bluuebunny/crossref_metadata_2025 huggingface dataset:
Incorporating The Variable Contributing Area Concept in The HYPE Modelling Framework
Authors: Ahmed Mohamed Ismaiel , Shook Kevin , Pietroniro Alain , Stadnyk Tricia , Pomeroy John W. , Pers Charlotta , Gustafsson David
Published: February 2023

Modelling the hydrology of the North American prairie region is complicated by the dominance of cold region processes and by the flat topography, which contains millions of depressions. The depressions contribute to variable contributing areas in prairie basins, due to their varying water storage. The relationships between the depressional storage, and the contributing fraction are hysteretic and strongly influence the basin responses. Most hydrological models do not represent these complex hysteretic relationships, and therefore struggle in simulating the hydrology of the region. In this study, we propose a novel Hysteretic Depressional Storage (HDS) algorithm that is based on the known hysteretic properties of prairie depressions. HDS is implemented into the HYPE modelling framework to improve the simulations of prairie streamflow by accounting for the variable contributing area. The modified HYPE, and the original program are tested on two depression-dominated basins in Saskatchewan, Canada. The modified HYPE model show improved simulation of streamflows compared to the original HYPE model. The HDS algorithm can contribute to improving the streamflow simulation of not only the North American prairie region, but also in the arctic and Siberian regions, which are dominated by the same complex depressional storages. The modified HYPE model should also improve the estimates of surface water storage and the resulting evaporative fluxes in these regions, increasing model fidelity and improving water budget estimates in these complex terrains, especially under changing climates.
Globsim v.3 – Improvements to an open-source software library for utilizing atmospheric reanalyses in point-scale land surface simulation
Authors: Brown Nick , Gruber Stephan , Cao Bin
Published: February 2023

The lack of long-term and consistent meteorological observations limits the application of land-surface simulators (e.g., of phenomena in hydrology, the cryosphere, ecology) at remote locations. For example, most permafrost areas are remote and lacking consistent meteorological time series, models that describe permafrost change over time cannot be driven for comparison with observations or for impact studies. Reanalysis-derived time series are valuable because they are available with global coverage, for a long time period, and for a broad set of physically consistent variables. Multiple reanalyses can be used to provide estimates of uncertainty. Practically, however, this data is difficult to use for several reasons: grid-scale reanalyses must be downscaled and interpolated horizontally (and vertically within the atmospheric column for mountains regions) to the site‑scale, differences in variables, units, and delivery between reanalyses must be reconciled, and large volumes of data need to be handled. Globsim is an open-source python library (available via GitHub) that was developed to handle these challenges and to facilitate a simulation workflow that takes advantage of the multiple reanalysis products available today. It outputs sub-daily meteorological time series that resemble meteorological stations for any location on the planet. Since the release of the first version of Globsim, we have improved usability, refactored code for maintainability and speed, and fixed a number of bugs. We also added support for ERA5 ensemble data, and added more sophisticated heuristic downscaling algorithms, including TOPOscale for elevation-adjusted radiative fluxes. We use Globsim as a core tool in a multi-model permafrost simulation workflow and, as a future step, we intend to use it as part of a debiasing routine to make predictions of permafrost using climate scenarios. We expect this tool to be broadly applicable to climate change impact modelers and other scientists using climate driven simulations working in (remote) locations that lack meteorological data of sufficient quality and duration for their application.
The Development of a ML-based Estimator to Reconstruct Water Table Depth over the Contiguous US
Authors: Ma Yueling , Leonarduzzi Elena , Defnet Amy , Melchior Peter , Condon Laura , Maxwell Reed
Published: February 2023

Groundwater is one of the most valuable resources in the US. The United States Geological Survey (USGS) reported that about 26% of the water used in 2015 came from groundwater. Due to the scarcity of groundwater observations, it is still challenging to monitor groundwater resources at the watershed scale (where local decision making occurs). In addition, for long-term high-resolution simulations, physically-based models become very computational demanding and data hungry. With much less computational time and physical knowledge, machine learning (ML) techniques are able to capture complex nonlinear connections between groundwater dynamics and atmospheric and land surface processes from historical data. Recent studies have shown their success in groundwater modeling.In this study, we develop a ML-based estimator to produce water table depth (WTD) estimates over the Contiguous US (CONUS) at a spatial resolution of 1 km using USGS WTD observations and other hydrometeorological data. The WTD estimator consists of two components. One component captures spatial variations in WTD using random forests and the other component learns temporal variations in WTD by Long Short-Term Memory networks. We combine the results from the two components to obtain WTD estimates. The estimated WTD are compared to USGS WTD observations to show their reliability. Based on the WTD estimates, we study groundwater changes in the Upper Colorado River Basin (UCRB) in recent drought years, which is one of the principal headwater basins in the US. To better interpret the performance of the WTD estimator, we conduct sensitivity analyses on input variables for both components. Moreover, we assess the uncertainty of the WTD estimator in estimating WTD over the CONUS. Our study demonstrates that the WTD estimator can generate reasonable WTD estimates over CONUS, thereby facilitating understanding of groundwater systems in the US. The WTD estimator can also be transferred to other regions in the world that have a similar hydrologic regime to a region in the US.
Generation of sub-ion scale magnetic holes from electron shear flow instabilities in plasma turbulence
Authors: Arrò Giuseppe , Pucci Francesco , Califano Francesco , Lapenta Giovanni
Published: February 2023

Magnetic holes are coherent structures associated with a strong depression in the magnetic field amplitude. Such structures are ubiquitous in space plasmas and are observed in the solar wind, in planetary bow shocks and magnetosheaths, in the Earth's magnetotail and around comets. Magnetic holes may have very different sizes and properties. The largest ones have a size of hundreds of ion gyroradii while the smallest ones are sub-ion scale structures of the order of a few electron gyroradii. The drop in magnetic field amplitude associated with magnetic holes is often sustained by an increase in plasma density and enhanced ion and electron temperature anisotropies, with temperatures that are typically higher in the plane perpendicular to the local magnetic field. These properties seem to suggest that the generation of magnetic holes may result from the nonlinear evolution of mirror modes whose growth is fed by perpendicular temperature anisotropies and that are characterized by anticorrelated magnetic field and density perturbations. Some observational and numerical studies seem to support the idea of a scenario in which magnetic holes are generated by the mirror instability but in many cases this picture is not consistent with observations, especially in the case of sub-ion scale magnetic holes for which a number of possible generation mechanisms have been considered. Hence, the origin of magnetic holes is still controversial and under debate. Plasma turbulence is also known as a driver for the generation of coherent structures and may play a key role in the formation of magnetic holes, especially in the solar wind and in the Earth's magnetosheath that are in a turbulent state. Indeed, numerical simulations of plasma turbulence show that sub-ion scale magnetic holes can develop self-consistently out of small scale magnetic fluctuations that locally reduce the magnetic field amplitude and trap hot electrons. However, it is still unclear how such small scale fluctuations can emerge in a turbulent plasma where energy is typically injected at large scales. In this work, we study the formation of sub-ion scale magnetic holes by means of fully kinetic particle-in-cell simulations of plasma turbulence. We show that by injecting energy at scales relatively large with respect to ion scales, the turbulence naturally tends to generate sub-ion scale electron velocity shear layers associated with elongated magnetic field grooves. These elongated magnetic dips then become unstable and break up into sub-ion scale magnetic holes characterized by an intense azimuthal electron current and a strong perpendicular electron temperature anisotropy. We show that the properties of magnetic holes generated by this mechanism are consistent with satellite observations. Our results may provide a possible explanation of how magnetic holes develop in a realistic turbulent environment.
Distinct different climate evolution across inner Asia induced by the mountain building of the Tibetan Plateau and Central Asian Orogenic Belt
Authors: Sha Yingying , Shi Zhengguo
Published: February 2023

Incremental geological evidences reveal important climate reorganization in inner Asia and also the Asian mountain building since the late Oligocene-early Miocene. For the climate reorganization, the arid Asian inland has experienced several severe aridification periods and the Chinese Loess Plateau (CLP) shows abundant dust deposition from Red Clay in Neogene to loess-paleosol deposits in Quaternary. Meanwhile, more geological records indicate asynchronous growth of the Tibetan Plateau (TP) and the Central Asian Orogenic Belt (CAOB). Therefore, the question raises on how the stepwise growth of the TP and CAOB would influence the inner Asian climate reorganization. In order to answer the question, a set of numerical experiments is conducted by utilizing general circulation model CAM4. In the experiments, the main TP, Pamir Plateau (Pr), Tian Shan Mountains (TS) and Mongolian Plateau (MP) are successively included. Our modeling work shows that precipitation changes over arid inland and monsoon dominated CLP are different. With the inclusion of the main TP, Pr and TS, the precipitation and moisture reveal persistent reduction over the arid inland. On the contrary, the precipitation and moisture are significantly intensified over the CLP. The most intense decrease over the Tarim Basin (TB) is resulted by the inclusion of the main TP in warm season. Meanwhile, the increases over the CLP induced by the main TP and Pr-TS are comparable and both dominated in summer. After the final inclusion of the MP, the precipitation then reveal consistent reduction both over the arid inland and the CLP. The reduction is significant and dominated in summer. In addition, the precipitation in the TB portrays a spring-winter dominant pattern when the Pr and TS are removed. With the inclusion of the Pr-TS, the precipitation seasonality is transformed to peak in summer. Therefore, our results indicate the distinct differentiation of Asian climate regimes affected by the main TP, Pr, TS and MP. The results might provide new support for the evolution of Asian inland deserts  since the late Oligocene and the development of deposits over the CLP from Neogene Red Clay to Quaternary loess-paleosol deposits.
Seamless subseasonal probabilistic streamflow forecasting: MuTHRE lets you have your cake and eat it too
Authors: Thyer Mark , McInerney David , Kavetski Dmitri , Laugesen Richard , Woldemeskel Fitsum , Tuteja Narendra , Kuczera George
Published: February 2023

Subseasonal streamflow forecasts inform a multitude of water management decisions, from early flood warning to reservoir operation. ‘Seamless’ probabilistic forecasts, i.e., forecasts that are reliable and sharp over a range of lead times (1-30 days) and aggregation time scales (e.g. daily to monthly) are of clear practical interest. However, existing forecast products are often ‘non-seamless’, i.e., developed and applied for a single time scale and lead time (e.g. 1 month ahead). If seamless forecasts are to be a viable replacement for existing ‘non-seamless’ forecasts, it is important that they offer (at least) similar predictive performance at the time scale of the non-seamless forecast.This study compares forecasts from two probabilistic streamflow post-processing (QPP) models: the recently developed seamless daily Multi-Temporal Hydrological Residual Error (MuTHRE) model and the more traditional (non-seamless) monthly QPP model used in the Australian Bureau of Meteorology’s Dynamic Forecasting System. Streamflow forecasts from both post-processing models are generated for 11 Australian catchments, using the GR4J hydrological model and pre-processed rainfall forecasts from the ACCESS-S numerical weather prediction model. Evaluating monthly forecasts with key performance metrics (reliability, sharpness, bias and CRPS skill score), we find that the seamless MuTHRE model achieves essentially the same performance as the non-seamless monthly QPP model for the vast majority of metrics and temporal stratifications (months and years). As such, MuTHRE provides the capability of ‘seamless’ daily streamflow forecasts with no loss of performance at the monthly scale – the modeller can proverbially ‘have their cake and eat it too’. This finding demonstrates that seamless forecasting technologies, such as the MuTHRE post-processing model, are not only viable, but a preferred choice for future research development and practical adoption in streamflow forecasting.
Microstructure linking external forcing to supereruption
Authors: Liu Boda , Qi Chao
Published: February 2023

Large rhyolitic eruptions with ejecta of transcontinental scale have catastrophic effects on the environment. Despite its importance in volcanic hazard assessment and potentially influencing climate, the triggering of supervolcanoes remains enigmatic. Many valid mechanisms for mobilizing an eruptible magma reservoir exist, however, the fundamental question of how to initially form the magma reservoir responsible for a supereruption is unknown. Here we show that the deformation microstructure of partially molten rock could accelerate melt extraction and assemble a large eruptible magma reservoir. By modeling observed shape and orientation of melt pockets in deformed samples, we predict that deformation microstructure forms a melt network that enhances melt flux by up to 30 times. Our results suggest that compressing a crystal-rich magmatic mush in volcanic arcs or under glacial loading can assemble a large crystal-poor magma reservoir in a few thousand years, a timescale in consistent with petrological evidence of rapid assembly. Because external stress is common to most magmatic systems, deformation microstructure could be a ubiquitous catalyst for magmatic activities including supereruptions.
Strategic expansion of the Arctic-Boreal carbon flux network
Authors: Arndt Kyle , Natali Susan ,   Permafrost Pathways Flux Steering Committee
Published: February 2023

Permafrost soils store vast amounts of carbon, twice as much as the atmosphere. With climate warming occurring at a rate three to four times the global average in Arctic-boreal ecosystems this carbon is at risk of being released to the atmosphere in the form of carbon dioxide or methane (hereby, carbon fluxes) exacerbating global climate warming. However, gaps in carbon flux data in high latitude ecosystems limit our ability to understand, upscale, model, and project carbon fluxes, which in turn limit our ability to set accurate emissions reduction targets to stay within globally agreed upon temperature thresholds such as 1.5 or 2°C. To address this, we are strategically expanding the informal Arctic-boreal carbon flux network through the installation of ~10 new eddy covariance sites and supporting expanded measurements (during winter and for CH4) at existing sites. To guide site selection decision making, we are using a representativeness analysis of the current eddy covariance network, determining the Euclidean distance in environmental data space using key carbon flux drivers at a 1 km2 resolution across the Arctic-boreal region (Pallandt et al., 2022). Analyses show a lack of representation in the high Arctic, Siberia, and Eastern Canada, and representation is substantially lower when considering only sites with year-round measurement or that measure methane, limiting our ability to estimate the full impact of carbon fluxes from the Arctic-boreal region. Additional consideration is given to logistical constraints, partnerships, and modeling gaps. Work has begun including a re-installation in Churchill, MB, and upgrades for year-round and additional instrumentation for 4 towers in Alberta and the Northwest Territories and a site in Iqaluit, NU. We will further synthesize existing network data to inform the Dynamic Vegetation [Model] Dynamic Organic Soil Terrestrial Ecosystem Model (DVM-DOS-TEM) model and use machine learning approaches to upscale Arctic-boreal carbon fluxes.
High temperature fluid flow through active décollement at the Nankai subduction zone
Authors: Kamiya Nana , Kinoshita Masataka , Lin Weiren , Hirose Takehiro , Yamamoto Yuzuru , Bowden Stephen A , Tsang Man-Yin , Tonai Satoshi
Published: February 2023

Temperature is one of the important parameters to understand complex dynamics, because temperature of the crust is changed by some events such as volcanic activities and a passage of high temperature fluid, which affects physical property, chemical cycle and also microbiosphere. Therefore, information about temperature allow us to understand the dynamics of the active subduction zone.IODP Site C0023, located at the tip of subduction zone in the Muroto transect of the Nankai Trough, was drilled by IODP Expedition 370. There, we measured the vitrinite reflectance which is an index of the maximum temperature experienced by the sediments. Comparing the measured reflectance and the model values calculated by assuming the past heat flow, it was found that Site C0023 experienced a higher heat flow than the present, which was approximately 160 mW/m2. However, the vitrinite reflectance is significantly higher than that in the above model just below the décollement, which suggested that another thermal anomaly originated directly under the décollement in addition to the high heat flow from the basement. With assumptions on the temperature of the heat source and the duration of heating below the décollement, we calculated the vitrinite reflectance in different models.As a result, it was found that heat source temperature of 200˚C and heat generation duration of 500-1000 years are required just below the décollement to explain the depth distribution of the measured values. At Site C0023, a high pore pressure zone is distributed just below the décollement, which can serve as a path for fluids from deeper part. Considering that the temperature at the depth corresponding to the seismogenic zone in the Muroto area of the Nankai Trough is approximately 200˚C, and that a specific high temperature has not been confirmed just below the décollement of C0023 at present, the origin of the high-temperature fluid would be the deep seismogenic zone. Furthermore, the advection of high-temperature fluids is thought to be intermittent. In other words, the high reflectance just below the décollement is considered to indicate the advection of the high-temperature fluid from deep to shallow areas at the time of past earthquakes.
Predicting the 1 AU Arrival Time of Coronal Mass Ejections Based on Convolutional Neural Network
Authors: Yang Yi , Shen Fang , Li Yucong , Lin Rongpei
Published: February 2023

Coronal mass ejections (CMEs) are one of the most violent solar eruptions, which can burst out large amounts of magnetized plasma with speeds up to thousands of kilometers per second. When it reaches the Earth, a CME can cause geomagnetic storm, affecting aviation safety, satellite operations, communications systems and power facilities. Therefore, fast and accurate prediction of CME arrival time is crucial for avoiding severe damaging effects and reducing economic losses. The initial morphology and kinematics of a CME in the corona can be observed by the coronagraphs equipped on the Solar and Heliospheric Observatory (SOHO), so that the coronagraphs should be useful to predict the CME arrival times. In this study, convolutional neural network (CNN) is used to obtain the features of SOHO/LASCO coronagraph pictures related to the CME transit time, and establish a model capable of predicting the CME arrival time. The influence of different hyperparameters of CNN on the prediction results is studied. Further, we add a physical information constraint of the initial velocities of CME to the basic CNN outputs, and found that smaller prediction errors can be obtained. 
Analysis of variables for the modeling of aerobic processes on the treatment of the organic fraction of solid waste in megacities
Authors: Becerra Quiroz Ana Paola , Solano Meza Johanna Karina , Rodrigo Clavero Maria Elena , Rodrigo Ilarri Javier
Published: February 2023

The organic fraction of municipal solid waste (MSW) in megacities is usually managed by composting. In this technique the decomposition and stabilization of organic matter occurs under thermophilic conditions. Currently, composting systems range from simple garden piles and bins to highly engineered computer controlled mechanized processes. Composting is used worldwide, currently treating 5.5% of total urban solid waste. Therefore, modeling aerobic processes becomes important since it is the basis for determining the optimal conditions of the system and a fundamental tool to define its relevance and quantify environmental impacts.
However, biological processes such as composting require complex methods and specific software to predict the behavior of organic waste through mathematical models. In the case of the treatment of the organic fraction of urban solid waste, it is necessary to develop this type of models to enhance the recovery of the waste and determine the impacts associated with this technology. For this reason, modeling of organic waste processes is one of the priorities solid waste managing in megacities, where the development of technologies of greater complexity and magnitude is necessary due to the large population.
Success in determining feasibility in a predictive model is based on the parameter calibration process. Model results are dependent on the accuracy of the input variables and the way in which the collection and statistical treatment of the information is be carried out. Despite this need, the information associated with the management of solid waste in megacities is often scarce and incomplete. This is usually due to the poor information systems available in many countries for recording all the stages involved in MSW management.
Therefore, this research seeks the determination and standardization of the variables required for the mathematical modeling of aerobic processes of the organic fraction of solid waste in megacities. The proposal includes the definition of technical but also environmental, social, economic, administrative and financial variables for the case study of the megacity of Bogotá (Colombia).
Probabilistic ambient noise imaging of the Macquarie Ridge Complex using ocean-bottom and land-based seismometers
Authors: Pham Thanh-Son , Tkalcic Hrvoje , Ma Xiaolong , Pickle Robert , Muir Jack , Duru Kenneth , Winder Tom , Rawlinson Nicholas , Eakin Caroline , Coffin Millard , Stock Joann ,   Macquarie Ridge 3D Team
Published: February 2023

The Macquarie Ridge Complex, located at the boundary between Indo-Australian and Pacific plates in the southwest Pacific Ocean, hosts the largest sub-marine earthquakes in the 20th century, not associated with ongoing subduction. We deployed 27 ocean-bottom seismometers, of which 15 have been recovered successfully, to understand the origin of the sub-marine earthquakes and their potential earthquake and tsunami hazards to Australia and New Zealand. Additionally, we deployed five land-based seismometers on Macquarie Island.We explore state-of-the-art processing methods to analyze the new seismic dataset from the retrieved seismic stations. One of the goals is to image the tectonic settings beneath the MRC. Here, we present a first-order tomographic model and its relevant uncertainty estimate of the region constructed from ambient noise surface waves using a probabilistic inversion framework. The tomographic image will be complemented with receiver-based imaging results such as those from P-wave coda autocorrelations and receiver functions to confirm the existence of possible geometries. The results are expected to supply a fresh understanding of the tectonic settings under the MRC and unpuzzle the origin of the significant underwater earthquakes in the 20th century.
Volatiles Release from Metal-Silicate Interactions in Magma Oceans During Planetary Accretion
Authors: Morra Gabriele , Honarbakhsh Leila , Mora Peter
Published: February 2023

During planetary accretion, impacts vary in mass, velocity, and angle, producing magma oceans of different sizes and temperatures. Large impactors, more common in the late accretionary stages, contain iron cores that can emulsify into extremely small drops, which then rain down into the rocky planetary core. During its descent, metal and silicate chemically react, stripping the mantle of siderophile (iron-loving) elements and leaving lithophile (rock-loving) elements behind. To estimate the fraction of volatiles remaining in the magna ocean vs. the one stored into the core is essential to model the properties of the atmosphere of newly formed rocky planets. Further, the composition of the atmosphere influences the cooling rate of the magma ocean itself. A single simulation that can quantify this entire dynamics is presently beyond existing techniques. Using a newly developed fluid-dynamic numerical approach, based on the Lattice Boltzmann Method for fluid-dynamics, and Rothman-Keller approach for multiphase flow, we model the fate of the metal-silicate fluid dynamics in response to a wide range of realistic magma ocean scenario, considering impactors falling a different angles, iron continent, speed. Our approach tracks the descent of diapirs, each representing a coherent cloud of iron drops, through an entire magma ocean, identifying the descent environment (Pressure and Temperature vs depth, collective speed, volume of the magma ocean entrained into the cloud of diapirs). 
Investigations of Vanadiferous Titanomagnetite Deposit using Drone Magnetic and Electrical Resistivity Surveys in Korea
Authors: Kim Changryol , Son Jeongsul , Bang Eunseok , Park Gyesoon , Kim Bona
Published: February 2023

Recently, the demands for energy storage minerals such as vanadium and lithium are increasing as the use of the batteries for electrical vehicles has increased. Vanadium is one of the energy storage minerals occurred in Korea. In this study, vanadium mineralized zones of the ore deposit, named as Gwanin deposit, was investigated using geophysical exploration techniques. The mineralized zone is known as vanadiferous titanomagnetite (VTM) deposit, originated from pre-cambrian igneous intrusions (850-870 m.a.), located in the northwest region of Korea. Since the vanadium has occurred along with magnetite (low electrical resistivity and high magnetic susceptibility) in the study area, geophysical exploration techniques such as magnetic and electrical resistivity surveys were employed. For magnetic exploration, the drone magnetic survey technique was used since it provides more precise and higher resolution data than any other aerial magnetic exploration techniques for relatively small and mountainous areas. In addition, electrical resistivity data were obtained from the six survey lines in the study area. 3D inversion was performed with magnetic and resistivity data. The anomaly zones of low electrical resistivities and high magnetic susceptibilities were interpreted as VTM mineralized zones from the two different inversion results. The mineralized zones were identified from the drilling investigation for overlapping locations of the anomaly zones. The results of the study have shown that magnetic and electrical resistivity techniques are very effective tools for exploring ore deposits of vanadium resource accompanied with magnetite. In the future, drone magnetic exploration technique combined with other (surface) geophysical exploration techniques would provide more effective results of precise geophysical surveys for relatively small and mountainous areas with similar ore deposit environments.
Ongoing and projected future intensification of North American pluvial and drought extremes relative to the pre-Industrial millennium
Authors: Stagge James , Sung Kyungmin
Published: February 2023

Assessing precipitation non-stationarity beyond the modern, instrumental record is valuable for disentangling the impacts of anthropogenic climate change from natural climate variability. This study evaluated changes in 3-month meteorological drought and pluvial extremes by merging tree-ring reconstructions, observations, and climate model simulations spanning 850 – 2100 CE across North America; to determine whether the Industrial era and projected future changes are outside the range of natural climate variability. To accomplish this, we utilized a non-stationary version of the commonly used Standardized Precipitation Index (SPI), modified to capture the slow progression of underlying statistical distributions through time. Within this non-stationary framework, multi-dimensional splines simultaneously model annually recurring seasonality and seasonally specific trends, constrained to mimic the WMO 30-year reference period, for each distribution parameter. The non-stationary SPI framework was further developed to merge tree-ring proxy data, 20th century observations, and CMIP6 climate model output into a common millennial-scale model by accounting for seasonal and data-specific biases.Results show that many regions of North America have already experienced significant intensification of drought and pluvial extremes relative to the previous 1,000 years of presumed natural climate variability. These appear as widespread exacerbation of both extremes, especially summer drought and winter pluvials with consistent spatial signals: overall drying trends in the west and south, wetting trends in the northeast, and increased interannual variability across the east and north. Climate change projections indicate a continued intensification of these trends by 2100. These results underscore the need for reassessing severities of recent drought and pluvial events relative to a changing climatological baseline and a need for incorporating climate non-stationarity when assessing future drought and pluvial risk. 
Causal Mechanisms of Sea Level Variations along the U.S. West Coast
Authors: Fenty Ian , Wang Ou , Fukumori Ichiro
Published: February 2023

Tide-gauge records along the U.S. West Coast since the mid-1920’s show large ENSO-correlated sea-level variability and a below-average linear trend relative to the global mean over the past three decades. On weekly and longer timescales, sea-level variations in the region are primarily steric, reflecting variations in coastal ocean temperatures rather than that of mass. Previous research into sea-level variability in the region identified coastally-trapped waves forced by nonlocal winds as the main source of long-lasting sea-level variability. Here we offer a rigorous quantification of the contributions of wind-stress and buoyancy forcing anomalies across the entire Pacific Basin on the U.S. West Coast Sea level using a global data-constrained ocean and sea-ice model of the Estimating the Circulation and Climate of the Ocean (ECCO) consortium. Causal relationships are quantified using the model’s adjoint and mechanisms are elucidated via perturbation experiments.By convolving the adjoint sensitivities with atmosphere forcing anomalies we find that long-term (>1 week) sea level variations along the U.S. West Coast are almost entirely due to wind-stress anomalies while buoyancy anomalies, in contrast, contribute virtually nothing. Interestingly, the wind stress anomalies that contribute to sea level variations in the region come from two sectors: i) a coastally-confined region from 0-45N and ii) and the open-ocean Pacific equatorial waveguide (roughly -/+ 10 degrees latitude). Wind stress anomalies in the coastally-confined sector induce coastally-trapped waves which propagate poleward, depress the thermocline, reduce upwelling/air-sea heat loss and, thereby, lead to positive ocean temperature / steric height anomalies. Zonal wind stress anomalies in the equatorial waveguide induce eastward-propagating equatorial Kelvin waves, some energy of which is converted to coastally-trapped waves upon reaching continent, which lead to positive steric height anomalies following the same causal chain.This study highlights the benefits of applying the complimentary tools of adjoint-based convolution and perturbation experiments to explain the origin of regional sea-level anomalies.
Community-based monitoring to understand changing tidewater glacier-ocean interactions in the Canadian Arctic Archipelago
Authors: Bhatia Maya , Waterman Stephanie , Bertrand Erin , Myers Paul , Hamilton Andrew , Noah Terry , Burgess David , Brossier Eric , Pinczon du Sel France , Parrott Claire , White Patrick , Williams Patrick , Roberts Megan , Cavaco Maria , Spence Jenifer , Heras Duran Ana
Published: February 2023

Tidewater glaciers are defining coastal features in Canadian high Arctic marine systems. Rapid Arctic climate warming is dramatically altering the nature of these coastlines and adjacent waters through changing atmospheric forcing, a lengthening open-water season, and accelerating glacier retreat. These changes have a broad range of impacts enhancing glacier meltwater discharge, shifting coastal biological productivity patterns, and changing upper ocean freshwater variability and circulation. For the community of Aujuittuq (Grise Fiord), Canada’s northernmost community and ‘the place that never thaws’, these impacts have critical implications for local infrastructure, travel safety and food security. Over the last decade, Aujuittuq community members have noted significant recession of glaciers, as well as changes in the fjords surrounding their home and hunting grounds. To better understand these changes, for the last several years, we have been collaborating with the community to collect year-round marine observations in Jones Sound, home of the Inuit of Aujuittuq. Our observations span the nearshore coastal zone to the open Sound, comparing glacierized and non-glacierized fjords and multiple glaciers of varying type (land-terminating, tidewater), grounding line depth, and size draining surrounding ice caps. In total these observations represent over 400 casts measuring water column temperature, salinity, turbidity, dissolved oxygen, and chlorophyll a, with paired bottle samples characterizing carbon, nutrient, metal, and phytoplankton community composition and activity to elucidate how these properties evolve with distance from the shore. In 2022, we worked with 12 local youth, adults, and elders to make these observations. Our efforts aim to establish a long-term, community-led monitoring program centered around the co-consideration of Indigenous and scientific knowledge to understand ongoing change in high Arctic coastal environments. Results from this study substantially further our holistic understanding of glacier-ocean impacts in the sparsely sampled Canadian Arctic Archipelago and beyond, while also providing data critical to accurate future projections of high-latitude marine change in regions that are a hotspot for tidewater glacial retreat and meltwater runoff to the ocean.
The deep subduction earthquake machine: A synoptic view of the Chile Subduction Zone.
Authors: Julve Joaquín , Moreno Marcos , Barbot Sylvain , Tassara Andrés , Araya Rodolfo , Catalán Nicole
Published: February 2023

In the last 20 years, the Chile Subduction Zone (CSZ) has hosted two deep-located subduction events, the 2007 Mw 7.7 Tocopilla earthquake at the Mejillones Peninsula, and the 2016 Mw 7.6 Melinka earthquake at the south of the Chiloé Island. Interseismic seismicity at the Northern and Southern segments of the CSZ, show that in both cases, the ruptures initiated at the down-dip limit of the seismogenic zone. Locking degree models suggest that hypocenter location of this kind of megathrust earthquakes is spatially related with the transition from strongly to weakly locked areas. There are major differences in fault geometry, temperature-pressure regime, petrology at the plate interface and forearc structure between the North and South of the CSZ, raising the question about how such different tectonic settings allow a similar style of rupture. By constructing geologically and geophysically constrained dynamic numerical simulations, here we show that moderate-to-large deep nucleated earthquakes are controlled by petrology and pressure-temperature conditions at the plate interface, along with the structure of the forearc wedge. Our results explain the occurrence, recurrence times and coseismic upper crust deformation of both earthquakes, suggesting that blind ruptures are not only generated at specific conditions, but a suitable combination of the aforementioned parameters is needed. Since the Northern Chile subduction zone has no sediments at the megathrust, the frictional behavior is controlled by altered basalt at the seismogenic depth, and seismicity shows a strong temperature-dependence. Once altered basalt no longer behaves as a velocity weakening material, blueschist rocks allow slow-slip events to develop. The Southern Chile subduction zone is filled with Pliocene-to-present sediments feeding a quartz-dominated subduction channel that defines the seismogenic limit. Within this framework, basal accretion structures are overlapped with a fluid concentration zone at the Moho depth, where the Melinka earthquake initiated. These synoptic views of the CSZ manifest a strong interaction between fluid-rock and forearc structures, which explains the occurrence of blind ruptures at the subduction seismic cycle.
Tibetan Plateau warming-induced abnormal distribution of south Asian monsoon precipitation contributes to Pakistan's fatal flood in 2022
Authors: Li Hua
Published: February 2023

Devastating floods in July-August 2022 led to one-third of Pakistan being under water. The rainfall over Pakistan in these months was extreme—four to six times the 30-year average. We investigate the cause of this historically unprecedented flooding and extreme rainfall using station measurements and reanalysis datasets. In July-August 2022 there was an abnormal distribution of south Asian summer monsoon (SASM) precipitation characterized by more precipitation in Southern Pakistan and Central India but less precipitation in the south of the western Tibetan Plateau. The abnormal distribution of monsoon rainfall was dominated by the weakening of the 200-hPa northern westerly winds and SASM, and associated with anomalous westward moisture transport in the south of the Tibetan Plateau. Moreover, the temperature of the western Tibetan Plateau reaches its peak in 2022. The “heat pump effect” of the Tibetan Plateau led to positive geopotential height anomalies over Pakistan and the western Tibetan Plateau in the mid-to-upper troposphere. This blocked the 200-hPa northern westerly winds and shifted them northward. At the lower troposphere, the easterly winds are enhanced, and the SASM is suppressed. Furthermore, the Tibetan Plateau warming caused increased glaciers melt and large amounts of meltwater that feed the upper Indus River and worsened the floods. In the context of global warming, summers temperatures and melting will increase in the Tibetan Plateau. Our results indicate that this will cause massive flooding over Pakistan, such as in 2022, to become a common occurrence.
South China coastline will face more furious storm surges at the end of the 21st century
Authors: Li Zhenning , Fung Jimmy C.H. , Wong Mau Fung , Lau Alexis K.H.
Published: February 2023

South China, with a long and meandering shoreline and well-developed economy, is highly vulnerable to tropical cyclone (TC)-caused storm surges and extreme sea states. The current global warming is expected to continue or even worsen in the rest of the 21st century. Therefore, the warmer sea surface temperature (SST) and lifted mean sea level tend to fuel much more ferocious storm surges. In this study, three severe landfalling TCs have been reproduced by a sophisticated air-wave-ocean coupled model of ultra-high spatial resolution (1-km atmosphere and 500-m wave and ocean). The present-day and pseudo-global warming context mimicking the 2090s have been simulated to investigate the climate change effect. Results indicate that the coupled model can accurately reproduce the air-wave-ocean status during the TC episodes. The 2090s thermodynamic status will effectively increase the intensity of the severe TCs. Typhoon Vicente (2012) even attained a 30% increase in 10-meter wind speed due to its 24-hour stagnant track over the northern South China Sea. On average, the maximum storm surges are lifted by 0.3-0.8 meters over the open sea while aggravating much higher along the coastline, especially for narrowing estuaries where the maximum surge level can be elevated up to 2 meters. Changes in maximum significant wave height show more complicated patterns due to their sensitivity to TC tracks. For Typhoon Vicente (2012), a more than 2-meter wave height increase is observed both in open sea and along the coastline. In the 2090s context, a combination of mean sea level rise, storm surge, and wave height can reach more than 4 meters increase in total water level at certain coastal hot spots.  This will cause much more severe damage and losses at the end of the 21st century.
The Global Meridional Overturning Circulation of the Paleozoic Ocean
Authors: Yuan Shuai , Hu Yongyun , Liu Yonggang , Lunt Dan
Published: February 2023

  The global meridional overturning circulation (GMOC) plays an important role in transporting oceanic heat from one hemisphere to the other. At present, the AMOC descends in the North Atlantic and is responsible for transporting large amount of heat from the Southern Hemisphere (SH) to the Northern Hemisphere (NH). In the early Paleozoic, the continental configuration was nearly opposite to that of the present, with most of the landmass located in the SH and an ocean world of the NH. Here, we present simulation results to demonstrate that the GMOC in the Paleozoic was anticlockwise, with upwelling in the NH and descending in the SH, which is opposite to that of the present. The anticlockwise GMOC in the Paleozoic is mainly due to hemispheric asymmetry of wind stresses and freshwater input into the ocean. Stronger wind stress in the NH drives upwelling in the NH extratropics. Less freshwater input into the SH ocean causes saltier and heavier seawater, which is conducive to deep water formation in the SH ocean. These hemispheric asymmetries of wind stresses and freshwater are because of land-sea distribution in the Paleozoic. Two datasets are used, which show consistent results in general.
LISIRD: Making Solar Data More Accessible
Authors: Leise Hunter , Christofferson Ransom , Lindholm Chris , Lindholm Douglas , Spangler Slaton , Béland Stéphane , Coddington Odele , Woodraska Donald , Pankratz Christopher
Published: February 2023

Finding quality solar data can be difficult, and getting data in an analysis-ready format can be even more cumbersome. The LASP Interactive Solar IRradiance Datacenter (LISIRD), https://lasp.colorado.edu/lisird/, seeks to eliminate these burdens. LISIRD is a website where researchers can discover, visualize, and download solar data from a variety of missions, instruments, models, and laboratories. LISIRD provides solar data that is openly available and easy to analyze through an intuitive user interface, detailed metadata, interactive plotting capabilities, and a catalog of over 100 datasets. The majority of these datasets are measurements and model results from NASA missions and NASA research projects.

After a complete redesign, LISIRD now supports image datasets through an interactive image viewer, easier comparative analysis by displaying multiple datasets at once, the ability to save and share plot configurations, and improved dataset transparency through more comprehensive metadata.

This presentation will illustrate the key features of LISIRD, provide details on the datasets it serves, showcase its current technology infrastructure, and consider opportunities for future improvements and community collaboration.
Observations and modelling of GIA in the Ross Sea region, Antarctica
Authors: Konfal Stephanie , Wilson Terry , Whitehouse Pippa , Nield Grace , Hermans Tim , van der Wal Wouter , Bevis Michael , Gómez Demián , Kendrick Eric
Published: February 2023

ANET-POLENET (Antarctic Network of the Polar Earth Observing Network) bedrock GNSS sites in the Ross Sea region of Antarctica surround an LGM load center in the Siple region of the Ross Embayment and record crustal motion due to GIA.  Rather than a radial pattern of horizontal motion away from the former load, we instead observe three primary patterns of deformation; 1) motions are reversed towards the load in the southern region of the Transantarctic Mountains (TAM), 2) motions are radially away from the load in the Marie Byrd Land (MBL) region, and 3) an overall gradient in motion is present, with magnitudes progressively increasing from East to West Antarctica.  We investigate the effects of alternative Earth model and ice loading scenarios, with the goal of understanding these distinct patterns of horizontal bedrock motion and their drivers. Using GIA models with a range of 1D Earth models, alternative ice loading scenarios for the Wilkes Subglacial Basin (LGM time scale) and the Siple Coast (centennial and millennial time scales) are explored.  We find that no 1D model, regardless of the Earth model and ice loading scenario used, reproduces all three distinct patterns of observed motion at the same time.  For select ice loading scenarios we also examine the influence of more complex rheology by invoking a boundary in Earth properties beneath the Transantarctic Mountains.  This approach accounts for the strong lateral gradient in Earth properties across the continent by effectively separating East and West Antarctica into two different Earth model profiles.  Some of our GIA models utilizing 3D Earth structure reproduce predicted motions that match all three observed patterns of deformation, and we find that a multiple order magnitude of change in upper mantle viscosity between East and West Antarctica is required to fit the observations. 