bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of sulfur oxidation on cloud and aerosol properties in UKESM1 CMIP6 historical experiments
Authors: Sakulsupich Vichawan , Griffiths Paul T. , Archibald Alexander T.
Published: February 2023

Understanding the link between anthropogenic emissions and radiative forcing remains a grand challenge in the field of climate research. Linkages arise between emissions, atmospheric chemistry and climate through the formation of secondary aerosols such as sulfate, nitrate and organic aerosols. Sulfur dioxide (SO2) is an important aerosol precursor with the largest sources coming from anthropogenic activity. Unlike well-mixed greenhouse gases, anthropogenic aerosols are heterogeneously distributed because of localised emissions and the short atmospheric residence time. Thus SO2 conversion to aerosol is dictated by its emission location and the locally available oxidants; both of which are changing rapidly and disparately with time.This work uses the UKESM1 to investigate the modelled response of sulfate aerosol properties and cloud properties to emissions increases and oxidant changes over the period 1850-2014. We compare modelled hydrogen peroxide, which is important for SO2 oxidation, with observations. From an analysis of the CMIP6 and AerChemMIP experiments, we show that there have been significant changes in the atmospheric oxidation processes of SO2 over this period with consequences for the calculated radiative forcing. In UKESM1 historical experiments, the gas-phase reaction with hydroxyl radicals dominates the oxidation pathways in most regions. This channel is the most sensitive to oxidant changes and contributes to new aerosol particle formation. In contrast, in the aqueous-phase reaction, the oxidation of SO2 by ozone decreased in the European region in 1980 and oxidation by hydrogen peroxide increased in Eastern Asia in 2014. We present an analysis of the impacts of these sulfur oxidation changes on cloud properties and radiative forcing. Ultimately, this work contributes to the improvement of our process-level understanding of Earth system models that interactively simulate aerosol from precursors and aims to improve the accuracy of aerosol radiative forcing predictions.
Numerical Assessment of Hydrogen and Gas Mixture Storage in Salt Caverns
Authors: Wallace Richard , Cai Zuansi
Published: February 2023

With the UK recently doubling its hydrogen production goals to adjust to the market demand the necessity for storage is becoming realised [1]. There are several options for utility-scale storage including salt caverns, deep saline aquifers and depleted gas fields. Salt caverns hold the unique benefit over porous storage of being capable of numerous cycles due to the dynamics of gas withdrawal, making them indispensable in the hydrogen storage strategy of each country. This is exemplified in the UK where it is anticipated to range up to 56TWh. Unfortunately, these are not as readily available as porous storage and hence, competition between different energy storage types may cause problems.Of the subsurface energy storage systems, natural gas has been in operation for decades and is an established technology with numerous papers investigating different aspects of its operation and development. However, with the ambition of phasing out fossil fuel energy sources compressed air energy storage (CAES) and hydrogen storage are considered in Salt Caverns. It is also understood that during the transitionary period a gas blend may be utilised for the heating, currently, the maximum this stands at is 80:20 %vol of CH4 to H2. In most instances (at least for the UK), these systems will compete for storage as offshore wind farms, gas reservoirs and the national transmission system (gas grid) align [2]. Due to the different thermodynamic properties of each gas, it is important to know the impact of cyclic loading of each system on both the gas temperature and how this translates to its surrounding rock.To investigate this, an idealised model of the NK1 cavern at the Huntorf CAES facility is developed and a historical operational cycle is simulated. Methane, Hydrogen and a Gas blend (80:20 %vol of CH4:H2) will be simulated and compared to that of the compressed air energy storage in[3]. This is then furthered by creating a mass-balanced cycle based on the initial cycle and extended for one month to see how these variations develop. The significance of this is to provide insight for the decision-making in which energy storage facility is appropriate for the region as a result of the numerical modelling. ReferencesHydrogen Strategy update to the market: July 2022, E.I.S. Department for Business, Editor. 2022: London, United Kingdom.
Wallace, R.L., Z.S. Cai, H.X. Zhang, K.N. Zhang, and C.B. Guo, Utility-scale subsurface hydrogen storage: UK perspectives and technology. International Journal of Hydrogen Energy, 2021. 46(49): p. 25137-25159.
Guo, C.B., L.H. Pan, K.N. Zhang, C.M. Oldenburg, C. Li, and Y. Li, Comparison of compressed air energy storage process in aquifers and caverns based on the Huntorf CAES plant. Applied Energy, 2016. 181: p. 342-356.
Projected Changes in Peak Discharge Across the Contiguous United States
Authors: Villarini Gabriele , Kim Hanbeen
Published: February 2023

Floods affect many aspects of our lives, and our improved understanding of the processes driving the historical changes in this natural hazard can provide basic information to enhance our preparation and mitigation efforts. Here we analyze thousands of long-term streamgages across the contiguous United States and attribute the changes in flood extremes to precipitation and temperature. We then leverage these physical insights to assess the future changes in flooding using outputs from global climate models part of the Coupled Model Intercomparison Project Phase 6. We find that flood peaks are projected to change across the contiguous United States. This is true even when flood changes are not detected in the more recent decades, highlighting the current needs for incorporating climate change in the future infrastructure designs and management of the water resources.
Groundwater monitoring using fibre-optics and DAS: Application to the Lyon water catchment area.
Authors: Nziengui Bâ Destin , Coutant Olivier , Jestin Camille
Published: February 2023

Water resource management is a crucial socio-economic issue that requires developing high-resolution monitoring techniques, including non-invasive geophysical methods. Among them, passive seismic interferometry takes advantage of natural ambient seismic noise to recover the slight variations of the seismic wave velocity induced by changes in the groundwater level. In this study, we present the time and space monitoring of groundwater changes artificially generated by infiltration ponds at the exploitation field of Crépieux-Charmy (Lyon, France).  We deployed 3km of optical fibre and a dense array of fifty 3C geophones around infiltration basins. We recorded several cycles of filling-emptying with a DAS using a 2m spatial sampling (i.e., 1500 fibre sensors). The recorded signals are mainly associated with local anthropogenic noise (highways, trains, pumping, etc.). We could track seismic velocity variations with high temporal and spatial resolutions using ambient noise interferometry techniques. These variations are associated with the interaction between the water diffused from the basins and water table variations. This dynamic information helps understand and model water exchanges on the ground. The study confirms the possibility of groundwater monitoring using DAS records of ambient noise for seismic interferometry in a highly urbanized zone.
The Evaluation of Modified YSU Scheme and Parameter Adjustment on the Simulation of Fog over the North China Plain
Authors: Tian Meng , Wu Bingui
Published: February 2023

Recent studies showed that the modified YSU scheme, which added a fog top-down diffusion mechanism (ysu_topdown_pblmix), facilitated the bottom lifting of valley fog and sea fog by taking into account the “top-down” turbulent mixing and entrainment enhancement due to radiative cooling at the fog top, thus eliminating false fog areas. The applicability of this scheme to fog processes over the North China Plain is of interest. In this paper, we compared and analyzed the simulated effects of the modified YSU scheme on three fog events over the North China Plain with conventional ground-based data, 15-layer gradient and 5-layer eddy-related observations from atmospheric boundary tower. It was found that, unlike the results of existing studies, considering the fog-top turbulent diffusion mechanism resulted in lower TS scores for the fog area in the North China Plain, especially for the deep fog processes. A specific analysis of the simulated performance of a frontal fog on 17-20 December, 2016 showed that although the modified YSU scheme improved the simulation of nighttime near-surface temperature, humidity and vertical development of the fog layer, the simulated fog-top turbulence was too strong compared with the actual observations, resulting in a shorter fog duration and a significantly reduced fog area. By adjusting the parameter to reduce the intensity of the fog top turbulence entrainment, this operation can effectively reduce the under-reporting of the fog area and improve the simulation of fog over the North China Plain.
Polar heat transport enhancement in sub-glacial oceans on icy moons
Authors: Hartmann Robert , Stevens Richard J.A.M. , Lohse Detlef , Verzicco Roberto
Published: February 2023

The icy moons of the solar system show several phenomena in their polar regions like active geysers or a thinner crust than at the equator, all of which might be related to a non-uniform heat transport in the underlying ocean of liquid water. We investigate the potential for local heat transport enhancement in these sub-glacial oceans by conducting direct numerical simulations of rotating Rayleigh-Bénard convection (RRBC) in spherical geometry at a water-like Prandtl number Pr=4.38, Rayleigh number Ra=106, and Rossby number ∞≥Ro≥0.03 (or in terms of the Ekman number ∞≥Ek≥6.28·10-5). We probe two ratios of inner to outer radius η=ri/ro=0.6 and η=0.8, which is closer to the presumed conditions on most icy moons, for different gravitational laws g(r)∝rγ. The simulations cover the full range from zero to rapid rotation close to where convection ceases, and therefore cross the rotation-affected regime of intermediate rotation rates with a potentially enhanced dimensionless heat transport Nu>Nunon–rot as known from planar RRBC.Although the global heat transport does not increase (Nuglobal≤Nunon–rot), we find an enhancement up to 28% at high latitudes around the poles (Nuhl>Nunon–rot), which is compensated by a reduced heat transport at low latitudes around the equator (Null<Nunon–rot). In the tangent cylinder around the poles, Ekman vortices connect the inner and the outer shell, which allows for a more effective transport of heat through the bulk by Ekman pumping, whereas these vortices impede radial heat transport towards the equator. Interestingly, the polar enhancement decreases for the thinner shell (η=0.8 compared to η=0.6) with a larger tangent cylinder, but still remains significantly larger than the non-rotating reference value (≈10%).We also analyze the thicknesses of the thermal and kinetic boundary layers λΘ and λu to identify whether a ratio λΘ/λu≈1 is beneficial for the maximal polar heat transport, as hypnotized from planar RRBC. Overall, our study reveals that the same mechanisms, which govern the heat transport enhancement in planar RRBC, also enhance the heat transport in the polar regions in spherical RRBC. On the bigger picture, our results may help to improve the understanding of latitudinal variations in the crustal thickness on icy moons.
Understanding the role of precipitation intermittency on changes in extreme flooding
Authors: Livneh Ben , Bjarke Nels , Modi Parthkumar , Furman Alex
Published: February 2023

Extreme precipitation is projected to increase in many parts of the world, leading to concern over flooding and associated hazards. Despite the intuitive causal link between extreme precipitation and extreme flooding, observations and models suggest that other factors, in particular, low antecedent moisture may obscure or offset this relationship. Low antecedent soil moisture can arise through evaporation—driven by atmospheric warming that is projected to continue—but moisture is also reduced through an increase in the length of the time between storms, i.e., ‘storm intermittency’, which has been less studied and which can be derived directly from precipitation data. In this presentation, we focus on the modulating role of storm intermittency on the relationship between extreme precipitation and both flood potential, i.e., both flood peaks and volumes. We create an observation-based historical baseline of storm intermittency, 1950-2015, from a set of case-study basins to understand the relationship across a range of hydrometeorological settings. Next, the storm intermittency from a set of 16 CMIP6 climate models is evaluated relative to the baseline, and the evaluation is used to project future intermittency and likely outcomes on flood potential for the period 2016-2100. This projected flood potential is compared with hydrologic simulations from downscaled land surface models forced by the same CMIP6 models and differences between the projected and modeled outcomes are assessed in the context of simulated soil moisture and other hydrologic factors. Overall, we seek to understand the utility of storm intermittency as a predictor of flood potential and to understand the impacts of projected intermittency on future flood hazards.
What is the cause of the present-day uplift across the central Southern Alps, New Zealand?
Authors: Liu Shaozhuo , Jónsson Sigurjón
Published: February 2023

Surprisingly fast bedrock uplift of ~5 mm/yr is observed by both GNSS and InSAR measurements across the central Southern Alps where oblique convergence is accommodated by the Alpine fault and other tectonic structures. This mountain range also features anomalously heavy precipitation and high erosion on the western side of the main divide. Since vertical motion is sensitive to perturbations from surface processes, we first evaluate how surface processes operating at different time scales (e.g., erosion, (de)glaciation, and hydrological loading) impact the present-day GNSS measurements. Erosion-induced rebound might be significant, but with an upper limit below 2 mm/yr uplift across the central Southern Alps, whereas elastic rebound caused by modern glacier melting and hydrological loading are secondary, as the magnitude is below 0.3 mm/yr at the locations of GNSS stations. Next, we use elastic dislocation models to explore the geometry and kinematics of a ramp-décollement system consistent with the GNSS-derived shortening and remaining vertical motions. Our best-fit model has 5.5-6.5 mm/yr reverse slip on the 40-50°SE-dipping Alpine fault locked above ~9 km depth, connected to a flat décollement accommodating 7.5-11.0 mm/yr of shortening. The remaining far-field shortening might be taken up by folding near the ramp-décollement junction and/or reverse slip along a NW-dipping backthrust in the hinterland. Our results present how climate-related surface and endogenic tectonic processes modulate the present-day vertical deformation across the central Southern Alps, giving new insights into active mountain building for this mountain range.
Improved field-aligned current and radial current estimates at low and middle latitudes deduced by the Swarm dual-spacecraft
Authors: Wang Fengjue , Luehr Hermann , Xiong Chao , Park Jaeheung , Zhou Yunliang
Published: February 2023

The Swarm satellite constellation provides an excellent opportunity to explore ionospheric current systems. In this study we performed a detailed analysis of the ionospheric radial current (IRC) and inter-hemispheric field-aligned current (IHFAC) estimates at equatorial and low latitudes derived from the single-satellite and dual-spacecraft (dual-SC) approaches. We found that the diurnal variations of average IHFACs from both approaches agree qualitatively with each other for all seasons. But the amplitudes of single-satellite results reach only about 70% of those from the dual-SC. This difference is attributed to the fact that only the magnetic field By component is utilized in the single-satellite approach, while both Bx and By components are considered in the dual-SC approach. Above the magnetic equator, the IRCs derived from single-satellite approach show spurious tidal signatures, caused by equatorial electrojet (EEJ) contributions to the dBy component. The EEJ does not contaminate dual-satellite results. Further, we improved the IHFACs from the dual-satellite approach by considering the local influence of the ambient magnetic field on current densities and normalize them to their ionospheric E-region footprints. Then we extend the analysis to ±60° MLat; the middle latitude IHFACs show features different from those at low latitudes. They are dominated by longitudinal wave-1 and wave-2 patterns. A superposition of these tidal components reflects confinement of the IHFAC modulation to daytime and the western hemisphere. The tidal signatures at middle latitudes are better organized in universal time than in local time. The strongest IHFACs appear at 18-19 UT, near noon in the American sector. This is related to the overlap with the South Atlantic Anomaly.
Nutrient and carbon dynamics along the river-estuary-ocean continuum on Central European scale
Authors: Schütze Claudia , Kamjunke Norbert , Brix Holger , Flöser Götz , Bussmann Ingeborg , Achterberg Eric , Ködel Uta , Fischer Philipp , Rewrie Louise , Sanders Tina , Borchardt Dietrich , Weitere Markus
Published: February 2023

Nutrient and carbon dynamics within the river-estuary-coastal water systems are key processes to understand the matter fluxes from the terrestrial environment to the ocean. In a large-scale study we analysed those dynamics with the focus of the prevailing low water conditions by following a sampling approach based on the travel time of water.We started with a nearly Lagrangian sampling along the River Elbe (German part; 580 km within 8 days travel time). After a subsequent investigation of the estuary, the plume of the river was followed by raster sampling the German Bight (North Sea) using three ships simultaneously. In the river, intensive growth of phytoplankton was determined connected with high oxygen saturation and pH values as well as under-saturation of CO2, whereas concentrations of dissolved nutrients declined. In the estuary, the Elbe shifted from an autotrophic to a heterotrophic system: Phytoplankton died off upstream of the salinity gradient causing minima in oxygen saturation and pH, supersaturation of CO2, and a release of nutrients. In the coastal region, phytoplankton and nutrient concentrations were low, oxygen close to saturation, and pH in a typical marine range. We detected a positive relationship between pH values and oxygen saturation and a negative one between pCO2 and oxygen saturation. Corresponding to the significant particulate nutrient flux via phytoplankton, flux rates of dissolved nutrients from the river into the estuary were low and determined by depleted concentrations. In contrast, fluxes from the estuary to the coastal waters were higher and the pattern was determined by tidal currents.Overall, the presented observation approach is appropriate to better understand land-ocean fluxes, particularly if it is performed under different hydrological conditions including extremes and seems to be suitable to investigate the impact of such events in freshwater on coastal systems in future.The study was conducted within the frame of the Helmholtz MOSES initiative (Modular Observation Solutions for Earth Systems) targeting processes and impacts of hydrological extremes.
Characterizing melt water properties in the periglacial active layer through seasonal and yearly variations in catchment hydrology.
Authors: Culha Cansu , Kirchner James
Published: February 2023

Permafrost, the frozen layer beneath a freezing and thawing active layer, is an impermeable frozen soil that persists for multiple years. The gradual thawing of permafrost and thickening of the active layer allows a glimpse into the evolution of the hydraulic processes that shape the periglacial landscape. One question in understanding the governing mechanics within the rapidly evolving periglacial landscape is how water retains within or segregates through the active layer to eventually feed rivers. In this exploratory study, we analyze data from multiple periglacial hydraulic catchments over time and characterize their hydraulic response rate to stressors. We test whether deconvolution and demixing of noisy time series can isolate precipitation from thawing permafrost signals in river discharge. We use the Ensemble Rainfall-Runoff (ERRA) script, which is effective in inferring nonstationary and nonlinear responses to precipitation using Runoff Response Distribution (RRD), to further test temperature signatures. Using this tool, we measure the RRD for the same catchments both over the years and over the summer months. We hypothesize that an increase in active layer thickness over years and over summer months will delay the RRD due to an increase in water storage.By analyzing the parameters that change the RRD of periglacial systems with time, soil moisture content, average seasonal and yearly temperatures, and precipitation, we can begin a systematic understanding of how the active layer modulates hydraulic responses and how the responses may be different from other hydraulic systems.
Drought influence on flood dynamics: a global overview
Authors: Matano Alessia , Berghuijs Wouter , de Ruiter Marleen , Ward Philip , Mazzoleni Maurizio , Van Loon Anne
Published: February 2023

Floods and drought affect millions of people each year, but what if a riverine flood rapidly follows or occurs during a hydrological drought?The 2022 summer drought in Europe, for instance, was punctuated by flash floods, affecting societies, economies and the environment already impacted by the persistent drought. In the same summer, in Iran and Afghanistan, devastating riverine floods followed a severe drought, causing displacement and human losses. Although the abrupt transitions between opposite hydrological extremes can pose huge risks for societies, the processes behind and effects of drought-flood interactions remain largely unknown, as most studies address droughts and floods separately. This research provides the first global study of compound and consecutive drought-flood events, shedding light on the underlying hydrological interactions between opposite hydrological extremes.By analysing timeseries of hydro-meteorological and other biophysical variables for 8255 catchments globally, we reconstruct the propagation of droughts and floods through the hydrological cycle, thereby identifying and characterizing flood events that follow or compound with drought conditions. We use variable and fixed threshold-level approaches to detect extreme dry and wet conditions, and seasonality statistics to analyse the timing of riverine floods. Our results show that close succession between drought and flood occurs mainly during the transition between seasons: from winter to spring in mid-latitude areas and from dry to wet at the equator and polar regions. Although these events are rare, they have increased over time, especially in countries such as France and Germany, southern Brazil, and India. Furthermore, drought conditions often shift the flood timing, resulting in later winter floods in Europe, in the north-eastern coast of the United States and western Canada, and earlier summer floods in Central America and Northern Brazil.This study shows that although drought and flood events evolve from different hydrological processes and atmospheric dynamics, these hydrological extremes interact with the same hydrological system, resulting in system alterations that may modify flood dynamics.
Simulated cycles of East Asian temperature and precipitation over the past 425 ka
Authors: Dai Gaowen , Zhang Zhongshi
Published: February 2023

Records from a wide range of geological archives covering the last few glacial-interglacial cycles show large inconsistencies in the East Asian summer monsoon variability, which severely hampers our understanding of the evolution and potential mechanisms of the regional East Asian climate on orbital timescales. Here, we examine the simulated temperature and precipitation in East Asia based on a series of equilibrium simulations conducted for the past 425 ka, and we investigate the sensitivity of temperature and precipitation to potential forcings. Our simulations show that, in East Asia, the seasonal mean temperature is dominated by a ∼20-kyr cycle, and the annual mean temperature (AMT) is dominated by a ∼100-kyr cycle, which is consistent with previous modeling efforts and geological reconstructions. Additional sensitivity experiments indicate that the greenhouse gas concentration, in combination with the ice volume, is the dominant force for the variations of AMT in East Asia on orbital timescales. For the precipitation in East Asia, our equilibrium simulations and additional sensitivity experiments, together with comprehensive model-data intercomparison analysis, suggest that the cycles of simulated annual mean precipitation over East Asia are highly model-dependent, although the dominant ∼20-kyr cycle in summer precipitation appears to be a robust feature. Overall, the results highlight the large model uncertainty with regard to the relative roles of forcings in hydroclimate variations in East Asia on orbital time scales. There is, therefore, an urgent need to implement more realistic precipitation schemes in models in order to decrease the model spread in simulated precipitation.
Low carbon transition of global power sector may enhance sustainable development goals
Authors: Peng Kun
Published: February 2023

Low-carbon power transition, key to combatting climate change, brings far-reaching effects on achieving Sustainable Development Goals (SDGs), in terms of resources use, environmental emissions, employment, and many more. Here we assess the potential impacts of power transition on multiple SDGs progress across 49 economies under six socio-economic-climate scenarios. We find that the low carbon power transition under Representative Concentration Pathway (RCP) 2.6 scenarios could lead to approximately 10% improvement in global SDG index score from 65.30 in 2015 to 71.62-71.64 in 2050. However, the improvement would be significantly decreased to 1.91%-4.98% and 3.42%-5.24% under RCP6.0 and RCP4.5 scenarios, respectively. Power transition could improve the overall SDG index in most developed economies under all scenarios while undermine their resources-related SDG scores. The power transition induced changes in international trade would improve developed economies’ SDG progress, but jeopardize that of developing economies which usually serve as resource hubs to meet the demand for low carbon power transition in developed economies. 
2D Geothermal model across the Peru-Chile trench and the Andean Cordillera above the Nazca Ridge subduction
Authors: Ciattoni Sara , Basilici Matteo , Stefano Mazzoli , Antonella Megna , Stefano Santini
Published: February 2023

The Nazca Ridge is a wide aseismic ridge subducting beneath the South American margin at latitude about 15°. The buoyancy of the thickened oceanic crust of the Nazca Ridge produces localized flat subduction influencing the geometry and the geological history of the whole area.  With the aim of analysing the spatio-temporal evolution of the deformation and uplift/subsidence history of the lithosphere above the Nazca Ridge flat slab, we have started from the study of the geothermal structure of the upper plate. We have built a crustal section with a length of 1000 km that reaches a depth of about 130 km. The section runs from the top of the Nazca Ridge in the west to the Amazonian Basin in the east, progressively crossing the Peru-Chile trench, the East Pisco Basin and the Andean Cordillera. Thereafter we have elaborated a 2D geothermal model based on the crustal section. We have considered the whole lithosphere composed of two main geological units: (i) crystalline basement, (ii) sedimentary cover (including the whole lithostratigraphic succession). For each unit we have assigned the following parameters: thickness, density, heat production and thermal conductivity. Moreover, we have also taken into account the friction coefficient, the convergence rate of the plates, the heat flux of the Moho, and the slip rate of the megathrust. Model parameters have been set up in order to obtain the best simulation of the heat flow contribution due to the large reverse fault responsible for the coastal seismic event of November 12, 1996, with epicentre on the section trace. Using these parameters and applying an analytical methodology we have calculated isotherms and geotherms. The resulting model may provide an important contribution on the investigation of the effects of the Nazca Ridge subduction and the associated flat slab geometry on the tectonic evolution of the area.
TerraNeo: Ongoing development of a scalable mantle convection code for exascale computing
Authors: D'Ascoli Eugenio , Brown Hamish , Kohl Nils , Mohr Marcus , Bunge Hans-Peter
Published: February 2023

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 rheology, and testable preconditions, such as dynamic topography. The vertical deflections predicted by such models may then be tested against the geological record. Considering realistic Earth-like Rayleigh numbers (∼ 108) a resolution of the thermal boundary layer on the order of ∼ 10 km is necessary considering the volume of the Earth’s mantle. Simulating Earth’s mantle convection at this level of accuracy requires solving sparse indefinite systems with more than a trillion degrees of freedom, computational feasible on exascale HPC systems. This can only be achieved by mantle convection codes providing high degrees of parallelism and scalability. Earlier approaches from applying a prototype framework using hierarchical hybrid grids (HHG) as solvers for such systems demonstrated the scalability of the underlying concept for future generations of exascale computing systems. In consideration of 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 parallelization 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 a resolution on the order of ∼ 1 km.
Application Continuity Equation to Analyze the Hydraulic Performance of Nature Water Retention Measures
Authors: Huang Yao-Sheng , You Jiing-Yun
Published: February 2023

Flood is one of the most frequent and costly natural disasters worldwide. In many cases, implementing flood protection measures is limited due to land or resource availability. Natural Water Retention Measures (NWRMs), a more cost-effective approach, have recently drawn the attention of many researchers. Instead of infrastructure construction, NWRMs aim to reduce the risk of flooding and economic loss by land use and water management practices without many construction applications. Much previous literature qualitatively investigates the mechanisms of NWRMs, however, only a few focus on the hydraulic characteristic and the effectiveness of flood reduction of NWRMs. To improve the understanding of NWRMs, this study clarifies and analyzes the hydraulic performance of NWRMs. We consider the triangular inflow hydrograph based on the continuity equation with the Muskingum-Cunge method to derive the outflow of the channel, as well as the weir equation to the outflow of the retention area. Following, the continuity equations are formulated as a first-order ordinary differential equation in dimensionless form. The conceptual model built from the equations could denote the primary hydraulic mechanism in the original channel and the additional retention area. Two important parameters include the ratio of peak maximum outflow and peak inflow, and the ratio of maximum storage and total flood volume can be obtained by solving the equations. The results show that the relationship between two dimensionless parameters are nonlinear. Also, in the channel, the relationship is sensitive to the shape factor in the Muskingum-Cunge method, especially in a lower ratio of maximum outflow and peak inflow. With this model, the study following examined the different proportional of flood volume flowing in retention areas and calculate the downstream outflow. The result shows the effectiveness of flood reduction and the proportional of flood volume in retention areas are nonlinear relationships. Briefly, there is an optimal operation of NWRMs by balancing the flood volume in the river and retention could induce the minimum outflow. The findings in this study represent the hydraulic performance of NWRMs. The results can also improve the design and operation of NWRMs appropriately.
Greenhouse gas dynamics across a latitudinal gradient of thermokarst lakes
Authors: Valiente Nicolas , Grau Oriol , Martin Victoria , Janssens Ivan , Van de Putte Inge , Dörsch Peter , Schmidt Hannes , Richter Andreas
Published: February 2023

The Arctic is warming at a faster rate than the rest of the planet due to climate change. The warmer temperatures are causing, among other effects, the permafrost to thaw. When ice-rich permafrost thaws, thermokarst features form due to subsidence of the ground surface and the creation of dynamic depressions, basins, and lakes. As a result, the hydrological cycle in these latitudes is intensifying, causing an increase of nutrients and organic carbon in surface waters. Such impacts on freshwaters affect microbial community composition, and thus, these systems are good sentinels to study processes in primary ecological succession related to ecosystem processes such as productivity and greenhouse gas (GHG) emissions. This study aims to improve the current understanding of microbial processes leading to release of GHG in thermokarst lakes. To that end, we sampled a total of 12 thermokarst basins in August 2022 along a latitudinal gradient (67ºN - 69ºN) in the Northwestern Territories (Canada). The basins were selected so that half were in the taiga biome and half in the tundra biome. In addition, based on satellite images and in-field observations, half of the lakes sampled were in expansion and the other half were undergoing drainage. Water samples were collected for the analysis of GHGs (CH4, CO2, N2O), major ions, dissolved nutrients (organic C, δ13C-DOC, organic and inorganic -N) and microbial community composition (16S rRNA gene metabarcoding). We used Ar-corrected gas saturation of each GHG as a proxy of net metabolic changes. Our first results show that both expanding and shrinking lakes were strongly oversaturated in CH4 andCO2, slightly saturated in N2O, and slightly undersaturated in O2, pointing out higher respiration activity than primary production. Microbial mineralization of organic matter was used as a proxy for GHG production. We found higher concentrations of dissolved organic C in shrinking lakes compared to expanding ones. Following the latitudinal gradient (i.e. biomes), higher temperatures were found in lakes sampled in the taiga compared to those located in tundra, together with deeper permafrost table depths. In surface waters, pH values and dissolved O2 concentrations were significantly higher in tundra lakes compared to taiga lakes, probably as a result of lateral DOM fluxes in more productive ecosystems (i.e. boreal forests). Differences between microbial communities in both biomes are therefore expected, which we will verify once the ongoing sequencing analyses are available. Our study advances the current knowledge of GHG dynamics in thermokarst lakes and helps to predict future effects of climate change impacts in northern latitudes.
Promote Ecosystem Services for Sustainable Development Goals
Authors: Zhao Wenwu , Yin Caichun
Published: February 2023

Ecosystem services are the benefits that humans obtain from ecosystems, which support human well-being from basic livelihood (e.g., water and food) to higher-level needs (e.g., garden cities and ecotourism), contributing directly or indirectly to Sustainable Development Goals’ achievement. In order to promote Ecosystem Services for Sustainable Development Goals, we conducted ecosystem service assessment, revealed the trade-offs and synergies of multiple ecosystem services, and discussed the impact of ecosystem services on regional sustainable development and its mechanism. Our work proposes the optimal regulation strategy of ecosystem services to promote the progress of the Sustainable Development Goals, and provides scientific basis for ecological restoration and SDGs-oriented optimization of ecosystem management. For the future research, we not only need to protect ecosystem for better ecosystem services, but also integrate ecosystem services into the achievement of sustainable development goals, and make the best use of ecosystem services for a better future.
Confidence intervals for the reliability diagram
Authors: Verkade Jan
Published: February 2023

The reliability diagram is often used to assess the reliability of a set of probabilistic forecasts. It plots the observed relative frequency of an event against its predicted probability. Reliability is evaluated by assessing the distance of the plotting positions from the diagonal which designates 'perfect reliability'. The reliability diagram is easy to construct and to understand. However, there is a caveat: it is not immediately clear which distance from the diagonal would still be considered 'reliable'. Due to finite sample size, even a perfectly reliable forecasting system could result in a reliability diagram where not all points are on the diagonal. Various authors have proposed visual guidance that allows a forecaster to assess whether the observed relative frequencies fall within the variations that can be expected even when a forecasting system is perfectly reliable. These include 'consistency bars', a modified version of the reliability diagram which is plotted on probability paper and  a 'standardized reliability diagram' based on the Normal transform of the Poisson binomial distribution. The present contribution provides another method to visualize the expected deviation from the diagonal: confidence intervals based on the Poisson binomial distribution. The application is demonstrated in various case studies.
Connecting Coronal 3D Electron Density from Tomographic Reconstruction to In-situ Measurements from Parker Solar Probe
Authors: Lamy Philippe , Wojak Julien
Published: February 2023

There are few possibilities to put the in-situ measurements of the coronal electron density such as obtained by the Parker Solar Probe (PSP) in the context of the 3D configuration of the corona and its structure. One of them consists in using MHD models relying on synoptic maps of the photospheric magnetic field, but their accuracy is subject to questions, especially in the case of complex coronae of the maximum type. The 2D inversion of white-light coronagraphic images requires the simplified assumption of spherical symmetry of the corona which basically washes out the longitudinal variations. We will present preliminary results of a new method which makes use of the 3D time-dependent tomographic reconstruction of the coronal electron density based on accurately corrected and calibrated LASCO-C2 images of the polarized brightness of the corona. It is performed over a sliding window of 14 days (half a Carrington rotation) centered at the times of the PSP perihelion with a time interval of 4 days. The resulting “cubes” of the 3D electron density Ne are visualized from six different vantage points and with movies. The orbit of PSP is projected on a synoptic map of Ne extracted from the cubes at a heliocentric distance of 5.5 Rs; the track extends from Perihelion-5 days to Perihelion+5 days. The electron density at the heliocentric distances of PSP is extrapolated radially from the values at 5.5 Rs using an inverse square law and compared with the in-situ measurements collected by PSP/FIELDS. We will present results from the first PSP encounters.
The integrated observation network of land-atmosphere interactions over heterogeneous landscapes of the Tibetan Plateau
Authors: Xie Zhipeng , Ma Yaoming , Hu Zeyong , Ma Weiqiang , Chen Xuelong , Wang Binbin , Han Cunbo
Published: February 2023

The Tibetan Plateau (TP) plays a central role in the water and energy cycle, atmospheric circulation patterns, and regional and global climate, and it is sensitive and vulnerable to global climate change. Land-atmosphere interactions are an important topic in climate change studies because they encompass a wide range of intricate processes and feedback. However, because of the high elevation and harsh climate conditions, knowledge of the land-atmosphere interactions in the TP has been greatly impeded by the extremely sparse and unevenly dispersed in-situ monitoring network in this region. Although automatic weather stations have been widely established throughout the TP, they provide only a single layer of meteorological measurements. Profile measurements of temperature, humidity, and wind may aid in understanding land surface processes and boundary layer dynamics over the complex terrain of the TP. With the support of various agencies in the People's Republic of China and over 17 years of efforts, we have established an integrated observation network of land-atmosphere interactions over heterogeneous landscapes of the TP. The observation network consists of 18 stations covering various landscapes (e.g., alpine meadow, alpine desert, desert grassland, alpine wetland, alpine woodland, glaciers, and alpine lake), measurements made by planetary boundary layer towers, eddy covariance systems, wind profilers, microwave radiometers, radiosonde systems, FlowCapts, and cloud and precipitation radars will be detailed introduced. The contributions of the integrated observations to the understanding of energy and water exchanges, key land surface parameters, turbulent characteristics, atmospheric vertical structures, local circulation characteristics, and the impact of complex terrain on local atmospheric circulation patterns will be demonstrated using the National Observation and Research Station of China for Qomolangma Special Atmospheric Processes and Environmental Changes as an example. Furthermore, a long-term dataset of hourly integrated land-atmosphere observations on the TP has been released and can be freely accessed. We are confident that the integrated observations will benefit a broad multidisciplinary community by enabling the evaluation and development of existing or novel remote sensing algorithms as well as geophysical models for climate research and forecasting.  
Role of thermodynamic processes in driving Monsoon Intraseasonal Oscillations (MISO) away from the Equator
Authors: Masiwal Rajat , Dixit Vishal , Seshadri Ashwin K
Published: February 2023

Monsoon intraseasonal oscillation (MISO) is an important aspect of the monsoon variability on various timescales, accounting for short-term variability as well as about 40% of total seasonal rainfall variance. MISO plays an important role in modulating the active (wet) and break (dry) spells of monsoon, and its low-frequency component has a time period of 30-60 days and exhibits northward propagation from the equatorial Indian Ocean to the Himalayan foothills. This northward propagation is generally attributed to generation of positive barotropic vorticity to the north of the previous convection centre. However, using ERA5 reanalysis composites we show that the relation between convection centre and positive barotropic vorticity undergoes significant change as MISO propagates away from the equator. Close to the equator (0-15°N), barotropic voriticty is either in-phase or leads rainfall, whereas further poleward (15°N-25°N), this relationship reverses and rainfall leads vorticity by 1-2 days. This contrast is closely tied to changes in the vertical structure of vorticity: near the equator, the vorticity maximum lies in the middle troposphere, while poleward of 15°N it is in the lower troposphere. The vorticity budget at each pressure level reveals the importance of vertical advection of vorticity for its near-barotropic structure, together with the importance of thermodynamic influences on vorticity, especially poleward where the vortex stretching term grows. Such findings point to the central role of feedback on the dynamics from the thermodynamic processes away from the equator. Furthermore, it closely ties the ability of models to reproduce MISO to their ability to represent convective processes. 
Bringing AMS and NOAA Oceanic water testing field experience in a chemistry class
Authors: Rawal Bhavna , Raw Nundini
Published: February 2023

The purpose of this conference to attend round table discussions, presentations and talks on Oceanic chemistry and geo chemistry. We did research and collected water samples and did various testing over the Gulf of Mexico on a NOAA vessel called the R/V Walton Smith ship from August 6-10. In our chemistry class, we talk about pH of water, dissolve oxygen in water, CO2 analysis, temperature effect, salinity etc. and its calculations. We brought our first-hand experience of what we did and how we performed real oceanic water testing over the Gulf of Mexico. How testing was done in a small lab on a Walton smith vessel, how we collected data and interpreted to help survey the oceanic water over the Gulf of Mexico and importance of it. We will present new perspective on science education. We will also include graduate courses taken and how our learning about these courses influenced in our lesson planning. These courses were offered by AMS with full scholarship. 