide new constraints for interpreting the variability in δ15N and δ18O of NO3–in natural systems, with implications for estimating relative rates of fixed N turnover processes.