bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydroxyl radicals in the Amazon tropical troposphere measured during the CAFE-Brazil field campaign with HORUS
Authors: Holzbeck Philip , Sreekumar Sreedev , Tsokankunku Anywhere , Marno Daniel , Rohloff Roland , Martinez Monica , Nussbaumer Clara , Fischer Horst , Curtius Joachim , Pöhlker Mira , Lelieveld Jos , Harder Hartwig
Published: February 2023

The campaign Chemistry of the Atmosphere Field Experiment (CAFE) Brazil was conducted in the Amazon rainforest in December 2022 and January 2023 to study new particle formation in the outflow of convective systems over the Amazon rainforest. In the framework of this campaign, photochemical and aerosol processes in the tropical troposphere were investigated at different altitudes from the boundary layer up to 14 km using the High Altitude and Long Range Research Aircraft (HALO).The HydrOxyl Radical measurement Unit based on fluorescence Spectroscopy (HORUS) measures the OH and HO2 abundances as a highly relevant tracer for photochemical and aerosol processes in the tropical troposphere and new particle formation. The Hydroxyl radical (OH) oxidizes trace gases transported by convective systems from the boundary layer into the upper troposphere, leading to the formation of condensable matter. Contrasting conditions were measured, from pristine rainforest to polluted biomass burning and pollution conditions, and the occurrence of HOx during the day and nighttime in the outflow of electrified and non-electrified convective systems.The first results of these measurements will be presented, providing unique insights into the air chemistry and lifecycle of aerosols and clouds in the Amazon rainforest.
How non-asset-based disaster loss models better quantify risk: A case study of coastal flooding in the Philippines.
Authors: Choong Jeanette , Wagenaar Dennis , Lallemant David
Published: February 2023

Conventional disaster loss models measure risk and impact solely based on the volume of assets potentially lost to a disaster. While asset-based metrics are useful in providing an overview of the immediate physical losses, they neither fully capture the disparate impacts on different social groups nor the knock-on impacts that people continue to experience post-disaster. The problem with relying on asset-based metrics alone is that it leads to decisions that gravitate towards the protection of asset-rich areas as they seemingly have more to at risk. In doing so, it obscures the protection needs of asset-poor regions, and in extreme cases, could further exacerbate impacts and issues of inequity. Since one of the main goals in disaster risk modelling is to effectively inform disaster risk reduction strategies, the approach decision makers use to quantify risk matters. This is especially important in geographies that experience both high levels of disaster risk and inequity. In this study, we highlight the utility of ‘non-asset-based’ disaster loss models for equitable planning outcomes through the following contributions: (1) A literature review comparing the types of existing non-asset-based disaster loss approaches; (2) An applied comparison of the conventional asset-based approach and select non-asset-based approach(es) for the case of coastal flooding in the Philippines. We use this comparison to emphasize the need for better risk and loss metrics for planning and decision-making by demonstrating that moving from asset-based to non-asset-based approaches leads to a shift in municipalities prioritised for protection.
Using top-down and bottom-up approaches to advance diversity, equity and inclusion
Authors: O'Halloran Lydia , Patricio Sulliván Mažeika
Published: February 2023

Only when we approach science from multiple perspectives will we accelerate our understanding and protection for the earth we all share. Institutional barriers – such as lack of time, resources, or recognition – can impede academic engagement in diversity, equity, and inclusion (DEI) related activities. To minimize these barriers and effectively promote DEI activities in our institutions, we propose a model across multiple scales of engagement: from the individual/personal scale to working/research groups to administrative units such as departments, schools, and field stations. We provide examples of a combination of both top-down and bottom-up approaches to remove barriers that limit DEI in the geosciences. We highlight ideas for theoretical contemplation as well as concrete action items from the Baruch Institute of Coastal Ecology and Forest Science in South Carolina, USA. Some of these actions include working with local community groups to bridge the gap between scientific needs of the local community and the scientific community at large; grant writing to meaningfully engage with marginalized communities that rely on natural resources; and opening discourse to uncover barriers to more equal representation. The goal is to provide a DEI structure that blends individual contributions and initiative with administrative support and leadership, therein supporting geoscientists across career stages that are diverse in their backgrounds, motivation and intended work arenas to advance science from multiple perspectives for an enriched scientific legacy. 
A Simple Method of Water Valuation for Climate Planning
Authors: Ward Frank
Published: February 2023

Economic analysis has considerable power to guide a number of water development proposals to inform climate adaptation planning.  Much work has appeared in recent years on valuing water resources to support that planning, but little theoretically rigorous analysis exists on valuing resources in over a wide range of physical and economic conditions in a general equilibrium setting.   Moreover, no published work to date has solved the inverse problem of inferring the parameters of a system of water production functions when observed data are constrained by a single observation.  This paper addresses an important inverse problem in water economics, namely the process of inferring from a single observation on land and water use the parameters of the underlying production functions. It solves an inverse problem by going from data on observed factor use, factor prices, commodity production, and commodity prices to the underlying production function parameters.  From the recovered production function parameters, marginal values of water are calculated over a wide range of water supply and economic conditions.   An example is illustrated for land and water development planning in the American Southwest.  This paper’s original contribution can inform policy debates internationally over competing proposals for climate adaptation planning.
Air Quality Monitoring & Data Sharing in Africa and South/Southeast Asia: A Scoping Review
Authors: Rosales Colleen Marciel , Sawant Viraj , Isied Margaret , Biggs Russ , Hagerbaumer Chris
Published: February 2023

Reliable data on air pollution are fundamental to understanding and taking corrective action to improve air quality. In addition, where data are shared with the public, everyone across private, public and civil society can innovate, collaborate, and apply effective solutions towards clean air. However, air quality (AQ) monitoring, as well as AQ data sharing, are both limited in many low- and middle-income countries. While a few reviews of air quality in Africa and South/Southeast Asia exist, a review focused on monitoring capabilities and data sharing is necessary, especially with growth in non-traditional, non-reference monitoring technologies. We conducted a scoping review based on the Arksey and O’Malley methodological framework along with updates proposed in literature consistent with the PRISMA-ScR (Scoping Review Extension). We implemented a search strategy that was iteratively refined to review diverse sources including scientific and gray literature, air quality data aggregators, and publicly internet-available documents of national governments. We complemented our findings by consulting with experts. We found that AQ monitoring in Africa and South/Southeast Asia is lacking, with very few countries having reference-grade monitoring programs and few sharing the data they collect publicly. We recommend leveraging emerging lower-cost alternatives along with traditional (“reference”) technologies. This is supported by our review of emerging approaches and highlighted case studies of countries like Uganda and Cambodia that have adopted such approaches. 
Trend and seasonal cycle of US methane emissions
Authors: Hu Lei , Andrews Arlyn , Montzka Stephen , Dlugokencky Ed , Miller Scot , Ibarra-Espinosa Sergio , Sweeney Colm , Bruwhiler Lori , Miles Natasha , Davis Kenneth
Published: February 2023

Methane is a major greenhouse gas (GHG) that has contributed to one third of the warming induced by all GHGs since the preindustrial era (IPCC, 2021).  Reliable quantification of methane emissions is critical for tracking progress towards methane mitigation, especially for the countries that join the Global Methane Pledge and that have firm plans for reducing methane emissions over the next decades, such as the US.  In this study, we quantified US methane emissions using inverse modeling of ground- and airborne- methane measurements made from the NOAA Greenhouse Gas Reference Network for 2007 – 2021. We conducted 12 inversion runs using two high-resolution transport models (HYSPLIT-NAMs and WRF-STILT), three background estimates, and two prior emission fields.  Multiple estimates of wetland emissions were considered and subtracted from our inversion-derived total emission estimates.  Our derived anthropogenic emissions show a consistent increasing trend after 2015 across our inversion ensemble members and a seasonal cycle in emission magnitude that repeats every year during our study period.  Both the trend and seasonal variation seem to correlate with US natural gas consumption.  A similar seasonal variability has been reported previously, but only on an urban scale; this is the first time it has been derived on a national scale.  Furthermore, we also compared our estimates with US EPA’s national GHG inventory reporting and investigated the impact of the COVID-19 pandemic on emissions in 2020 relative to 2019 and 2021.    
Exploring the feasibility of seismic monitoring using ambient noise coda Q: Experiments in the Aegean (Greece)
Authors: Ranjan Pratul , Stehly Laurent , Delouche Estelle
Published: February 2023

Ambient noise cross-correlations or auto-correlations provide near real-time information about subsurface properties. Changes in the Green’s function obtained from auto-correlations/cross-correlations inform us about velocity changes in the medium (dv/v). Numerous studies have found good correlation between dv/v and medium changes related to a large earthquake, volcanic activity, or even seasonal changes at shallow depths. Another seismic parameter which helps estimate such medium changes is the rate of decay of coda waves or the coda Quality factor (Qc). Low Qc estimates from earthquake data has been shown to represent cracks/fracture as well as fluid migration. Application of ambient noise data for Qc estimation are relatively recent (past 5 years), especially in the Alps and Japan, where good correlation was found with the regional geology. Qc measurements using ambient noise data can ensure continuous monitoring unlike those from earthquakes. In this work, we evaluate the feasibility of monitoring medium changes with Qc by using ambient noise data from Greece. We perform autocorrelation of noise data from the permanent network in Greece over a period of 2010-2021. Preliminary analysis shows a seasonal pattern in Qc at several stations when considering short period bands, which is likely related to seasonal changes at shallow depths due to precipitation. Stations with clear seasonal pattern in the dv/v are correlated with the seasonal pattern in Qc, which confirms that Qc perturbations indeed represent physical changes. Stations which show weak seasonality in dv/v have a seasonality pattern in Qc with a lag of similar number of days. These results suggest than Qc based monitoring has the potential to act as a supplementary data set to dv/v and may even provide more information about the nature of medium change based on whether Qc is related to scattering or intrinsic attenuation. 
Daisy chain method applied to mapping the asthenosphere
Authors: Cathles Lawrence , Fjeldskaar Willy , Amantov Aleksey
Published: February 2023

The discovery of very rapid uplift rates under areas recently de-glaciated and the realization that such rapid uplift can stabilize ice sheets has generated interest in determining the properties of the asthenosphere.  The asthenosphere is also important to plate tectonics, and to the proper interpretation many important Earth observations.  The current approach to determining the properties of the asthenosphere is to calculate the observed rate of uplift in an area for a great many deglaciation and earth models, calculate the difference between the observed and calculated uplift rates and histories, and find the earth model (with error bars) that best matches the observations.  A faster, simpler, and in some ways better assessment method is to compute the isostatic adjustment response to a loading history consisting of linear segments.  This method determines the central response time from the dimensions of the load, the loading history, the lithosphere flexural rigidity (often not important), and the present rate of uplift.  The last can be easily measured today with GPS in INSAR.  Asthenosphere properties are indicated by the central response time so determined. The Daisy chain method will be described, evaluated against data and conventional modeling in northern Norway, and then applied to infer asthenosphere properties in a number recently-deglaciated continental localities.
Quantitative estimation of fresh submarine groundwater discharge in Jeju island using geographic information system
Authors: Kim Il Hwan , Chang Sunwoo
Published: February 2023

Water use in island is mostly dependent on groundwater. Saltwater intrusion has occurred in aquifers in island, and available freshwater is decreasing. Sea level rise due to the climate crisis is increasing the range of saltwater intrusion in coastal aquifers. Saltwater intrusion is driven by complex mechanisms in coastal aquifers, including sea level rise, decrease of fresh submarine groundwater discharge (FSGD) and pumping from coastal aquifers, and geologic properties of coastal aquifers. FSGD from coastal aquifers, coupled with sea level rise, has a significant impact on saltwater intrusion and can reduce the amount of available water resources. Previous FSGD studies have focused on local areas where a large amount of discharge is observed. The existence of FSGD was diagnosed or estimated through various approaches such as field observation, isotope tracking, and water balance analysis. In this study, quantitative analysis of FSGD was performed using the freshwater-saltwater interface estimation formula of coastal aquifers. The location of the freshwater-saltwater interface was calculated using the Ghyben-Herzberg (G-H) equation, and the freshwater above the interface was estimated by FSGD. The geographic information system (GIS) was used to estimate FSGD using observation data over a large area. It was used to interpolate the observation data in a large area in grid units, and the Inverse Distance Weight method was used as the interpolation method. The interpolated data was used to input data for estimating FSGD. The study area was Jeju Island, the largest island in Korea. Quantitative estimation of FSGD can be used as a scientific basis for establishing water resource management plans in island.AcknowledgementResearch for this paper was carried out under the KICT Research Program (project no.20220275-001, Development of coastal groundwater management solution) funded by the Ministry of Science and ICT. 
Impact of social networks on fertilizer use efficiency of kiwifruit production in China- Mediator effectof green fertilization technologies adoption
Authors: Chang Fangyuan , Wang Yu , Liu Li , Liu Jundi , Bai Xiuguang
Published: February 2023

Improving the fertilizer use efficiency (FUE) is an effective way and key factor point to achieve reduce negative the growth usage of fertilizer and reduce surface non-point source pollution in agriculture production in China. Existing research related to the influencing factors of fertilizer use efficiency ignores the impact of famers’ social networks, which can affect the fertilizer use and then its efficiency. This paper analyzed the impact of social networks on fertilizer use efficiency and the mediator effect of green fertilization technology adoption, based on the measurement of farmers' fertilizer use efficiency using stochastic frontier method with a household survey of 569 farmers in Shaanxi of China, which was conducted in 2021. The results shows that the fertilizer use efficiency of kiwifruit production had a low FUE, with an average value of 0.333, which means fertilizer input had a 66.7% reduction potential without the reduction of output. Social network had a significant positive impact on FUE, in which social network trust and learning had a greater impact on FUE. Farmers’ adoption of green fertilization technology played a positive mediator effect in the process of social networks influencing their fertilizer use efficiency, which was mainly promoted by social network trust and learning.Household characteristics such as age, gender, education level and years of agricultural production,farm characteristics such as cultivation scale, number of laborers and whether they join cooperatives, and village characteristics such as the number of village agricultural supply points all have significant effects on FUE.
Assessment of 1-dimensional marine ecosystem model in reproducing the seasonal patterns in the Yellow Sea Large Marine Ecosystem
Authors: Kwon Young Shin , Kang Hyoun-woo , Choi Dong Han , Noh Jae Hoon , Lee Yeonjung , Seo Ok Hee
Published: February 2023

The large marine ecosystems (LMEs) are described as regional units for the marine research, monitoring, and management. The Yellow Sea (YS), located between Korean Peninsula and continental North China, is known as one of the most important LMEs in the world due to its high biodiversity and complex food web dynamics. Yellow Sea Cold Water Mass (also called YSCWM) formed by the remnant of winter cold water (<~11 °C) in the central Yellow Sea remains throughout the summer, which is a striking hydrological phenomenon in the Yellow Sea and has important effects on the marine ecosystem. Against this background, we undertook a modelling study as a part of a research program of Korea Institute of Ocean Science and Technology (KIOST) to improve the understanding of the ecosystem structure and function and the physical-biological processes in the YS and to predict changes in the the fishery resources under future climate change scenarios. First of all, we applied the 1-dimensional marine ecosystem model (ERSEM-GOTM) to the station (35°N, 124°E) near the central YS affected by the YSCWM. Some inconsistencies between the model and the observations were founded: For examples, while primary production and bacteria carbon mass were overestimated in the model, the zooplankton carbon mass remaining high even after summer season were not represented, which shows clearly the need for model improvements to better capture the cycling of the YS biogeochemistry. Here we present the evaluation of the main aspects of the model behavior and discuss how we optimize the model performance for proper representation of the YS system.
Towards mechanistic representation of wildfire effects on soil – downscaling to quantify subsurface heat fluxes
Authors: Or Dani , Vahdat-Aboueshagh Hamid , Furtak-Cole Eden , A. McKenna Sean
Published: February 2023

Advances in wildfire modeling have focused on refining atmospheric interactions for obvious links between local airflows, combustion dynamics, fire line advance and smoke plume transport. Yet, lasting impacts of wildfires on landscapes are linked primarily with changes in soil characteristics and alteration of ecological and hydrologic processes. Quantitative assessment of wildfire impacts requires metrics for fire-surface thermal interactions beyond qualitative surrogates such as burn severity used for ecological assessment. The highly transient and localized nature of wildfire intensity and its coarse spatial and temporal representation hinder quantitative translation of wildfire dynamics to soil heat fluxes even with the most advanced wildfire models (e.g., QuicFire, WRF-Fire, WFDS). Inspired by the pioneering works of Byram, Rothermel and Albini, we seek to derive high resolution information on fire line intensities from highly resolved fuel maps informed by fire line dynamics derived from numerical wildfire model representation. This hybrid downscaling approach (limited by the quality and resolution of fuel maps) offers a means for constraining soil surface heat fluxes at resolutions relevant to quantifying critical temperatures and duration at depth to estimate pyrolysis of soil organic carbon and the degree of soil structure alteration. Examples will be presented and discussed. 
Subsurface evidence for potentially seismogenic structures in the offshore Grand Banks region of Newfoundland, eastern Canada: present-day reactivation of inherited passive margin structures
Authors: Rimando Jeremy , Alexander Peace , Guna Ai Gusti , Goda Katsuichiro
Published: February 2023

Earthquakes in the offshore Grand Banks region of Newfoundland pose a risk to lives and property in nearby coastal communities and to crucial commercial infrastructure and operations in offshore areas. The 1929 M7.2 Grand Banks earthquake, which was associated with a tsunamigenic landslide, devastated the coastal communities in southern Newfoundland and ruptured several trans-Atlantic telecommunications cables. Despite this event, we still know little about the structural setting and neotectonics of the area. In this study, we identified potentially active tectonic structures, and associated secondary deformation features, affecting the youngest strata and the seabed in this region through the interpretation of offshore two-dimensional (2D) seismic reflection profiles. Analysis of these profiles also allowed us to interpret the relationship of the younger, potentially seismogenic structures to inherited passive margin structures at depth. Our findings on the locations and geometries of potentially active faults can be utilized as a basis for seismic hazard inputs for the modelling of earthquake scenarios, which are useful for estimating the potential impacts of the rupture of faults/fault segments on certain populations and assets.
OBSPicker: A generalized transfer-learned OBS phase picker
Authors: Niksejel Alireza , Zhang Miao
Published: February 2023

Offshore earthquakes recorded by Ocean Bottom Seismometers (OBS) are crucial to studying tectonic activities in the subduction zones and mid-ocean ridges. In recent years, the ever-advancing Machine Learning (ML)-based phase pickers have shown promise in land earthquake monitoring, but there are few available ML models to handle OBS data due mainly to the lack of labelled training sets and low signal-to-noise ratios. Though land ML-based phase pickers may roughly work for OBS data, they introduce a large number of false negatives and false positives, leading to numerous events being missing and fake.In this study, we create a tectonically inclusive OBS training data set and develop a generalized deep-learning OBS phase picker - OBSPicker using the EQTransformer (EQT; Mousavi et al., 2019) and the transfer learning approach. To create an inclusive OBS training data set, we collect earthquake waveforms from routine catalogues recorded at 11 OBS networks worldwide with different tectonic settings and geographic locations. Earthquakes are recorded in local and regional distances with diverse magnitudes (ML 0.0-5.8), source depths (0-250 km), and epicentral distances (0-3 deg). To label their phase picks, we adopt a sequence of processing steps including 1) initial phase arrival detection and picking by EQT, 2) identifying and discarding samples with multiple (unwanted) events using STA/LTA method, and 3) refining phase picks using the Generalized Phase Detection method (GPD, Ross et al., 2018), resulting in ~38,000 well-labelled earthquake samples. In addition, we also collect ~150,000 OBS noise samples from the same OBS networks for training augmentation instead of using the commonly adopted Gaussian noises. Those OBS noise samples are used to simulate low-magnitude earthquakes under different marine environments. Initial results show that our transfer-learned OBS phase picker outperforms the EQTransformer base model in both accuracy and precision, especially in presence of higher levels of noise.
Ancient scars and rotating ribbons: how Appalachian-Caledonian orogenic inheritance seeded the rotations of the Flemish Cap and the Porcupine Bank during the Mesozoic rifting of the North Atlantic Ocean
Authors: Welford J. Kim , King Michael T. , Yang Pei
Published: February 2023

The rifted continental margins of the modern Atlantic Ocean, spanning from pole to pole, encompass the full gamut of margin types and structural styles, with the Newfoundland-Iberia margins arguably having received the greatest amount of scientific scrutiny and attention. Still, the most interesting segment of the Atlantic appears to correspond to the Newfoundland-Galician conjugates and the Newfoundland-Irish Atlantic conjugates, where classic passive margin templates are suddenly replaced by failed rifts and numerous continental ribbons, still tethered to their continents (e.g., Flemish Cap and Porcupine Bank). This region of increased complexity corresponds exactly with the intersection of the Mesozoic rift with pre-existing, and obliquely-oriented, scars from the Paleozoic Appalachian-Caledonian Orogen, providing a world-class laboratory for investigating the influence of inheritance on rifting.
A recently published numerical modelling study, simulating the interaction of propagating rifts, revealed that such rifts, when laterally offset by approximately 400 km, can successfully generate and rotate continental ribbons away from their respective rifted continental margins. In particular, that study provided a compelling mechanism to explain the rotation of the Flemish Cap. In this work, we argue for the broader extrapolation of those modelling results to explain the rotations of both the Flemish Cap, offshore Newfoundland, and the Porcupine Bank, offshore Ireland, with the first rift corresponding to the northward propagating Atlantic rift and the second apparent rift corresponding to reactivated Appalachian-Caledonian scars. Consistent with the numerical modelling results, this conceptual rifting model results in failed rifts both within the Orphan Basin, offshore Newfoundland, and within the Porcupine Basin, offshore Ireland, with those failed rift features supported by numerous complementary geophysical studies. Future numerical modelling efforts will be dedicated to testing this relatively simple model of rift-inheritance interactions for the southern North Atlantic to confirm that they are sufficient to explain the observed complexity of margin structures between offshore Newfoundland and its conjugates.
The importance of salt fingers in diapycnal mixing parametrization in Eastern Boundary Systems: Study Case in the Oxygen Minimum Zone off Central Chile
Authors: Pinto Mauro , Pizarro Oscar , Rodriguez Ángel , Valencia Luis , Ulloa Osvaldo
Published: February 2023

Recent studies have highlighted the importance of double diffusion instabilities in the diapycnal transport of dissolved substances in large regions of the oceans. Off central Chile (30-38°S), waters with very low dissolved oxygen are present at intermediate depths (between 50 m and 400 m depth) in a region where double diffusion instabilities can take place. This oxygen minimum layer (OML) is closely related to Equatorial Subsurface Waters (ESSW), a relatively salty and warm water mass that is transported poleward along the continental slope by the Peru-Chile Undercurrent (PCUC). Thus, this water mass –and so the OML– is delimited between two water masses of southern origin that are well-ventilated, relatively fresh, and cold, namely: the Eastern South Pacific Intermediate Water (ESPIW) and the Antarctic Intermediate Water (AAIW). In this study, we analyzed the role of diapycnal mixing in the dissolved oxygen fluxes in the upper and lower oxyclines that delimit the OMZ in the water column off central Chile (~36.5°S). Special emphasis is given to the evaluation of the contribution of salt fingers to these fluxes. We use a set of observations of fine structure (1-10 m) and microstructure (<1m) using CTD casts and a vertical microstructure turbulence profiler (VMP-250), respectively, along with current profiles obtained with ADCPs. The net diapycnal mixing is estimated using mixing models that allow us to separate the relative contributions of turbulent shear processes and instabilities associated with salt fingers. The thermohaline contrast in the ESSW-AAIW transition conditions the region for the development of double diffusion instabilities by salt fingers, which significantly contribute to the oxygen transport from the lower oxycline, thus favoring the ventilation of the OMZ from the AAIW.
Microphysical modeling of water ice aerosols in the ice giant atmospheres
Authors: Barth Erika L. , McGouldrick Kevin
Published: February 2023

The temperature regimes and observed species abundances indicate that water should condense in the stratospheres of each of the giant planets. Water reaches its condensation temperature at higher altitudes than hydrocarbon photochemical products, and water ice particles could then act as condensation nuclei for hydrocarbons deeper in the lower stratosphere. This is especially true for Uranus, where sluggish atmospheric mixing confines hydrocarbons to relatively low altitudes. Additionally, water ice particles could explain the high-altitude hazes seen in high-phase angle Voyager 2 images of Neptune. Using PlanetCARMA  - an aerosol microphysics model which simulates nucleation, condensation, evaporation, coagulation, and vertical transport in a column of atmosphere – we will describe particle number density profiles and size distributions of water ice particles in the atmospheres of Uranus and Neptune. Sensitivity tests include (1) nucleation – homogeneous vs. heterogeneous (including varying size, abundance, and contact parameter for the cloud condensation nuclei); (2) Vapor pressure equation; (3) water abundance and flux; and (4) degree to which physical processes are important, such as coagulation, condensation, and evaporation. Understanding the role of water ice in the ice giant atmospheres is important to further our understanding of the observed stratospheric hazes as well as the more optically thick methane clouds seen in the troposphere.
A geodynamic framework for 2 billion years of tectonic evolution: From cratonic amalgamation to the age of supercontinent cycle
Authors: Li Zheng-Xiang , Liu Yebo , Ernst Richard
Published: February 2023

An advanced understanding of how tectonic plates have moved since deep time is essential for understanding how Earth’s geodynamic system has evolved and interacted with the plate tectonic system, i.e., the longstanding question of what “drives” plate tectonics. In this work, we take advantage of the rapidly improving database and knowledge about the Precambrian world, and the conceptual breakthroughs both regarding the presence of a supercontinent cycle and possible dynamic coupling between the supercontinent cycle and mantle dynamics, to establish a full-plate global reconstruction back to 2000 Ma. We utilise a variety of global geotectonic databases to constrain our reconstruction, and use palaeomagnetically recorded true polar wander events and global plume records to help evaluate competing geodynamic models regarding the origin and evolution of first-order mantle structures, and provide new constraints on the absolute longitude of continents and supercontinents. After revising the configuration and life span of both supercontinents Nuna (1600–1300 Ma) and Rodinia (900–720 Ma), we present here a 2000–540 Ma animation featuring the rapid assembly of large cratons and supercratons (or megacontinents) between 2000 Ma and 1800 Ma after billion years of dominance by many small cratons, that kick started the ensuing Nuna and Rodinia supercontinent cycles and the emergence of hemisphere-scale (long-wavelength) degree-1/degree-2 mantle structures. We further use the geodynamically-defined type-1 and type-2 inertia interchange true polar wander (IITPW) events, which likely occurred during Nuna (type-1) and Rodinia (type-2) times as shown by the palaeomagnetic record, to argue that Nuna assembled at about the same longitude as the latest supercontinent Pangea (320–170 Ma), whereas Rodinia formed through introversion assembly over the legacy Nuna subduction girdle either ca. 90° to the west (our preferred model) or to the east before the migrated subduction girdle surround it generated its own degree-2 mantle structure. Our interpretation is broadly consistent with the global LIP record. Using TPW and LIP observations and geodynamic model predictions, we further argue that the Phanerozoic supercontinent Pangaea assembled through extroversion on a legacy Rodinia subduction girdle with a geographic centre at around 0°E longitude before the formation of its own degree-2 mantle structure, the legacy of which is still present in present-day mantle.   
Ecogeomorphological assessment of a mangrove wetland in the Pacific Islands
Authors: Jorquera Eliana , Saco Patricia , Verdon-Kidd Danielle , Rodriguez Jose
Published: February 2023

Coastal mangroves are essential areas for the habitat of coastal and marine ecosystems, which are under constant anthropogenic and climatic pressure. Sediment and biological accretion can attenuate the effects of sea-level rise by rising the ground level. The balance between the soil accretion and the sea-level rise under climate change conditions will determine the response of the mangrove and its adaptation/survival.This contribution presents the ecogeomorphological assessment of the Dreketi river wetland (northern coast of Vanua Levu - Republic of Fiji). This mangrove wetland belongs to the central area of the Great Sea Reef, which was declared as Ramsar site in 2018. The Dreketi river catchment is the main contributor of water and sediments to the wetland. The amount of water and sediments generated in the catchment were determined using a hydro-sedimentological, physically based watershed scale model (SWAT). Then, the response of the Dreketi mangrove wetland to sea-level rise and climate change was analysed using an eco-geomorphological (EGM) model.The hydro-sedimentological model proved to be suitable to represent the sediment concentration in the Dreketi river catchment with a good performance against sediment concentrations obtained using remote sensing products. The EGM was able to represent the spatial distribution of suitable areas for mangrove habitats, given the current conditions. Under sea-level rise events, after 100 years, a significant amount of the suitable area could disappear for a sea-level rise. The model showed the profound effect that sea-level rise and sediment accretion have on the wetland's future evolution, highlighting the importance of the sediment input from the contributor catchment.
The tropical response to a collapse of the Atlantic Meridional Overturning Circulation
Authors: DiNezio Pedro
Published: February 2023

A collapse of the Atlantic Meridional Overturning Circulation (AMOC) could drive widespread changes in tropical rainfall, but the underlying physical mechanisms are poorly understood. Numerical simulations validated against hydroclimate changes during Heinrich Stadial 1(HS1) – the most recent, best-documented AMOC collapse – show a global response driven by cooling over the tropical North Atlantic. This pattern of ocean cooling is key to link changes in rainfall across the tropics with the reductions in AMOC strength. Cooling over the tropical North Atlantic drives changes over the Pacific and Indian oceans that uniquely explain the paleoclimatic evidence. A similar response is active in simulations of future greenhouse warming, but model disagreement regarding the pattern of AMOC-induced tropical cooling produces divergent rainfall predictions across the tropics. Models with responses consistent with the paleodata predict more pronounced rainfall reductions across the tropics, revealing a heightened risk of drought over vulnerable societies and ecosystems worldwide.
Turbulent Fluxes Within and Above the Amazon Roughness Sublayer
Authors: Dias-Junior Cléo Quaresma , Dias Nelson , Acevedo Otávio , Mortarini Luca , Brondani Daiane , Oliveira Pablo , Araújo Alessandro , Oliveira Leonardo , Ferreira Rosaria , Acosta Ricardo , Takeshi Bruno , Quesada Carlos Alberto
Published: February 2023

For tropical forests, such as the Amazon Forest, the turbulence intensity at the forest-atmosphere interface is high since in this region there is strong convective activity during the day and the aerodynamic roughness of the forest canopy is high. Heat and other scalar properties are exchanged between the flow and the canopy. Understanding these exchange mechanisms is essential for a variety of applications in various fields of science. Furthermore, it is known that the Amazon region has a strong influence on the transport of heat and water vapor to regions located at higher latitudes and plays an important role in the carbon cycle. Measurements carried out in micrometeorological towers are crucial for the correct quantifications of the turbulent fluxes. However, the use of micrometeorological towers in the Amazon is recent. High frequency measurements (eg Eddy covariance systems) in the Amazon rainforest were usually performed at a single point, often above the forest canopy. The first analyses from the fast response data clearly showed the existence of what is now known as the roughness sublayer (RSL). In these works, it was speculated that the surface boundary layer, was higher up. Within Amazonian RSL, important discoveries have already been made, for example: (i) the Monin-Obuhkov similarity functions are not the most appropriate for estimating turbulent fluxes in the region immediately above the forest canopy. (ii) The Amazonian nocturnal boundary layer is often populated by submeso phenomena, which create episodes of intermittent turbulence and increase the complexity of exchange processes between the forest and the atmosphere during the night. (iii) Above the Amazonian RSL, it was possible to verify that there is no evidence of a classic inertial layer. Since July 2021, the ATTO (Amazon Tall Tower Observatory) tower has been performing continuous measurements, carried out by nineteen 3D-sonic installed from 5 m (inside the forest canopy) to 316 m (above the RSL). Therefore, in this work we will show the profiles of different turbulent fluxes measured since mid-2021 under different stability conditions and at different periods of the year (dry and rainy season). These new measurement profiles, with high vertical resolution, are unique and they will allow us to understand the turbulent exchange processes in regions of the Amazon planetary boundary layer that have not been previously explored.    
A Study on the Bedload Discharge Estimation using CNN
Authors: Jung Minjin , Jun Kyewon , Kim Sunguk , Jang Changdeok
Published: February 2023

Localized torrential rain, which has recently increased in frequency due to abnormal climate, accelerates erosion in the river basin and increases sediment transport into the river. The movement of inflowed sediment is one of the most important factors in the development and management of water resources.Among the mechanisms of sediment transport in rivers, bedload has limitations in direct measurement due to the risk it poses and inaccuracy in the existing measurement methods. Measurement equipment based on new concepts is continuously being developed to overcome these limitations. A representative equipment is a pipe hydrophone, which indirectly measures the bedload discharge by collecting and analyzing acoustic data when soil collides with a metal tube with a built-in microphone.To estimate the bedload discharge, this study acquired data through indoor experiment and applied them to the learning process of the Convolutional Neural Networks(CNN). First, an indoor hydraulic experiment device was built with a pipe hydrophone installed at the bottom of the water outlet of the indoor waterway. Then, a system for analyzing and displaying graphs for the impact sound of bedload, and data acquisition storage programs therein, was established. Finally, learning for bedload discharge estimation was conducted using CNN, and the accuracy of the estimation was reviewed.As a result, the F1-score for the accuracy of bedload discharge estimation was 61%, and the accuracy was higher when bedload discharge was 3kg and 10kg, compared to other weight ranges. Considering that the accuracy of 61% is an insufficient level to completely trust the estimated result, more efficient measurement would be possible by combining this method with the previously developed measurement methods in a complementary manner. In future studies, additional experimental data under various conditions will be secured and applied, to increase the accuracy of bedload discharge estimation. "This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(C20017370001)"
Development of Guidelines on the Application of Urban Flood Sensors
Authors: Kim Sunguk , Jun Kyewon , Jung Minjin
Published: February 2023

In recent years, the frequency and intensity of localized torrential rains in Korea have increased due to climate change, thereby increasing human and property damage through frequent urban flooding. Research on urban flood forecasting is mainly focused on numerical modeling and rainfall-based flood prediction, but the analysis technology of quantitative flood measurement data is lacking. In addition to flood mapping and verification of flood prediction results, it is necessary to develop urban flood management technologies using sensor-based quantitative flood depth measurements. The existing flood sensors have different management regulations depending on the development entities, and there are no set standard or basic performance standards, causing inefficiency in their budget and maintenance. Therefore, in order to improve the efficiency and prevent trial and error, this study proposes the performance standards and installation methods as guidelines, necessary for the installation and operation of flood sensors. To this end, firstly, domestic and foreign cases for urban flood sensors were reviewed for their installation procedures, installation location selection, measurement intervals, inspection and management plans, etc. The table of contents of the guidelines was derived through case analysis, consisting of a standard model installation plan that describes the detailed composition and operation principle of flood sensors, sensor installation plans for each measurement point such as the surface and sub-surface, on-site installation procedures, and instructions on a test run. These guidelines are expected to be followed to strengthen a proactive urban flood response system by effectively operating flood sensors. Acknowledgment: This research was support by a (2022-MOIS63-002) of Cooperative Research Method and Safety Management Technology in National Disaster funded by Ministry of Interior and Safety(MOIS, Korea).
Disentangling the influence of vegetation structure and physiology on land-atmosphere coupling
Authors: Li Wantong , Migliavacca Mirco , Konings Alexandra G. , Duveiller Gregory , Reichstein Markus , Orth René
Published: February 2023

Terrestrial vegetation is a key component of the Earth system as it mediates the exchange of carbon, water and energy between the land and the atmosphere. Thereby, the vegetation affects the climate through changes in its structure (such as leaf area index, LAI) and its physiology (such as stomatal conductance); However, their relative contributions and respective processes on the land-atmosphere coupling are not yet understood. For instance, increased LAI, referred to as structural changes, promotes transpiration and vegetation productivity, and increases the surface albedo in most cases. In contrast, decreased surface conductance, referred to as physiological changes, could reduce transpiration and productivity. Therefore, the overall feedback of vegetation to climate change via water, carbon and energy exchange will depend on the relative importance of structural and physiological responses. Here we study to what extent dynamic changes in global vegetation structure and physiology modulate land-atmosphere coupling using satellite remote-sensing, data-driven, and earth system modelled vegetation data, as well ashydro-meteorological reanalysis. The land-atmosphere coupling is quantified through the correlation between soil moisture and lagged vapor pressure deficit determined with a moving time window. We employ random forests to quantify vegetation physiology by accounting for functional variability (e.g. GPP and ET) explained by hydro-meteorological data but not by the vegetation structure. Then using an explainable machine learning approach (SHAP), we determine the contributions of vegetation structure and physiology where we find overall larger contributions of structure on regulating land-atmosphere coupling during the growing season. The relative importance of vegetation structure differs across ecosystems, with stronger contributions in dry ecosystems. Furthermore, we analyze the variations of the relevance of vegetation structure over time and in particular during warm and dry periods. The results are partially backed up by using in-situ measurements of physiological traits to interpret the large-scale observed physiological patterns.
The value of distributed snow cover and soil moisture data for multi-objective calibration of a conceptual hydrologic model
Authors: Tong Rui , Parajka Juraj , Tian Fuqiang , Széles Borbála , Greimeister-Pfeil Isabella , Vreugdenhil Mariette , Komma Jürgen , Blöschl Günter
Published: February 2023

The latest advances and availability of satellite observations have great potential for improving hydrological model simulations of the water cycle. The recent study by Tong et al. (2021) showed that satellite observations of snow cover and soil moisture could improve river runoff simulations of conceptual hydrologic models with lumped model parameters. Still, the value and potential of spatial patterns of satellite observations for hydrologic model parametrization need to be better understood. This study aims to evaluate and compare different multiple-objective calibration strategies that use model inputs and satellite observations for the model calibration in lumped, spatially distributed and stepwise ways. We aim to test the potential of daily MODIS (Moderate Resolution Imaging Spectroradiometer) snow cover and ASCAT (Advanced Scatterometer) soil water index images observed over 204 Austrian catchments in 2000-2014. Results show that stepwise calibration strategies that first calibrate the snow model parameters to satellite snow cover data followed by calibrating the remaining model parameters outperform (particularly in lowlands) the classical calibration strategies estimating model parameters in one single calibration step. The use of distributed snow cover and soil moisture patterns in model calibration improves the snow and soil moisture simulation performance of the model. The use of MODIS snow cover data has a more significant contribution to the overall improvement in model performance than ASCAT soil moisture data. References:Tong, R., Parajka, J., Salentinig, A., Pfeil, I., Komma, J., Széles, B., Kubáň, M., Valent, P., Vreugdenhil, M., Wagner, W., and Blöschl, G.: The value of ASCAT soil moisture and MODIS snow cover data for calibrating a conceptual hydrologic model, Hydrol. Earth Syst. Sci., 25, 1389-1410, 10.5194/hess-25-1389-2021, 2021.