bluuebunny/crossref_metadata_2025 huggingface dataset:
Silicate weathering estimates from paleogeographic and biogeochemical cycling models of orogens and ophiolite obduction during the Phanerozoic
Authors: Zahirovic Sabin , Schmaltz Tom , Tu Addison , Pinto Cherene Viana Rafael , Hao Kevin , Leonard Jonathon , Mallard Claire , Salles Tristan
Published: March 2024

Collisional settings that terminate subduction are most often associated with orogenesis, and in many cases are also associated with the obduction of oceanic crust into the suture zone. These events are key components of the planetary carbon cycle, where the subduction-related volcanic outgassing is generally shut down, and instead dominated by processes of erosion and silicate weathering and carbon dioxide drawdown. This is particularly intense where silicate rocks are being exhumed, and especially where fresh ophiolitic crust is exposed, to intense weathering in the near-equatorial humid belts.Here we use a new compilation of Phanerozoic orogens and ophiolites in a (py)GPlates workflow to analyse the distribution of these orogenic and obduction events in time and space. We test different tectonic reference frames, as well as explore different assumptions of the distribution of the near-equatorial humid belt through time. We compare our datasets and analysis with previously published models, and link the time series to the COPSE biogeochemical cycling model. In addition, we evaluate the implications of erosion and weathering from recent global landscape evolution models to explore the role of the near-equatorial humid belt precipitation and mountain areas.The analysis suggests that large areas of mountains resided in the near-equatorial regions in the late Cambrian to Ordovician, late Carboniferous, the Cretaceous, and in the Neogene. One obvious challenge that emerges is the need to designate actively-uplifting versus inactive orogens, as the paleogeographic reconstructions do not yet discriminate between these categories. However, using our (py)GPlates workflows and other geological data (such as magmatic zircons), we can use the plate tectonic reconstructions to infer which orogens are proximal to plate boundaries and more likely to be actively uplifting, in contrast to mountains that are passively being denuded.Although this approach sees an improvement to the constraints on the areas of elevated crust for the use in biogeochemical cycling, it remains challenging to infer the paleo-altimetry of these orogens in deep time. In addition, other geological time series inputs require further work (e.g., volcanic and orogenic/metamorphic degassing). Ongoing work is quantifying self-consistent tectonic parameters that can be incorporated into the biogeochemical cycling models to help improve the constraints on these models. More broadly, this approach provides a pathway towards more robust and geologically-constrained Earth Systems Models that have implications for our understanding of paleo-climate and carbon cycling in deep time.
Preliminary study on the characteristics and slip rate of the Quaternary fault in Mogod, Mongolia
Authors: Kim Dong-Eun , Choi Jin-Hyuck , Klinger Yann , Lee Tae-Ho , Lee Hoil , Cheon Youngbeom , Choi Yire
Published: March 2024

A comprehensive, interdisciplinary study was carried out to investigate the characteristics of the 1967 magnitude 7.1 earthquake along the right-lateral strike fault in Mogod, Mongolia. This fault consists of three segments—two strike faults and a reverse fault spanning from north to south. Recent research revealed a 25 ka cycle in the movement of the reverse fault segment located in the south (Bollinger et al., 2021).To understand two remaining faults, four excavation surveys (T1, T2, T3, T4) were conducted along the two northern segments. Optically Stimulated luminescence (OSL) was used to track the deposition period in unconsolidated sedimentary layers where surface ruptures occurred, aiding in estimating the recent earthquake of the fault. An additional excavation survey was conducted near the river crossing the fault (at location T4) to determine the thalweg for evaluating geological displacement over the geological timescale.The excavation results revealed Quaternary surface ruptures in three trenches with OSL sampling. A total of 51 samples were respectively collected from Trench T2 (24 samples), T3 (18 samples), and T4 (9 samples). The Quaternary sediment layers have been deposited since the Last Glacial Maximum (LGM), around ~20 ka. Excavation sites (3 upstream and 4 downstream) intersecting the fault line (T4) aimed to assess displacement caused by seismic activity.In summary, seismic movements resulting in surface ruptures were detected in the northern two segments around the 20 ka. Further analysis would provide a more precise earthquake recurrence cycle, potentially revealing the timing of subsequent seismic events. Furthermore, completion of the identifying the thalweg, it is expected to reveal the slip rate over geological time scales.
Study of the Relationship Between Surface Fluxes and Convective Boundary Layer Dynamics with Lidars. 
Authors: Abbas Syed Saqlain , Branch Oliver , Behrendt Andreas , Lange Diego , Wulfmeyer Volker
Published: March 2024

The atmospheric boundary layer (ABL) is the lowest part of atmosphere. It is directly influenced by the Earth's surface. To understand the influence of surface fluxes on ABL turbulence processes during daytime in convective conditions, the use of lidars and Eddy covariance stations are essential. Such better understanding will then help to improve weather and climate models. The Land-Atmosphere Feedback Observatory (LAFO) at the University of Hohenheim, Stuttgart, Germany is a designated study site for agricultural experiments equipped with various sensors to analyze state variables from the soil to the lower free troposphere (Späth et al., 2023). To investigate boundary layer turbulence, two Doppler lidars, a Doppler Cloud Radar, the lidar Atmospheric Raman Temperature and Humidity Sounder (ARTHUS) (Lange et al., 2019), and two Eddy covariance stations are deployed at LAFO to capture high-resolution data. Two Doppler lidars are continuously operated, one in vertical pointing mode and the second in six-beam scanning mode (Bonin et al., 2017) to measure high spatial and temporal resolution vertical and horizontal wind data. The turbulent surface fluxes significantly impact the ABL exchange processes. Therefore, it is very interesting to integrate the continuous high temporal resolution measurements of Eddy covariance sensors with lidars measurement. The key turbulent variables are retrieved from high frequency vertical wind data. These turbulence statistics are transversal temporal autocovariance functions, its coefficients in the inertial subrange using appropriate fit lags, atmospheric vertical wind variance, integral time scale, turbulence kinetic energy dissipation (Wulfmeyer et al., 2023), cloud base height and ABL depth. We have used two methods to determine the ABL depth. The first retrieval method is based on fuzzy logic (Bonin et al., 2018) which uses atmospheric vertical velocity variance profiles. The second method employs Haar wavelet transform (Pal et al., 2010) on water vapor mixing ratio and potential temperature profiles.In this contribution, we are presenting our analyses on correlation statistics between surface fluxes and ABL depth and influence of these surface fluxes on turbulence variables covering different daytime weather conditions from June to August in 2021.Bonin et al, 2017,  https://doi.org/10.5194/amt-10-3021-2017Bonin et al, 2018,  https://doi.org/10.1175/JTECH-D-17-0159.1Lange et al, 2019, https://doi.org/10.5194/egusphere-egu22-3275Pal et al, 2010, https://doi.org/10.5194/angeo-28-825-2010Späth et al, 2023, https://doi.org/10.5194/gi-12-25-2023Wulfmeyer et al, 2023, https://doi.org/10.5194/amt-2023-183
Comparative Analysis of Seismic Clustering: Deterministic Techniques vs. Probabilistic ETAS Model
Authors: Falcone Giuseppe , Spassiani Ilaria , Gentili Stefania , Console Rodolfo , Murru Maura , Taroni Matteo
Published: March 2024

Short-term seismic clustering, a crucial aspect of seismicity, has been extensively studied in literature. Existing techniques for cluster identification are predominantly deterministic, relying on specific constitutive equations to define spatiotemporal extents. Conversely, probabilistic models, such as the Epidemic Type Aftershock Sequence (ETAS) model, dominate short-term earthquake forecasting. The ETAS model, known for its stochastic nature, has been employed to decluster earthquake catalogs probabilistically. However, the challenge arises when selecting a probability threshold for cluster identification, potentially distorting the model's underlying hypothesis.This study aims to assess the consistency between seismic clusters identified by deterministic window-based techniques specifically, Gardner-Knopoff and Uhrhammer-Lolli-Gasperini and the associated probabilities predicted by the ETAS model for events within these clusters. Both deterministic techniques are implemented in the NESTOREv1.0 package and applied to the Italian earthquake catalog spanning from 2005 to 2021.The comparison involves evaluating, for each event within an identified cluster, both the probability of independence and the expected number of triggered events according to the ETAS model. Results demonstrate overall agreement between the two cluster identification methods, with identified clusters exhibiting consistency with corresponding ETAS probabilities. Any minor discrepancies observed can be attributed to the fundamentally different nature of the deterministic and probabilistic approaches.This research is supported by a grant from the Italian Ministry of Foreign Affairs and International Cooperation.
Observing the fate of methane utilizing Ocean Network Canada's cabled seafloor NEPTUNE Observatory
Authors: Scherwath Martin , Riedel Michael , Marcon Yann , Römer Miriam , Thomsen Laurenz , Purser Autun , Chatzievangelou Damianos , Du Preez Cherisse
Published: March 2024

Cabled ocean observatories enable permanent continuous observations in situ in addition to regular sampling during observatory maintenance expeditions, which allow for some of the most comprehensive monitoring to understand the fate of methane all the way from below the seafloor (with instrumented boreholes), through the seafloor (with bottom sensors, cameras or cabled vehicles) into the water column (with sonars). Ocean Networks Canada is operating the NEPTUNE observatory off the coast of Vancouver Island since 2009 with two of its instrument nodes at gas hydrate sites. The first site, Clayoquot Slope, is at around 1200 m water depth and is a site of high fluid expulsion including large amounts of methane gas seepage, which has been observed for over a decade with permanent sonar scanning. The second site, Barkley Canyon, is at about 900 m water depth and has hydrate mounds with exposed gas hydrate on the seafloor, and is unique for its thermogenic methane and also oil seepage, and the most important observations have been made by a remotely-operated cabled and instrumented a seafloor crawler called Wally. This presentation will provide a few highlights on gas hydrate observations and invites the research community for new ideas how to expand the use of the permanent and continuous data flow opportunities that stem from the 24/7 presence of power and communication availability at the two different hydrate sights.
Atmospheric moisture transport in Central Europe – rivers or streams
Authors: Wypych Agnieszka
Published: March 2024

The diversity of water vapor content in the air is crucial for the regional analysis of atmospheric precipitation occurrences. The amount of water vapor carried by the air mass over a specific area can vary significantly depending on the current characteristics of air circulation, with a key role played by atmospheric rivers. These rivers originate from the meridional transport of water vapor and have a significant impact on Europe through the interaction with extratropical cyclones.The aim of the work is to assess the intensity of water vapor transport over Europe and the extent of its inland penetration.Atmospheric rivers/streams will be identified based on ECMWF ERA5 reanalyses data from 1991 to 2023 and CMIP6 future projections until the year 2100.Selected cases of intense water vapor transport over the European region, especially Central Europe, will be compared with the occurrence of atmospheric precipitation.
Paleoseismic records around epicenter of the 2017 Pohang earthquake, SE Korea
Authors: Lee Seongjun , Cheon Youngbeom , Han Jong-won , Ha Sangmin , Choi Jeong-Heon , Seong Yeong Bae , Kang Hee-Cheol , Son Moon
Published: March 2024

The 2017 Pohang earthquake (ML 5.4) ranked as the second-largest instrumental earthquake in Korea and the most destructive seismic event. Before this event, the absence of documented instrumental seismic activity and no mapped Quaternary faults near the epicenter raised questions about the paleoseismic history of the region. This study aims to gather and trace evidences of the paleoseismic ruptures along the surface projection of seismogenic fault, reported by previous study, and interpret their implications. To achieve it, we conducted comprehensive paleoseismological investigations, including geomorphic analysis, fieldwork, drilling survey, trench excavation and numerical age dating. Through geomorphic analysis and drilling survey, we identified two lineaments: NNE–SSW-striking Fault-1 and NE–SW to NNE–SSW-striking Fault-2. In the excavation site of fault-1, stratigraphic features and numerical ages indicate that the PE event occurred between 11±1 ka and 2.6±0.1 ka, and then the MRE event activated after 0.17±0.01 ka.  On the other hand, the combined results of two outcrops of Fault-2 show that the MRE and PE of Fault-2 could be constrained to have occurred between 148±7 ka and ca. 40 ka and around 200 ka, respectively. Our findings present that even before the 2017 Pohang earthquake, seismic events causing surface ruptures of moderate to large magnitude have occurred at least three times in this area during the late Quaternary.This work was supported by a grant (2022-MOIS62-001) of National Disaster Risk Analysis and Management Technology in Earthquake funded by Ministry of Interior and Safety (MOIS, South Korea).
Application of shore sediments accumulated in navigation channel for restoration of sandy beaches around Pärnu City, SW Estonia
Authors: Männikus Rain , Tõnisson Hannes , Palginõmm Valdeko , Alari Victor , Kont Are , Vilumaa Kadri
Published: March 2024

Sandy beaches high in recreation value provide 16% of over 4,000 km long shoreline of Estonia. The shore processes associated with climate change have remarkably accelerated over the last decades. Many sandy shores have suffered from strong erosion including an excellent former beach at Valgeranna. The jetties, which were built in the 1860s to protect the navigation channel of Port Pärnu from choking, have prevented the natural sediment transport along the coast from south to north. At the same time, the sandy beach in Pärnu is expanding and part of the sand accumulates with strong storms also in between the jetties reducing the width of the shipping channel. The channel needs regular dredging but the dredged sediment has been taken far away to the open sea and accumulated on the seabed so far. The current paper addresses the possibilities of using that sand for beach restoration in destructed and eroded areas. An overview of the applied methods and measurements during the field studies are given. The results of modelling the processes of wave activity and sediment transport are discussed. Recycling of shore sediments is an important measure in sustainable coastal zone management. Different options and scenarios are analysed in order to find out the most reasonable ways to bring the sand back onto the beaches and stabilize the natural processes. Support from the state by working out respective laws and regulations would be motivating as well.
Assessing habitat area changes from large-scale nature-based solutions
Authors: Abebe Yared Abayneh , Chhetri Samikshya , Ruangpan Laddaporn , Vojinovic Zoran
Published: March 2024

One of the benefits of nature-based solutions (NBS) is providing environmental benefits, which regulate and maintain ecosystem services and foster positive impacts on ecosystems. Environmental benefits of NBS include enhancing water quality, habitat changes, improving biodiversity and carbon sequestration and storage. In this research, we developed a method to assess changes in habitat areas using remote sensing data.Since mapping habitats is a harder task, our method is based on mapping and detecting changes in land cover over a region and translating that to changes in habitat area. We employed the CORINE Land Cover (CLC) classes and EUNIS habitat classes, two commonly used classification systems for land cover and habitat types, respectively. To assess the change in habitat type and area before and after implementing NBS, the CLC Level III classes were transformed into EUNIS Level I habitat types. The CLC datasets of 2000 and 2018 were used as the land covers before and after implementing an NBS. We applied the method in Aarhus, Denmark, in two study areas called Egå Engsø and Lystrup. An artificial lake and wetland that covers an area of 115 hectares was implemented in 2006 in Egå, surrounded by 35 hectares of grazed meadows. The NBS in Lystrup includes basins, gullies and rainbeds. The purposes of the NBS are to reduce the flood risk from the river Egå and isolated storms, reduce the nitrogen supply to Aarhus Bay and improve the natural conditions in the area.Results showed the conversion of a cultivated habitat to an inland surface water habitat. A bogs, mires and fens habitat had also emerged west of the wetland. In the southwest of the wetland, an agricultural habitat had changed to a complex habitat, and the south of the region was surrounded by an artificially dominated habitat. Finally, a complex habitat had changed to a constructed habitat in the southeast of the wetland. On the other hand, habitat changes had not altered significantly in Lystrup despite the implementations of NBS projects. It is also possible that NBS-induced modifications could not be recorded by the method as the area was a complex habitat characterized by a heterogeneous blend of different habitats. One limitation of this method could be that it is difficult to delineate changes within complex habitats. Additionally, the limitation arises from the translation of the land cover classes to habitat classification. However, the research offers a method to quantify one of the environmental benefits NBS generate to encourage decision-makers to implement and scale them up further.
The metamorphic dehydration of subducted metabasalts in the Catalina Schist: Does epidote record fluid production at the depths of deep slow slip and tremor?
Authors: Lindquist Peter , Condit Cailey , Hoover William , Guevara Victor
Published: March 2024

Dehydration reactions in the subducting slab have been suggested as a fluid source for high pore fluid pressures that are inferred in the environment that hosts deep slow slip and tremor in subduction zones. Using petrography, major and trace element geochemistry, and petrologic modeling, we study the record of dehydration reactions in exhumed metabasalt from the Catalina Schist in southern California, USA to explore potential sources of the fluids that produce high pore fluid pressures at the plate interface. The Catalina Schist comprises tectonic slices that were underplated in a subduction zone at lawsonite blueschist to amphibolite facies conditions. Metabasalts from the epidote-amphibolite facies unit here represent a coherent section of oceanic crust that was underplated during subduction at ~550°C and ~1 GPa, and are  ~100 m structurally below an ultramafic-metasedimentary mélange unit interpreted to be a paleosubduction interface from ~35 km paleodepth. Previous thermodynamic modelling suggests that epidote minerals may be common reaction products during prograde dehydration reactions along typical warm subduction geotherms, particularly at the conditions of slow slip and tremor. We therefore focus on epidote textures and trace-element compositions to provide insights into the metamorphic reactions experienced by these metabasalts, and by extension reconstruct the dehydration history of this subducted slab. Pairing these analyses with phase equilibrium modeling, we estimate the P-T path experienced by these metabasalts and the conditions at which epidote may be growing or reacting out. Epidote textures vary significantly across outcrops and appear in various settings including: epidote-rich veins and vein-like dehydration networks, and porphyroblastic epidote in surrounding host rocks. Oscillatory zoning in synkinematic epidote porphyroblasts further suggests episodic growth under varying conditions or fluid compositions. Variations in the major element and trace element geochemistry of epidote across these domains, coupled with petrologic modeling helps to reveal the metamorphic reactions that occurred in these rocks, and allows us to begin quantifying the volumes of fluids that may be released during prograde metamorphism near the conditions of deep slow slip and tremor.
Using satellite images to monitor the spatiotemporal distribution and irrigation dynamic of paddy fields
Authors: Zhang Yi-Ting , Liu Feng-Wei , Syu Chien-Hui
Published: March 2024

Rice is the staple crop with the largest cultivation area and water demand in Taiwan. An accurate and rapid understanding of rice planting time, area, and growth period is beneficial for overall planning and improving the efficiency of agricultural water resource management. Remote sensing provides information such as high coverage, real-time, multispectral images, and multi-angle images. Various agricultural monitoring technologies have been developed for crop planting areas, yield estimation, and pest warnings. However, Taiwan, located in the tropical/subtropical region, faces challenges in obtaining high-quality optical satellite images due to rainfall and cloud cover. This leads to reduced accuracy in interpreting planting time and area. Therefore, the purpose of this study is to monitor the spatiotemporal distribution of paddy fields and irrigation dynamics using optical and radar satellite images. The study area is in western Taiwan, where the first rice planting period extends from January to March, with harvesting taking place from May to July, covering an area of approximately 90,000 to 120,000 hectares. Optical (Sentinel-2) and radar (Sentinel-1) image signals, along with the Maximum Likelihood method (supervised classification), were used to interpret the irrigation and rice planting distribution during the early stages of the first rice crop from 2021 to 2023. Finally, the rice planting area in the test area from January to March was calculated based on the irrigation distribution results, and the performance of the rice distribution area interpretation was evaluated. The results indicated that the average Kappa value for paddy field area interpretation was 0.92. The percentage of rice planting from January to March was 48±13%, 32±4%, and 29±14%, respectively. The monitoring process established in this study for rice irrigation and distribution areas contributes to government planning and decision-making regarding overall agricultural water allocation.
Low-angle normal faulting triggered by fluids
Authors: Pagli Carolina , La Rosa Alessandro , Keir Derek , Hurman Gareth , Wang Hua , Doubre Cecile , Viltres Renier , Raggiunti Martina , Ayele Atalay
Published: March 2024

In extensional settings under Andersonian mechanics, low-angle normal faults should not form in favour of steeply dipping normal faults. However, InSAR shows that a seismic sequence including an earthquake with magnitude Mw 5.6 on August 1st, 2023 (NEIC - National Earthquake Information Center) at the northern end of the Afar rift was caused by normal faulting on a low-angle 35° dipping plane. Our best-fit InSAR model shows that the low-angle normal fault occurred on the west margin of the rift axis, it was relatively deep (6.7 km) and it slipped fully seismically, having a geodetic magnitude of Mw 5.66 in agreement with the global seismic recordings (NEIC). Temporally, the faulting occurred at the end of a one-year period (December 2022-December 2023) of increased seismicity in the northern sector of Afar, with swarms of seismicity migrating northward along the rift. The seismic characteristics, fault location and kinematics are consistent with the low-angle normal fault being triggered by fluids that locally could be released by a deep magmatic heat source along the rift axis under high extensional stresses. Our observations show that low-angle normal faults can form in rifting settings, are activated seismically and are likely fluid-induced.
Photosynthetic responses of Pinus densiflora seedlings are affected by accumulated heat under artificial warming
Authors: Jo Heejae , Kim Gwang-Jung , Kim Jinseo , Kim Gaeun , Kwon Minyoung , Lee Jeong-Min , Son Yowhan
Published: March 2024

Photosynthetic responses of Pinus densiflora seedlings to warming in different seasons were investigated. In March 2023, four temperature treatments with five replicates were conducted in an open-field nursery site located in Seoul, South Korea: constant warming (April 15th-October 15th), spring and fall warming (April 15th-May 31st and September 1st-October 15th), summer warming (June 1st-August 31st), and control. In each plot, 108 1-year-old P. densiflora seedlings were planted. The temperature of the warming plots was set to increase by 4°C compared to control plots using infrared heaters. Photosynthetic responses of seedlings were measured on the 10th of each month from May to October and linear mixed-effect models were used to analyze the effect of treatments on photosynthetic responses. Net photosynthetic rate was not affected by any of the treatments until June but decreased by 12.7% under summer warming compared to spring and fall warming in July. In August, both constant warming and summer warming treatments decreased the net photosynthetic rate by 18.0% and 12.3%, respectively, compared to the control. However, in September, following the cessation of the summer warming and the initiation of the fall warming treatment, seedlings only subjected to constant warming exhibited a significant reduction in net photosynthetic rate, with a 33.0% decrease compared to the control. This reduction increased to 41.2% in October, whereas summer warming and spring and fall warming treatments did not affect photosynthesis in the same month. This study indicates that warming might result in losses in plant photosynthesis, and those losses could be higher during summer. In addition, although the spring and fall treatment did not independently affect net photosynthetic rate of seedlings, the accumulated heat during spring and fall appears to have attributed to the photosynthetic reduction under the constant warming treatment. * This research was carried out with the support of the Korea Forest Service Government (KFSG) as [Graduate School specialized in Carbon Sink].
Identification and variations of the components of a regional groundwater flow system with intensive exploitation based on historical hydrogeochemical records in a coastal flow system.
Authors: Priscila Medina-Ortega , Oscar Escolero-Fuentes , Eric Morales-Casique , Selene Olea-Olea
Published: March 2024

The Costa de Hermosillo is a coastal flow system located in the northwest of Mexico. Since 1954, it has been subject to intensive exploitation of groundwater resources, resulting in a significant drop in the water table. It is important to note that the water table is now several meters below sea level. As a result, seawater intrusion has extended tens of kilometers inland. The impact of this problem on the region is significant in economic, social, and environmental terms. Extensive agricultural areas have been abandoned due to the salinity of the water extracted from wells affected by seawater intrusion.The present study proposes a statistical methodology based on historical hydrogeochemical data from the Hermosillo coast to determine three fundamental aspects. 1) determining the number of flow components in the groundwater, 2) identifying the proportion of each component in the wells, and 3) analyzing the spatial and temporal distribution of these components.  The research involved three main aspects: To begin, historical data on hydrogeological and hydrogeochemical aspects, climatic variables, and static water level elevations in the area were compiled. This data was then subjected to rigorous quality control to select appropriate years for analysis. The analysis focused on wells that had records of major ions and some physical parameters for the years 1980, 1987, 1989, 1991, 1992, and 1993. Statistical techniques were used to identify four components present in the study area and to determine their proportions in the wells.The identification and hydrogeochemical characterization of groundwater constituents are essential to enhance knowledge of the region. This approach is based on analyzing the concentrations of dominant ions in wells, which allows the establishment of relationships with the hydrogeological environment. The main objective is to overcome the current limitations of groundwater management in the coastal region of Hermosillo. The hydrogeochemical characterization proposed here is a crucial step toward addressing interrelated challenges and achieving integrated and sustainable water resource management in the region.
Quantifying the impact of latent heat on urban climate: a perspective from a novel parameterization scheme
Authors: Yu Miao
Published: March 2024

Urban latent heat processes are neglected or oversimplified in most mesoscale models in previous studies, leading to large uncertainties in modelling urban climate. By coupling our newly developed urban hydrological parameterization scheme in the mesoscale model WRF/BEP+BEM, we conducted three one-month simulation tests to quantify the impact of latent heat processes on urban climate, which is induced by urban ground greening, green roofs and surface water. It is found that urban latent heat significantly reduces maximum temperatures and improves comfort, especially during heatwaves, but it does not markedly influence mean air temperature. Compared to ground greening, green roofs provide enhanced cooling advantages. Overall, all three latent heat processes produce a more spatially dispersed distribution of precipitation with a reduction of 25% in total precipitation amount. This can be attributed to the reduced urban heat island intensity by latent heat and the enhanced stability of the planetary boundary layer. The finding has implication for the measures that can be taken in reducing the adverse impact induced by rapid urban expansion.
 
Soil Moisture estimation using GNSS- A spatiotemporal analysis
Authors: Somaskandan Kirthana , Kumar Ravi prakash , Devaraju Balaji
Published: March 2024

Soil moisture plays a predominant role in driving the hydrological cycle, being the initial terrestrial variable to interact with precipitation. Its inherent temporal and spatial variability leads to complexity in estimation. Numerous hydrological and climate models adopt a simplified approach by treating soil moisture as a constant parameter in certain regions. While this simplification is intended to streamline complexity, it often introduces inaccuracies and uncertainties into these models. Conventional methods of measuring soil moisture are point-based, requiring labor-intensive, time-consuming, and often destructive procedures. The Soil Moisture Active Passive (SMAP) satellite, designed for soil moisture estimation, operates with a temporal resolution of 3 days and fails to capture the occurrences of extreme events. This study tries to overcome those limitations by estimating soil moisture daily using GNSS-Reflectrometry mission CYGNSS, which has a temporal resolution of 7 hours. The primary observable is the surface reflectance which depends on the surface property of the ground. Ulaby developed a water cloud model to estimate soil moisture using surface reflectance irrespective of LULC. An extended water cloud model was proposed that includes the Leaf Area Index of the land cover in the Chambal sub-basin of Ganga Basin, India. Using SMAP as a reference, The extended water cloud model achieved a correlation of 76.16 % in barren land (RMSE of 0.014) which is higher than in vegetated land with a correlation of 74.42 %. 
Realtime monitoring of urban flooding by ensemble Kalman filters
Authors: Duc Le , Jo Juyoung , Sawada Yohei
Published: March 2024

Urban drainage models have been used in many cities for analysis, prediction, and control related to urban flooding. Many sources of uncertainties exist in these models comprising model parameters, meteorological forcings, and surface conditions. Thus, it is necessary to calibrate models before using them in reality. A common choice in calibration is to fit the model outputs with observations through many cases. This strategy is known as the offline mode in calibration and works on the stationary assumption of model parameters. If parameters vary in time, this method usually yields the climatological range of the parameters, which are not necessarily optimal in specific cases. In this study, instead of the offline model we follow the online mode in estimating model parameters by using an ensemble Kalman filter (EnKF). Furthermore, we estimate not only model parameters but also model states simultaneously utilizing the EnKF. Note that originally, EnKF is a data assimilation technique that is based on sampling in estimating any system states given observations, and later is used for the purpose of parameter estimation. The combination of EnKF and an urban drainage model is expected to lead to a real-time monitoring system for urban flooding similar to reanalysis systems in numerical weather prediction.
Compound Heat and Dry Events Influenced by the Pacific–Japan Pattern over Taiwan in Summer
Authors: Lin Szu-Ying , Tseng Wan-Ling , Wang Yi-Chi , Lo MinHui
Published: March 2024

Compound dry and hot events, characterized by elevated temperatures and reduced precipitation, pose interconnected challenges to human social economics, necessitating comprehensive strategies for mitigation and adaptation. This study focuses on the Pacific-Japan (PJ) pattern, a significant climate variability influencing summer climates in East Asia. While previous research has explored its impact on Japan and Korea, our investigation delves into its effects on Taiwan, a mountainous subtropical island with a population of approximately 24 million. Utilizing long-term temperature and rainfall data, along with reanalysis dynamic downscaling datasets, we examine the interannual impacts of the PJ pattern on summer temperature and compound heat and dry events. Our findings reveal a significant temperature increase during the positive phase of the PJ pattern, characterized by anticyclonic anomalous circulation over Taiwan. Additionally, both the Standardized Precipitation Index and soil water exhibit a decline during this phase, reflecting meteorological and hydrological drought conditions. A robust negative correlation (-0.7) between drought indices and temperature emphasizes the compound effect of heat and dry events during the PJ positive phase. This study enhances the understanding of the PJ pattern as a climate driver, describing its role in hot and dry summers over Taiwan. The insights gained, when integrated into seasonal prediction and early warning systems, can aid vulnerable sectors in preparing for potential heat and dry stress hazards.
Space Weather Ionospheric Network Canada (SWINCan)
Authors: Watson Christopher , Jayachandran Thayyil , Kascheyev Anton
Published: March 2024

Space Weather Ionospheric Network Canada (SWINCan) will establish a pan-Canadian infrastructure of ground-based sensors that will provide state-of-the-art, real-time monitoring of the ionosphere spanning polar, auroral, and sub-auroral latitudes. SWINCan is an expansion and modernization of the Canadian High Arctic Ionospheric Network (CHAIN), one of the world’s largest networks for ionospheric research operated by the Radio and Space Physics Laboratory (RSPL) at the University of New Brunswick (UNB). SWINCan will deploy 100 specialized Global Navigation Satellite System (GNSS) receivers and 10 modular ionospheric sounder (MODIS) systems across Canada, while enhancing the 28 GNSS and 10 ionosonde systems currently installed in the Canadian Arctic as part of CHAIN. SWINCan GNSS receivers are high-rate (100 Hz) ionospheric scintillation and total electron content (TEC) monitors (GISTMs) that will provide real-time data and enhance multi-scale observation of the ionospheric structure and dynamics. MODIS systems being developed by RSPL are next generation, low power high frequency (HF) systems that take advantage of the latest developments in software defined radio and signal processing technology to reduce power consumption and increase ionospheric measurement capabilities in harsh, remote environments such as the Canadian Arctic. SWINCan is designed to take advantage of the unique natural laboratory of the Canadian Arctic for the fundamental study of solar-terrestrial interactions, and will provide essential input for mitigation of space weather effects on modern technological systems such as GNSS, radio communication, and over-the-horizon-radar, services critical to social, military, science, and major economic sectors.
BrGDGTs-based seasonal paleotemperature reconstruction for the last 15,000 years from a shallow lake on the eastern Tibetan Plateau
Authors: Hou Xiaohuan , Wang Nannan , Sun Zhe , Yuan Kan , Cao Xianyong
Published: March 2024

Understanding Holocene temperature changes is vital for resolving discrepancies between proxy reconstructions and climate models. The intricate temperature variations across the Tibetan Plateau (TP) add complexity to studying continental climate change during this period. Discrepancies between model-based and proxy-based reconstructions might stem from seasonal biases and environmental uncertainties in the proxies. Employing multiple proxies from a single sediment core for quantitative temperature reconstructions offers an effective method for cross-validation in terrestrial environments. Here, we present an ice-free-season temperature record for the past 15 ka from a shallow, freshwater lake on the eastern TP, based on brGDGTs (branched glycerol dialkyl glycerol tetraethers). This record shows that the Holocene Thermal Maximum lags the pollen-based July temperature recorded in the same sediment core. We conclude that the mismatch between the brGDGTs-based and pollen-based temperatures is primarily the result of seasonal variations in solar irradiance. The overall pattern of temperature changes is supported by other summer temperature records, and the Younger Dryas cold event and the Bølling–Allerød warm period are also detected. A generally warm period occurred during 8–3.5 ka, followed by a cooling trend in the late Holocene. Our findings have implications for understanding the seasonal signal of brGDGTs in shallow lakes, and provide critical data for confirming the occurrence of seasonal biases in different proxies from high-elevation lakes. To further investigate the significance of the brGDGTs and temperature patterns on the TP, we examined existing brGDGTs-based Holocene temperature records, which interpret these compounds as indicators of mean annual or growing season temperatures. The existing/available temperature records show complicated patterns of variation, some with general warming trends throughout the Holocene, some with cooling trends, while some with warm middle Holocene. We analyzed the possible reasons for the diverse brGDGTs records on the TP and emphasize the importance of considering lake conditions and modern investigations of brGDGTs in lacustrine systems when using brGDGTs to reconstruct paleoenvironmental conditions.
A high-resolution emission inventory of anthropogenic pollutants for an industrial city in Eastern India
Authors: patel shubham , ibrahim Shamjas , verma Dr. Shubha
Published: March 2024

A high-resolution emission inventory was prepared for the anthropogenic sources of primary air pollutants with a spatial resolution of 1km×1km for the Haldia region in the Indian state of West Bengal. The Haldia region is a core of major petrochemical industries, oil refineries, and port activities. For the preparation of the emission inventory, the source sectors were divided into residential, industrial, transportation, marine, crematoria, thermal power plants, solid waste burning, and brick kilns. The emissions of seven primary pollutants, sulfur dioxide (SO2), nitrogen oxides (NOx), particulate matter (PM2.5), black carbon (BC), organic carbon (OC), and non-methane volatile organic compounds (NMVOC) were estimated. To collect activity-based information, municipal authority, annual reports of industries, and publicly accessible data were consulted. Emission factors from various literature were used for the estimation of emissions. The emission inventory was developed using a bottom-up approach for base year 2021 and the spatial maps were prepared using ArcGIS.The transportation sector was responsible for 71%, 42%, and 75%, respectively of NOx, BC, and NMVOC emissions. Industries and thermal power plants were the primary contributors to SO2 emissions, accounting for 38% and 36%, respectively of total SO2 emissions. In addition, the residential sector accounted for 53%, 40%, and 44% of OC, PM2.5, and CO emissions respectively. The Haldia Municipality wards 5, 6, 9, 11, and 13 were identified as emission hotspots. Terapakhya town was the hotspot for all pollutants except NOx and NMVOC emissions. Traffic intersections at city centre and ranichak were the highest emitters of NOx emissions.This emission inventory serves as the first baseline information for the emissions in the region and can be further utilized to perform initial air quality studies for the Haldia region. A comprehensive plan to eliminate air pollution in Haldia and the encompassing area can be developed with the use of this emission inventory.
Radiation budget and surface energy balance of green roofs using flux profile method
Authors: Seo Yongwon , Jeong Woo Chang
Published: March 2024

One of the primary advantages offered by a green roof is its ability to regulate indoor temperatures more effectively in response to changing outdoor temperatures, in contrast to a traditional concrete roof on a building. This advantage aids in decreasing the amount of energy needed to cool the building during warm seasons and heat it in colder seasons. This investigation gathered data from four recently constructed detached buildings: one with a bare concrete roof, another with a highly reflective paint roof, and two with green roofs. The focus was on examining the complete radiation budget and surface energy balance of green roofs compared to other roof types during a summer season in Korea. The thorough data collected allowed for a quantitative assessment of how green roofs behave in terms of energy balance, particularly when compared to bare concrete roofs. The monitoring period for this study took place over a week, from July 21, 2021, to July 28, 2021. Results indicated that, on average, green roofs reduced the maximum indoor temperature by 6.83℃ compared to buildings with bare concrete roofs, potentially resulting in significant energy savings required for cooling. Additionally, the analysis of energy balance using the flux profile method highlighted the significance of the difference in ground heat flux in determining indoor building temperature. The findings also revealed that green roofs utilized a substantial portion of net radiation for latent heat flux (70.7%), but a minimal amount for ground heat flux (0.5%). Conversely, bare concrete roofs used a larger portion of net radiation for ground heat flux (16.2%) and sensible heat flux (45.3%), resulting in greater warming of both indoor building areas and the air near the surface. These outcomes illustrate that green roofs not only stabilize indoor temperature fluctuations but also directly assist in mitigating the heat island effect.
Modelling soil creep dynamics based on meteoric and terrestrial Be-10 coupling: validation on a hillslope profile in northern Abukuma Mountain, Japan
Authors: Kondo Arihito , Matsushi Yuki , Matsuzaki Hiroyuki
Published: March 2024

                 Soils on hillslopes in humid temperate regions move slowly downward with varying fluxes depending on depth. The soil creep contributes to enhance soil depth in head hollows and develop soil layer structures in a long time scale, which regulate short-term subsurface hydrological processes and hence slope instability by rainwater infiltration. This study attempted to model long-term soil creep processes, based both on terrestrial Be-10 concentrations in bedrock and depth profiles of meteoric Be-10 abundance in soil columns on a hillslope. The soil creep model developed here composes of two velocity profiles corresponding to viscous transport by plastic deformation of soil mass and discrete particle-flow transport due to the external disturbance from the soil surface. By coupling these distinct transport laws, the depth profile of soil creep rates was modeled as a combined formula of two exponential functions. Soil production function determined by terrestrial Be-10 and spatial distribution of soil depths combined with topographic curvature provided the rate and mass-budget constraints for the model, while meteoric Be-10 inventory in the soil columns served a clue to fix model parameters for the subsurface soil creep pattern. The model fitting to the meteoric Be-10 profiles output the soil residence time, which was then examined by C-14 dating for the charcoals obtained from the soil column.             Model validation was conducted at a hillslope underlain by granodiorite in northern Abukuma Mountains, Japan. The target hillslope exhibits a convex ridge top with a planar midsection that becomes slightly concave toward downslope. A thick soil layer (>1 m) covers the entire hillslope, which characteristically composed of two layers: upper soft and lower stiff parts divided around 40–60 cm in depth. Bedrocks were sampled at bottoms of several soil pits excavated on hill-noses for terrestrial Be-10 measurement. Soil samples for meteoric Be-10 analysis were collected sequentially from ground surface to ~2 m depth in 10 cm interval at four pits located along a transect from the ridge to hollow. Charcoal grains imbedded in the soil layer were also collected for C-14 dating. The datasets of meteoric Be-10 profiles were well explained by fitting the two-layered soil creep model under the terrestrial Be-10 derived soil production rates and depth-dependent soil residence time evidenced by the charcoal ages.