bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding the geomorphic impacts of Leaky Wooden Dams (LWDs) through utilising analog physical models, structure from motion photogrammetry and surface velocimetry.
Authors: Carter Chloe , Coulthard Thomas , Thomas Robert , McLelland Stuart
Published: March 2022

In the UK Leaky wooden dams (LWD) have become an increasingly popular method of Natural Flood Management (NFM) and river restoration. LWD are in and/or across channel structures made from woody material designed to mimic naturally occurring woody debris that is often found in riverine environments. LWDs aim to reduce flooding downstream by holding back water and promoting flow onto the floodplain, increasing connection with the floodplain and infiltration by diverting water onto the floodplain. A key difference between woody debris and LWD are that LWD are usually secured and unable to move and adjust within the river and LWD are sometimes placed in areas where woody debris would not naturally occur. With the large scale and quick implementation of LWD there is a lack of critique or investigation into the geomorphic impacts of LWD. Instead, researchers and practitioners have been using what is known about the geomorphic impacts of natural woody debris to explain and predict the geomorphic impacts of LWD – even though it has been established that they are fundamentally different. This project investigates the geomorphic impacts of different styles and configurations of LWD through the use of analog physical models, surface velocimetry and structure from motion photogrammetry. Using these techniques this research aims to identify any patterns in flow and sediment dynamics both up and downstream of LWDs and to further our understanding of the specific geomorphic impacts of different LWD structures. Identifying the specific geomorphic impacts of LWD is important to be able to understand if they are having a detrimental impact to the river systems where they have been installed in the UK and to be able to inform best practice for the future.
Extension of marine ice-sheet flux conditions to effective-pressure-dependent and hybrid friction laws
Authors: Gregov Thomas , Pattyn Frank , Arnst Maarten
Published: March 2022

Marine ice sheets are complex systems with a highly non-linear behavior. There remains a large uncertainty about how various physical processes such as the basal friction and the subglacial hydrology affect the dynamics of the grounding line (GL). One possibility to better understand their mechanical behavior consists in adopting a boundary-layer analysis close to the GL. Specifically, one can derive a so-called flux condition, which is an analytical expression for the amount of ice that flows through this GL per unit time. In turn, this flux condition can provide useful information about the grounding-line dynamics, including the presence of hysteresis (Schoof, 2007b).

Several studies have introduced hybrid friction laws to model friction between the grounded part of the ice sheet and the bedrock (Schoof, 2005, Gagliardini et al., 2007). These friction laws behave as power-law friction laws far from the GL and plastically closer to it. Recent experiments have shown that these models are more realistic than the usual power-law friction (Zoet and Iverson, 2020). In parallel, sophisticated models for the subglacial hydrology have been developed (Bueler and van Pelt, 2015).

In this presentation, we show that the flux conditions previously derived for the Weertman friction law (Schoof, 2007a) and the Coulomb friction law (Tsai et al., 2015) can be extended to a flux condition for the general Budd friction law, with two different simple effective-pressure models for the subglacial hydrology. Using asymptotic developments, we provide a justification for the existence and uniqueness of a solution to the boundary-layer problem. Finally, we generalize our results to hybrid friction laws, based on a parametrization of the flux condition.
Unleashing the power of the interdisciplinary in disaster risk reduction: reflections from an early career researcher group developing a risk-informed decision support environment for Tomorrow’s Cities
Authors: Filippi Maria Evangelina , Sakic Trogrlic Robert , Cremen Gemma , Barcena Alejandro , Mentese Emin , Gentile Roberto , Creed Maggie , Jenkins Luke , Muthusamy Manoranjan , Tarbali Karim , Dhakal Aditi , Manandhar Vibek , Rai Miksen , Adhikari Sangita , Kalaycioglu Mehmet , Barake Bosibori , Poudel Dilli Prasad , Galasso Carmine , McCloskey John
Published: March 2022

The concept of disaster risk is multidisciplinary by nature. Responding to disasters and increasingly preventing new and reducing existing disaster risk has become the backbone of various disciplines. Yet, moving from various disciplinary perspectives to integrated approaches remains a fundamental challenge. This talk reflects on the experience of a group of early-career researchers, including physical scientists, engineers and social scientists from different organisations and countries, who came together to lead the refinement, operationalisation and testing of a risk-informed decision support environment (DSE) for Tomorrow’s Cities. Drawing on the notion of “boundary objects” and reflexive elicitation, members of the group explored enabling and hindering factors to interdisciplinary research across four case studies that unfolded between July-December 2021, namely: operationalisation process of the DSE; development of a testbed as a demonstration case for the implementation of the DSE; consolidation of frequently asked questions about the DSE; and elaboration of a multi-media communication tool for outreach to various audiences. The study argues that enablers of interdisciplinarity can be synthesised across a range of factors, including exogenous, governing, learning and attitudinal, and that diversity of boundary objects as convening spaces for disciplinary interaction can propel integration. It is further suggested that a similar rationale can be applied when moving towards co-producing knowledge with non-academic actors in a transdisciplinary manner. Strengthening the interdisciplinary capacities of early career researchers across disciplines and geographies is a fundamental step and promising pathway towards transformation.
Presentation of a high-resolution present-day joint atmosphere-land surface-hydrology simulation dataset for South Africa
Authors: Zhang Zhenyu , Laux Patrick , Arnault Joel , Baade Jussi , Urban Marcel , Schmullius Christiane , Kunstmann Harald
Published: March 2022

Due to the high variability of climate variables under climate change, the assessment of the climate impacts on water management, ecosystems restoration, as well as climate change adaptation requires very detailed climate information regionally and ideally at a local scale. State-of-the-art coupled land-atmosphere numerical models incorporate the water and energy exchange processes in the soil–vegetation–atmosphere continuum in a physically consistent way, thereby their simulations capture the complete evolution of state variables and provide the complex linkages across compartmental boundaries in the Earth system. As an effort to contribute to climate- and water-related research in South Africa, we present a high spatial and temporal resolution climatological atmosphere–land surface–hydrology analysis dataset covering the period 2000-2020. This analysis dataset is dynamically downscaled from ERA5 reanalysis using the Weather Research and Forecasting Model Hydrological modeling system (WRF-Hydro). This dataset covers the territory of South Africa with a grid resolution of 4 km and a time interval of 1 hour.

As a result, a comprehensive analysis dataset is provided, including the land surface and atmosphere state conditions, as well as the water flux components for the joint atmospheric-terrestrial water balance. The model performance is evaluated based on in-situ measurement records and remote sensing results. For instance, we evaluate the soil moisture and soil temperature using continuous in-situ measurement over six South Africa locations following a climate gradient, and the spatiotemporal trends of soil moisture are further evaluated using a newly developed radar-retrieved Surface Moisture Index (SurfMI). Biases of simulation results have been identified that should be taken into account in any application.
Arctic sea ice dynamics forecasting through interpretable machine learning
Authors: Sangiorgio Matteo , Bianco Elena , Iovino Doroteaciro , Materia Stefano , Castelletti Andrea
Published: March 2022

Machine Learning (ML) has become an increasingly popular tool to model the evolution of sea ice in the Arctic region. ML tools produce highly accurate and computationally efficient forecasts on specific tasks. Yet, they generally lack physical interpretability and do not support the understanding of system dynamics and interdependencies among target variables and driving factors.

Here, we present a 2-step framework to model Arctic sea ice dynamics with the aim of balancing high performance and accuracy typical of ML and result interpretability. We first use time series clustering to obtain homogeneous subregions of sea ice spatiotemporal variability. Then, we run an advanced feature selection algorithm, called Wrapper for Quasi Equally Informative Subset Selection (W-QEISS), to process the sea ice time series barycentric of each cluster. W-QEISS identifies neural predictors (i.e., extreme learning machines) of the future evolution of the sea ice based on past values and returns the most relevant set of input variables to describe such evolution.

Monthly output from the Pan-Arctic Ice-Ocean Modeling and Assimilation System (PIOMAS)  from 1978 to 2020 is used for the entire Arctic region. Sea ice thickness represents the target of our analysis, while sea ice concentration, snow depth, sea surface temperature and salinity are considered as candidate drivers.

Results show that autoregressive terms have a key role in the short term (with lag time 1 and 2 months) as well as the long term (i.e., in the previous year); salinity along the Siberian coast is frequently selected as a key driver, especially with a one-year lag; the effect of sea surface temperature is stronger in the clusters with thinner ice; snow depth is relevant only in the short term.

The proposed framework is an efficient support tool to better understand the physical process driving the evolution of sea ice in the Arctic region.
Bias Correction and Spatiotemporal Scales for Downscaling Future Projections of Northwest Atlantic Circulation and Sea Ice
Authors: Renkl Christoph , Oliver Eric
Published: March 2022

In the Northwest Atlantic (NWA), including the Labrador Sea, interactions between the atmosphere, ocean circulation, and sea ice play a critical role in regulating the global climate system. The ocean and climate in this region observe rapid and unprecedented, anthropogenically forced changes to the physical environment and biosphere with downstream effects. Future projections of NWA circulation and sea ice can help address pressing questions about these changes and mitigate their potential impacts on the global carbon cycle, coastal communities, and transportation. However, the spatial resolution of current climate models is often insufficient to accurately represent important features in the NWA, such as the location and strength of the Gulf Stream and Labrador Current and their dynamical interactions. This can lead to biases in the model’s mean state, and a misrepresentation of the temporal and spatial scales of ocean variability, e.g., mesoscale eddies, deep convection. Regional ocean models with grid spacing <10 km, forced by global climate simulations, can be used to improve estimates of historical and future circulation and hydrography. However, given the limited spatial resolution and biases in global climate models, a challenge of downscaling their simulations is the appropriate reconstruction of the forcing fields.

Here, we present preliminary results of future projections of NWA circulation and sea ice based on downscaled global climate simulations. These projections are performed using an eddy-resolving, coupled circulation-sea ice model based on the Regional Ocean Modeling System (ROMS) and the Los Alamos Sea Ice Model (CICE). We will focus on the value of correcting biases in the mean and variance of the forcing. We further explore the need of including missing spatial and temporal scales in the atmospheric forcing that are not captured by the global models. Implications for the design of model experiments for future projections will be discussed.
Proposal for an international effort aimed at quantifying the impact of a realistic representation of vegetation/land cover on seasonal climate forecasts (GLACE-VEG)
Authors: Alessandri Andrea , Balsamo Gianpaolo , Boussetta Souhail , Ardilouze Constantin
Published: March 2022

Several works have been showing the importance of vegetation/land cover in forcing interannual climate anomalies and in modulating the influence from soil moisture and/or snow. The aim of this initiative is to exploit the latest available observational data over land to improve the representation of vegetation and land cover that can positively contribute to skillful short-term (seasonal) climate predictions. However, the lack of observations in the past has often determined diverging representations of the processes related to land cover and vegetation among different land surface models. It is therefore fundamental to use the multi-model approach.

A coordinated multi-model prediction experiment will be designed to demonstrate the improvements of the predictions at seasonal time scale due to the enhanced representation of land cover and vegetation. Building from already established efforts (e.g. SNOWGLACE, LS3MIP, ESM-snowMIP, LS4P, CONFESS) we will involve the climate prediction community to develop a common experimental protocol for a multi-model coordinated experiment for the robust evaluation of the performance effects on state-of-the-art dynamical prediction systems. In addition, the verification of the coordinated multi-model predictions will provide understanding and guidance about the better approaches to pursue in the future to model land-vegetation processes.

The initial group of cooperative institutions include ISAC-CNR, ECMWF, Meteo France, while other relevant modeling groups already expressed interest to join. It is expected that a good representation of the centres previously involved in GLACE-2 initiative will participate in this coordinated effort.

The details of experimental protocol will be implemented during the second half of 2022. Simulations are expected to begin in 2023. To facilitate the spread of the initiative among the prediction community and the engagement with stakeholders, a proposal for a new Community Activity in the framework of GEO has been submitted. The initiative is also supported by the GEWEX-GLASS panel that will push it further within the related community.
Extending a ML impact-based forecasting model for typhoons in the Philippines with a rainfall threshold for consecutive landslide events
Authors: Free Renske , van den Homberg Marc , Sperna Weiland Frederiek , Teklesadik Aklilu , Melillo Massimo , Bogaard Thom
Published: March 2022

Anticipatory action requires models that can accurately predict the impact of both the primary hazard and its consecutive events. In the Philippines, typhoons trigger 90% of landslides, causing a lot of fatalities and damage to infrastructure and agriculture. The lack of information on past landslides hampers the development of accurate forecasting models of landslide occurrence and impact. An impact-based forecasting model for typhoons currently operational in the Philippines predicts impact due to the high wind speeds associated with typhoons and includes the possible impact due to landslides only via a static landslide susceptibility map. This study expands the impact-based forecasting model of 510, an initiative of the Netherlands Red Cross, with a dynamic landslide component via hybrid modeling for two typhoon events in the Bicol region in the Philippines.

A hydrometeorological model to forecast landslide occurrences was successfully created, even with the limited data on landslide occurrences and rainfall available. The newly established regional event duration threshold was applied on the case study events with an increased impact boundary of 300 km compared to the typhoon impact boundary of 100 km. The dynamic multi-hazard model showed an improved impact forecast - compared to the model considering solely static input of landslides - both in geographical impact extent and accuracy: the True Positives doubled, whereas the False Negatives reduced by half. A separate landslide forecasting model as an extension of the existing ML model provided additional benefits as the models can be decoupled to optimize the performance and reliability of both models. This study resulted in a prototype of an impact-based multi-hazard or consecutive event model for the Philippines and demonstrated the importance of considering the impact from consecutive hazards.

Keywords: Landslide, typhoon, consecutive hazards, impact-based forecasting, rainfall, machine learning, Philippines
Dyke-induced vs tectonic-controlled graben formation in a heterogeneous crust: Insights from field observations and numerical models
Authors: Drymoni Kyriaki , Russo Elena , Tibaldi Alessandro , Bonali Fabio Luca , Corti Noemi
Published: March 2022

Dyke propagation is the most common way of magma transfer towards the surface. Their emplacement generates stresses at their tips and the surrounded host rock initiating surficial deformation, seismic activity, and graben formation. Although active deformation and seismicity are studied in monitored volcanoes, the difference between dyke-induced and tectonic-controlled grabens is still less understood.

Here, we explore the difference between dyke-induced vs tectonic-controlled graben formation in stratovolcanoes with heterogeneous crustal properties like Mt. Etna (Italy) and Santorini (Greece). The field observations are related to Mt. Etna's 1928 AD fissure eruption, which partly generated dyke-induced grabens along its expression, and to the Santorini volcano, where tectonic-controlled grabens become pathways for later dyke injections. Field campaigns have revealed the stratigraphic sequence of the shallow host rock successions that became the basis of several suites of numerical models. The latter investigated the boundary conditions (overpressure or external stress field) and the geometrical and mechanical parameters that i) could produce temporary stress barriers and hence stall the propagation of a dyke towards the surface, and ii) shall form a graben at the surface. The detailed analysis, results and interpretations propose that soft materials in the stratigraphy, such as pyroclastic rocks, suppress the stresses at the vicinity of a propagating dyke and do not promote the generation of a graben above a propagating dyke. Also, the study explores the conditions where inclined ascending dykes produce semi-grabens and the generation of wide or narrow graben structures. Finally, the results give valuable insights on the field-related parameters that can encourage dyke deflection in pre-existing grabens in the shallow crust. All the latter can be theoretically applied in similar case studies worldwide.
Plant available phosphorus by H3A, M3 and AL methods in Estonian soils
Authors: Tonutare Tonu , Sihver Anne , Kõster Tiina , Tõnutare Tõnis , Krebstein Kadri , Kõlli Raimo
Published: March 2022

Phosphorus (P) is after carbon and nitrogen the third most important nutrient element for plant growth. Most of the phosphorus needed for plant development is taken up by roots from soil. Typicaly the soil total phosphorus content is from 200 up to 3000 mg kg-1, with an average of 1200 mg kg-1. Phosphorus is present in composition of organic and inorganic (35-70%) compounds depending from the soil type. Most phosphorus containing compounds belong to groups of undissolvable and heavily dissolvable compounds. Only a small proportion of phosphorus participate in soil as easily soluble form. For development the plants can use only this minor part of soil phosphorus.

For farmers it is very important to have adequate information about the resources of plant available phosphorus in soil. Therefore, for the determination of soil plant available phosphorus content,  many different methods are developed. The oldest method, which is also used nowadays in Europe is the Dyer method, developed already in 1894. Most of the methods were created in the period from 1940-s up to 1970-s. From the chemical viewpoint these methods are extraction methods, which use aqueous diluted solutions of different salts and/or acids. These methods differ also by pH of extraction solution , duration of extraction and used soil : extraction solution ratio.

In the early years of method development the main aim was to find extragent with best extraction possibilities for phosphorus extraction from soil. Due to economical reason the main aim of researches of soil analytical laboratories is to find the best extragent for simultaneous extraction of all plant macroelements (K, Mg, Ca) and also microelements (Zn, Fe, Cu, Mn, B, S) from soil with one step. Typically, in older methods the extragents were prepared from easily accessible chemicals. These chemicals are not natural components in soil and rhizosphere. Therefore the extraction process of P from soil to solution does not take place in normal rhizosphere conditions. The natural soil rhizosphere environment is imitated for P and other plant nutrient extraction in a method called H3A. This method was developed by Haney R.L and coworkers in 2006 and modified in 2017. They proposed to mimic the plant root environment by utilizing organic acids of plant root exudates to extract nutrients at ambient soil pH.

In the experiment, determination of plant available P by H3A method was investigated and comparison was made with results obtained with Mehlich 3 and AL (Egne-Riehm-Domingo) method. In the provided experiment soil samples from Estonian agriculturally used fields by H3A; Mehlich 3  and AL methods were analyzed. For detection of P in extracts the MP-AES was used. The correlation between methods was investigated and the effect of different factors (pH, texture , organic carbon) to the correlation was also investigated.
TROPoe: Tropospheric Remotely Observed Profiling via Optimal Estimation
Authors: Turner David , Löhnert Ulrich , Gebauer Josh , Bell Tyler , Blumberg Greg
Published: March 2022

Ground-based remote sensing instruments provide a unique and powerful view of the thermodynamic structure and evolution of the atmospheric boundary layer.  A range of different technologies have been developed over the past 40 years to observe profiles of temperature and humidity from the ground.  These methods include passive techniques, such as single- and multi-channel microwave radiometers (MWRs) and infrared spectrometers (IRS), and active approaches, such as Raman lidars (RLID), differential absorption lidars (DIALs), and radio acoustic sounding systems (RASS).  All of these techniques have strengths and weaknesses, and it can be challenging to evaluate the relative differences in their information content in a consistent way.  Furthermore, this leads to questions on how to combine observations from multiple instruments synergistically.  Additionally, the profiles derived from many remote sensors have correlated errors between different height levels, and thus the covariance of the profile needs to be understood if the profiles are to be properly assimilated into a weather forecast model.

 

To address these questions, we have developed the TROPoe retrieval software package.  TROPoe is a 1-dimensional variational algorithm, based upon optimal estimation, that incorporates forward models for all of these instruments to allow an iterative solution to be determined.  A climatology, usually of historical radiosondes launched near the instrumented site, is used to provide a constraint to the retrieved solution. Uncertainties from the observations, the sensitivity of the forward models, and the uncertainty in the prior are all propagated to provide a full error covariance matrix for each retrieved thermodynamic profile. Retrievals using single instrument configurations (e.g., MWR-only, IRS-only, DIAL-only) as well as multi-instrument retrievals (e.g., MWR+IRS, MWR+DIAL, IRS+RLID, MWR+IRS+DIAL) have been performed.  Since the same retrieval framework and prior dataset was used, the uncertainties and information content for each instrument complement can be directly compared.  We will present some examples in the differences in the information content among these different instrument combinations.

 

The TROPoe software is being packaged into a Docker container, which will facilitate the use of the software easily by a wide range of users.  We will present our vision for how TROPoe could be used to provide consistent retrievals for the ground-based remote sensing community, including how to assimilate these data, regardless of the actual instrument datasets used in the analysis.
Nucleation and arrest of aseismic fault slip, during and after fluid pressurization
Authors: Jacquey Antoine , Viesca Robert
Published: March 2022

Fluid pressurization of preexisting faults due to subsurface energy and storage applications can lead to the onset of aseismic slip and microseismicity, and possibly to major induced seismic events.

Fluid injection decreases the fault shear strength and slip occurs when the in situ shear stress on the fault exceeds its shear strength. The nature of slip (aseismic or seismic) depends on the rate at which it occurs and thus on the stability of the deformation. Understanding the mechanics controlling the onset and arrest of aseismic slip and the transition to seismic slip is therefore key to design mitigation strategies for the safe utilization of the subsurface.

In this contribution, we investigate using theoretical and numerical techniques how aseismic slip on a fault plane nucleates, evolves and stops in response to fluid pressurization and its relaxation. We analyze the impacts of the stress regime and the duration of the pressurization event on the aseismic slip propagation and the time to arrest of fault slip after stopping injection. We demonstrate conditions under which there is spatio-temporal self-similarity of (i) aseismic slip profiles during pressurization and (ii) aseismic slip rate profiles after pressurization. We show that post-injection progression and arrest of slip are proportional to the duration of injection. The results presented here provide insights into the mechanics controlling the arrest of aseismic slip after fluid pressurization as a first milestone towards induced seismicity mitigation strategies.
Accelerating Open and FAIR Data Practices Across the Earth, Space, and Environmental Sciences
Authors: Erdmann Christopher , Stall Shelley
Published: March 2022

Data underlying published studies is difficult to find or access, which can hinder new scientific research. Currently, only about 20% of published papers have their supporting data in discoverable and accessible repositories. The AGU, working with our partners (Dryad, CHORUS, ESIP, Wiley), and supported by the National Science Foundation (NSF), will focus on improving guidance and workflows to properly manage, link, and track data and software references throughout the publication pipeline. The resulting best practices will serve as a resource for AGU editors, reviewers, and authors and help advance data and software publication policies. Beyond AGU, this work will serve as a model for linking information across funders, data repositories, and publishers, and improving public access to research outputs. In this talk, current publication practices as they relate to the FAIR principles will be described, together with lessons learned, and how workflows and guidance are being improved.
First views from assimilation of a new ‘tomographic’ circum-Pacific plate reconstruction into mantle circulation models
Authors: Wu Jonny , Lin Yi-An , Colli Lorenzo , Chen Yi-Wei , Fuston Spencer , Wu Tsung-Jui Jeremy
Published: March 2022

One of the greatest challenges of modeling the plate tectonic history of Earth during the Mesozoic and Cenozoic eras lies in reconstructing the Pacific Ocean and its predecessor ocean, Panthalassa.  A major reason for the plate tectonic uncertainty in this region is extensive subduction, which has consumed most (>95%) of the Pacific-Panthalassan ocean lithosphere formed since 150 Ma (Törsvik et al., 2019) and recycled it into the mantle, destroying the information on past plate motions recorded by seafloor magnetic lineations.  Consequently, many circum-Pacific margin plate tectonic models, including the popular GPlates models (e.g. Matthews et al., 2016; Müller et al., 2019), necessarily extrapolate 1000’s of km of subducted seafloor (i.e. synthetic seafloor isochrons).  Given the limited constraints, it is understandable that such models also prefer more straightforward solutions with a smaller number of larger plates, avoiding the complexities of modeling intra-oceanic subduction despite geological evidence from accreted circum-Pacific oceanic terranes.

Here we build the first topologically-closed, global plate tectonic model of the circum-Pacific using structurally-restored slabs from mantle seismic tomography as our primary constraint.  We use the numerical code TERRA to assimilate three variants of our ‘tomographic’ global plate model into mantle circulation forward models and assimilate the default GPlates model as a reference.  We show our preliminary geodynamic modeling results and test our model predictions against observed mantle structure, Earth’s geoid, and oceanic realm dynamic topography. 

All cases favor plate models that incorporate intra-oceanic subduction within Pacific-Panthalassa, particularly within the northern Pacific.  We find robust support for significant slab lateral advections (i.e. non-vertical slab sinking) under NW Pacific basin.  We discuss similarities and differences between our new ‘tomographic’ plate models and the GPlates model, which has been used for almost all geodynamic studies of the circum-Pacific to date. 
Evaluation of radar rainfall nowcasting techniques to forecast synthetic storms of different processes
Authors: Abdelhalim Ahmed , Rico-Ramirez Miguel , Han Dawei
Published: March 2022

Early hydrological hazard warning demands precise weather forecasts to accurately predict the timing and the location of intense precipitation events which can cause severe floods/landslides and present risks to urban and natural environments. Extrapolation of precipitation by radar rainfall products at high space and time scales with short lead times outperforms forecasts of numerical weather prediction. Therefore, developing and improving of rainfall nowcasts systems are essential. Rainfall nowcasting is the process of forecasting precipitation field movement and evolution at high spatial and temporal resolutions with short lead times(<6h) in which the advection of the precipitation fields is estimated by extrapolating real-time remotely sensed observations. Radar rainfall nowcasting is increasingly applied because of the high potential of radar products in short-term rainfall forecasting due to their high spatiotemporal resolutions (typically, 1 km and 5 min). It consists of two procedures in tracking precipitation features to calculate the velocity from a series of consecutive radar images and propagating the most recent precipitation observation into the future using the obtained velocity. Optical flow represents one of the most used methods for tracking the motion fields from consecutive images. Deep learning techniques are those machine learning methods that utilise deep artificial neural networks. Deep learning has become one of the most popular and rapidly spreading methods in different scientific disciplines including water-related research. Deep learning applications in radar-based precipitation nowcasting is still in its early stage with many knowledge gaps and their full potential in rainfall nowcasting requires more investigation. This work evaluates the performance of a deep convolutional neural network (called rainnet) and three optical flow algorithms (called Rainymotion Sparse, Rainymotion Dense, Rainymotion DenseRotation) compared with Eulerian Persistence to assess their predictive skills in nowcasting. Synthetic precipitation scenarios have been created with different motion fields (linear and rotational motions), velocities, intensities, sizes, and locations. The models have been evaluated to forecast different precipitation processes that contribute mainly to model errors such as constant and accelerated linear and rotational motions, growth and decay in both size and intensity. Different verification metrics have been used to evaluate the skill of the forecasts.

 

Keywords: radar rainfall nowcasting; deep learning; optical flow; extrapolation; rainnet; rainymotion
Development of a New Reservoir Trapping Efficiency Parameter for Large Scale Sediment Modeling using Remote Sensing of Fluvial Sediment
Authors: Moragoda Nishani , Cohen Sagy , Gardner John
Published: March 2022

Among the greatest stressors on global riverine sediment transport are the 48,000+ existing large dams and the ~3,700 dams that are planned or under construction. They directly obstruct sediment flowing to the ocean, alter downstream flow regimes, modify sediment carrying capacities, trigger hazardous bank erosion and riverbed incision, and influence river water quality. Understanding the role of dams in sediment retention is crucial for quantifying the anthropogenic influences on global fluvial systems. Representation of sediment trapping by dams is currently a major source of bias in continental- and global-scale hydro-geomorphic modeling frameworks. This study focuses on developing a new reservoir trapping efficiency (Te) parameter to account for the impacts of sediment trapping behind dams in hydrological modeling efforts. This will be done by harnessing a novel remote sensing data product, developed using Machine Learning within Google Earth Engine (GEE) to generate high-resolution and spatially continuous maps of sediment concentration across the CONUS. Sediment trapping is calculated for 400+ dams across the CONUS using pre-reservoir and post-dam sediment fluxes, and various explanatory variables including attributes of dams, topography, land use and land cover characteristics, soil parameters, and fluvial properties, are evaluated to estimate their contribution for predicting sediment trapping. This study provides a robust framework for isolating and quantifying the influence of anthropogenic factors on fluvial fluxes by informing more realistic trapping of sediment at dam locations.
Identification of European heatwave families 
Authors: Hellmig Julia , Strnad Felix , Goswami Bedartha
Published: March 2022

Mainly caused by anthropogenic climate change occurring heatwaves have become more frequent and extreme throughout the 21th century. Summer heatwaves over Europe are mainly caused by positive phases of the North Atlantic Oscillation (NAO) and jet stream anomalies, subsequently causing atmospheric blocking over different parts of Europe. With this work we aim to define families of European heatwaves caused by different atmospheric regimes. In the long run this could help predicting European heatwaves and their length, intensity and spatial extend. To identify European heatwaves and their spatial extend we use the graph framework DeepGraphs. Within this framework every extreme heat day isconsidered a node and a heatwave is defined as the union of all nearest neighbour nodes (which are connected by edges). 

Two clustering steps are applied to cluster the heatwave into families depending on their length, season and spatial extend. 

Our results reveal a promising way to classify European heatwaves based on their atmospheric cause which could help forecasting heatwaves in the future.
Evapotranspiration and photosynthetic parameters determined by eddy covariance and infrared photosynthesis analyzers in a drip-irrigated olive grove on western coastal South America
Authors: Cosio Eric , Salinas Norma , Tito Richard , Nina Alex , Cruz Rudi
Published: March 2022

Peru and Chile occupy second place in South America in area devoted to olive cultivation. Although small by Mediterranean standards, the 21,000 ha in each country represent a significant recent expansion of olive cultivation, 500 years after its introduction from Europe. The main climatic characteristic of olive cultivation in Peru is the coastal desert environment with moderate temperatures (12-28 oC), almost nil precipitation and high atmospheric water content in the winter season. There is still insufficient information about olive physiology and water management under these climatic conditions. This report is part of a long-term study of water and carbon fluxes in a drip-irrigated olive grove in sandy soil, located in the Pisco province in Peru (13°45'03.25" S, 76°09'36.77" W at 74 m elevation). Due to the absence of precipitation during the main growing season, plants depend on the local aquifer and drip irrigation for growth and yields. We installed an eddy covariance system in September of 2019 in a 9 m tower over a 5 m canopy height. The canopy covered 60% of the surface, the rest being sandy soil with very limited grass cover. The flux footprint of the system covered 3 ha for 80% of the information gathered. Peak average hourly water flux from the grove to the atmosphere in the summer season took place at 1 pm, with values of 1.8 m3 ha-1 h-1.  Average daily fluxes ranged from 5 m3 ha-1 day-1 in August (winter) to 20 m3 ha-1 day-1 in February (summer). EddyPro-calculated ET values are essentially similar and represent 41% of ETo as calculated by the Penman-Monteith equation and 58.6% using a crop coefficient correction. Drip irrigation was set at 63 m3 ha-1 day-1 during the growing season (October through April) and reduced to half that amount in the winter. Optimization of water usage in relation to productivity has been pursued by monitoring photosynthetic efficiency and transpiration with an Li 6800 system in sun and shade leaves of the canopy along with use of Ekomatik digital dendrometer monitoring as a proxy for sap flow.
Ongoing crustal deformation and earthquake swarm in the Noto Peninsula, central Japan
Authors: Nishimura Takuya , Nishikawa Tomoaki , Sato Daisuke , Hiramatu Yoshihiro , Sawada Akihiro
Published: March 2022

Earthquake swarms are generally interpreted as phenomena related to external stress perturbation including slow slip events and magma intrusion or weakening of fault strength due to pore pressure increase. Extensive swarm activities accompanying geodetically detectable deformation are often observed along plate boundary faults and volcanic areas. However, an extensive seismic swarm started in December 2021 at the northern tip of the Noto Peninsula, central Japan, which is a non-volcanic/geothermal area far from the major plate boundaries. We present a preliminary report of observed seismicity, crustal deformation, and their interpretation. The swarm activity started with several episodic earthquake bursts in the first several months and turned to be a continuous activity. The number of M≥1 earthquakes has been roughly constant at ~120 per week since July 2021, as of January 2022. The largest M5.1 earthquake occurred on September 16, 2021. Focal mechanisms of large earthquakes including the largest one suggest reverse faulting with a compressional axis of NW-SE. The focal depth ranges between 10-18 km. Transient displacements are observed at three permanent GNSS stations operated by the Geospatial Information Authority of Japan within 30 km from the epicentral region of earthquake swarms. The annual observed displacement from December 2021 suggests inflation with up to 12 mm of horizontal displacement and 30 mm of uplift. We installed four new GNSS stations near the epicentral area in September 2021 and found rapid extensional deformation around the epicentral area. Assuming a spherical inflation (Mogi) source, we estimated an annual volumetric increase of ~2.5 x 107 m3 at a depth of ~12 km. We speculate the volumetric increase is caused by upwelling water originally dehydrated from the subducted Pacific plate. Although the estimated source predicts to increase of the Coulomb stress in the epicentral area, the temporal evolution of crustal deformation and earthquake activity is not always synchronized. It may suggest fault weakening due to pore fluid migration into the fault zone.
Air-Sea, Ice-Sea, and Effective Wind Forcing of the Beaufort Gyre
Authors: Webb Elizabeth , Straub David , Tremblay Bruno , Nadeau Louis- Philippe
Published: March 2022

Surface heat and momentum fluxes between the atmosphere and ocean are mitigated by sea ice cover, resulting in an effective net forcing that can be very different in character from the wind stress alone. The effective stress is often expressed as a weighted sum of air-sea and ice-sea stresses. This is appropriate for levitating ice. Allowing instead for floating ice, one can rewrite the effective forcing in a way that makes no explicit mention of the ice-ocean stress. Instead, the net forcing becomes a linear sum of air-sea and internal ice stresses. These differences are explored in the context of the Beaufort Gyre. Previous studies have introduced the ice-ocean governor as a regulating mechanism for the gyre, and in this limit, the ice-ocean stress is assumed to vanish. For floating ice, the governor limit can be thought of instead as a balance between the wind stress and the internal ice stress. Note that this balance would seem to be unlikely in that the internal stress is associated with small-scale linear kinetic features, which are very different in character from the mesoscale and synoptic features that determine the wind stress. High-resolution ECCO data will be used to examine the instantaneous and time-averaged spatial structure of the various terms that drive the Beaufort Gyre. Future work will also examine the air-sea-ice interface in different wind and ice regimes, as well as the role of eddy fluxes in the gyre dynamics. 
Linking the Budyko framework with the complementary evaporation principle for proper consideration of surface energy availability
Authors: Kim Daeha , Chun Jong Ahn
Published: March 2022

The widely-used Budyko framework synthesizes the competition between water and energy availability simply using climatological mean precipitation (P) and potential evaporation (PE). While PE within the Budyko framework is often regarded as the atmospheric evaporative demand (AED), AED can substantially differ from PE assuming ample water availability due to its responsive behavior to soil moisture. This could violate the independence assumption between P and PE underpinning the Budyko framework, potentially leading to ill-posed parameterization of land-surface properties. Here, we showed that the use of AED as PE in a Budyko equation could significantly disturb a global runoff sensitivity assessment to climatic and land-property changes. By linking a two-parameter Budyko equation and the complementary evaporation principle (CEP), we found that climatic changes play a more important role in altering runoff than a prior assessment would suggest. This study also suggests that linking the Budyko equation with CEP can isolate the responsiveness of AED to soil moisture, allowing more proper consideration of surface energy balance.
Key Results from the Emirates Ultraviolet Spectrometer on the Emirates Mars Mission
Authors: Chaffin Michael , Almazmi Hoor , Chirakkil Krishnaprasad , Correira John , Deighan Justin , England Scott , Evans J. Scott , Fillingim Matthew , Holsclaw Greg , Jain Sonal , Lillis Rob , Lootah Fatma , Raghuram Susarla , Al Matroushi Hessa
Published: March 2022

The Emirates Mars Ultraviolet Spectrometer (EMUS) instrument is one of three science instruments on board the “Hope Probe” of the Emirates Mars Mission (EMM). EMM arrived at Mars on February 9 2021, in order to explore the global dynamics of the Martian atmosphere, while sampling on both diurnal and seasonal timescales. The EMUS instrument is a far-ultraviolet imaging spectrograph, jointly developed by the Mohammed Bin Rashid Space Centre (MBRSC) in Dubai, UAE and the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado Boulder, which measures emissions in the spectral range 100-170 nm. Using a combination of its one-dimensional imaging and spacecraft motion, it makes two-dimensional far-ultraviolet images of the Martian disk and near-space environment including the Lyman beta and alpha atomic hydrogen emissions (102.6 nm and 121.6 nm), two atomic oxygen emissions (130.4 nm and 135.6 nm), and the carbon monoxide fourth positive group band emission (140-170 nm). Measurements of radiance at these wavelengths are used to derive the column abundance of atomic oxygen and carbon monoxide in the Martian thermosphere, and the density of atomic oxygen and atomic hydrogen in the Martian exosphere both with spatial and sub-seasonal variability. We will present a survey of results from EMM/EMUS including observed variability in atomic oxygen and carbon monoxide emission, two kinds of aurora, and the status of atmospheric retrievals.
Kill dates from re-exposed black mosses constrain past glacier advances along the western Antarctic Peninsula
Authors: Groff Dulcinea , Beilman David , Yu Zicheng , Ford Derek
Published: March 2022

Glaciers retreating along the western Antarctic Peninsula (AP) reveal previously entombed soils and plants. We collected black (dead) mosses to constrain the timing of late Holocene glacier advances at four sites along the AP from ice-free terrain and from rapidly retreating ice margins. The results of radiocarbon measurements from 39 black mosses were used to infer glacier activity over the past 1500 years along with established criteria for sample collection. The criteria ensure robust estimates of when plant growth ended, referred to hereafter as “kill date”. From these kill dates we report distinct periods of ice advance during ca. 1300, 800, and 200 calibrated calendar years before 1950 (cal yr BP) and the first estimates of glacier rate of advance around 800 cal yr BP of 2.0 and 0.3 meters per year from Gamage and Bonaparte Points (southern Anvers Island), respectively. Kill dates reveal a narrow range of ages within a region, suggesting that multiple glacier termini advanced together, and that the rate of local advances may have varied by an order of magnitude. Other evidence for glacier advances in the northern AP ca. 200 cal yr BP and ages of penguin remains (a proxy for penguin colony abandonment) centered ca. 800 cal yr BP from several sites across the AP coincide with our kill dates. Combining several lines of terrestrial evidence for past glacier activity is critical to improving our understanding of the regional synchroneity of glacial dynamics and cryosphere-biosphere connections.