bluuebunny/crossref_metadata_2025 huggingface dataset:
Upwelling induced productivity and coastal eutrophication in the eastern Arabian Sea since the late Marine Isotope Stage 3
Authors: Majumder Jeet , Gupta Anil , Mohanty Rudra Narayan
Published: March 2024

We present the multiproxy record of relative abundances of benthic foraminifera, planktic foraminifer Globigerina bulloides, and dissolution and replacement features in the tests of foraminifera from Core SK291/GC17, located on the outer continental shelf of the eastern Arabian Sea (EAS). The sediment cores encompass an age range of ~40,000 to 3,500 calibrated years before present (cal yr BP). Distinctly high relative abundance of G. bulloides suggests strong upwelling and associated high productivity caused by intense Indian summer monsoon (ISM) winds in the EAS during ~40,000-29,000 cal yr BP, i.e., the late Marine Isotope Stage 3 (MIS 3). As the sea level was about 60-80 m lower than the recent time, increased continental influx driven by high monsoonal precipitation caused a eutrophic condition in the shallow EAS. This eutrophication led to an oxygen-deficient state at the sediment-water interface, evident from the dominance of dysoxic-suboxic and synchronous subjugation of oxic benthic foraminifera. Partial pyritization of foraminifera tests was observed during this interval, suggesting iron-rich continental influx to the study area. During the Last Glacial Maximum (LGM), a lower mean sea level and weak upwelling caused a mesotrophic and relatively well-oxygenated condition at Core SK291/GC17. The gradual rise of sea level till the early-middle Holocene increased the distance between the studied core and the coastline, thus reducing the influence of terrigenous influx. Further, the studied core has been below the upper horizon of the Oxygen Minimum Zone since the early Holocene, which is corroborated by the decline of the oxic group of benthic foraminifera and the low diversity index.
Novel Use of Integrated Water System Model for Decision-Making Processes at Different Scales
Authors: Zhang Ziyan , Rico Carranza Eduardo , Mijic Ana
Published: March 2024

The increasing population and new urban developments have posed challenges to urban water management, such as domestic water scarcity and deteriorated water quality.  Meanwhile, the existing development planning frameworks fail to facilitate an effective approach to enhance an efficient and sustainable urban water design. They tend to isolate groups and evidence by relying on different independent models. The state-of-the-art Water Systems Integrated Modelling framework (WSIMOD), which simulates the terrestrial water cycle integrally including physical and human processes, has been developed to provide holistic and integrated evidence to help with decision-making processes. The WSIMOD model has been previously implemented at the river sub-catchment resolution, while a complete decision-making process usually involves different groups, such as city authorities, water companies and environmental regulators, with multiple objectives at multiple spatial resolutions. In the current work, we propose the novel use of the model for multi-resolution simulations (local, borough and river sub-catchment), and aim to help multi-stakeholders and decision-makers understand potential challenges to achieving multi-objectives in a coordinated way. We will also explore the effectiveness of measures to offset urban water issues induced by new developments in the current and future scenarios. Our work can provide insight into efficient and sustainable urban water management strategies for multi-stakeholder planning and future adaptation under uncertainty.
Calibration and Validation of Low Earth Orbit Observations From NOAA to Support Global Environmental Monitoring
Authors: Kalluri Satya , Cao Changyong
Published: March 2024

The National Oceanic and Atmospheric Administration’s (NOAA) Joint Polar Satellite System (JPSS) provides critical observations of the Earth and its atmosphere from the ultraviolet region to the microwave region in Leo Earth Orbit (LEO). The mission now has three satellites in the same orbit: NOAA20 the primary satellite, NOAA21 as secondary and Suomi National Polar-orbiting Partnership (Suomi NPP) as the tertiary satellite. The primary and secondary satellite provide redundancy since measurements from the mission provide critical inputs to global numerical weather prediction. Since 2011, the multi-mission series of Low Earth Orbit (LEO) polar-orbiting environmental satellites is serving as one of the most important sources of continuous state-of-the-art observations of the Earth’s land, oceans, and atmosphere to protect lives and property, and support the global economy by providing accurate and timely environmental information. The Visible Infrared Imaging Radiometer Suite (VIIRS), the Cross-track Infrared Sounder (CrIS), the Advanced Technology Microwave Sounder (ATMS), the Ozone Mapping and Profiler Suite (OMPS), and the Clouds and the Earth’s Radiant Energy System (CERES) observe a large part of the electromagnetic spectrum from the UV region to the microwave region. All the sensors have state of the art onboard calibration sources and the data undergo extensive pre and post launch calibration and validation activities before the data are declared operational. Additionally, NOAA/NESDIS center for satellite applications and research maintains an integrated calibration and validation system to continuously monitor and track the performance of the sensors through the mission life cycle. NOAA also co-leads the Global Space-based Inter-Calibration Sytem (GSICS) which is an international collaborative effort initiated in 2005 by the World Meteorological Organization (WMO) and the Coordination Group for Meteorological Satellites (CGMS) to monitor, improve and harmonize the quality of observations from operational weather and environmental satellites of the Global Observing System (GOS). The level 2 geophysical measurements and products also go through extensive verification and validation through comparison of satellite products with surface-based, airborne, and/or space-based observations that are extensively documented and shared with users. This presentation will highlight the calibration activities and the performance of JPSS sensors and products.
Investigating the fractionation behaviour and mass balance of cadmium isotopes during continental weathering and marine burial.
Authors: Baburaj Neeraja , Dickson Alexander , Elms Hannah
Published: March 2024

Organic carbon burial plays an important role in the global carbon cycle, and changes in the magnitude of such carbon burial have the potential to impact the global climate. Recent studies have shown that stable cadmium isotopes (δ114/110Cd) have potential as a tracer for marine organic carbon burial. However, the input and output fluxes and isotopic fractionation behaviour of Cd in the marine system are currently insufficiently constrained for robust application as a paleo-proxy. For example, while the main input flux of Cd to the oceans is from rivers, the isotopic behaviour of Cd during its passage through estuarine mixing zones is poorly understood.
In this study we will present Cd concentration and isotopic measurements of waters spanning a salinity gradient of 34–1 PSU and bedload sediments collected from the Milford Haven estuary in Pembrokeshire, western Wales, The aim is to test the conservative behaviour of Cd in the estuarine mixing zone, to constrain the composition of Cd from weathering in a shale and sandstone dominated catchment, and to investigate the fractionation of Cd during catchment weathering. These data will help in better understanding the riverine input flux of cadmium into the oceans, and the marine cadmium budget.
Assessments of Brazilian water utilities' perception and potential uptake of index-based insurance schemes to cope with hydroclimatic extremes
Authors: Jesus da Silva Greicelene , Kreibich Heidi , Cominola Andrea , Mendiondo Eduardo Mario
Published: March 2024

Risk management is of paramount importance in the water supply sector, as the occurrence of drought and flood events can directly affect water availability and damage water utility infrastructure, leading to water supply interruptions and increased infrastructure maintenance costs. Index-based insurance schemes may reduce the vulnerability of water utilities in the face of such extreme hydrological events. However, there is scarce knowledge and practical adoption of index-based insurance schemes for water utilities in Brazil, despite the new regulatory framework for water security under climate change. To gain a clearer picture of the potential uptake of index-based insurance in the water utility sector in Brazil and foster the development of new schemes, we interviewed experts from 10 selected Brazilian water utilities, responsible for the supply of 30 municipalities in the southeast region of the country. Respondents are involved in strategic decision-making in the respective water utilities. For the interviews, we developed a structured questionnaire containing information on how index-based insurance works, followed by questions regarding how often the utility was hit historically by droughts and floods, their willingness to pay for index-based insurance schemes covering damage from drought and flood, and their perceived importance and likelihood of acquisition. When asked about the importance and likelihood of adopting at least one of the proposed index-based insurance on a scale from 0 (no importance/not likely at all) to 5 (significant/high likelihood of acquiring insurance), interviewees gave an average score of 2.7 (importance) and 2.2 (probability of uptaking). The detailed results from our survey presented here show that the majority of the water utilities are willing to pay for at least one of the presented index-based insurance schemes, as they attribute a relevant degree of importance to them. The majority of them would uptake flood insurance schemes. However, half of the respondents declared they would not be willing to pay anything for drought index-based insurance. The reasons given for no uptake were: (i) utilities were not affected by drought or flood events during the last 10 years, (ii) there is disagreement with the proposed trigger and the type of financial losses covered, and (iii) the availability of other surface and groundwater resources can mitigate supply interruptions from the main source. Overall, our results demonstrate that there is quite some uncertainty regarding the perception and design of new index-based insurance products in the water utilities sector, which emphasizes the need for further research and co-design with utility stakeholders.
Source apportionment for PM2.5 and trace element bound PM2.5 using PMF and PCA at three sites in South Africa
Authors: Howlett-Downing Chantelle
Published: March 2024

Source apportionment by means of factorization is the traditional means of assigning of sources to factors in air pollution studies. Both PCA and DN-PMF have assumptions, strengths, and limitations. In common these two models have the assigning of sources to factors which can be subjective and dependent on limited information. PCA and DN-PMF is performed on data from three cities which were sampled at the same time, 16 April 2017 to 18 April 2018. The PCA will determine how many factors are assigned and the DN-PMF will determine the assigning of sources to factors. The geographical origin of the air particulates was modelled by means of HYsplit. The DN-PMF was able to give seasonal information to support the source apportionment. Results of the PCA included 6 factors for Thoyohandou and Pretoria and 7 factors for Cape Town. Where PCA produced strong statistical support to the number of factors chosen, correlations between HYsplit and DN-PMF and seasonal output corroborated the assigning of sources to factors. Utilising two models for factorization during source apportionment limits the error due to subjectivity where one method of PM2.5 sampling was used.
Modeling seismic wave propagation across complex volcanic structures of the Hawaii-Emperor Ridge
Authors: Fujimoto Megumi , Dunn Robert , Xu Chong
Published: March 2024

Volcanic seamount chains are widespread throughout ocean basins, but their formation and structure are not well understood. Active-source refraction seismology can provide images of the interiors of these volcanoes via P wave travel time tomography, but that requires proper identification of seismic phases that are generated by and propagate across complex volcanic structures. Unfortunately, the current limitation on the number of seismic phases that can be included in tomographic analyses leads to less detailed images and a limited geological understanding of the structures being imaged. The primary objective of this study is to compare recorded seismic wavefields from recent surveys across the Hawaiian-Emperor Seamount Chain with synthetic wavefields generated through waveform modeling. We use simplified yet realistic models of volcanic edifices, the underlying oceanic crust, and the mantle to better understand observed seismic phases and their origins. In previous studies (Dunn et al., 2019; Watts et al., 2021; Xu et al., 2022; MacGregor et al., 2023), several seismic phases were identified in recorded sections along the Hawaiian-Emperor Chain. However, interpreting the origins of some of these phases remains challenging. In this study, we developed an idealized seamount model based on the seismic structure of Jimmu Guyot in the Emperor Ridge (Xu et al., 2022). We calculated the seismic P-SV wavefield for various source and receiver positions using a finite difference wavefield modeling code (Levander, 1988; Lata and Dunn, 2020). Our goal is to model the observed seismograms and identify additional phases, including P-to-S converted waves. Additionally, we aim to verify recent tomographic images of the Hawaiian-Emperor Seamount Chain created by P wave travel time inversion via wavefield comparison. By resolving ambiguities and pinpointing new seismic phases, our aim is to improve seismic images of the Hawaiian-Emperor Chain. This contribution will enhance our understanding of specific structures, such as volcanic cores (a high-density and high-wave-speed interior core of the seamount), the hypothesized magmatic underplating of the oceanic crust by mantle melts rising beneath the volcanic chain, and the nature of the Moho and upper oceanic crust beneath these volcanic edifices.
Local and remote sources of error inMJO forecasts in the Navy ESPC 
Authors: Rushley Stephanie , Janiga Matthew , Reynolds Carolyn
Published: March 2024

The Navy Earth System Prediction Capability (ESPC) is the Navy’s coupled ocean-atmosphere-sea ice model.  The current version of the Navy ESPC has 16 ensemble members and been operational since August 2020. The Navy ESPC has known biases in Madden-Julian Oscillation (MJO), which has a too strong amplitude and too fast propagation speed. During boreal winter, the MJO in the Navy ESPC is too strong due to biases in the vertical motion, which supports larger vertical moisture advection.  The MJO is too strong in this season due to excessive evaporation in the western Pacific supporting moistening to the east of the MJO convective center.  In this study, we examine the boreal winter MJO in the operational Navy ESPC ensemble.  We use process oriented diagnostics to explore the local and remote sources of biases that drive good and poor MJO forecasts. MJO forecasts are split into those that are well predicted and those that are poorly predicted.  Individual MJO events are tracked following Chikira (2014), using Hovmöllers of MJO filtered OLR averaged between 10N and 10S.  The MJO forecast performance is determined by comparing the forecasted MJO to the observed MJO based on the magnitude of the maximum amplitude of the MJO, the phase speed, duration of the event, and the location of the MJO convection.  Using the moisture mode framework, we examine the maintenance and propagation of moisture anomalies to identify how the local and remote sources of error affect MJO skill.  We use a moisture budget analysis to diagnose and understand the difference between the forecasts that performed well and those that performed poorly.  Additionally, we examine the effects that these forecast errors in the MJO have on extratropical cyclones, surface winds, and clouds in the Navy ESPC and how biases in the extratropics affect the skill of MJO-teleconnections.
Effects of a volatile phase on the Creation and Dynamics of Lower Crustal Magma Reservoirs: A Three-Phase Numerical Model Study
Authors: Hu Haiyang , Jackson Matthew , Booth Catherine
Published: March 2024

We use a one-dimensional numerical model to investigate how the presence of a volatile phase such as water impacts the creation and dynamics of a magma reservoir in the mid- to lower crust. We assume that the reservoir is created and sustained by the repeated intrusion of mantle-derived basalt sills containing a few wt% volatiles. Our numerical model solves the equations governing heat transfer by conduction and advection; two- and three-phase flow of the solid, melt and volatile phases assuming porous flow and compaction at low melt fraction and hindered settling at high melt fraction; and handles phase exchange using a two-component (SiO2 and volatile) chemical model fitted to experimental melting data.  The solidus and liquidus temperatures are functions of bulk SiO2 content and melt volatile content. The volatile exchange between solid and melt phases is modelled using a partition coefficient and the maximum volatile content of the solid phase is capped based on mineralogical data. The melt phase has a maximum volatile saturation above which a free volatile phase is formed. There is no direct transfer of volatiles from the solid to the volatile phase.We find that the highly non-linear coupling between melt volatile content and the solidus and liquidus temperatures, flow of melt and (when present) volatile phases, and the exchange of latent heat, gives rise to complex emergent behaviour.  We do not observe a simple, upwards propagating volatile front below which melt is always present in a stable mush column as has been proposed in some previous studies.  Rather, we observe the formation of transient, high melt fraction, evolved and volatile-rich layers interspersed with refractory and volatile-poor mush.  The high melt fraction layers can propagate upwards, merge and split.  The layers are typically thin and likely below geophysical resolution.  The dynamics of mush reservoir growth are strongly influenced by the fertility of the overlying crust: if the crust can melt in response to the addition of heat and volatiles, then the top of the reservoir migrates upwards until it reaches mid-crust depth, creating a reservoir that spans the lower- to mid-crust and hosts numerous melt-rich layers.  Our results so far suggest a highly dynamic magmatic system characterized by significant melt fraction variations in time and space.  Much of this dynamic complexity is lost in geophysical images that are interpreted to suggest reservoirs have low and uniform melt fraction.
The FISC-Cerrado near-real time web-system for predicting fire spread
Authors: Oliveira Ubirajara , Soares-Filho Britaldo
Published: March 2024

Firefighting has become increasingly difficult and costly due to climate change. In response, new tools, including online platforms, are emerging to help prevent and promptly combat ever more destructive wildfires. While those initiatives only provide maps of fire risk based on environmental and climatic conditions, which in general have a medium predictive capability, fire propagation models, although successful in predicting fire behavior and spread, particularly at local scale, can become impractical during emergency situations, since they require lots of spatial data that must be obtained, processed and input by the user. To overcome these limitations, we have developed a fire-spread prediction system for the Brazilian Cerrado, the biome most affected by wildfires in South America. The system, named as FISC-Cerrado, automatically uploads hot pixels and satellite data to calculate maps of fuels loads, vegetation moisture, and post-probability of burning for simulating fire spread thrice a day for the entire Cerrado at 25 ha and for nine conservation units at 0.09 ha spatial resolution. Unlike the requirements to operate fire spread models, the user-friendly interface of FISC-Cerrado, alongside the automatization of the entire chain of tasks, allows its use by practitioners who do not have technical skills, such as GIS knowledge. Model results together with ancillary data, e.g., historical burned areas and annual CO2 emissions from fires, are available on an interactive web-platform (https://csr.ufmg.br/fipcerrado/en/), which is being used for daily operations by the fire brigades of the selected conservations units. 
PAHs and levoglucosan in particulate matter sources apportionment through GC-C-IRMS and GC-MS
Authors: Di Rosa Davide , Marzaioli Fabio , Di Rosa Maria , Di Rosa Salvatore , Rubino Mauro
Published: March 2024

Air pollution is a leading cause of human health problems. Among various dangerous substances that may be found in atmosphere, Particulate Matter (PM) is one of the main concerns , since small size particles (
ResRadNet: A 3D-Residual Neural Network Approach for Temporal Super-Resolution and Ground Adjustment of Weather Radar Rainfall Estimates
Authors: Polz Julius , Glawion Luca , Gebisso Hiob , Altenstrasser Lukas , Graf Maximilian , Kunstmann Harald , Vogl Stefanie , Chwala Christian
Published: March 2024

Weather radars are advanced tools for atmospheric observations that provide QPE with a high spatial representativeness and a high temporal resolution (e.g. 5-minutes). However, due to their indirect measurement aloft, strong systematic errors as well as temporal sampling errors compared to rain gauge measurements at even higher resolution (e.g. 1-minute) persist. As a solution, bias and advection correction techniques are used. Residual neural networks have proven to be efficient tools to approximate the behavior of dynamical systems. Here, we present ResRadNet, a 3D-residual neural network (3D-RNN), that is capable of correcting biases and increasing the temporal resolution of weather radar based quantitative precipitation estimates (QPE). ResRadNet is trained to correctly reproduce 1-minute rain gauge data from sequences of 5-minute radar images and information about the orography. The dataset used in this study consists of 8 years of country-wide rainfall observations in Germany. The weather radar composite used as model input is based on reflectivity derived rainfall information from 17 C-band radars. The rain gauge reference consists of 1066 rain gauges with a 1-minute resolution used to train and test ResRadNet. An additional 1138 rain gauges with a daily resolution are used for long-term evaluation of remaining biases. The results showed that ResRadNet can significantly increase the linear correlation and reduce the root mean squared error of the QPE field compared to rain gauge data at 1- and 5-minute, as well as daily resolutions. A qualitative analysis also showed that ResRadNet is a suitable optical flow estimator and that the provided rainfall fields are not subject to temporal or spatial inconsistencies even though spatio-temporal consistency was not enforced during training. Therefore, our study shows how using 3D-RNNs can provide accurate 1-minute, ground-adjusted, and advection-corrected QPE.
Graphical representation of global water models participating in the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP2b)
Authors: Müller Schmied Hannes , Müller Laura , Gosling Simon N. ,   ISIMIP2b water model diagram team
Published: March 2024

Numerical models are simplified representations of the real world at a finite level of complexity, which means they are not exhaustive in the number of processes they include. Global water models are used to simulate the global water cycle and their outputs are used to estimate important natural and societal issues, including water availability, flood risk, and ecological functioning.Whilst global water modelling is an area of science that has developed over several decades, and individual model-specific descriptions exist for some models, there has to date been no attempt to visualize how several models work, using a standardized visualization framework. Here, we address this gap, by presenting a set of visualizations of several global water models participating in the Inter-Sectoral Impact Model Intercomparison Project phase 2b.The diagrams were co-produced between a graphics designer and in total 16 modelling teams, based on extensive discussions and pragmatic decision-making that balanced the need for accuracy and detail against the need for effective visualization. The model diagrams are based on a standardized "ideal" global water model that represents what is theoretically possible to model with the current generation of state-of-the-art global water models. Model-specific diagrams are then copies of the "ideal" model diagram, with individual processes either included or greyed out.As well as serving an educational purpose, we envisage that the diagrams will help researchers in and outside of the global water model community to select the right model(s) for specific applications, stimulate a community learning process, and identify missing components to help direct future model developments.
Impact of tropical cyclones on ocean biogeochemistry in a high resolution Earth system model
Authors: Chegini Fatemeh , Nielsen David , Salinas Mariana , Casaroli Lucas , Brüggemann Nils , Hohenegger Cathy , Ilyina Tatiana
Published: March 2024

Tropical cyclones (TCs) and oceans are a tightly coupled system. On the one hand, the ocean physical conditions such as stratification and eddies can change the intensity of TCs. On the other, TCs can strongly affect the physical and biochemical structure of the upper ocean by e.g. increasing mixing and primary production and impacting the ocean pCO2.While previous studies have explored the impact of TCs on the global upper ocean biogeochmistry using observational data or coarse resolution stand-alone ocean models, their effect on ocean pCO2 and primary production remain unexplored within Earth system models. In this study, we investigate the response of ocean biogeochemistry to TCs through a high resolution simulation using the ICON-ESM model. The simulation features a spatial resolution of 5km for both the atmosphere and the ocean, resolving mesoscale eddies in the ocean and convective storms in the atmosphere. We quantify the contribution of TCs to changes in air-sea CO2 flux and primary production globally and in different basins.
Biases in stratosphere-troposphere coupling processes in S2S forecast systems
Authors: Butler Amy , Garfinkel Chaim , Lawrence Zachary
Published: March 2024

Two-way coupling between the stratosphere and troposphere is recognized as an important source of subseasonal-to-seasonal (S2S) predictability. Extratropical coupling between the stratosphere and the surface may modulate the tropospheric circulation in predictable ways and/or provide forecast windows of opportunity. S2S forecast models may struggle to represent such coupling processes; at longer lead times, drifts in a model’s circulation related to model configurations, biases, and parameterizations have the potential to feedback and affect stratosphere-troposphere coupling. This presentation will highlight results from an international SPARC-SNAP (Stratospheric Network for the Assessment of Predictability) community effort to diagnose and characterize biases in stratosphere-troposphere coupling in S2S models. We find that in the Northern Hemisphere, the S2S forecast systems struggle to reproduce the strength of observed upward coupling from the troposphere to the stratosphere, while downward coupling is mostly well represented. In the Southern Hemisphere, forecast systems generally overestimate downward coupling strength, despite underestimating radiative persistence in the lower stratosphere.
Cross-Scale Processes of Magnetic Reconnection
Authors: Hwang Kyoung-joo , Nakamura Rumi , Eastwood Jonathan , Fuselier Stephen , Hasegawa Hiroshi , Nakamura Takuma , Lavraud Benoit , Dokgo Kyunghwan , Turner Drew , Ergun Robert , Reiff Patricia
Published: March 2024

Various physical processes in association with magnetic reconnection occur over multiple scales from the microscopic to macroscopic scale lengths. This presentation reviews multi-scale and cross-scale aspects of magnetic reconnection revealed in the near-Earth space beyond the general global-scale features and magnetospheric circulation organized by the Dungey Cycle. Significant and novel advancements recently reported, in particular, since the launch of the Magnetospheric Multi-scale mission (MMS), are highlighted being categorized into different locations with different magnetic topologies. These potentially paradigm-shifting findings include shock and foreshock transient driven reconnection, magnetosheath turbulent reconnection, flow shear driven reconnection, multiple X-line structures generated in the dayside/flankside/nightside magnetospheric current sheets, development and evolution of reconnection-driven structures such as flux transfer events, flux ropes, and dipolarization fronts, and their interactions with ambient plasmas. We emphasize key aspects of kinetic processes leading to multi-scale structures and bringing large-scale impacts of magnetic reconnection as discovered in the geospace environment. These key features can be relevant and applicable to understanding other heliospheric and astrophysical systems.
Eighteen Degree Water Dynamics Viewed from an Ensemble 
Authors: Sun Luolin , Uchida Takaya , Penduff Thierry , Deremble Bruno , Dewar William
Published: March 2024

The subtropical mode water in the North Atlantic, often referred to as ‘eighteen-degree water’ (EDW), has been investigated based on observational and theoretical studies. We here discuss the mechanism of EDW by using an ensemble-based approach which offers the advantage of separating the eddy field from the mean flow without making implicit assumptions on the temporal or spatial scales of the eddies. We employ an ensemble of North Atlantic Ocean simulations partially coupled with the atmosphere at mesoscale permitting resolution (1/12°), and determine EDW as a pool of the Ertel potential vorticity (PV) lower than the surroundings. Our results suggest that the maintenance of EDW can be explained by the down-gradient eddy PV fluxes balancing the mean flow: the low PV in the formation region is transported by the eddy fluxes to the pool and mixes with the surrounding high PV.  
TerraNeo: Development of a scalable mantle convection code for exascale computing
Authors: D'Ascoli Eugenio , Burkhart Andreas , Kohl Nils , Bunge Hans-Peter , Mohr Marcus
Published: March 2024

Simulating the Earth’s mantle convection at full convective vigor on planetary scales is a fundamental challenge in Geodynamics even for state of the art high-performance computing (HPC) systems. Realistic Earth mantle convection simulations can contribute a decisive link between uncertain input parameters, such as the mantle viscosity structure, and testable preconditions, such as dynamic topography. The vertical deflections predicted by such models may then be tested against history of dynamic topography from stratigraphic observations. Considering realistic Earth like Rayleigh numbers (∼ 108 ) a resolution of the thermal boundary layer of 10 − 50 km is necessary considering the volume of the Earth’s mantle.Simulating Earth’s mantle convection at this level of resolution requires solving sparse indefinite systems with more than 1012 degrees of freedom, computationally feasible only on exascale HPC systems. This is achievable only by mantle convection codes providing high degrees of parallelism and scalability. Earlier approaches with prototype frameworks using hierarchical hybrid grids (HHG) as solvers for such systems demonstrated the scalability of the underlying concept for future generations of exascale computing systems.Building up on the TerraNeo project here we report on the progress of utilizing the improved framework HyTeG (Hybrid Tetrahedral Grids) based on matrix-free multigrid solvers in combination with highly efficient parallelisation and scalability. This will allow to solve systems with more than a trillion degrees of freedom on present and future generations of exascale computing systems. We also report on the advances in developing the scalable mantle convection code TerraNeo using the HyTeG framework to realise extreme-scale mantle convection simulations with realistic, Earth like parametrisation and a resolution in the order of ∼ 1km.
Urban Heat and Mitigation Potential in the Kansas City Metropolitan Area: Insights from Integrated Numerical Modeling and Heat Mapping
Authors: Sun Fengpeng
Published: March 2024

Urban Heat Islands (UHIs) represent a climatic consequence of urbanization, leading to elevated temperatures within cities compared to surrounding rural and suburban areas. Addressing this human-induced phenomenon demands effective mitigation strategies. This study quantifies the UHI in the Kansas City Metropolitan Areas (KCMA) in the United States and investigates the potential of albedo modification, particularly through the cool roof implementation, as a means to mitigate UHI effects within the KCMA.Utilizing the Weather Research and Forecasting (WRF) model, we first designed a suite of high-resolution simulations, examined UHI dynamics during a heatwave event across various scenarios within the KCMA, and determined the effectiveness of mitigation strategies in reducing temperatures within the KCMA. Specifically, we simulated two cool roof scenarios: one representing "newly installed" cool roofs with an albedo of 0.8 and another reflecting "aged" cool roofs with an albedo of 0.5. Our findings reveal that cool roof materials significantly mitigated surface UHI effects during evenings, delaying the onset of UHI effects until later in the day. Moreover, our study showcases the more profound impact of cool roofs on surface skin temperature, influencing the surface energy balance by altering sensible and ground storage heat fluxes and the planetary boundary layer.Leveraging numerical modeling, we led and launched an Urban Heat Island Mapping Campaign in Kansas City. It is a volunteer-based community citizen science field campaign that builds upon local partnerships among academia, local government agencies, non-profits, and private sectors. This campaign engages Kansas City's local residents in a scientific study to map and understand how heat is distributed in the communities and the factors affecting the uneven distribution of heat. It raises awareness about the adverse impacts of extreme heat and excessive urban heat and presents actionable measures for urban planners and policymakers to address heat-related challenges in metropolitan areas.
Bootstrapping Image Histogram for Simplifying Climate Snapshots: Exploring the Application to Indo-Pacific Warm Pool Expansion Research
Authors: Leung Jeremy Cheuk-Hin , Gan Qiuying , Liu Shengyuan , Kong Hoiio , Zhang Banglin
Published: March 2024

Thanks to the recent advancements in climate observation methods and numerical simulation performance, there has been a significant increase in the availability climate datasets, which offer finer resolutions and broader coverage of variables than ever before. In contrast to the past, when scientists faced challenges due to limited data, the challenge now lies in extracting meaningful information from high-dimensional climate data. In climate analyses, each timestep of data provides a snapshot of atmospheric/oceanic conditions, analogous to a photograph. In such sense, techniques from the field of computer vision can serve as valuable tools for analyzing these climate snapshots.This presentation aims to introduce the concept of the Bootstrapping Image Histogram, a fundamental idea in computer vision, and demonstrate its usefulness in simplifying climate snapshots and reducing the dimensionality of climate data. Additionally, given the crucial role of the Indo-Pacific warm pool (IPWP) in driving the global climate system, this presentation also showcases two applications of the Bootstrapping Image Histogram approach to IPWP expansion research, as recently published.(1) Recent observed weakening of IPWP seasonality: We find that the amplitude of seasonal cycle of the IPWP size has decreased significantly since 1950, despite the sea surface warming being rather uniform across seasons. Analysis results suggest that the climatological spatial pattern of sea surface temperature (SST) over the Indo-Pacific Ocean is the primary factor contributing to the weakening IPWP seasonality. (https://doi.org/10.1088/1748-9326/acabd5)(2) Overestimated IPWP expansion under greenhouse warming: The IPWP drives the global climate system by consistently supporting and maintaining atmospheric deep convection. For this reason, the IPWP is defined as the region where the SST exceeds a pre-condition necessary to favor deep convection (σconv). Previous conclusions regarding the rapid expansion of the IPWP were based on a constant σconv (typically 28°C). However, our analysis results reveal that σconv is indeed increasing under climate change, which corresponds to a slower IPWP expansion speed. This highlights the necessity of considering the response of the relationship between deep convection and SST to climate change when studying the long-term variability of the IPWP and its impacts on the climate system. (https://doi.org/10.1038/s41612-022-00315-w)
Coevolving aerodynamic and impact ripples on Earth: unifying bedforms on water, Earth and Mars
Authors: Duran Vinent Orencio , Yizhaq Hezi , Tholen Katharina , Saban Lior , Lester Conner , Kroy Klaus , Pähtz Thomas , Katra Itzhak
Published: March 2024

Wind-blown sand surfaces on Earth, Mars, and other planetary bodies are covered by multiscale bedforms. The long-standing consensus has been that meter- to kilometer-scale dunes and decimeter-scale ripples on Earth emerge via two distinct physical mechanisms. Dunes evolve from a flat sand bed due to a hydrodynamic instability, as topography and turbulent flow are out of phase. So-called impact ripples are commonly associated with a granular transport instability, related to the spontaneous synchronization of the hopping grains with the emerging surface corrugation. Recent wind tunnel experiments show that on relatively fine monodisperse sand (d = 90microns), centimeter-scale ripples can coevolve with decimeter-scale ripples, suggesting two distinct mesoscale instabilities. This new centimeter-scale ripples are reproduced by direct simulations of granular transport and are thus consistent with “impact” ripples. We then conclude, in contrast with the existing consensus, that decimeter-scale ripples have a hydrodynamic origin, similarly to large Martian ripples and water ripples. Indeed, their wavelength rescaled by the viscous length is in the same range as ripples in water and Mars. The formation of decimeter-scale ripples as a hydrodynamic instability is captured by existing morphodynamic models assuming the existence of two transport relaxation (or saturation) lengths: a large one, of about 0.5m, that has been proposed to scale with the drag length of sand grains, and a small one, of about 1cm, that is consistent with the average hop length of grain trajectories. We confirmed the values of the small saturation length by measuring the phase lag of the transport rate relative to the calculated bed shear stress. 
ESTHER: a small project to investigate gamma-ray emissions in thunderstorms and volcanic lightning
Authors: Ursi Alessandro , Reitano Danilo
Published: March 2024

Detecting terrestrial gamma-ray flashes (TGFs) from the ground is a relatively new frontier in atmospheric science and has opened up new avenues for research. Also, the recent detection of a TGF produced during the massive Hunga Tonga–Hunga Ha'apai eruption, pointed out the possibility that even volcanic lightning might produce gamma-ray emissions at MeV energies.In this context, we present the Experiment to Study Thunderstorm High-Energy Radiation (ESTHER), a small project funded by the Italian National Institute for Astrophysics (INAF), aimed at monitoring from the ground gamma-ray emissions produced during thunderstorms and, possibly, by volcanic lightning. The ESTHER set-up consists of a gamma-ray detection system and a VLF radio receiver, to be installed on the top of the Etna volcano (Italy). The selected installation site is the Etnean Observatory of the Italian National Institute of Geophysics and Volcanology (INGV), located at 2,818 m altitude and laying less than 2.7 km from the main volcano craters.An extensive analysis of the flash rate recorded at Mt. Etna in the last eight years pointed out that the mountain top is interested by strong lightning activity in the summer months, making it a suitable location for the investigation of lightning and associated high-energy phenomena. In particular, the largest fraction of discharges turned out to cluster nearby the mountain peak and right above the main volcano craters, where the frequent presence of volcanic ashes possibly increases the electrical conductivity, under conditions of humid air typical of thunderstorms, making the region above the volcano's top a natural trigger for lightning. Moreover, as for other volcanoes around the world, Etna has been documented to produce volcanic lightning (last times in 2015 and 2022). As a consequence, given the proximity of the Etnean Observatory to the main craters, ESTHER will enjoy a privileged location for investigating potential gamma-ray emissions produced either by thunderstorms and volcanic lightning. In conditions of clear sky, ESTHER will also provide an as much as possible continuous monitoring of the environmental gamma-ray background, allowing to point out potential variations of it before, during, or after volcanic eruptions. The ESTHER set-up will be installed and start its first data acquisitions in spring 2024.
Mapping intertidal mudflat gross primary production (GPP) by hyperspectral imagery, coupling with atmospheric CO2 fluxes at varied temporal and spatial scales: from the lab to the ecosystem level, through the seasons.
Authors: Méléder Vona , Polsenaere Pierre , Launeau Patrick , Jesus Bruno , Zhang Meng , Lavaud Johann , Giraud Manuel , Rosa Philippe , Deborde Jonathan , Geairon Philippe , Grizon James , Lamaud Eric , Bonnefond Jean-Marc
Published: March 2024

Intertidal mudflats, present all over the world are excluded from global carbon budget calculation; while these ecosystems are increasingly recognized to be as productive as tropical forests. With an annual global productivity estimated to be in the order of 500 million tons of carbon, mudflats can therefore represent up to 20% of the global production of the oceans, whereas they occupy only 0.03% of their surface, with a total area estimated at 130,000 km2. Despite their potentially high contribution to the overall carbon budget, their actual contribution remains unknown. Moreover, these ecosystems are currently under threat from global climate changes and increased human activities. In this context, estimating the actual carbon uptake by these ecosystems from the local to the global scale is a challenge that has to be tackled, which is the objective of this project.The main innovation of our project resides in coupling hyperspectral remote sensing, with CO2 fluxes measured at different spatial and temporal scales using benthic chambers and atmospheric eddy covariance. The first results shown the effect of seasons, tide, and habitats on CO2 fluxes, making intertidal mudflats as a sink, rather than a source of CO2. The final objective is to map the gross primary production (GPP) to estimate for the first time the contribution of these ecosystems at the global carbon cycle and more specifically, to the Blue Carbon. Such tools and results will help predicting what will happen to the tidal ecosystems due to changes linked to global climate changes and assist in developing mitigation and adaptation strategies to comply with the objectives of the Paris Agreement.
Improving precipitation nowcasting using deep generative models: a case-study and experiences in R2O 
Authors: Whan Kirien , Cambier van Nooten Charlotte , Schmeits Maurice , Wijnands Jasper , Schreurs Koert , Shapovalova Yuliya
Published: March 2024

Precipitation nowcasting is essential for weather-dependent decision-making. The combination of radar data and deep learning methods has opened new avenues for research. Deep learning approaches have demonstrated equal or better performance than optical flow methods for low-intensity precipitation, but nowcasting high-intensity events remains a challenge. We use radar data from the Royal Netherlands Meteorological Institute (KNMI) and explore various extensions of deep learning architectures (i.e. loss function, additional inputs) to improve nowcasting of heavy precipitation intensities. Our model outperforms other state-of-the-art models and benchmarks and is skilful at nowcasting precipitation for high rainfall intensities, up to 60-min lead time. 

Transferring research to operations is difficult for many meteorological institutes, particularly for new applications that use AI/ML methods. We discuss some of these challenges that KNMI is facing in this domain. 
The effect of land use types and climate change on soil moisture profile dynamics
Authors: Wu Mengqi , Klauder Tobias , Tarkka Mika , Vetterlein Doris , Schlüter Steffen
Published: March 2024

Soil moisture, as a key indicator of soil functionality, is significantly influenced by the evolution of soil-plant systems and the hydrologic cycle. Little long-term data is available about how land use and climate change affect the spatial and temporal distribution of soil water. In particular the variations in deeper subsoil layers are poorly documented. Here, the effects of five land use types, including two croplands with conventional and organic farming (CF and OF) and three grasslands with intensive and extensive meadow (IM and EM), as well as extensive pasture (EP) on soil moisture profiles were investigated at the Global Change Experimental Facility (GCEF), at Bad Lauchstädt in the German dryland belt. The facility harbors two climate treatments. The ambient climate and a future climate with increased temperature by ~0.55 ◦C across seasons, and the altered precipitation patterns by ~9 % additional irrigation in spring and autumn, and ~21 % reduction in summer. The soil moisture profiles were bi-weekly monitored with a portable probe (TRIME Pico IPH) down to 110 cm for two continuous years.Soil moisture content in topsoil and subsoil reflected the presence and size of transpiring plants, i.e. from October to next April, the soil water content was lower in grasslands than in croplands, which planted winter crops. During summer, there was a marked decrease in soil water content in the deeper soil layers of grasslands, while the crop on the cropland was already harvested. As a result, the recovery of soil water storage was faster during winter in croplands than in grasslands. Within croplands, OF had higher moisture than CF below 30 cm during the whole growing season and beyond due to less vigorous growth imposed by nutrient deficits. Within grasslands, differences in soil moisture only emerged in deeper soil (> 70 cm). In general, soil moisture in the shallow soil layers (0 - 20 cm) was very similar across land uses and climate scenarios and these clear differences only emerged in deeper soil. In the deeper soil (< 50 cm), croplands and extensively used grasslands showed an obvious increase of soil moisture in future treatment, especially during wet spring and summer.Our results clearly indicate long-term differences in soil moisture between the land uses. Climate manipulation at the GCEF only manifests itself in the subsoil (> 50 cm), by contrast, topsoil (< 30 cm) was more controlled by short-term dynamics induced by evaporation and precipitation. These findings stress the importance of deep soil moisture monitoring for a more comprehensive assessment of the water budget. 