bluuebunny/crossref_metadata_2025 huggingface dataset:
CMIP6 projected response of the East Asian winter climate to the sea ice-free Arctic
Authors: Song Ziyi
Published: February 2023

This research evaluated the performance of 19 Coupled Model Intercomparison Project phase 6 (CMIP6) models in simulating the Arctic sea ice from the perspective of annual cycle, spatial pattern and temporal variation. Based on the evaluation, five models with better comprehensive performance capacity were optimized as the ensemble to project the response of the East Asian winter climate to the sea ice-free Arctic occurring under the SSP2-4.5 and SSP5-8.5 scenarios, respectively. The ensemble projections indicate that the sea ice-free Arctic is followed by a weakening of the East Asian winter monsoon, which is characterized with the shallower East Asian trough and weaker East Asian jet stream. Concurrently, the winter surface net radiation flux is projected to increase in the East Asian-western North Pacific region. These changes favour large-scale warming in the East Asian-western North Pacific region. Moreover, the warming is more pronounced under the sea ice-free Arctic of SSP2-4.5 than under that of SSP5-8.5. The winter precipitation tends to increase along the East Asian coast from South China to the Sea of Okhotsk. Such an increase is closely associated with the enhancement of low-level moisture. Due to larger enhancement of moisture, there appears greater increase of precipitation in the monsoon region from South China to Japan under the sea ice-free Arctic of SSP5-8.5 compare to that under SSP2-4.5. Substantial changes are also projected for the temperature and precipitation extremes, such as a general increase in warm days and warm nights and an overall intensification of extreme precipitation in the East Asian-western North Pacific region.
Molecular characterization of methanol-soluble BrC using 1H NMR fingerprinting and high-resolution mass spectrometry.
Authors: Rana Archita , Sarkar Sayantan
Published: February 2023

Brown carbon (BrC) is the light-absorbing fraction of organic aerosols that can affect atmospheric photochemistry and influence regional and global climate. BrC can be emitted directly from incomplete combustion or formed through multiphase reactions. BrC consists of both water-soluble and methanol-soluble fractions (Me-BrC), with the Me-BrC fraction exhibiting greater absorption compared to the aqueous fraction owing to greater extraction potential. It is important to characterize the molecular composition of BrC to gain a better understanding of the link between BrC chromophores and their light absorption properties. In this study, proton nuclear magnetic resonance (1H NMR) and high-performance liquid chromatography (HPLC) coupled with a diode array detector (DAD) and a time-of-flight mass spectrometer (TOF-MS) with an electrospray ionisation (ESI) source are used to comment on the molecular composition of Me-BrC. For this purpose, daytime and nighttime PM2.5 samples collected from April 2019 to February 2020 in a rural area in the eastern Indo-Gangetic Plain (IGP) were used.  Both ESI- and ESI+ modes were utilized due to their respective affinity towards acidic and basic functional groups and about 500-2000 molecules were classified into four major compound classes: CHO, CHON, CHONS and CHOS. Among these, CHO- (25-32%) was the most abundant group followed by CHONS- (25-30%), CHON- (21-28%) and CHOS- (13-17%) in the negative mode whereas CHON+ (42-50%) showed the highest abundance in the positive mode followed by CHONS+ (30-38%) and CHO+ (6-14%) and CHOS+ (5-13%). 1H-NMR showed dominance of saturated oxygenated compounds (H-C-O) for all seasons, which is consistent with the high O/C ratio and OSc (oxidation state), with increasing Ar-H and hence double bond equipment (DBE) towards winter. Higher O/C (>0.3) and lower DBE of CHON+ and CHONS+ showed their significant contribution towards H-C-O type of BrC along with CHO-. CHON species can be formed by atmospheric reactions involving NOx (oxidised N-containing groups (O/C: 0.4, H/C: 1.5)) or NH3 (reduced N-containing groups (O/C: 0.2, H/C: 1.9)) with CHON- containing more organic nitrate moieties (−(O)NO2); (O/N >3)). Lower CHON towards the night time cross all seasons corresponds to the lower relative percentage of the H–C–C= type in NMR. High CHONS+ suggest presence of nitroxy organo-sulfate (formed via photooxidation of BVOCs under high NOx) or come from coal combustion. CHOS+ showed greater fraction of high‐molecular weight organosulfate compounds (low DBE or high H/C) which increased towards the winter. Also CHOS+ with high DBE (>4) with O/C (<0.4) suggests presence of reduced S‐containing compounds which are more likely to be originated from primary emissions. These findings provide the first insights into the chromophoric composition of the Indo-Gangetic Plain outflow.  
Simulating the impacts of pollen on cloud formation by heterogeneous ice nucleation
Authors: Zhang Yingxiao , Subba Tamanna , Hendrickson Brianna N. , Brooks Sarah D. , Steiner Allison L.
Published: February 2023

Primary biological aerosol particles (PBAPs) are emitted from Earth’s biosphere, including pollen, fungal spores, virus, bacteria, and plant debris. PBAPs are linked to adverse health effects and have the potential to influence ice nucleation at warmer temperatures. Anemophilous (or wind-driven) pollen is one type of PBAP, and the emitted pollen grains can rupture under high humidity to form smaller sub-pollen particles (SPP). Both pollen and SPP can be lifted to the upper troposphere under convective conditions, readily take up water and serve as cloud condensation nuclei (CCN) and ice nucleating particles (INPs), and therefore impact cloud formation and reflectivity. Although these biological aerosol have proven to be effective INPs in previous studies, they are typically not included in emission inventories. Therefore, it is difficult to quantify their effects on cloud formation and local climate.Here, we include the emission and rupture of pollen in WRF-Chem simulations and investigate the impacts of pollen and SPP on both warm and ice clouds in the United States South Great Plains (SGP) from April 11-20, 2013, a period with high pollen emission and convective events. We update the Morrison microphysics scheme inside WRF-Chem using aerosol-aware INP parameterizations, considering different freezing mechanisms including heterogeneous freezing (immersion, contact, and deposition freezing) and homogeneous freezing. We further incorporate heterogeneous ice nucleation from pollen and SPP in the model to evaluate pollen effects on ice cloud formation. The corresponding pollen and SPP INP parameterizations are obtained by laboratory experiments that indicate pollen grains are more efficient INPs than SPP and could contribute to ice cloud formation. The model simulation results are evaluated using observational data from Atmospheric Radiation Measurement (ARM) SGP sites.  We conducted a suite of sensitivity tests to examine the impacts of pollen and SPP on one convective event (April 17-18, 2013), and compare the newly developed pollen and SPP INP parameterizations with those developed in previous literature. Our results highlight that the addition of PBAPs such as pollen could shift the convective event onset timing and vertical structure. 
Paleocene-Eocene carbon isotope excursion recorded in the western Jianghan Basin, China
Authors: Luo Xingyu , Wang Ping , Luo Cairong , Lv Miao , Li Shanying , Wei Xiaochun
Published: February 2023

Paleocene-Eocene Thermal Maximum (PETM), occurring at Paleocene/Eocene boundary, was a rapid global warming event caused by the release of massive carbon into ocean-atmosphere system. The western Jianghan Basin in central China was documented as a sedimentary archive spanning the Paleocene/Eocene boundary, but the PETM event has never been well constrained. Here, we report the carbon isotope results of pedogenic carbonate and lacustrine carbonate from a newly exposed section in the western Jianghan Basin (close to Yidu city). The ~80-m-thick section consists of Gongjiachong and Yangxi Formations, which can be interpreted as being deposited in a marginal lacustrine environment, dominated by interlayered, medium to thick-bedded gray limestone, calcareous sandstone, and red siltstone with minor conglomerate. From bottom upward, the carbon isotope of total carbon (δ^13 C) shows a rapid decrease from -6.5‰ to -13‰, while the carbon isotope of organic matter (δ^13 C_org) decreases from -24.5‰ to -27.4‰, suggesting a carbon isotope excursion in a short period of time. The carbon isotope records, like the ocean record, clearly show a “Three-Phase Model”: it starts with a rapid carbon isotope negative excursion from about 15 to 20 meters, followed by a slow decline trend from 20 to 36 meters, and then a gradual recovery to the pre-PETM level from 36 to 46 meters. This pattern of carbon isotope change corresponds to a positive feedback process of carbon in the Earth's surface system. Our findings indicate a possible records of PETM events and provide a new perspective for studying early Cenozoic climate change in central China.
Predicting river water quality under different environmental factors and its significance with Machine Learning approach
Authors: Shim Sun Hee , Lee Hye Won , Choi Jung Hyun
Published: February 2023

River Water Quality (RWQ) is significantly influenced by natural and anthropogenic activities such as land use and land cover changes. Urbanization has led to an increase in impervious surfaces, which alters hydrological flow pattern and delivers non-point pollutants to the stream more efficiently. In addition, intensification of agricultural activities can result in the increased nutrient loads due to alternations in surface soil properties. Hence, it is necessary to understand the impact of surrounding environment with specific emphasis on geographical factors (e.g. climate change, land use patterns and landscape metrics) on the RWQ in order to develop sustainable water quality management strategies effectively. We collected pollutant concentration Biochemical Oxygen Demand (BOD), Total Phosphorus (T-P), and  Total Organic Carbon(TOC) from monitoring stations in the Nakdong River watershed. To utilize field monitoring data, we developed a Machine Learning (ML) models (DNN, XGBoost and Random Forest) to predict RWQ in accordance with different environmental factors. SHapley Additive exPlanations (SHAP) was used to illustrate the significance of land uses and landscape patterns on RWQ in Nakdong River. The results of this study can (1) demonstrate the relationship of water quality variables with land uses and landscape patterns, (2) identify pollution sources and factors that affect Nakdong River, and (3) support catchment managers and stakeholders in evaluating the benefits and risks of water management strategies in priority areas.
Statistical downscaling of precipitation with deep neural networks
Authors: Gong Bing , Ji Yan , Langguth Michael , Schultz Martin
Published: February 2023

Accurate weather predictions are essential for many aspects of social society. Providing a reliable high-resolution precipitation field is essential to capture the finer scale of heavy precipitation events,  which is normally poorly represented in the numerical models. Statistical downscaling is an appealing tool since it is computationally inexpensive. Thus, it has been widely used over the last three decades. In recent years, super-resolution with deep learning has been successfully applied to generate high-resolution from low-resolution images in the computer vision domain. This task is somewhat analogous to downscaling in the meteorological domain.Inspired by this, we explore the use of deep neural networks with a super-resolution approach for statistical precipitation downscaling. We apply the Swin transformer architecture (SwinIR) as well as convolutional neural network (U-Net) with a Generative Adversarial Network (GAN) and a diffusion component for probabilistic downscaling. We use short-range forecasts from the Integrated Forecast System (IFS) on a regular spherical grid with ΔxIFS=0.1° and map to the high-resolution observation radar data RADKLIM (ΔxRK=0.01°). The neural networks are fed with nine static and dynamic predictors, similar to the study by Harris et al., 2022. All the models are comprehensively evaluated by grid point-level errors as well as error metrics for spatial variability and the generated probability distribution. Our results demonstrate that the Swin Transformer model can improve accuracy with lower computation cost compared to the U-Net architecture.  The GAN and diffusion models both further help the model to capture the strong spatial variability from the observed data.   Our results encourage further development of DNNs that can be potentially leveraged to downscale other challenging Earth system data, such as cloud cover or wind. 
Projection of local sea-level rise under CMIP6 scenarios (SSP1-2.6, SSP5-8.5) in the Northwestern Pacific marginal seas using dynamical downscaling.
Authors: Kang Yu-Kyeong , Cho Yang-Ki , Kim Yong-Yub , Kim Bong-Kwan , Seo Gwang-Ho , Kwon Seok-Jae , Oh Hyun-Ju
Published: February 2023

The global mean sea level has been rising with an acceleration since the twentieth century. Sea level rise is not spatially uniform but shows large regional variation. Local sea level can change due to various physical processes like changes in ocean circulation, atmospheric pressure, and mass redistribution. Projections of global sea level changes are available from the Coupled Model Intercomparison Project Phase 6 (CMIP6) database. However, Global climate models (GCMs) are limited in simulating spatially non-uniform sea level rise in marginal seas due to their coarse resolution and the absence of rivers and tides. High-resolution regional ocean climate models (RCMs) that consider tides and rivers were used to address these limitations in the Northwestern Pacific (NWP) marginal seas through dynamical downscaling. Four GCMs were selected for dynamical downscaling based on a performance evaluation of SST and the SSH along the RCM boundaries. A regional model with high resolution (1/20°) was simulated to project spatially non-uniform changes in the sea level under two CMIP6 scenarios (SSP1-2.6 and SSP5-8.5) from 2015 to 2100. Sea level rise in the NWP marginal seas was ~82 cm under SSP5-8.5 scenario and ~47 cm under SSP1-2.6 scenario, respectively. Under both scenarios, the predicted local sea-level rise was higher in the East/Japan Sea (EJS), where the currents and eddy motions are active, than in the Yellow and East China Seas. 
Radial Variation of Suprathermal Particles Associated with Corotating Interaction Regions
Authors: Allen Robert , Ho George , Mason Glenn , Kouloumvakos Athanasios , Wimmer-Schweingruber Robert , Rodríguez-Pacheco Javier
Published: February 2023

The first three years of Solar Orbiter operations have enabled robust sampling of the intensity and composition of suprathermal particles within the inner heliosphere. This includes a multitude of observations of suprathermal ions associated with Corotating Interaction Regions (CIRs), with corresponding observations at 1 au with measurements from the Ultra-Low-Energy Isotope Spectrometer (ULEIS) on the Advanced Composition Explorer (ACE) mission and the Suprathermal Ion Telescope (SIT) on the Solar-Terrestrial Relations Observatory-Ahead (STEREO-A) spacecraft. Comparing observations between these spacecraft allows for a statistical view of the radial variations of CIR-associated suprathermal particles by composition in the inner heliosphere, allowing for greater insight into energetic particle transport within the inner heliosphere. This study expands on early results from Solar Orbiter and ACE to now encompass the first three years of Solar Orbiter operations, as well as include STEREO-A measurements. Comparisons to historical studies of CIR-associated energetic protons are also expanded in the survey of CIR-associated suprathermal particles from Solar Orbiter, ACE, and STEREO-A.
Cumulative disturbance effects on phosphorus mobility in a gravel-bed river at the catchment scale
Authors: Stone Michael , Watt Caitlin
Published: February 2023

Landscape disturbance pressures in forested headwater regions can modify both the supply and transport of sediment from hillslopes to river networks. The effects of these pressures on phosphorus (P) mobility in rivers vary regionally depending upon the type and severity of the disturbance as well as interactions amongst other watershed scale controls such as climate, geology, hydrology and vegetation. The present study examines P dynamics in a gravel-bed river across multiple disturbances during environmentally sensitive periods of summer low-flow. Six study sites were selected to represent a gradient of sediment pressures from landscape disturbances (e.g., roads, harvesting, wildfire, sewage) in the Crowsnest River, Alberta. Interactions between fine bed sediments and soluble reactive phosphorus (SRP) were examined using equilibrium phosphorus concentrations (EPC0) and diffusive fluxes of SRP from the riverbed sediments. Diffusive fluxes at each site were estimated using gradients of SRP between pore-water in the bed and water column, determined from vertical distributions of SRP in the gravel matrix measured with pore-water peepers. SRP concentrations in pore-water were variable among depths and sites but were elevated downstream of the stream reach receiving primary sewage effluent outflow. Larger SRP concentration gradients were observed at sites that had either smaller substrate or increased biofilm activity. The EPC0 and diffusive pore-water flux data suggest that fine sediment in the riverbed acted as a source of SRP to the water column under low-flow conditions when the risk for eutrophication is higher and such conditions favor the growth of biofilms. EPC0 concentrations showed large inter- and intra-site variability indicating heterogeneous responses to disturbance. Furthermore, overlapping, and varying proportions of historic and contemporary harvesting, roads, road-stream or culvert crossings, and OHV use confounds the apportionment of landscape impacts. This study provides insight into the potential for the regulation of P by sediments in gravel-bed rivers following a range of landscape disturbance effects.
Application of Bayesian Network in Analysis and Management of Agricultural Water - Taking Kinmen for Example
Authors: Su Yi , Yu Hwa-Lung
Published: February 2023

By calculating the water demand and programming a fine irrigation project, the management and cultivating efficiency of traditional agriculture can be greatly improved. Taking rotational irrigation for example, the efficiency of irrigation can be maximized by adjusting water distribution routes, irrigation area allocation, and irrigation schedule planning. However, in actual operation, some problems are often encountered, such as how to persuade farmers and promote the designed irrigation project, and the negotiation of various stakeholders. Generally, due to the complexity of the irrigation design model, it is impossible to have an effective and immediate communication or presentation. Therefore, this study introduces the Bayesian network to presents the key points of the irrigation project after simplifying the relationship. In addition to being simpler for stakeholders to understand, it is also possible to adjust various parameters in time to obtain rough estimation results.The research area of this study is a 100-hectare farmland, which is located in Kinmen County, Taiwan. For many years, local farmers have only relied on precipitation to cultivate sorghum, wheat and other crops. However, the precipitation in Kinmen is semiarid and unstable. In the past five years, the annual rainfall has been lower than the average in previous years, which directly led to a very bleak crop harvest. Therefore, we hope to establish an irrigation project in Kinmen, using recycled water as the water source to provide local farmers with a reliable water source.The Bayesian network used in this study is a directed acyclic graphical (DAG) model based on conditional probability and Bayesian theorem to express the possible relationship between variables. In terms of operation, the different influencing factors in the research topic are converted into nodes, and the relationship between nodes is given by different conditional probabilities. This study uses GeNIe to establish a Bayesian network that can be used to estimate water profit and loss and other results. This Bayesian network can be divided into four sub-blocks, which are the relevant data of the irrigation area, the water demand, the water supply, and the final result calculation. Therefore, when the stakeholders are negotiating the irrigation project, they can discuss the different estimation results by adjusting each node of the first three sub-blocks.
Assessing Experimental Methods for the Quantification of Particle Size Segregation in Large Scale Flume Tests using Image Analysis
Authors: Kimball Julia , Bowman Elisabeth , Gray Nico , Take Andy
Published: February 2023

Particle size segregation is a phenomenon that generates preferential sorting of particles, based on size, in material flows of non-uniform size distribution. Landslide hazards, such as debris flows, involve materials of non-uniform particle sizes and therefore generate flow structures which arise from particle size segregation. The mobility, distal reach and impact forces associated with these natural hazards are influenced by these processes. Understanding the mechanisms of this phenomenon is essential for acquiring accurate input parameters that are needed to model these flows and properly design debris flow barriers and retaining structures. While the dynamics of particle size segregation in flow and deposition have been furthered through studying granular flows, studies to date have had several limitations. They primarily examine flows of bidispersed material, are small in scale, and rely on observations from flume sidewalls, precluding the study of dynamics along the centreline of flows. In this study, a large scale 6.8 m long and 2.1 m wide slope inclined at 30 degrees was used to generate dry tridispersed granular flows with 0.6 m3 of material. The tridisperse mixture consisted of even proportions by mass of 3 mm, 6 mm and 12 mm diameter spherical particles. Replicate tests were conducted to observe flow dynamics and assess methods for sampling along the internal plane of the test deposit. Image analysis techniques were developed to quantify particle size distributions within the deposit. Flume sidewall and internal observations were found to differ significantly from each other, in that side wall observations contained significantly higher proportions of the largest particle size. Additional replicate tests were conducted with saturated material to further examine the impact of pore fluid on segregation. This work will allow for future calibration of both numerical and theoretical models of particle size segregation and ultimately enable better debris flow modelling and mitigation practices.
Central tropical Pacific convection drives extreme high temperatures and surface melt on the Larsen C Ice Shelf, Antarctic Peninsula
Authors: Clem Kyle , Bozkurt Deniz , Kennett Daemon , King John , Turner John
Published: February 2023

Northern sections of the Larsen Ice Shelf, eastern Antarctic Peninsula (AP) have experienced dramatic break-up and collapse since the early 1990s due to strong summertime surface melt, linked to strengthened circumpolar westerly winds. Here we show that extreme summertime surface melt and record-high temperature events over the eastern AP and Larsen C Ice Shelf are triggered by deep convection in the central tropical Pacific (CPAC), which produces an elongated cyclonic anomaly across the South Pacific coupled with a strong high pressure anomaly over Drake Passage. Together these atmospheric circulation anomalies transport very warm and moist air to the southwest AP, often in the form of “atmospheric rivers”, producing strong foehn warming and surface melt on the eastern AP and Larsen C Ice Shelf. Therefore, variability in CPAC convection, in addition to the circumpolar westerlies, is a key driver of AP surface mass balance and the occurrence of extreme high temperatures.
Comparison of Characteristics of MEMS and Geophone Sensors for Earthquake Detection
Authors: Seo Jeong Beom
Published: February 2023

Recently, various attempts for earthquake detection and seismic observation using low-cost vibration sensors are being actively conducted, and among them, MEMS and Geophone are the most frequently attempted sensors. MEMS and Geophone sensors have different characteristics and strengths and weaknesses, and it is necessary to understand them to select a sensor suitable for the purpose. In this study, MEMS and Geophone sensors were compared and tested for P-wave detection for earthquake early warning and ground and structure earthquake motion observation. For this purpose, the two types of sensors were mounted together on one aluminum plate, vibration table tests were conducted, and earthquake detection results were compared through real-time earthquake detection over several months. Through this, only for the tested sensor models, we could conclude that Geophone is suitable for P-wave detection and pattern extraction for noise classification, and MEMS is suitable for strong vibration measurement.
Greenland in the Anthropocene: an archive of microplastic pollution
Authors: Parga Martinez Karla B , Andersen Thorbjørn J , da Silva Vitor , Strand Jakob , Posth Nicole R
Published: February 2023

Glacimarine sediment results from glaciers weathering the rock exporting silt and clay into the ocean. Such fine sediments are also exported from the Greenlandic Ice Sheet where new sources of plastic pollution like seasonal ice thawing may be releasing microplastics (MP) back to the environment. MP could be then transported to the seafloor via sediment burial and incorporated into the layers of the geological record. However, the purification and extraction of MP from such a fine-grain matrix is challenging, as the small grains remain in suspension and can form aggregates. In order to look for a footprint of the Anthropocene in Greenland, a sediment core was analyzed to generate a record of MP by comparing a pre- and post-plastic boom period. Using 210Pb and 137Cs dating, the chronology was established from 1861 to 2015 ±5 yrs bridging the plastic boom of the 1950s. Using a 4-step methodology developed for fine-grain matrices, MP particles were characterized via FT-IR imaging. QC/QA protocols were applied throughout the process to reduce the risk of contamination. More than 1000 particles were found in total ranging from 20 µm to 600 µm and going as far back as 1930. Nine polymer types were found, the most common being PE and PP accounting for 84% of all particles. This is the first sediment record of MP pollution in the Arctic, which shows that once thought pristine regions have in fact being polluted for a long time, which in turn implies that the impact might be greater than previously thought. In addition, this long-term accumulation in Greenlandic marine sediment could be compared to global horizons in the search for markers of the Anthropocene.
Re-examining phosphorus limitations on photosynthesis and productivity in forests around the world
Authors: Dong Ning , Prentice Iain Colin
Published: February 2023

Tropical forests have played a key role in absorbing anthropogenic emissions of carbon dioxide, yet too little is known about (present or potential) phosphorus (P) limitation on carbon (C) uptake. We have re-examined a recently published data set that was designed to quantify the dependence of photosynthetic capacities (Vcmax25, Jmax25) on leaf N and P concentrations – from an alternative perspective, considering leaf nutrients as consequences, rather than causes, of leaf function. We found that leaf N per unit area can be expressed a linear combination of components related to leaf mass per area and Vcmax25, whereas leaf P per unit area can be expressed a linear function of Jmax25. Globally, both Vcmax25 and Jmax25 increase with light intensity, but decrease with temperature – both responses supported by experiments. Vcmax25 decreases with soil C:N ratio, while Jmax25 increases with soil pH. Together, these various environmental factors explain almost 50% of global variation in photosynthetic capacities. These findings provide a promising route towards an optimality-based approach to modelling leaf traits and their relationships to properties of climate and soils.
Improved data assimilation in regional frequency analysis of rainfall extremes across large and morphologically complex geographical areas
Authors: Magnini Andrea , Lombardi Michele , Ouarda Taha B. M. J. , Castellarin Attilio
Published: February 2023

In locations where measured timeseries are not available or not sufficiently long, reliable predictions of the rainfall depth associated with a given duration and exceedance probability may be obtained through regional frequency analysis (RFA). The scientific literature reports on a large number of different approaches to RFA of rainfall extremes, each one characterized by specific advantages and disadvantages. One of the most common drawbacks is that regional models specifically refer to a single duration or a single exceedance probability. Second, several approaches require the definition of a homogeneous region where the model is trained; this leads to higher accuracy, but also the applicability of the model is limited to those locations that are hydrologically similar to the homogeneous group used in the training. Moreover, most models require filtering the available gauged stations based on the length of the measured timeseries to perform reliable frequency analysis. These aspects lead to discard a significant amount of data, which could turn out to be detrimental to the accuracy of the regional prediction in some cases.We set up a few alternative models aiming to investigate and discuss a different and innovative approach for RFA of rainfall extremes. We want to address three main research questions: (1) Can a single model represent the frequency of extreme rainfall events over a large, climatically, and morphologically complex geographical area? (2) Can a single RFA model handle all sub-daily  durations (i.e., from 1 to 24h)? (3) Is it possible to exploit all available annual maximum series, regardless of their length (i.e., very short ones too)? We select a large study area that is located in north-central Italy. We make use of more than 2300 Annual Maximum Series of rainfall depth for different time-aggregation intervals between 1 and 24 hours, that have been collected between 1928 and 2011 in the Italian Rainfall Extreme Dataset (I2-RED). For each gauged station, several morpho-climatic descriptors are retrieved (e.g., minimum distance to the coast, elevation of orographic barriers, aspect, terrain slope, etc.) and used as covariates for the prediction models. Our models are based on ensembles of unsupervised artificial neural networks (ANNs) and are able to predict parameters of a Gumbel distribution for any location and any duration in the 1-24 hours range based on the morphoclimatic descriptors. Through the analysis of results over 100 gauged validation stations, a profitable discussion is enabled on the potential and drawbacks of ensembles of unsupervised ANNs for regional frequency analysis of sub-daily rainfall extremes.
Long-term dynamics of 137Cs accumulation at an urban pond
Authors: Kurosawa Honoka , Nanba Kenji , Wada Toshihiro , Wakiyama Yoshifumi
Published: February 2023

It is known that the semi-enclosed water area such as pond and dam reservoir is readily subject to 137Cs accumulation because of the secondary inflow from the catchment area. We present the long-term monitoring data of the 137Cs concentration in bottom sediment and pond water in an urban pond located in the central area of Koriyama City, Fukushima Prefecture to discuss the 137Cs dynamics of the urban pond. The pond was decontaminated by the bottom sediment removal in 2017. The bottom sediment core and pond water were collected in 2015 and 2018-2021. The inflow and outflow water were collected in 2020-2021. The river water around the pond was collected in 2021. The bottom sediment and water samples were measured for 137Cs concentration, particulate size distribution, and N and C stable isotopes. Compared between 2015 and 2018, the 137Cs inventory and 0-10 cm depth of 137Cs concentration in the bottom sediment at 7 points were decreased by 81 % (mean 1.50 to 0.28 MBq/m2) and 85 % (mean 31.5 to 4.8 kBq/kgDW), respectively. Although mean 137Cs inventory in bottom sediment did not drastically change during 2018-2021, its variability became wider. Points with increased 137Cs inventory in bottom sediment showed year-by-year increase in thickness of layer with concentrations higher than 8 kBq/kgDW, a criterion for considered decontamination. The 137Cs concentration in suspended solids (SS) in pond water was lowered after decontamination, although it still remained above 8 kBq/kgDW. The 137Cs concentrations in SS of inflow water were also high, exceeding 8 kBq/kgDW. The 137Cs concentration in SS of the river water around the pond was higher when it passed through the urban area, suggesting that the inflow of particles from urban origin maintained high 137Cs level in the pond. 
Modeling of the Subsolar Magnetopause Motion Under Interplanetary Magnetic Field Southward Turning
Authors: Xu Qiuyu , Tang BinBin , Sun Tianran , Zhang Xiaoxin , Wei Fei , Guo Xiaocheng , Wang Chi
Published: February 2023

In this study, a new analytical model to describe the time-dependent subsolar magnetopause motion under interplanetary magnetic field (IMF) southward turning has been developed. This model, based on the scenario of magnetopause erosion due to magnetic reconnection, can be approximated by both linear and non-linear functions. The linear function is simplified under the assumption of constant magnetopause erosion under southward IMF, and the non-linear function is derived by assuming that the magnetopause erosion decays exponentially. In the limit of a short time, the non-linear function is essentially the same as the linear function. By comparing with global MHD simulations, the linear function performs well within the first ten minutes, and the error then increases with time. The non-linear function describes the magnetopause motion more accurately with respect to, and consistent with simulations for a time interval of $\sim 40$ minutes. This model has also been successfully applied to data-driven simulations of the 17 March 2015 geomagnetic storm event, suggesting the possible applicability of this model in reality. 
Seasonal and Interannual Variations of Global Tides of Neutral Winds in the Mesosphere and Lower Thermosphere
Authors: Liu Yangkun , Xu Jiyao , Smith Anne , Liu Xiao
Published: February 2023

The seasonal and interannual variations of global tides of neutral winds in the mesosphere and lower thermosphere (MLT) are investigated based on the neutral horizontal wind data measured by TIMED Doppler interferometer (TIDI). The particular focus is on how the seasonal variation of tidal amplitude varies in response to solar cycle (SC) and to the quasi-biennial oscillation in winds in the lower stratosphere (SQBO). We find that the responses of seasonal variations of tides to SQBO and SC are comparable in magnitude to those of their corresponding annual means. Further, we show that the response patterns of seasonal variations of tides to SQBO and SC are not always similar to those of their corresponding annual means, which indicates that the tidal responses differ at different times of the year. In addition, we reveal that migrating tides show strong terannual oscillations (TAO) especially in meridional wind, whereas nonmigrating tides do not show obvious TAO.
RIME-REASON synergistic opportunities for surface and near-surface investigations of icy moons
Authors: Chan Kristian , Grima Cyril , Gerekos Christopher , Blankenship Donald D.
Published: February 2023

The near-surface (i.e., depths of tens of meters from the surface) of icy environments is subject to various processes resulting in changes to its structure, density, and composition. On Earth, surface meltwater can refreeze in firn to form meters-thick ice layers, which can inhibit subsequent vertical infiltration in favor of lateral runoff. On icy worlds such as Ganymede, landform degradation processes, such as mass wasting and impact erosion, could leave behind layered deposits of dark material of varying density and thickness. Therefore, characterizing such heterogeneity (layering) can reveal much about the different processes acting on the near-surface environment. These processes can be studied with a multi-frequency/bandwidth approach applied to surface radar reflectometry measurements.Airborne ice-penetrating radar, traditionally designed to study the subsurface of ice sheets on Earth, can also be used to study the surface and near-surface ice. Upcoming missions to the Jovian icy moons will carry ice-penetrating radars, namely the Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) on the Europa Clipper mission and the Radar for Icy Moons Exploration (RIME) on the JUpiter ICy moons Explorer (JUICE) mission. REASON will operate at center frequencies of 60 MHz and 9 MHz, with bandwidths of 10 MHz and 1 MHz, respectively. RIME will operate with only a center frequency of 9 MHz but with dual-bandwidth capabilities of 2.8 MHz and 1 MHz.The Radar Statistical Reconnaissance method was applied to dual-frequency/bandwidth radar observations collected over Devon Ice Cap, Canadian Arctic, to deconvolve the total surface power into its coherent (Pc) and incoherent (Pn) components. Both Pc and Pn are used to map the spatial distribution and constrain the vertical thickness of ice layers embedded within firn. We extend this approach to Ganymede and assess its utility for studying near-surface layering in the context of rough surfaces. We simulate the radar surface echo with a generalized version of the multilayer Stratton-Chu coherent simulator previously published, but now compute the scattering contributions from every frequency component within the bandwidth of the emitted chirp. Simulated data are shown to validate the assumptions of the insensitivity to surface roughness parameters representative of Ganymede, when observing with different bandwidths but at the same center frequencies. Finally, we outline strategies for using RIME and REASON together for near-surface reflectometry studies over planned observations of the Jovian icy moons. Using observations obtained with the frequencies and bandwidths from both radars, particularly at crossover locations, can provide valuable knowledge of the near-surface structure, even when the surface may appear rough.
Boulder Dislodgement By Storms: What can we learn from the boulder fields Central-Western Ireland?
Authors: Weiss Robert , Cox Ronadh
Published: February 2023

Coastal boulder deposits of western Ireland include over 1200 boulders and megagravel documented to have moved during storms in the winter of 2013 - 2014. The data come from seven areas on the mainland and outlying islands. The mass spectrum for the transported clasts ranges from 0.1 tonnes for the lightest boulder to 620 tonnes for the heaviest megagravel. This is a unique dataset that provides the opportunity for detailed quantitative analysis of dislodgement criteria.We employ the Boulder Dislodgement and Sliding Model of Weiss et al (2022) to calculate dislodgement flow velocities for each boulder. In each of the seven areas, we derive the dislodgement flow velocity to mass (DV-M) relationships for each area and perform hypothesis tests to decern if the DV-M relationships in the different areas are governed by (a) the characteristics of the geological formation and topography from which the boulders are quarried, (b) the characteristics of the storm events, such as significant wave heights and period, or (c) a interactsions/combined influence of (a) and (b).Interrogating the boulder data and model results objectively, with statistical and other quantitative methods, will help to shed light on the question of whether coastal boulder deposits are useful event records in the context of non-linear wave-wave interactions nearshore that may result in significant under- and overestimations of the causative event if nonlinear wave-wave interactions are ignored. For example, constructive wave-wave interactions can result in a wave condition that is much larger and dislodges a significantly heavier boulder than the individual waves could. Similarly, destructive wave-wave interaction can also cause much smaller wave conditions than the individual waves indicate and cause only the dislodgment of much lighter boulders than the individual waves would.The wide range in boulder masses and topographic settings n the dataset can help to establish a better understanding of potential uncertainties for dislodgement velocities in general; and this approach should be valuable for application in other situations, for example, for isolated boulders in coastal settings or for cases in the stratigraphic record. 
WA array: the next state-wide passive seismic survey
Authors: Murdie Ruth , Yuan Huaiyu , O'Donnell John Paul , Chandra Subhash , Johnson Simon
Published: February 2023

The Government of Western Australia, through the Geological Survey of Western Australia, is funding a passive seismic acquisition  program, WA array, which has been designed to map Earth’s lithosphere at an optimal level of station spacing across the state of WA (over 2.5 million square kilometres).The program, which started on 1 July 2022 will involve the deployment of an “array” of 165 seismometers arranged in a grid pattern spaced at 40 kilometre intervals, moving progressively across the state over a period of ten years. Instruments will be relocated on an annual basis across nine regional areas.It is primarily designed to investigate the crustal and lithospheric mantle structure with the aim of identifying prospective regions for mineral exploration, especially in areas undercover. At the continental scale, the large lithospheric models will target the bulk lithospheric velocities and upper mantle discontinuities, which will provide direct information to better constrain tectonic deformation processes that operated through time. From the Archean nuclei to the Phanerozoic passive margins, WA is composed of many domains with a rich tectonic history; thus WA array will also provide an unprecedented opportunity to study lithospheric structure related to early Earth tectonics, Earth evolution and the Earth today.The results of the program will step change in our understanding of Western Australia’s lithospheric architecture. This knowledge will provide a sound scientific basis for mineral and energy exploration, but also for evaluating crucial land use decisions over the coming decades, at a time when large areas of the State are expected to accommodate renewable energy projects.In addition, the data will be used to evaluate the risks from seismic events, which would contribute to risk assessments for the placement industrial infrastructure such as pipelines and hydrogen generation and storage installations as well as building codes for housing and other buildings.The first deployment of stations is now in the ground with 158 stations currently running. The first results and raw data will become available at the end of 2024. We will present and discuss the design of the array, initial modelling status and model updates, and related program applications.
Performance evaluation of 20CRv3 downscaling using WRF over southern Alaska with focus on temperature and precipitation in glaciated areas
Authors: Koenigseder Sandra , Barrows Timothy , Fisher Jenny , Evans Jason , MacColl Chesley
Published: February 2023

Global warming has raised mean surface temperatures by 0.99 ± 0.15 °C from 1850-1900 to 2011-2020. The temperature rise has been greatest in the high latitudes. Alaska has one of the largest temperate and subarctic glaciated areas in the world, which is highly sensitive to climate change. Currently, the mass loss from these glaciers contributes to about a third of the global sea-level rise. For example, the tidewater glacier Columbia Glacier located within Prince William Sound is the largest single contributor to sea level rise through its rapid retreat, which started in the early 1980s. Although internal controls strongly influence the tidewater glacier cycle, the ubiquitous retreat of Alaskan tidewater glaciers indicates climatic forcing is involved. However, it is unlikely climate controls the rate of retreat. There are insufficient meteorological observations from this region to assess the role of climate across a whole tidewater cycle. This project reconstructs the regional climate of southern Alaska from 1836–2015 using dynamical downscaling of the NOAA-CIRES-DOE 20th Century Reanalysis (20CRv3). To do this, the Weather Research and Forecasting model (WRF) has been used to spatially downscale the reanalysis data to produce high-resolution 4 km (convection permitting) output for southcentral/southeastern Alaska. Five different physics parametrisations have been tested for the year 2010. The model output of these five configurations were evaluated using observational records from the Global Surface Summary of the Day (GSOD). The physics scheme that performed most realistically was identified using root mean square error, R squared and normalized mean error for temperature and precipitation. The study shows that 20CRv3 can successfully be downscaled for the study region. As a result, the leading parametrisation was used for a long-term simulation (179 years) to reconstruct local climate and weather over southern Alaska over a significant part of a tidewater glacier cycle. The results will be used to evaluate the influence of climate on these glaciers for the downscaling period from 1836 to 2015.
Does Uncertainty-Based Multi-Site Multi-Variate Calibration of Hydrological Models Influence Projected Flow Regimes and Other Climate Risks? 
Authors: Srivastava Saumya , Kumar D Nagesh
Published: February 2023

Quantifying the projected changes in flow regimes and increase in climate change risks remains a challenge due to the diverse uncertainties arising from hydrological as well as climate models. These uncertainties and projected climate change impacts depend on the scheme chosen for the calibration of the hydrological models to a great extent. In this study, five multi-site and/or multi-variate calibration scenarios are devised and subbasin-wise quantification of various sources of uncertainties (parametric, observational, model simulation, and sampling uncertainty of performance measure) is done for a large river basin (142,000 square kilometers) in India. The aggregated uncertainty for each sub-basin is found by averaging the various sources of uncertainties and the optimal parameter ranges for each sub-basin are derived from the calibration scenario that gives minimum aggregated uncertainty for that sub-basin. These sub-basin-wise optimal parameters are used to drive the simulations of a semi-distributed hydrological model by using the climate projections from an ensemble of 13 global climate models for 3 Shared Socioeconomic Pathways (SSP2-2.6, SSP2-4.5, and SSP5-8.5) as forcing data. The differences in the projected flow regimes for the five calibration scenarios are estimated using various Indicators of Hydrological Alteration (IHA) and indicators of climate risk representing risk hazard, exposure, and vulnerability. The climate risk indicators are for floods, droughts, population, agricultural land, forest, and infrastructure risk. The results of this study help in highlighting the hydrological as well as socio-economic risks of the projected climate change across large river basins, while ensuring minimum aggregated uncertainty by using multi-site multi-variate hydrological model calibration for various subbasins.