bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlocal energy fluxes and fractional operators in updated, stochastic, Budyko-Sellers models
Authors: lebiadowski dustin , Lovejoy shaun
Published: March 2024

We introduce a stochastic, energy-balance, climate model defined over the macroweather regime (approximately 15 days or longer). Together, the energy balance principle, combined with the model’s natural scaling, demonstrate quite promising results despite the relative simplicity. A special case of the model can also be derived from a very classical basis, and, because of some similarities, we propose this model as a development upon the work of Budyko and Sellers.When the classical Budyko-Sellers energy balance model is updated by using the (correct) radiative-conductive surface boundary conditions, one obtains the Fractional Energy Balance Equation (FEBE). The FEBE involves fractional space-time operators and its generic solutions are scaling, in agreement with much atmospheric and oceanic data. In time, it implies long range memories that have been successfully used to make both multi-decadal climate projections as well as monthly and seasonal (long range) forecasts. In space, the FEBE is nonlocal so that energy flux imbalances at any location can affect the balance in locations far away. This is possible because the model operates over monthly and longer time scales; over these scales, energy can be both stored and transported in the atmosphere, ocean, and subsurface.Until now, the FEBE’s full nonlocal space-time interaction operator has been only approximated. Here, by introducing a numerical model, the nonlocal dynamics of the FEBE and corresponding Earth-system FEBE energy flows over the 2D Earth surface are fully detailed.We propose the FEBE as an alternative to more conventional, deterministic, weather-regime-based climate models. Given the generality of the ideas pursued here - the use of fractional operators; the use of stochasticity and the macroweather regime - there seems a great potential for these to be used much more widely. Hopefully this research, and possibly related works, will encourage a greater diversity of pursuits and be inspiring to others in their own work.
Sequence: A coupled sequence-stratigraphic model built using Landlab
Authors: Hutton Eric , Steckler Michael , Tucker Gregory
Published: March 2024

Landlab is an open-source Python package that streamlines the creation, combination, and reuse of 2D numerical models and is a key element of the Community Surface Dynamics Modeling System (CSDMS) Workbench. The Landlab Toolkit provides building blocks for model development such as grid data structures, input/output functions, and a library of several dozen components that each model a separate physical process. Additionally, it provides a framework for assembling integrated models from component parts. We've found that Landlab significantly accelerates model development, encourages user-developers to adopt standard practices and contribute new components to the library. It serves as a platform that nurtures a community of model developers, assisting them in creating coupled models to investigate non-linear interactions between geologic processes.Using the Landlab toolkit, we developed a new model, Sequence, which is a modular 2D (i.e., profile) sequence stratigraphic model that incorporates key geophysical processes influencing accommodation space in both terrestrial and marine environments. These factors include tectonics and faulting, eustatic sea level changes, flexural isostatic compensation of sediment and water, sediment compaction, and hypopycnal sediment plumes. Each process is encapsulated as an individual, standalone Landlab component, providing flexibility in the construction of new models. Sequence serves not only as a distinct model, but also as a scaffold for the development of new models.Sequence simulates the evolution of stratigraphy on a continental margin over time scales ranging from thousands to millions of years. Sediment transport and deposition primarily occur during infrequent, high-energy events like storms and floods. For these extended time frames, Sequence employs a scale-integral approach. This method utilizes differential equations to summarize the cumulative effect of sediment transport and deposition across different depositional environments over longer periods (e.g., on the order of a hundred years). The model features a moving-boundary formulation to track shoreline changes and partitions the domain into distinct areas: coastal plain, continental shelf, and upper and lower slope/rise. Submarine sediment transport and deposition are modeled through nonlinear diffusion, with a diffusion coefficient that varies inversely with water depth. The model tracks evolving stratigraphic layers and sediment lithology that is a mixtuer of two grain sizes (sand and mud) each with separate transport functions.
The perplexing warming trend over the Pacific Ocean and the key role of two-way teleconnections between the Southern Ocean and the tropical Pacific
Authors: Battisti David , Armour Kyle , Dong Yue
Published: March 2024

The planet is warming due to the burning of fossil fuels, but the geographical pattern of the observed temperature change over the Pacific Ocean over the past ~40 years is profoundly different from our expectations based on the CMIP5/6 climate model simulations of both historical and future warming. Here we will present an argument that the observed pattern of warming is consistent with a forced response to increasing atmospheric carbon dioxide shaped by two-way atmospheric teleconnections between the Southern Ocean and tropical Pacific Ocean. The same two-way atmospheric teleconnections might also be capable of yielding low-frequency natural variability in sea surface temperature and sea level pressure anomalies resembling the observed trend patterns. We will offer reasons why the observed pattern of warming is not simulated by the climate models. The observed pattern of warming in the Pacific has first-order implications for climate sensitivity as well as for the projected changes in global-scale precipitation.
Simulation Analysis of the Local Land-Atmospheric Coupling under a  Tibetan Plateau Vortex using the WRF_LES
Authors: Sun Genhou
Published: March 2024

     A series of simulation experiments on the local atmosphere-land coupling characteristics under the Tibetan Plateau vortex weather system using the WRF_LES model has been conducted. The chosen event occurred on July 7, 2017, starting at 02:00 on July 7th with the vortex center located at 33°N, 87°E, and ending at 20:00 on July 8th with the vortex center at 32°N, 103°E. We conducted a control experiment and sensitivity experiments with different initial soil moisture to explore how surface conditions affect the thermal state of the boundary layer and the free atmosphere under the vortex weather system. Based on the control experiment, we investigated the movement path and influence range of the vortex center under the Tibetan Plateau vortex weather system and investigated the local atmosphere-land coupling characteristics in terms of soil moisture distribution affecting surface flux, boundary layer height, wet static energy, lifting condensation level, and LFC in the distances relative to the vortex center. In conjunction with sensitivity experiments, we further explored the influence of soil moisture on the key variables mentioned above, including its possible effects on the intensity and path of the Tibetan Plateau vortex, as well as the corresponding changes in local atmospheric coupling variables. Based on this, we further discussion of the possible processes and mechanisms through which soil moisture influences these variables. This study is not only beneficial for understanding the vertical transport of energy and water vapor on the surface conditions of the Tibetan Plateau vortex weather system but also holds significant importance in comprehending the role of thermodynamics in the development and evolution of the Tibetan Plateau vortex.
Origin of pentlandite in Chang’e-5 lunar soils revealed by transmission electron microscopy
Authors: Tang Xu , Gu Lixin , Tian Hengci , Li Qiuli , Li Jinhua
Published: March 2024

Sulfides are common minerals in lunar rocks and have great implications for lunar magma origin and subsequent evolution. Pentlandite as an important sulfide, usually coexisted with troilite, which could indicate the geological thermal history of lunar rocks. Previous researchers proposed three potential mechanisms to explain the origin of pentlandite in lunar soil: (i) the reaction between mobilized sulfur and metallic FeNi, ilmenite and an Fe-bearing silicate; (ii) it is formed by the reaction between migrating Ni and troilite; (iii) pentlandite may exsolve from the Ni-rich troilite during the cooling of rocks. Here, we used the scanning electron microscopy (SEM), X-Ray electron probe micro-analyzer (EPMA) and transmission electron microscopy (TEM) to decipher the formation mechanisms of pentlandite in Chang’e-5 (CE-5) lunar soils. Our results show that pentlandites occurred as lamella and veinlets in troilites from basalts and breccias, forming a troilite-pentlandite assemblage. Crystallographic data from TEM provide the first robust evidence that pentlandites from both basalts and breccias were exsolved from the host troilite during the magma cooling, rather than formed by the reaction between mobilized sulfur and metallic FeNi, or mobilized Ni with troilite. Furthermore, we found taenite was exsolved from pentlandite in lunar breccia, forming a troilite-pentlandite-taenite assemblage. Given exclusively exsolved taenite and higher Ni content in troilite in breccia than that in basalts, it suggests the origin of pentlandite in breccia may involve a geological process involving the addition of exotic meteorite materials. Finally, we established two atom shuffling models to describe the transformation mechanism from troilite to pentlandite, and pentlandite to taenite. This work provides new insights into the origin and geological evolution of lunar sulfides, and also provides new method for the study of mineral evolution in other extraterrestrial samples.
An acoustic method to measure sea spray spume droplets in-situ
Authors: Voermans Joey
Published: March 2024

Sea spray spume, droplets generated through the interactions of wind and waves, can critically alter the heat, momentum, mass and gas exchanges between the ocean and atmosphere during extreme wind conditions. Most operational forecasting models, however, do not consider sea spray spume physics in their models as the uncertainty in sea spray parameterizations is simply too large (roughly three orders of magnitude). While this uncertainty is in part caused by the extreme complexity in the droplet generation physics, considerable uncertainty comes from the difficulty in measuring sea spray and, consequently, the near absence of field observations.Here, we present a new method to measure sea spray spume droplets in extreme winds based on acoustics. Specifically, hydrophones are positioned in the air flow laden with droplets to record droplet impact acoustics. The hydrophones were initially exposed to monodisperse free-falling droplets in the absence of wind in a first set of experiments. We find that both the magnitude and duration of the acoustic response to droplet impact are a function of the droplet diameter and the impact velocity. A second set of experiments were performed in a high-speed wind tunnel to validate the hydrophone’s response in extreme winds and under continuous exposure of droplets. Droplets ranging from less than 100 µm to 3 mm were released using a spray nozzle in winds up to 30 m/s, and their speed and diameter were independently measured using multiple exposure photography. Droplet impact measurements in the wind tunnel were found to be consistent with the initial experiments of free-falling droplets in stagnant air and provide estimates of the accuracy of the developed method. The range of droplet sizes that can be measured was found to depend on the size and sensitivity of the hydrophone, and wind speed. The results show that this new method provides significant opportunities in measuring sea spray spume droplets in situ at close proximity to the ocean surface. Field experiments to do so are currently in planning.
Accelerating Heatwaves Intensify Spatial Synchronization of Compound Drought and Heatwave Events
Authors: ul Hassan Waqar , Saharwardi Md Saquib , Prasad Dasari Hari , Gandham Harikishan , Hoteit Ibrahim , Abualnaja Yasser
Published: March 2024

Compound droughts and heatwaves (CDHWs) exert substantial socio-economic and ecological impacts, with their impacts reach epidemic proportions when CDHWs manifest simultaneously across multiple locations. Recent studies have begun to understand CDHWs, but their spatial compounding effects are not yet explored. This study utilizes weekly precipitation and temperature data to investigate the spatial synchronization of CDHWs and its changes. We define drought and heatwave weeks using the Standardized Precipitation Index (SPI 3-weekly) and the 90th percentile threshold of weekly temperatures. Our analysis reveals an unprecedented increase in the global land area and the number of regions experiencing concurrent CDHWs, particularly notable post-2000. The frequency of globally synchronized CDHWs (more than 5 regions affected simultaneously) has surged from 3 weeks (1982-1992) to 18 weeks (2012-2022), which is primarily attributed to a simultaneous global rise in temperatures driven by climate change. Analyzing CDHWs from observed data and counterfactual scenarios, where temperature data is detrended, we noted significantly higher likelihood of synchronization in observations due to intensified heatwaves in a warmer world. Notably, certain region pairs exhibit a higher likelihood of CDHW synchronization regardless being geographically distant. Spearman correlation and Granger causality analyses highlight major climatic modes, including El-Nino Southern Oscillation, Atlantic Multidecadal Oscillation, Western Tropical Indian Ocean, and Mode-2 of global Sea Surface Temperature, influencing changes in the areal extent of CDHWs globally as well as regionally. These insights are useful to predict the CDHWs and to quantify their socio-ecological impacts.
Optimizing managed Artificial Recharge backwash using a Multi-objective Particle Swarm Optimization coupled with a clogging simulation model 
Authors: Zhang tianjiao , Wen zhang , Zhu qi
Published: March 2024

Artificial Recharge (AR) is pivotal in managing groundwater resources and addressing hydrogeological issues. Over the past decades, significant research has focused on the clogging mechanisms but paid limited attention to devising effective strategies. This study introduces an optimization framework that integrates a clogging model with two objective functions aimed at minimizing clogging during groundwater recharg by using multi-objective particle swarm optimization(MOPSO) algorithm .The proposed clogging model for groundwater recharge accounts for both physical clogging and iron oxide clogging. It comprehensively addresses suspended solids' adsorption and iron oxidation reactions using a coupled COMSOL and PHREEQC approach. The MOPSO algorithm is employed to obtain Pareto bounds, aiding in identifying suitable recharge and backwash options among diverse groundwater recharge scenarios. This approach enables stakeholders to assess varied scenarios based on blockage conditions and recharge efficiency. The optimization findings underscore the effectiveness of proper backwashing in significantly reducing clogging and extending equipment life in groundwater recharge projects.
Extreme values of central Japan snowfall attributable to global climate change
Authors: Kuzuha Yasuhisa , Tachibana Yoshihiro , Mizuki Chiharu
Published: March 2024

. Objectives and dataTo investigate trends of heavy snowfall attributable to climate change, we use maximum snow depth data calculated during 1951–2010 with a climate model (experimentation by present climate). The Japanese hydrological–meteorological community used a climate simulation model to construct a huge database of hydro-meteorological values (https://www.miroc-gcm.jp/d4PDF/index_en.html), designated as d4PDF. It has data calculated under the present climate and data calculated under a future climate, which are affected by global warming. The "T-year value" is a stochastically and statistically estimated hydrological value for which the return period is T years.2. Extreme values of snowfallWe used hourly snow depth data of d4PDF around Japan. First, we calculated the annual maximum snow depth at each calculation grid. Because this database consists of ensemble calculations of 50 members, data for 3,000 years (60 years × 50 members) are included. We investigated trends of 50-year values for which the return period is 50 years. Specifically, 50-year snowfall and snow depth were estimated. The annual maximum of snow depth at each calculation grid was calculated. Our research theme evaluates the “T-year value” for which the return period is the T-year is itself, but we calculated it using a non-parametric method at this stage as described below.We assume that the population of this database is not stationary. Therefore, for example, for 1951, we use 500 data which consist of data of 10 years (1951–1960) of 50 members.
A 50-year value is the tenth largest value among 500 descending data.
For 1952–2010, 50-year values are estimated using the same procedure.
3. ResultFigure 1 presents the time variational 50-year-snow-depth at five grid points in central Japan. Figure 2 shows 50-year values of 24 h snowfall as the same grid points. These show no long clear increasing or decreasing trend. However, after 1985, it is apparent that the 50-year-annual maximum snowfall during 24 h decreases slightly.4. Future workAlthough we describe trends of 1951–2010 herein, we can describe some other results we are investigating now, as presented below.Optimal methods for estimating a T-year value require checking for optimal methods among non-parametric methods, methods using annual maxima, and methods using a partial duration series.
Although we use only a database for present climate conditions, we will present trends of the near future which are affected by global changes.
 Figure 1: Time variational 50-year snow depth at five grid points. Figure 2: Time variational 50-year snowfall at five grid points.
Constraining uncertainty in terrestrial tropical carbon flux dynamics requires capturing local biogeochemical influences on structure and function
Authors: Ordway Elsa , Asner Gregory , Burslem David , Davies Stuart , Lewis Simon , Mohiza Mohamad , Reuben Nilus , Michael O'Brien , Oliver Phillips , Lan Qie , Russo Sabrina , Xu Xiangtao , Longo Marcos , Moorcroft Paul
Published: March 2024

Spatial heterogeneity in tropical forest productivity and resulting rates of carbon uptake and storage emerge from variation in ecosystem structure and functional traits reflecting differences in climate, edaphic conditions, evolutionary history, and natural and anthropogenic disturbance histories. Yet, models poorly represent this heterogeneity. Remote sensing data provide landscape-scale measures of tropical forest heterogeneity in structure and functional traits that can be used to advance terrestrial biosphere models. To examine whether forest functional traits related to photosynthetic capacity can be used to improve predictions of tropical biomass dynamics and carbon fluxes, we parameterized the Ecosystem Demography model version 2.2 (ED2.2) using canopy traits derived from visible to shortwave infrared (VSWIR) airborne imaging spectroscopy data across an edaphic gradient in Borneo. We find significant site-level differences in relationships between SLA and foliar nutrient concentrations, suggesting that remotely sensed foliar traits can be used to capture variation in photosynthetic capacity at large, edaphically varying spatial scales. We further show that plant functional types parameterized with site-constrained trait values yield more accurate predictions of canopy demography, forest productivity and above-ground biomass dynamics than simulations that depend solely on parameterization of edaphic conditions. However, the most substantial improvements result from allowing for site-level variation in background disturbance rates in the model. Our study reveals the importance of capturing tropical forest heterogeneity in terrestrial biosphere models, particularly as it relates to nutrient availability and disturbance processes. 
Disentangling the driving mechanisms of tripole mode of summer rainfall over eastern China
Authors: Duan Yawen
Published: March 2024

The spatial distribution of summer rainfall anomalies over eastern China often shows a tripole pattern with rainfall anomalies over the Yangtze River basin varies in opposite phase with North China and South China. It is not clear whether this tripole pattern is an intrinsic atmospheric mode or it is remotely forced. Using two sets of model-outputs from 20 models participating in the fifth Coupled Model Inter-comparison Project (CMIP5), this paper investigates the driving mechanisms of this leading rainfall mode and its major influencing factors. One set (piControl) is fully coupled atmosphere-ocean simulations under constant pre-industrial forcing and the other (sstClim) is atmosphere-alone models forced by prescribed climatological sea surface temperatures (SSTs). By comparing results from these two different sets of simulations, it is found that the tripole pattern is the leading mode of summer precipitation variability over eastern China with or without oceanic forcing. It can be regarded as an intrinsic atmospheric mode although air-sea interaction can modify its temporal variability. The cyclonic/anti-cyclonic atmospheric circulation anomaly over the northern North Pacific is identified as a key factor in both experiments. As atmospheric internal variability, it is related to a circum-global zonal wave train propagating along the westerly jet stream. When air-sea interactions involved, modulation from SST anomalies is exerted through the meridional Pacific-Japan/ East Asia Pacific wave train propagating along the East Asian coast. Our results suggest that the North Pacific could be another key region providing potential predictability to the East Asian monsoon in addition to the Indo-Pacific.
Detection and Prediction for Sudden High Swells Along the East Coast of Korea
Authors: Oh Youjung , Moon Il-Ju
Published: March 2024

In recent several years, sudden high swell waves have often occurred on the east coast of the Korean Peninsula, especially in the winter season, which caused many casualties and property damage. These sudden swells have the characteristics of suddenly generating high waves even though the wind does not blow strongly, sweeping away unwary people on breakwaters or causing property damage such as ports and fish farms located on the coast. This study develops a detection and warning system for sudden high swells that frequently occur on the Korean Peninsula's east coast in winter. Using the calculated swell-wind wave height difference, significant wave height, and wind speed, we developed a sudden high swell warning system in three stages (Warning, Watch, and Attention). Analysis reveals that this system successfully detected three recent swell-related accidents on the east coast of Korea. Further experiments by applying the system to the prediction results of the wave model showed that the method successfully issued a warning 24 hours before a sudden high swell reached the east coast of the Korean peninsula. The developed system can provide quantitative and consistent forecast information, which will significantly contribute to preventing accidents caused by sudden high swells along the east coast of the Korean Peninsula. Lastly, we investigated the meteorological conditions that trigger sudden high swell based on reanalysis data and synoptic weather charts. Acknowledgement: This research was supported by the Korea Meteorological Administration Research and Development Program under Grant (RS-2023-00239702)
The role of soil moisture on summer atmospheric circulation climatology and persistent heatwaves in the Northern Hemisphere
Authors: Luo Fei , Selten Frank , Coumou Dim
Published: March 2024

Land-atmosphere interactions are crucial in both weather and climate extremes. Studies have revealed certain large atmospheric circulation patterns such as amplified circumglobal wave 5 and 7 play important role in generating and maintaining surface extremes. These extremes can occur at the same time but different locations, for example in 2010, the wave 5 pattern was the driver for Russian heatwave and Pakistan flooding. But how soil moisture and land-atmosphere interactions affect the climatology states of jetstreams, amplified waves, and hence persistent extremes still remains unclear.Here, we employ large ensemble simulations from climate model EC-Earth 3 to study the role of soil moisture in affecting large-scale atmospheric circulation for the period of 2009 to 2016. Three sets of experiments (each set has 100 ensemble members) are carried out with perturbed atmosphere-soil moisture interactions and one reference run (100 members) in which the interaction between the atmosphere and the land is fully interactive. We show that atmosphere-soil moisture interactions strongly influence the climatological mean states of atmospheric circulation in the Northern Hemisphere during the summer season (June to August) and especially in July. With the same soil moisture climatology, the reference run showed an overall land warming that led to poleward migration of jet and a more Arctic front jet state. Additionally, West Russia is chosen for the case study area as it is a hotspot for both amplified wave 5 and wave 7 heat extremes. We define the long duration heatwave event as near-surface temperature exceeding 30oC for at least eight days. The results show that with the soil-atmosphere interaction, the probability of such events increased from 2.2% to 5.8% for wave 5 and 0.47% to 4.5% for wave 7.
Rheological Behaviour of  the Deformation of the Back Arc in the Isthmus of Tehuantepec in South-eastern Mexico
Authors: Suarez Gerardo , Aguilar Sergio
Published: March 2024

The seismicity in the back arc of the Mexican subduction zone is relatively low.  An exception to this is the seismic activity observed in the Isthmus of Tehuantepec, where shallow earthquakes take place mostly along the coast of the Gulf of Mexico.  The largest recorded earthquake occurred on 26 August 1959 (Mw 6.9).  Other moderate earthquakes are recorded also in the southeastern margin of the Gulf of Mexico with magnitudes ranging from 5.3 to 5.9.  Data from the VEOX experiment that registered seismic data continuously on a cross-section across the Isthmus of Tehuantepec were analyzed.  Shallow earthquakes were culled from the continuous records, eliminating events within the subducted slab.  A total of ~40 shallow earthquakes were identified.  The linear geometry of the VEOX array made it difficult to locate the earthquakes.  Thus, additional stations from the Seismological Service of Mexico were used in the analysis.  Hypocentral locations were improved using the double-difference hypocentral algorithm.  The focal mechanisms obtained show consistently reverse faulting, where the axes of maximum compression are oriented NE – SW, like the 1959 earthquake.  This indicates that the lithosphere is deformed by compressive stress oriented in the direction of relative plate motion.  The best-located earthquakes show focal depths ranging from 20 to 50 km.  The depth of the Moho in the Isthmus of Tehuantepec is well controlled by receiver function results.  Therefore, it is possible to identify where the earthquakes occur relative to the depth of the Moho.  Unlike most upper plate deformation in the back arc of the subduction zones, earthquakes in the Isthmus of Tehuantepec occur both in the crust and the upper mantle.    Rheological models suggest that shallow earthquakes occur mostly in the seismogenic part of the upper crust and the upper mantle.  Our observations clearly show that in this region earthquakes reflect lithospheric deformation involving the crust and the upper mantle.  We are currently exploring rheological models that may help explain earthquakes in both the crust and upper mantle. The focal mechanisms suggest that the deformation may be induced by the subduction of the aseismic Tehuantepec Ridge in the Mexican subduction zone.
Geochemistry of the Northern Andean Volcanic Zone, Colombia
Authors: Marroquín-Gómez María P. , Ibañez-Mejía Mauricio , Johnson Aleisha C.
Published: March 2024

The North Volcanic Zone of the Andes is the result of an overall uniform subduction of the Nazca Plate beneath the South American Plate in Ecuador and Colombia; however, age, composition, and thickness of the continental crust and the distance between the trench and arc, among other components of this subduction system, vary significantly along this segment of the Andes (Stern, 2004). Those changes are most likely responsible for differences in the geochemical characteristics of volcanic products in different parts of the Colombian arc as discussed in Monsalve (2020). Although several works related to the isotopic geochemistry of the volcanic products have been carried out in Ecuador (Bryan et al., 2006; Chiaradia et al., 2009, references therein), there are few records of the same type of data for Colombia and those available focus on the SW part of the arc (Marín-Cerón, 2007). This study seeks to fill the gap and use this new data to elucidate processes of magma generation and differentiation currently occurring under the northern Andes. Whole rock major elements, trace elements, and 176Hf/177Hf analyses from main volcanic centers along the Colombian arc are used to track lithospheric and crustal processes of mixing, assimilation, and fractional crystallization as well as the main source materials and contributions in magma generation in the subduction zone. From a broader view, this new data helps to discuss regional comparisons of the geochemical expressions in the Andean arcs caused by different tectono-magmatic processes. Bryant, J.A., Yogodzinski, G.M., Hall, M.L., Lewicki, J.L. & Bailey, D.G. (2006). Geochemical constraints on the origin of volcanic rocks from the Andean Northern Volcanic Zone, Ecuador. Journal of Petrology, 47(6): 1147–1175.Chiaradia, M., Müntener, O., Beate, B., & Fontignie, D. (2009). Adakite-like volcanism of Ecuador: lower crust magmatic evolution and recycling. Contributions to Mineralogy and Petrology, 158, 563-588.Marín–Cerón, M.I. (2007). Major, trace element and multi–isotopic systematics of SW Colombian volcanic arc, northern Andes: Implication for the stability of carbonate–rich sediment at subduction zone and the genesis of andesite magma. Doctoral thesis, Okayama University, 140 p. Okayama, Japan.Monsalve–Bustamante, M.L. (2020). The volcanic front in Colombia: Segmentation and recent and historical activity. In: Gómez, J. & Pinilla–Pachon, A.O. (editors), The Geology of Colombia, 97–159.Stern, C.R. (2004). Active Andean volcanism: its geologic and tectonic setting. Revista geológica de Chile, 31(2), 161-206.
Construction of a semi-distributed hydrological model considering the combination of saturation-excess and infiltration-excess runoff space under complex substratum
Authors: Hu Caihong , Liu Chengshuai , Niu Chaojie , Yu Qiying
Published: March 2024

AbstractStudy region: Typical basin in humid areas in the Huaihe River Study focus: Accurate flood forecasting is essential for making timely decisions regarding flood control and disaster reduction. The theory of watershed runoff generation and convergence serves as a crucial foundation for flood forecasting, while the calculation of runoff is necessary to simulate flood discharge. Identifying watershed runoff generation mechanisms has been a challenging task, particularly under complex underlying surface conditions. To improve the accuracy of flood simulation, this study examines the underlying surface information in the watershed, such as particle composition and content, soil bulk density, geological slope, land use, and other spatial attributes, aiming to analyze the mechanisms of runoff generation. In the study of sub-watersheds, various combinations of runoff generation mechanisms are identified to determine the patterns of runoff. Subsequently, a semi-distributed hydrological model is developed, which incorporates both saturation-excess and infiltration-excess runoff, utilizing the information obtained from the underlying surface. The model is validated using rainfall-runoff data from 14 events at the Xiagushan watershed. New hydrological insights for the region: The analysis of the fundamental physical conditions of the underlying surface of the watershed revealed that 69.70% of the area is prone to saturation-excess runoff, with an additional 30.30% of the area being susceptible to infiltration-excess runoff. The model considers the spatial distribution of runoff patterns by incorporating complex underlying surface information and demonstrates high accuracy in simulating flood events (NSE= 0.87, Epeak = 12.08%, Wpeak = 13.16%, Tpeak = 0.14 hours, R2 = 0.90). The model is straightforward, practical, and exhibits promising potential in terms of timeliness and applicability, thus lending itself well to further application in other watersheds, contributing to the scientific foundation of flood warning and forecasting efforts.
Unraveling the Indian Monsoon's Role in Fueling the Unprecedented 2022 Marine Heatwave in the Western North Pacific
Authors: Song Qianghua , Wang Chunzai , Yao Yulong , Fan Hanjie
Published: March 2024

An unprecedented marine heatwave (MHW) event occurred in the middle-high latitude of the western North Pacific in the summer of 2022. We demonstrate that enhanced precipitation thousands of kilometers away fueled this extreme MHW event in July 2022. In the upper atmosphere of the MHW region, a persistent atmospheric blocking system is formed, which reduces convection and cloud cover and increases shortwave radiation at the ocean surface, leading to higher sea surface temperatures. Atmospheric perturbations induced by latent heat release from the extreme precipitation in the Indian summer monsoon region enhance this atmospheric blocking through the propagation of quasi-stationary Rossby waves. Our hypothesis is verified by using a numerical model that is forced with the observed atmospheric anomalous diabatic heating. This study sheds light on how a subtropical extreme event can fuel another middle-high latitude extreme event through an atmospheric bridge.
Climate Impacts of The Millennium Eruption of The Changbaishan Volcano
Authors: Yang Yuanyuan , Shi Feng
Published: March 2024

The Millennium Eruption (ME) of Changbaishan Tianchi Volcano is heralded as one of the largest explosive eruptions in the Late Holocene. The geochemistry method estimated that the ME not only produced huge quantities of volcanic debris and lava flows but also emitted up to 45 Tg of sulfur into the atmosphere. The sulfate emissions are higher than the Tambora eruption in 1815 CE, which caused a year without a summer in Europe. Despite such massive emissions, evidence for this eruption's climatic impact in East Asia remains elusive. To explain this contradiction, this study evaluated currently available high-resolution proxy records from the Northern Hemisphere spanning the past two millennia and conducted a volcanic sensitivity experiment using the Community Earth System Model (CESM). Results show that the high-resolution proxy records demonstrate an overall muted negative response during the period of the dating uncertainties, with 945 CE marking the most notable negative anomaly. The sensitivity experiment shows that ME caused significant negative anomalies in both temperatures and precipitation rates in East Asia. Based on the results, we infer that the contradiction between the high Sulfur emissions and a slight glacial sulfate signal may originate from the fact that the ME occurred in 945 CE instead of 946 CE, and the volcanic climatic effects were mitigated by the combined effects of the 945 CE El Niño-like Sea-surface temperatures (SSTs) and the Brewer–Dobson circulation. This study offers a novel perspective on the ME's climatic influence, reconciling previous discrepancies regarding its climatic impact.
Tracing the centennial variation of East Asian Summer Monsoon: Insights from three key periods
Authors: Fu Heng , Shi Feng
Published: March 2024

The centennial-scale variation of the East Asian Summer Monsoon (EASM) circulation has a long-term impact on regional ecosystems, agriculture and water resources. However, the feature and underlying mechanism of the centennial-scale variation in the monsoon system are not well-understood, largely due to the limited meteorological instrumental observation. To address this gap, we selected three characteristic periods (the pre-instrumental, the modern, and the future centennial periods) and compared them using a comparative approach that integrates proxy data analysis and climate model simulation. The results showed that EASM was significantly negatively correlated with temperature in the pre-tool period and the current warm period. On the contrary, under the RCP8.5 scenario, both EASM and future century temperature show an increasing trend. Additionally, we found that the main modes of precipitation in eastern China during the pre-instrumental period are the dipole mode or the monopole mode, while a shift in the dominant mode of precipitation over Eastern China from the dipole mode during the Current Warm Period (20th century) to the monopole mode in the future (21st century) . Our findings enhance the understanding of the centennial variation of the EASM and provide a foundation for projecting its future trend.
Chemical and biological information in dissolved organic matter across the land-ocean continuum 
Authors: Zheng Yan , Palomo Alejandro , Ma Yunjie , Hopwood Mark , Wang Junjian , Zhang Peng , Li Hailong , Feng Lian , Zheng Yi , Zhang Chuanlun
Published: March 2024

Biogeochemical cycling of organic matter across the land-ocean continuum (LOC) is important in driving energy and material exchange between the fresh water and saline water ecosystems, including the direction and magnitude of the uptake of carbon dioxide. The “reactivity” of dissolved organic matter (DOM) can range from highly bioavailable (labile) to hardly bioavailable (recalcitrant). Originated in soil biogeochemistry, “priming” refers to when something (nutrients such as inorganic N and P) is added to soil, it affects the rate of decomposition of the soil organic matter (SOM). This concept has recently been introduced to OM cycling across the LOC, for example, the “recalcitrant” DOM can become more bioavailable in coastal waters affected by high anthropogenic inputs of inorganic N and P. This study examines a set of surface fresh water, groundwater and coastal water samples in Pearl River Delta region to understand how biological information (eDNA, usually known with a short degradation time) may be interpreted in the context of still unclear mechanisms of how fast dissolved organic matter degrades in the environment, which we also characterize at molecular level. Metagenomics analysis of eDNA samples collected from Dapeng Bay, Shenzhen has revealed a high range of diverse antibiotic resistance genes (ARG), as well as over 100 genera of eukaryotes. In this highly anthropogenically affected Bay with elevated inorganic N and P inputs by a local stream, ARGs and human pathogens are abundant in the influent of a waste water treatment plant, though a large number of them were efficiently removed with the combination of a wastewater treatment plant and an engineered wetland. However, some ARGs and human pathogens persisted in fresh water downstream of the WWTP, in sea water collected at the beach and in the bay. It is worth noting that the groundwater collected at the beach exhibited the lowest abundance of ARGs and human pathogens. However, minor traces of sulfonamide (a group of semi persistent antibiotics) resistance genes were detected. This study hopes to shed light on whether the highly labile eDNA can be used as a biomonitoring tool or not across the LOC. This will likely depend on the understanding of how the sources and reactivity of DOM affect eDNA degradation. 
Earthquake surface ruptures mornitoring based on deep learning and remote sensing
Authors: Choi Yeonju
Published: March 2024

Surface expression of seismic rupture is a distinctive feature of large earthquakes, and the length of the surface rupture varies from several to several hundred kilometers depending on the magnitude of the earthquake. The structure and mechanical properties of fault zones strongly influence the behavior of earthquake ruptures, and detailed mapping and documentation of fault geometry such as fault bends, steps, branches, and their related segment geometry play a crucial role in determining the propagation and path of earthquake ruptures. The most precise method to map earthquake surface ruptures in detail might be manual mapping in the field by an expert; however, it takes a long time to analyze a vast area, and not everyone has access to the necessary expertise. As an alternative, rupture mapping based on remote sensing has been proposed to supplement the limitations of these field surveys.In this study, we propose a robust model for automatic detection and analysis of morphological features of surface ruptures using deep learning based on previous research results. Additionally, a skeletonization technique was developed for morphological analysis of detected fractures, and fractures of complex structures on the ground were objectified as individual fractures. Finally, the geometric quantitative characteristics of individualized fractures, including crack location, length, width, and direction, were automatically extracted. By comparing the detection results of the proposed model with the ground truth confirmed by the expert using a line map, the reliability of the entire model could be confirmed.To examine the applicability of the proposed model, the detection performance of various surface ruptures in localized areas was evaluated, and key characteristics, including rupture direction and pattern for extensive surface ruptures, were clearly identified. The satellite image-based surface destruction detection model proposed in this study can be used as a useful tool for field investigation and earthquake-related basic data collection by automatically detecting various surface destruction and deformations caused by earthquakes. Therefore, the proposed model, which enables fast and accurate fracture and fault mapping and quantitative analysis using high-resolution satellite data, is expected to be utilized as an important integrated solution. It would also be extremely beneficial in characterizing and comprehending the structural, geometrical complexity, and mechanical properties of fault zones.
Radiative effects of pre-monsoon dust and anthropogenic aerosols over India
Authors: Dubey Kanishtha , Verma Shubha
Published: March 2024

Recent investigation of aerosols from global aerosol multi-models show that forward model simulations were unable to reproduce the ground-based station-observed aerosol optical depth (AOD) and their spatial distribution over the Indian subcontinent. Estimation of aerosol-induced radiative effects and its impact on climate requires accurate analysis of aerosols optical properties. In the present study high-resolution aerosol transport simulations are carried out with a state-of-the-art Eulerian chemistry-transport model, CHIMERE, forced externally by Weather Research and Forecasting model as a meteorological driver in offline mode. Simulations are carried out over the Indian domain (6° N to 38° N and 68° E to 99.25° E) at a horizontal resolution of 0.25° × 0.25°. The spatial distribution of pre-monsoon mean AOD at 550 nm is compared with satellite observations for the year 2015. The spatial pattern of AOD showing high values in the Indo-Gangetic Plain (IGP, 0.45-0.55) is consistent with the features of observed AOD from satellite retrievals (0.4-0.55) with a slight over-estimation (30%) in the upper-IGP region. The IGP has a higher AOD than most parts of India attributed to high population density and greater emission sources. Large seasonal mean AOD values are also estimated over the Indian state of Telangana (0.5-0.6) which is over-estimated (25%-35%) as compared to satellite retrievals. The simulated AOD is also found to be in good agreement (NMB: 17% for 16 locations) with AOD from ground-based observations (AERONET and individual measurements) at stations over India. Assessment of anthropogenic and dust AOD showed high influence of anthropogenic aerosols over the IGP region while that of dust over north-western region.Further, the pre-monsoon shortwave radiative perturbation due to total, dust and anthropogenic aerosols over the Indian region is evaluated at surface (SUR), atmosphere (ATM) and top of atmosphere (TOA). The positive value of the radiative effect signifies warming due to aerosols and vice versa for the negative value of the radiative effect. The radiative effect at TOA due to total aerosols is negative over the north-western region and positive for other parts of India. The net radiative effect of total aerosols at the SUR is cooling (-70 to -80 W m-2) in contrast to warming (+65 to +80 W m-2) in the atmosphere. The magnitude of radiative perturbations caused by anthropogenic aerosols is higher compared to dust at SUR and ATM. Anthropogenic aerosols have a net warming effect at TOA (+20 to +50 W m−2) in contrast to a net cooling effect (-20 to -40 W m-2) by dust aerosols. The most substantial values of radiative perturbations due to anthropogenic aerosols are observed over the IGP region while the effect of dust aerosols is prominent over the north-western region of India.
Winter to summer evolution of pCO2 in surface water of northern Greenland fjords 
Authors: Akhoudas Camille , Stranne Christian , Ulfsbo Karl Adam , Thornton Brett , Jakobsson Martin
Published: March 2024

Ocean acidification induced by the absorption of anthropogenic CO2 and its consequences pose a potential threat to marine ecosystems around the globe. The Arctic Ocean, particularly vulnerable to acidification, provides an ideal region to investigate the progression and impacts of acidification before they manifest globally. Recent documentation of undersaturated surface waters in carbonate minerals in the Sherard Osborn fjord in northwest Greenland, a region visited for the first time in summer 2019, reveals inherent variability in biogeochemical processes. Associated with highly acidic surface waters, the partial pressure of CO2 (pCO2) was undersaturated relative to the atmosphere, indicating this study area as a CO2 sink. To comprehend variations in pCO2 in the northwest Greenland fjords and identify its drivers, we conducted a comparative study between two fjords in the region (Petermann and Sherard Osborn fjords) and used carbonate system data from the temperature minimum layer to examine the winter-to-summer evolution of pCO2 and influencing factors. Additionally, we evaluated pCO2 variations (δpCO2) concerning temperature, freshwater inputs, biological activity, and air-sea CO2 uptake to quantitatively assess the seasonal influencing factors on surface ocean pCO2. In the Sherard Osborn fjord, despite a substantial increase in surface temperature from winter to summer potentially increasing pCO2 and causing CO2 supersaturation relative to the atmosphere, freshwater inflow and biological activity reduced pCO2, resulting in CO2 undersaturation relative to the atmosphere. In the Petermann fjord, pCO2 remained lower than atmospheric levels due to a slight seasonal variation in surface temperature and significant biological activity, reducing pCO2 in surface water.