bluuebunny/crossref_metadata_2025 huggingface dataset:
Was the active Taiwan orogen one million years ago as high as today?
Authors: Wu Chun-Ran , Li Fang-Yu , Hsieh Meng-Long , Peng Kuan-Cheng
Published: March 2024

Tectonic uplift drives erosion which limits the height of a mountain. Many scholars regard the main part of the Central Range in the Taiwan orogen, now 3000 – 4000 m in elevation, as a paradigm that erosion dominated by river/hillslope processes for millions of years can offset active tectonics by which the mountain range has obtained the topographic steady state. Our observations, however, challenge this belief: (1) the glacier/periglacial remains (cirques/U-shaped valleys with talus slopes) > 3300 m in elevation are well preserved (even showing dissolution grooves where they are made up of limestones) since the deglaciation (starting ~8 ka ago); (2) there are commonly barely eroded low-relief surfaces, capped by bamboo grass and characterized by low-gradient channels/depressions, stranding on the major drainage divide > 3000 m in elevation; (3) rivers originating from > 3000 m-high mountains commonly show prominent knickpoints (including > 100 m-high waterfalls) where flowing downward to elevations < 1000 m; (4) modern landslides and alluvial terraces (evidence of paleo-landslides) sourcing from the > 3000 m-high mountains are far less than those in the mid-elevation regions which typically originated from the sides of hillslopes. The combination of these data points out the relatively slow erosion in the > 3000 m-high mountain areas, although they are undergoing the rapidest tectonic uplift (based on GPS and leveling surveys). We attribute this apparent hillslope stability to the rarity of large earthquakes in the high mountains (as the major seismogenic faults are all distributed around the orogen). It is noted that incised low-relief surfaces similar to those exhibited in the high mountains are widely distributed in the lower parts of the orogen down to hilly regions. This configuration suggests that the low-relief landforms now preserved in the high mountains were originally created in the low-elevation regions when both river incision and tectonic rates were low; they were then uplifted (while dissected and eroded) to their present elevations, apparently associated with the acceleration of river incision and tectonic uplift (perhaps starting as late as 0.5 Ma). We consider that when the low-relief surfaces were raised to > 3000 m in elevation, they facilitated snow accumulation and thus, glaciation (i.e., all the glacier landforms preserved are inherited from the preexisting low-relief surfaces). In sum, we propose the elevation of the Central Range has been increasing with the acceleration of tectonic uplift since < 1 Ma ago, and it is the glacial erosion that could balance the tectonic uplift in the future. (Keywords: River incision; landslides: glacial erosion; topographic steady state; the Taiwan orogen)
Fires history and the human impact during the mid-late Holocene in the mid-eastern Silk Roads
Authors: Zhang Shanjia , Dong Guanghui
Published: March 2024

The history of Holocene fire evolution and its influencing factors are hot scientific issues. The middle (Xinjiang) and eastern (Xi'an-Dunhuang) parts of the Silk Road were affected by different climatic systems, and there are obvious differences in the mode and intensity of human activities in the middle and late Holocene. Research on the history of paleo-fires in this region and their relationship with climate change and human activities has received extensive attention. Based on the analysis of black carbon in the sediments of two alpine lakes, and combining the available paleo-climatic results, archaeological and historical literature, we reconstructed the paleo-fire history of the middle and late Holocene in the  area. We revealed the relationship between paleo-fires and the changes in climate, vegetation, and human activities in different regions, and explored the differences in the patterns of paleo-fires in the study area in terms of temporal and spatial variations, and their possible driving mechanisms. The above work will help to understand the pattern and mechanism of ancient fires in the mid-eastern Silk Road on a centennial and millennial scale, which is of great theoretical value and practical significance for future fire prevention and control measures in the context of climate change, and also provides a valuable case study for understanding the impact of human activities on the environment.
Coupled atmosphere-sea-ice-ocean feedback accelerates rapid sea ice decline in Weddell Sea in high-resolution global climate model
Authors: Kim Dae-Won , Jung Thomas , Puthiyaveettil Navajyoth , Park Wonsun , Semmler Tido , Timmermann Axel , Zapponini Martina
Published: March 2024

Sea ice extent around the Antarctic exhibits a high level of variability on interannual and longer timescales, characterized by a positive trend since the satellite era and interruptions due to e.g., the emergence of the Maud Rise Polynya in 2016. Given the relatively short period of observational data and the high level of natural variability, it has remained challenging to unequivocally identify the anthropogenic fingerprint in Antarctic sea ice. Moreover, to properly study the Antarctic sea ice and its response to future warming, it is necessary to capture important dynamics, such as polynyas, the Antarctic slope current, and coastal leads. Many models within the CMIP6 model portfolio do not even have the spatial resolution to adequately resolve these features. This implies that their Antarctic projections may not be as trustworthy and robust as those for the Arctic Ocean.In this study we employ the high-resolution OpenIFS-FESOM (AWI-CM3) coupled general circulation (nominally 30 km atmosphere and 4-25 km ocean resolutions) to investigate the Antarctic sea ice response to greenhouse warming, following a SSP5-8.5 greenhouse gas emission scenario. Our simulation exhibits a sudden decline of Antarctic sea ice in the Weddell Sea (WS) which can be explained by a combination of physical processes that involve continued strengthening of westerlies, increased atmosphere-ocean momentum transfer due to sea ice decline, a spin-up of the Weddell-Sea Gyre and slope current and corresponding vertical and horizontal supply of heat into the Weddell Sea. The resulting decrease of sea ice further leads to heat accumulation in austral summer due to the absorption of short-wave radiation, which can further weaken winter sea ice extent and intensify the momentum transfer and associated heat transport into the Weddell Sea gyre.  Our study highlights the relevance of positive atmosphere-sea ice-ocean feedbacks in triggering the abrupt decline in Antarctic sea ice.  
Machine learning-based landslide susceptibility mapping for short-term risk assessment in South Korea
Authors: Lee Sujong , Roh Minwoo , Kim Uichan , Lee Woo-Kyun
Published: March 2024

Climate change impacts the frequency and intensity of extreme weather events, leading to an increase in natural disasters globally. Heavy rainfall is a notable extreme weather event, acting as an external factor for landslides. In South Korea, where approximately 70% of the terrain is mountainous, the susceptibility to landslides is high. Despite the development and implementation of landslide early warning systems by the Korea Forest Service for local governments, the extent of landslide damage has been significant, reaching approximately 2,345 hectares in the last five years. Especially, last year, landslides occurred more than 800 times with severe human costs. The current early warning system, which focuses on administrative boundaries, has limitations in accurately identifying high-vulnerability landslide areas. To address this issue, this study introduces a landslide diagnostic model designed to assess the daily susceptibility of South Korea with fine spatial resolution. The model employs a semi-automated process that encompasses the acquisition of short-term climate forecast data and the generation of daily landslide susceptibility maps. The core algorithm of the model is based on the random forest method, predicting susceptibility at a spatial resolution of 100 meters. The model integrates various feature datasets, including meteorological, topographic, and land surface data, which are closely linked to landslide occurrences. The training model utilized landslide inventory data from 2016 to 2022, with various performance indicators employed for calibration and validation. Additionally, the landslide inventory data from 2023 was utilized for final model verification. Notably, the model incorporates a 3-day climate forecast data process provided by the Korea Meteorological Administration, enabling the prediction of short-term daily landslide susceptibility. This landslide diagnostic model holds the potential to enhance landslide prevention and preparedness at both local and regional scales.
Influence of strip-irrigation on CRNS soil moisture measurements under heterogeneous soil properties
Authors: Nieberding Felix , Brogi Cosimo , Dogar Sardar Salar Saeed , Bogena Heye Reemt
Published: March 2024

In recent years, the use of Cosmic Ray Neutron Sensing (CRNS) for climate-compatible agriculture has attracted increasing attention, as it allows the soil moisture in the root zone to be determined continuously and non-invasively at field scale. However, the intrinsic integration of the neutron signal across the entire monitored field, and possibly beyond, can mask the distinct contributions from above-average dry or wet areas. This can potentially lead to biased soil moisture observations. In strip-irrigated fields, varying amounts of water are applied to different areas over the course of an irrigation cycle that, depending on field dimension and availability of machinery and water wells, can last multiple days. Hence, the neutron signal is not only affected by heterogeneities in soil properties but also by the irrigation pattern itself.To better understand the contribution of heterogeneous soils and irrigation patterns on the neutron signal, we ask the following research questions: 1) Can different irrigation events be sensed by the neutron detectors and by point-scale measurements alike? 2) How much do strip irrigation events that only affect a portion of the field contribute to the neutron signal? 3) What is the effect of soil heterogeneity on the signal contribution? 4) How sensitive does the CRNS need to be in a given environment? To answer these questions, three CRNS detectors with different sensitivities were installed across a 14 ha potato field with marked soil heterogeneity and compared to soil moisture measurements at point-scale using two different profile probes. Prior to the measurement campaign, the spatial distribution of soil characteristics was assessed using Electro-Magnetic Induction (EMI) and the measurement sites were chosen to cover the main soil types present in the field. To gain a better understanding of the effects of localized irrigation events on the neutron signal, we used the URANOS neutron transport model to simulate the movement of neutrons in the studied environment and under the observed soil moisture conditions, taking into account the soil and sensor characteristics.We found that the CRNS clearly outperformed the point-scale profile soil moisture probes, as these tend to lose contact with the soil due to erosion of the potato dams, thus leading to erroneous soil moisture measurements at all measurement sites. Despite the higher measurement accuracy of the CRNS, their sensitivity to irrigation decreased with the distance from the irrigated areas and not all irrigation events were sensed by all stations. Comparing CRNS with different measurement sensitivity, we found that using CRNS with only one proportional counting tube placed far from the center of the field was less suitable for detecting the irrigation events. On the contrary, the use of a CRNS with two proportional counter tubes placed in the center of the field provided sufficient sensitivity to adequately detect irrigation events.
VGOS – current status, challenges, and prospects
Authors: Haas Rüdiger
Published: March 2024

During the last decade, the next generation VLBI system, called the VLBI Global Observing System (VGOS), has been developed. It involves new, fast moving radio telescopes, that are equipped with dual-polarization broad-band receivers covering a broad frequency range from upper S-band to lower Ku-band. VGOS is planned to become the major VLBI contribution to the Global Geodetic Observing System (GGOS), surpassing the legacy S/X VLBI contribution by about one order of magnitude in terms of precision and accuracy of the geodetic products. While still being in its roll-out phase, VGOS started to become operational in 2020. The International VLBI Service for Geodesy and Astrometry (IVS) is now operating two VLBI networks in parallel, the legacy S/X VLBI network, and the new VGOS network. In early 2024, up to 13 VGOS stations are observing together in 24 h network sessions three times per month. These sessions are meant for the determination of the terrestrial reference frame (TRF), the earth orientation parameters (EOP), and the celestial reference frame (CRF). Additionally, several short (1 h) VGOS sessions are performed on several days each week, involving two or three VGOS stations only and focussing on the determination on earth rotation, i.e. the UT1-UTC parameter. There are several ongoing projects worldwide to establish further VGOS stations. It is expected that several of these will become operational in the near future, some even already in 2024, thus improving the geographical distribution of the VGOS network. In conjunction to an improved and densified VGOS network it is also planned to intensify the observation plan. In this presentation, the current status, challenges, and prospects of VGOS are reviewed and discussed. This includes a review of the expectations and obtained results of the geodetic parameters derived from the analysis of VGOS sessions.
Quantifying permafrost C-cycling by fusing process-models and observations 
Authors: Smallman Luke , Burke Eleanor
Published: March 2024

Globally permafrost soils store huge quantities of carbon (C) in dead organic matter (DOM). Currently, the permafrost region is estimated to be a small net C sink. However, as the climate warms permafrost soils have begun to thaw, making a massive quantity of DOM available for potential decomposition and likely shifting the region to a net source of C. Process-models of terrestrial ecosystems are a vital tool in evaluating our understanding of ecosystem function, but also in generating forecasts of C emissions under varied climate change scenarios in support of decision support. But different models contain competing hypothesise of ecosystem functioning, leading to divergent forecasts despite convergent estimates of contemporary net C emissions. These process-models also result in contrasting estimates of the internal C-cycling. We currently lack a consistent, rigorous observational constraint on ecosystem C-stocks and dynamics (particularly below ground) due to varied challenges across both in-situ and satellite-based Earth Observation (EO). Here, we present a Bayesian model-data fusion approach (CARDAMOM) which combines diverse observations of terrestrial ecosystems (e.g. leaf area, soil C, biomass, net C exchange) to calibrate an intermediate complexity model (DALEC). CARDAMOM generates a probabilistic estimates of DALEC parameters at pixel scale based on local information. Using these local calibrations, DALEC offers a probabilistic, data-constrained estimate of current ecosystem C-cycling including its internal dynamics, which can be used to evaluate large scale process-models. We evaluate process-model estimates of key ecosystem properties, e.g. DOM residence time, and their climate sensitivity. Through this process we can identify and exclude process-models which are inconsistent with data from forecast analyses.
Teaching Climate change at school: increasing sustainable minded students and communities.
Authors: Porazzi Elena , Maiolino Antonio , Martorana Maria , Marra Paola
Published: March 2024

The high school “Liceo Scientifico V. Sereni” teachers are aware of climate change impacts and aim, through their teachings, to increase students' awareness and attention towards this issue. This year students are involved in two main projects on climate change: “Green School” and “Green It Up”. The “Green School” project aims to reduce schools' environmental impact through the implementation of sustainable practices and environmental education to promote ecological awareness among students and school staff. Last year, the entire school participated led by the 4LES class; this year, the entire school is involved again, coordinated by the 2LES and 4A classes in Laveno and 4C in Luino. The main activities that engaged students included:Initial analysis of water, energy, and paper consumption; interviews with school staff and class representatives to understand any difficulties in implementing serious waste separation.
Contacts with the Municipality to highlight issues (water leaks, lack of suitable bins for waste collection).
Creation of news broadcasts to inform about proposed good practices.
Meetings with experts on various subjects: bloggers for textile impact, a lake expert on temperature rise consequences.
Designing and implementing a challenge in various classes to identify and reward the most eco-friendly class.
Designing sustainable packaging for take-away food.
This year our school participates also to "Green It Up" with two classes: 2A in Luino and 3A in Laveno. “Green It Up” is an interdisciplinary educational project addressing biodiversity loss and climate change. It engages students in understanding the causes and effects of these issues while offering practical solutions for sustainable development. Through workshops and hands-on activities, students learn about environmental and social impacts of human actions and develop their own project on biodiversity. Community involvement is crucial: the project not only educates students but also encourages their active engagement in promoting sustainable practices within the school and the community. The project's impact is twofold: it educates and empowers students as change agents. Participants become ambassadors for eco-friendly solutions, positively influencing their communities and advocating for responsible lifestyles. The aim of both projects is to move students from climate change awareness to action.
Climate prediction of the seasonal sea ice early melt onset in the Bering Sea
Authors: Tian Baoqiang , Fan Ke
Published: March 2024

The Bering Sea is a marginal sea that stretches between the Bering Strait and the Aleutian Islands to the west of Alaska, connecting the Arctic and Pacific Oceans. Sea ice in the Bering Sea is not only a crucial component of the Arctic climate system but also has significant impacts on various sectors. Based on the impact of large-scale circulation anomalies on sea ice melting, this paper develops a statistical forecasting model for the seasonal sea ice early melt onset (EMO) in the Bering Sea using the interannual increment prediction method. The prediction model considers three physically meaningful predictors: January Beaufort High (P1-H500), November sea-level pressure (P2-SLP) over Eastern Siberia, and November snow cover over the Eastern European Plain (P3-Snowc) are considered. The January Beaufort High can influence the sea surface temperature (SST) anomaly in the Bering Sea through ocean-atmosphere interactions, and this SST anomaly can persist from January to March. Subsequently, it affects the EMO in the Bering Sea. The P2-SLP exhibits a close association with the east part of mid-latitude North Pacific SST in November. The colder mid-latitude North Pacific SST anomalies, which persist from November until January and February of the following year, will be accompanied by warmer SST anomalies in the Bering Sea, which result in a decreased sea-ice extent and a later-than-usual EMO. The Arctic dipole anomaly in January is one of the ways in which the P3-Snowc affects the EMO in the following year. The predicted EMO shows good agreement with the observed EMO in the cross-validation test for 1981−2022, with a temporal correlation coefficient of 0.45, exceeding the 99% confidence level. The prediction accuracy of the prediction model for positive and negative abnormal years of EMO is 60% and 41%.
Weather and Climate conditions over the Arctic and mid-latitude regions affecting air quality
Authors: Park Jeong-Min , Lee Dasom , Kim Kwanchul , Kim Seong-min , Lee Gahye , Lee Kwon Ho
Published: March 2024

Recently, it has been noticed that weather and climate changes over the Arctic and mid-latitude regions may have influenced the particulate matter concentrations and haze over East Asia. Among the various weather and climate conditions and climate indices could be an important factor in affecting variation of particulate matter (PM) concentrations. In this study, we examined the long-term changes in the sea ice cover, soil moisture, near-surface temperature and its link with the lower atmospheric circulation over Arctic and mid-latitude from 1950 to 2022, using modern reanalysis datasets. Long-term analyses show negative trends in sea ice cover over the Arctic and positive trends in near-surface temperature and SST, implying atmospheric stagnant and variation of PM concentration. Additionally, climate indices, related to teleconnection between the Arctic region and mid-latitude, co-related with understanding air quality. Based on climate indices, we have developed the air quality prediction model for reflecting variations in weather and climate conditions. Therefore, the findings in this study can likely be used for actual prediction systems based on long-term weather measurement datasets over the Arctic region.Acknowledgment: This research was supported by a National Research Foundation of Korea Grant from the Korean Government (MSIT ; the Ministry of Science and ICT) (NRF- 2023M1A5A1090715).
First principle investigations on the water budget in olivine phases: Implications towards the behavior of hydrous mantle
Authors: Das Pratik Kumar , Karangara Anjitha
Published: March 2024

Several studies have already concluded the presence of 7-8 ocean equivalent water (OCE) in the mantle of earth, structurally occurring as H+/OH–. This can affect the seismic anomaly, mechanical strength, ionic diffusion, etc. of the mantle. The upper mantle is primarily composed of olivine, which first transforms to wadsleyite and then to ringwoodite at ~13 and ~18 GPa, respectively. Petrological and mineralogical experiments have demonstrated that H, occurring as point defects can act as a source of water in the upper mantle. Being the abundant mineral in upper mantle, it is very important to investigate the ability of olivine to act as a potential mineral phase to house water. Incorporation of water in mantle minerals has been a burning topic for many theoretical and experimental works. Even a trace amount of water in mineral structure can significantly alter their physical (e.g., elastic behaviour, seismic velocities, etc.) and chemical properties (e.g., ionic diffusion, electrical conductivity, etc.). FT-IR studies suggested that a rapid diffusion of H+ in olivine makes it a better candidate for point defects compared to larger and heavier OH– ions. Karato & Jung (2003)  showed that increment of H concentration in olivine decreases its strength. Later, Mao et al. (2008) and Panero et al. (2010) observed qualitatively similar trend in high pressure olivine polymorphs. They observed drastic reduction in selective elastic constants of C11compared to C12 and C44 as H content increases in ringwoodite. Huang et al. (2005) found that temperature and water increases electrical conductivity in both the polymorphs. Yoshino et al. (2009) reported that a hike in temperature switches H-diffusion mechanism in olivine from proton conduction to small polaron conduction. The H diffusion in Fe-bearing olivine is experimentally shown to be dictated by (i) Proton-polaron (PP) mechanism and (ii) Proton-vacancy (PV) mechanism in
Sharing Small Resources and Making Joint Efforts for the Improvement of Climate Prediction Model in South Korea
Authors: Sohn Soo-Jin
Published: March 2024

While dynamical seasonal prediction models offer many benefits, it is challenging for most National Hydrological and Meteorological Services (NMHSs) to develop and operate their own expensive models. Given the limited human and computing resources in South Korea’s modeling communities, increasing our capacity to share small resources and generate joint efforts for a better climate prediction system is thus essential. The Korean Meteorological Administration (KMA) adopted the Global Seasonal Forecasting System version 6 (GloSea6) from the United Kingdom Met Office (UKMO), and has being operated the prediction system for the real-time climate forecasting since 2022 March. The domestic and multi-institutional efforts are currently underway to advance the prediction system in collaboration with academic societies and the APEC Climate Center (APCC), which is a research partner of the KMA. By motivated by great needs for joint collaborative system between academy, research institute and organization, and NMHSs, as well as strengthened strategy of operationalization, we have once recalled the research-to-operation (R2O) process and finally invented the R2O structure customized for the dynamical prediction and modelling environments in South Korea (K-R2O). K-R2O represents technically sound and unique process from research and development to operation through testbed which individual components are carried out by different parties. The role of testbed and framework of standard verification for model development identified in K-R2O is highlighted. Lesson learned and further guidance for K-R2O are also discussed for many NMHSs facing similar situation to South Korea.
Magmatism in the Nansha Trough on the southern continental margin of the South China Sea: Recent evidence from seismic profiles
Authors: Guo Chufeng , Tang Yong
Published: March 2024

Nansha Trough, located in the southern part of Nansha Block, is an important boundary of the southern continental margin of the South China Sea, which has undergone complex tectonic superposition process, and is an important area for studying the subduction extinction of the Proto-South China Sea and the current expansion of the South China Sea. In this study, we make use of a new multi-channel seismic profile, which is almost parallel to the distribution of Nansha Trough, to systematically identify and analyze the magmatic activity in Nansha Trough for the first time, and combine the geophysical data such as gravity and magnetism to determine the attributes of seamounts in the trough. We found that all the seamounts in the trough were formed by magmatism, and underwent multiple episodes of magmatism, some of the seamounts were deposited with huge thick carbonate layers on the top. The magmatic rock mass in the trough shows different gravity and magnetic anomaly characteristics on the east and west sides, which may be related to magmatic stage, magmatic source and magmatic differentiation. Unlike the widely developed post-rift magmatism in the northern passive margin of the South China Sea, most magmatic activities in the Nansha Trough seem to ceased around 16Ma, which may be related to the dehydration and melting caused by the subduction plate rotation in the Proto-South China Sea.
Change of the locus of organic carbon burial in the aftermath of the Toarcian hyperthermal event: Patterns and drivers
Authors: Fantasia Alicia , Thibault Nicolas , Adatte Thierry , Mattioli Emanuela , Spangenberg Jorge E. , Regelous Marcel , Bodin Stéphane
Published: March 2024

Carbon cycle-climate dynamics were nonlinear through Earth’s history, driven by changes in internal and external forcing processes acting on various geological timescales. This study focuses on determining the relationship between volcanism, orbital parameters, and organic carbon burial during the Aalenian (Middle Jurassic) - a pivotal time at the dawn of the Mesozoic Marine Revolution, marked by a disruption of the carbon cycle and major climate shifts. Here, new high-resolution magnetic susceptibility and trace elements data are combined with previously published organic carbon isotopes and total organic carbon data from two sites in France and Chile. Our dataset shows for the first time a temporal coincidence between the major carbon cycle perturbation during the middle–late Aalenian and the onset of enhanced volcanic activity, suggesting a causality link. We propose that volcanic activity triggered a transient warming episode within the long-term Middle Jurassic coldhouse and played a key role in shifting organic carbon burial from the ocean to terrestrial settings. This period therefore contrasts with other Mesozoic carbon cycle perturbations, which generally record enhanced marine organic matter burial in oxygen-depleted environments during volcanism-triggered warming events.
The Impact of Compound Hot-and-Dry Events on Household Well-being
Authors: Schleypen Jessie Ruth
Published: March 2024

The socioeconomic impacts of compound extremes are sudden, severe, and multidimensional. Without precautionary measures, social and economic safety nets including community support and insurance, the negative effects of a single, short-run shock on households can extend to the long-run and persist over many years. Studies on the impacts of compound extremes have focused on objective measurements of well-being, including income, health, education; with much fewer studies on subjective well-being. Looking into subjective well-being takes an evaluative perspective on the quality of life, wherein the recovery from a disaster takes more than just the return to employment, for instance. Previous studies have shown that subjective well-being is also a good predictor of life expectancy, productivity, educational performance, and voting behaviour. Using econometric methods on sub-national, household panel data from the EU Survey of Income and Living Conditions (EU-SILC) and a composite index for the simultaneous occurrence of droughts and heatwaves, I quantify and compare the impacts of compound dry-and-hot events (CDHE) in Europe on objective and subjective measurements of well-being. The results of this study provide new information on the magnitude, as well as, the persistence of effects from CDHE, based on both the traditional income-based measurements versus the self-reported measurements of well-being.
GRACE-FO: science results, project status and further plans 
Authors: Flechtner Frank , Landerer Felix , Save Himanshu , Mccullough Christopher , Dahle Christoph , Bettadpur Srinivas , Gaston Robert , Snopek Krzysztof
Published: March 2024

The GRACE Follow-On satellite mission, a partnership between NASA (US) and GFZ (Germany), successfully completed its nominal five-year prime mission phase in May 2023, and has already entered its extended mission phase. GRACE-FO continues the unique essential climate data record of mass change in the Earth system initiated in 2002 by the GRACE mission (2002-2017). The combined GRACE & GRACE-FO data records now span over 22 years and provide foundational observations of monthly to decadal global mass changes and transports in the Earth system derived from temporal variations in the Earth’s gravity field. These observations have become indispensable for climate-related studies that enable process understanding of the evolving global water cycle, including ocean dynamics, polar ice mass changes, and near-surface and global ground water changes.In this presentation, we will present recent GRACE/GRACE-FO science and applications highlights, review key data processing and calibration approaches for GRACE-FO and lessons learned during the recent years, and discuss the GRACE-FO mission plan to operate and collect high-quality science data through the intensifying solar cycle 25, aiming for continuity with the upcoming NASA/DLR Continuation mission GRACE-C, targeted to launch in 2028.
Effects of permafrost thaw on vegetation productivity
Authors: Li Ting , Wu Xing , Fu BoJie
Published: March 2024

When the permafrost thaws, it brings changes in soil hydrothermal conditions and nutrient levels, which can influence vegetation dynamics. The impact of permafrost degradation on vegetation growth with a warming climate and rising carbon dioxide levels remains unclear. This presentation synthesizes various ground observation records, satellite data, and multi-model multi-scenario data from Phase 6 of the Coupled Model Comparison Project to drive the machine learning models to investigate the contribution of deepening active layers to vegetation productivity at different growth stages and how these changes may vary under different shared socioeconomic pathways in the Northern Hemisphere. The results show that the machine learning model effectively simulates changes in permafrost active layer in the northern hemisphere. Currently, most permafrost in the northern Hemisphere show a positive correlation between active layer thickness (ALT) and vegetation gross primary productivity (GPP), with ALT explaining 8.5%-21.5% of the variation in permafrost GPP across the region. Tundra, temperate coniferous forests, and alpine grasslands are the most impacted vegetation types as the active layer thickens due to tundra degradation. However, in the future, ALT's contribution to GPP is expected to weaken further, especially under the high emission scenario SSP585. These findings help to improve our understanding of permafrost-vegetation feedbacks under the influence of climate change and human activities, and can be leveraged for optimizing simulations of carbon cycle processes in terrestrial ecosystems.
Investigating post-glacial transient phases as hot-moments of landscape dynamics - combining numerical modelling and topographic analysis
Authors: Ariagno Coline , Steer Philippe , Valla Pierre
Published: March 2024

In steep alpine environments, the succession of glacial-interglacial cycles during the Quaternary led to multiple transient geomorphological phases. These periods are induced by an imbalance between the inherited shape of the topography and the dominant geomorphological processes. In particular, post-glacial periods are key transition phases experiencing rapid geomorphic changes, characterized by intense hillslope processes where ice and permafrost have shrunk. As landslides are the main factors controlling sediment production in steep mountain environments, we approach numerically their late-glacial to interglacial dynamics and explore the associated evolution of catchment topography across a wide range of morphological signatures (i.e. from fluvial to glacial initial topographies). Using the landscape evolution model ‘Hyland’, we quantitatively assess the response of each type of catchment to landsliding. We focus on the cumulative impact of landslides, during the post-glacial phase, on catchment slope distribution, hypsometry and produced sediment volume.  Moreover, glacial topographic inheritance seems strongly sensitive to hillslope processes with a non-homogeneous spreading of landslides over the catchments, both spatially and temporarily. Our results reveal a temporal change in slope-elevation distribution associated to a general lowering in maximum catchment elevations. On the contrary, fluvial catchments show more stable topography and less intense landslide activity. Landscape evolution models appear as a suitable tool to quantitatively explore (1) the role of different internal or external parameters (e.g., bedrock cohesion, return time of landslides), and (2) the non-linear interactions between landsliding and catchment topographic evolution, which are strongly influenced by external forcing such as climatic fluctuations in mountainous settings.
Molecular composition of secondary organic aerosol from α-pinene ozonolysis affected by relative humidity
Authors: Luo Hao , Guo Yindong , Shen Hongru , Huang Dan Dan , Zhang Yijun , Zhao Defeng
Published: March 2024

Biogenic volatile organic compounds (BVOC) can contribute a significant fraction to secondary organic aerosols (SOA) through atmospheric oxidation, which plays a critical role in climate change and human health. The ozonolysis of α-pinene, one of the most important BVOCs, is a canonical SOA system. At present, the effects of relative humidity (RH) on SOA composition from α-pinene+O3 reaction are still unclear. In this study, we report the SOA composition on molecular level formed in α-pinene+O3 reaction under various RH. The SOA components were measured by an Extractive ElectroSpray Ionization inlet coupled with a long Time-of-Flight Mass Spectrometer (EESI-TOF-MS). We observed RH-dependent SOA chemical composition, including larger contribution of monomer products with increasing RH, although the total O:C remained largely unchanged. The effect of RH may be attributed to the particle-phase reactions of SOA components. This study highlights the necessity of characterizing SOA composition on molecular level and of considering RH dependence of SOA chemical composition and physicochemical properties in atmospheric models.
How does land use change impact tropical peatland surface elevation changes? 
Authors: Murdiyarso Daniel , Saragi-Sasmito Meli F , Sasmito Sigit D , Rumbang Nyahu , Jaya Adi
Published: March 2024

Tropical peat swamp deforestation followed by extensive drainage and recurrence of fires leads to peat subsidence and subsequently carbon release to the atmosphere. While many previous studies have assessed the positive relationship between greenhouse gas (GHG) emissions and peat subsidence, an accurate field-based measurement of peat subsidence remains methodologically challenging. Between 2015 and 2020, we monitored peat subsidence (surface elevation change) in tropical peatlands of Central Kalimantan by using Rod Surface Elevation Table (RSET) installed across 22 locations representing range of land use types, including natural forest as reference. We observed that the largest net surface elevation loss was found in burned areas of -35.1 ± 87.2 mm yr-1, followed by the drained peatland sites with -11.1 ± 16.9 mm yr-1 and the agricultural impacted sites with -6.3 ± 13.1 mm yr-1. Further, we observed substantial net surface elevation loss in secondary protected forests by -12.1 ± 77.2 mm yr-1. By contrast, natural forest reference experienced net surface elevation loss as much as -8.8 ± 24.4 mm yr-1. Our findings suggest that all the study sites in the tropical peatlands of Central Kalimantan have experienced net surface elevation loss with their degree of losses vary depending on past land use and current land management.Keywords: peat subsidence, peat compaction, peat drainage, peat conversion, GHG emission
Integrated 3D Seismic Analysis of Pleistocene Tunnel Valleys and their infills in the German North Sea sector 
Authors: Breuer Sonja , Bebiolka Anke , Ehrhardt Axel , Noack Vera , Lang Jörg
Published: March 2024

Our research project is dedicated to the development of a comprehensive model for analysing the distribution, dimensions, and evolution of Pleistocene tunnel valleys and their deposits in northern Germany and adjacent areas. The primary objective is to leverage these findings to assess the likelihood of future tunnel-valley formation, with potential implications for the long-term (over the next 1 million years) safety of a radioactive waste repository.To achieve our goal, we are relying on a 3D seismic dataset. Previously, the mapping of tunnel valleys on land is primarily based on 2D seismic and boreholes, which unfortunately do not provide the required accuracy. Therefore, we have opted to utilize a marine seismic dataset. This 3D seismic dataset 'GeoBasis3D' was acquired by the BGR in 2021.The 3D seismic dataset is situated within the German Exclusive Economic Zone (EEZ) in the 'Entenschnabel' area. In this region, two intersecting tunnel valleys exist, with one located above the 'Belinda' salt dome. The interpretation of the tunnel-valley base based on the seismic data, and we will observe the influence of the crestal faults above the salt dome on the genesis and filling of the tunnel valley. The filling of the tunnel valleys will be described in terms of seismic facies. Different sedimentary processes can be interpreted from the seismic data. The deepest parts of the tunnel valley are directly filled, and the valley widens above. Some slumping can be detected along the steep slopes of the tunnel valley. Different phases of sedimentation can be observed within the tunnel valley, including both glacifluvial and glacilacustrine phases with parallel and homogenous reflectors. Since there are no available geological cores for the Quaternary in the area of the seismic surveys, we will have to rely on cores from Danish North Sea for the lithostratigraphic description of the sediments and for their chronological classification.Our aim is to analyse sediment facies to draw conclusions about the backfilling process and repeated erosion phases. This will enable us to compare the findings with the development of onshore tunnel valleys in the next step. The tunnel valleys are a type of glacial erosion that can reach depths of up to 600 meters above sea level in northern Germany. They can have an impact on the long-term safety of a repository, which is required by law to be located at a minimum depth of 300 meters below ground level.
Assessment of ARPEGE-Climat using a neural network convection parameterization based upon data from SPCAM 5
Authors: Balogh Blanka , Saint-Martin David , Geoffroy Olivier , Bhouri Mohamed Aziz , Gentine Pierre
Published: March 2024

Interfacing challenges continue to impede the implementation of neural network-based parameterizations into numerical models of the atmosphere, particularly those written in Fortran. In this study, we leverage a specialized interfacing tool to successfully implement a neural network-based parameterization for both deep and shallow convection within the General Circulation Model, ARPEGE-Climat. Our primary objective is to not only evaluate the performance of this data-driven parameterization but also assess the numerical stability of ARPEGE-Climat when coupled with a convection parameterization trained on data from a different high-resolution model, namely SPCAM 5. The performance evaluation encompasses both offline and online assessments of the data-driven parameterization within this framework. The data-driven parameterization for convection is designed using a multi-fidelity approach and is adaptable for use in a stochastic configuration. Challenges associated with this approach include ensuring consistency between variables in ARPEGE-Climat and the parameterization based on data from SPCAM 5, as well as managing disparities in geometry (e.g., horizontal and vertical resolutions), which are crucial factors affecting the intermodel parameterization transferability.
Olivine Fertilization for Carbon Dioxide Removal: Field Demonstrations and Insights in Diverse Forest Ecosystems in a Tropical Monsoon Climate
Authors: Yang Ci-Jian , Tseng Chun-Wei , Wang Chiu-Hsien , Shi Xinye , Tsui Chi-Wang
Published: March 2024

A novel geoengineering technique aims to counteract global warming caused by anthropogenic CO2 through artificially enhanced silicate weathering, achieved by the dissolution of olivine. Unlike other geoengineering concepts, CDR (carbon dioxide removal) techniques not only mitigate ocean acidification but also efficiently draw down atmospheric CO2. Models predict that we can sufficiently enhance silicate weathering enough for it to be a useful CDR strategy. The models typically rely on kinetic rate constants derived from benchtop experiments conducted under conditions far from equilibrium. Hence, empirical field demonstrations are crucial to validate the effectiveness of enhanced silicate weathering. Here, we implement additional olivine (Mg2SiO4) fertilization in three plots with the same dimensions but various forest forms, grassland, Chinese fir, and mixed woodlands. The olivine doses were equivalent to 200 tons ha-1 in this study. Combining monthly samplings of runoff chemistry with hourly runoff measurement, this study aims to delineate the chemical weathering flux. Preliminary findings reveal the concentration of Si4+,Mg2+, and Ca2+ within runoff at varying soil depths and forest forms. Specifically, in the Chinese fir plot, the concentration of Si4+ increased from 5.58 to 17.47 mg L-1 within the initial three months, subsequently diminishing to 5.54 mg L-1 after one year. Conversely, the grassland exhibited a decline from 4.20 to 2.46 mg L-1 in the same period. For mixed woodlands, Si4+ concentration elevated from 4.16 to 10.87 mg L-1 at three months, followed by a reduction to 5.54 mg/L after one year. The concentrations of Si4+ within the 30 to 85 cm depth exhibited minimal variation, fluctuating between 5–8 mg L-1. The initial concentrations of Mg2+ for the Chinese fir, grassland and mixed woodlands were 2.70, 0.19, and 1.19 mg L-1, escalating to 2.90, 1.76, and 2.14 mg L-1, respectively. Correspondingly, initial Ca2+ concentrations were 42.87, 37.13, and 24.07 mg L-1, increasing to 147.70, 49.40, and 45.58 mg L-1, subsequently declining to 21.70, 7.04, and 11.78 mg L-1. The observed trends suggest that nutrient deficiency in experimental plots prompts preferential Mg uptake by plants upon excess olivine addition, resulting in the release of Ca. These insights imply that olivine fertilization necessitates a minimum of three months and persists for at least 30 months in our case. Disparities in concentrations at different depths underscore the predominance of weathering in surface layers. While silicate weathering is more pronounced in forests compared to grasslands, excessive Mg addition may disrupt the equilibrium in plant nutrient uptake.
Leveraging renewable energy solutions for distributed urban water management: The case of sewer mining
Authors: Zisos Athanasios , Monokrousou Klio , Tsimnadis Konstantinos , Dafnos Ioannis , Dimitrou Katerina , Efstratiadis Andreas , Makropoulos Christos
Published: March 2024

As urban populations swell and infrastructure demands escalate, managing resources sustainably becomes increasingly challenging. This paper focuses on the energy challenges inherent in distributed water management systems, using sewer mining as an example. Sewer mining is a distributed water management solution involving mobile wastewater treatment units that extract and treat wastewater locally. In this context, we examine the integration of renewable energy sources, specifically solar photovoltaics, to reduce reliance on traditional power grids, highlighting a pilot implementation at the Athens Plant Nursery in Greece since 2021. The study evaluates various system configurations, balancing performance with landscape integration, to propose a scalable and robust model for distributed water management. This approach not only addresses the direct energy requirements of water treatment systems but also contributes to the broader agenda of circular economy, by enhancing the sustainability and resilience of urban water infrastructure.
This work is supported by IMPETUS research project that has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 101037084