bluuebunny/crossref_metadata_2025 huggingface dataset:
Impacts of Sea Level Rise and Tidal Restoration on Groundwater Dynamics in the Herring River Watershed, Cape Cod, USA 
Authors: Richins John , Befus Kevin , Naseri Kasra , Hummel Michelle
Published: March 2024

Sea levels are expected to rise due to global climate change, leading to significant impacts on coastal systems. One of these impacts is the decrease in the depth to groundwater in shallow coastal aquifers. This decrease could result in changes to groundwater discharge, increased groundwater shoaling, and the loss of dry land due to groundwater emergence and inundation.  

In the past, many tidally influenced coastal drainage networks were diked and drained for human use. However, there is now growing interest in restoring these diked systems to their natural tidal conditions. Tidal restoration will change the surface water levels of estuaries, which will affect the underlying groundwater in ways similar to sea level rise but potentially more rapidly. 

The Herring River watershed in Cape Cod, MA, USA is currently undergoing a tidal restoration project. We have chosen the Herring River as a case study to determine how tidal restoration and sea level rise will change conditions in the surrounding shallow aquifer. To predict the changes in groundwater conditions due to tidal restoration and sea level rise, a MODFLOW 6 groundwater model was coupled with a DELFT3D hydrodynamic model. The hydrodynamic model provided surface water boundary conditions for the groundwater model. Sea level is expected to rise by approximately one meter by the year 2100. Therefore, the model was run for several sea level rise scenarios, including the current sea level and projected sea level rise of 0.6 meters and 0.9 meters, for tidally controlled and restored conditions.  

The preliminary results of the model indicate an increase in groundwater shoaling and emergence as sea level rises and restoration occurs. This shallowing of the water table may also lead to more overall groundwater discharge to the drainage network and coastal waters. If tidal control does not allow sufficient drainage, increased groundwater discharge may become impounded behind similar diked systems leading to more overall flooding than if tidal conditions were restored. Showing how groundwater emergence, shoaling, and discharge will change with sea level rise and tidal restoration can help coastal stakeholders decide which management practices are best implemented during restoration efforts. 
Relations of rescaled to non-rescaled complementary models and improvement of evapotranspiration estimates by incorporating both climatic and land surface conditions
Authors: Mu Zhaotao , Liu Wenzhao , Ma Ning , Cheng Changwu , Zhou Haixiang
Published: March 2024

The estimation of actual evapotranspiration (ET) using both rescaled and non-rescaled complementary relationship (CR) models has become a hotspot in the research on terrestrial ET. This study explores the relationship between these two CR models and improves the method for calculating xmin in rescaled CR models. The rescaled and non-rescaled CR models can be functionally interconvertible, i.e., the non-rescaled CR model enables the rescaled simulation of ET and the rescaled CR model can also conduct a non-rescaled simulation. The parameter b or c in the non-rescaled CR models plays a role similar to xmin in the rescaled models. Based on the data from 15 catchments in the Loess Plateau of China, we validate this relationship between the two CR models. Meanwhile, we evaluate the formulation for xmin proposed by Crago et al. (2016) (the Crago’s xmin values) and the results show that the range of variation for the Crago’s xmin values is smaller than that for the xmin values obtained by inverse method from the models (the inversed xmin values) in the interannual process. The inversed xmin values of RCR-C2016 are mostly larger than that of RCR-S2017, while the Crago’s xmin values are in between these two values. The empirical function for xmin is developed using the aridity index (AI) and normalized difference vegetation index (NDVI) as independent variables in the interannual fluctuations. On the mean annual scale, the empirical function for xmin is expressed only using the AI. Cross-validation results show that the rescaled CR models combined with xmin determined by the empirical functions can more accurately estimate ET and simulate its interannual and spatial changes. (Supported by Project 41971049 of NSFC)
Synergistic effects between urban heat island and heat waves in China
Authors: Shi Zitong
Published: March 2024

Under the background of climate change and fast urbanization, climate extremes such as heat waves tend to be more frequent, more severe, and longer-lasting. Cities face a greater risk of heat waves due to population growth, industry concentration, and the superposition of their unique climate effects. Quantitative analysis of the combined effects of regional-scale heat waves and local-scale urban heat islands is important for urban adaptation to climate change and for urban disaster prevention and mitigation. On one hand, urban expansion, causing reduced evapotranspiration and weakened wind speed that normally cools the lower atmosphere by turbulent heat loss and cooled air advection, led to magnified heat extremes. On the other hand, synergistic effects between urban heat island and heat waves were found in most cities in China. Given this synergistic interaction between urban heat islands and heat waves, collaborative efforts will be necessary to implement climate adaptation and mitigation strategies aimed at reducing the serious heat-related health risks faced by urban residents.
Decline of water resources in Northern Hemisphere Mediterranean Climate Regions based on satellite observations.
Authors: Senigalliesi Vincenzo , Alessandri Andrea , Di Carlo Emanuele , Cherchi Annalisa
Published: March 2024

The Mediterranean Climate Regions (MCRs) share similarities in terms of experienced temperatures and precipitation patterns, resulting in similar vegetation, i.e. farms and agricultural approaches/strategies. Recent findings suggest that groundwater levels in the Euro-Mediterranean may experiencing negative trends, resulting from decreasing precipitation, increasing evapotransipration and/or increasing withdrawal. This suggests a potential dry transition in MCRs, affecting biodiversity and ecosystems. By focusing on the Euro-Mediterranean and California, this work characterizes the dry transition through soil water content analysis from observation. The Total Water Storage (TWS) variable provided by the GRACE/GRACE-FO mission is utilized, carrying information about groundwater, soil moisture, surface water, snow water equivalent, and water stored in biomass. Furthermore, the contribution related to the variability of TWS due to associated drivers, precipitation, and potential evapotranspiration (PET) is quantified. The methodology framework relies on Empirical Orthogonal Function (EOF) analysis and a Multivariate Linear Regression model (MLR) to characterize, respectively, the modes of variability of TWS and the relative influence of the drivers to the total variance of the field. Our results highlight a general drying trend for both regions; furthermore, they suggest that in certain domains, variations in TWS are more sensitive to specific drivers than others: the western Euro-Mediterranean (Spain, Portugal, and parts of North Africa) is more susceptible to precipitation variability than PET, as it is more influenced by Atlantic flows and the effects of the North Atlantic Oscillation; in contrast, the TWS in the eastern Euro-Mediterranean (Greece and Turkey) is predominantly affected by the increase in PET due to the temperature increase; on the other hand he central EuroMed (Italy and Tunisia) exhibit a mixed behaviour with influences of both precipitation and PET on TWS. Regarding California, similar to the Euro-Mediterranean, there is a negative trend in TWS in equatorward regions, where PET is the major source of variability. Conversely, starting from 43°N in the poleward regions, there is a positive trend in TWS, mostly due to the increase in precipitation in that area.
CO2 fertilization effects can fully offset the yield loss due to CO2 induced warming for major C3 crops
Authors: Sang Yuxing , Wang Xuhui , Wang Chenzhi , Müller Christoph
Published: March 2024

Rising atmospheric CO2 can enhance global crop yield directly through the CO2 fertilization effect (physiological effects, ), but can also reduce it indirectly through CO2-induced warming (radiative effects, ). The overall consequences of the two opposing CO2 effects have constituted large uncertainties in projecting future crop yields. Here, we first employ a site-level CO2 elevation experiment dataset to constrain the simulated  effect in yield projections of an ensemble of global crop models for four major cereal crops (wheat, maize, rice and soybean). Under well-watered and well-fertilized conditions, the constrained estimates show that elevated CO2 will increase yield of major C3 crops (spring/winter wheat, rice and soybean) by 16.7 ± 2.7% 100 ppm-1, 9.4 ± 2.7% 100 ppm-1, 11.2 ± 2.7% 100 ppm-1, and 12.9 ± 2.4% 100 ppm-1, respectively, while no significant yield gain was found for maize (1.6 ± 1.7% 100 ppm-1). Then, by combining CO2induced warming, crop yield response to warming and the interactive term of the physiological effects and radiative effects, we assess the integrated effects of increasing atmospheric CO2 on crop yield at global scale. The results show that the same level of increase in atmospheric CO2 tends to induce larger  than the yield loss by  for both wheat and rice. But for soybean and maize,  largely offsets , resulting in statistically not significant integrated effects of CO2 for soybean (4.2 ± 15.8%) and maize (-3.0 ± 4.6%).
Exploring Structural Activity Through Gravel Rock Fracture Characteristics: A Case Study of the Milun Fault in Hualien, Taiwan
Authors: Hsu Yi-Chun , Chang Chung-Pai , Huang Shao-Yi , Wang Chun-Chin , Yen Jiun-Yee
Published: March 2024

Hualien City in Taiwan is situated in the northernmost segment of the Longitudinal Valley, transitioning from the subduction of the Philippine Sea Plate to a collision environment. It is one of the most seismically active regions in Taiwan. The Milun Fault, a significant active fault, traverses through the urban area of Hualien, causing an uplift of the Milun Terrace and deformation and fracture of Milun gravel rocks in the hanging wall. The Milun Fault was the seismogenic fault for the 1951 Hualien earthquake (ML 7.3) and experienced approximately 70 cm of horizontal displacement triggered by the 2018 earthquake. The proximity of the Milun Fault to several secondary fault systems indicates complex structural activity.This study focuses on observing the gravel rock layers beneath the Milun Tableland along the northern coast, utilizing a well-cemented beachrock layer as a key bed to assess variations in uplift across different areas.  Based on the investigations, the gravel rock layers beneath the Milun Tableland can be broadly divided into three zones:(a) Southeast Stable Zone: Characterized by a low beachrock layer height of approximately 3 meters. Minimal evidence of fault activity is observed in this area. (b) Damaged Zone (Middle): Marked by a beachrock height reaching up to 4.5 meters. Multiple fault systems are developed within the gravel rock layers, leading to fragmentation and damage. (c) Northwest Stable Zone: With a beachrock height of less than 1 meter, this area shows observable fractures in the underlying gravel rock but lacks clear structural activity. Measurements of slickenside and identification of fracture axes in the gravel rocks provide the maximum stress direction for each zone, indicating stress orientations ranging approximately between 160-170. The inferred trend of the Principal Displacement Zone (PDZ) aligns with a strike of 010, consistent with the surface rupture observed during the 2018 Hualien earthquake.The field data from this study can offer additional information about the Milun Fault system. By incorporating the analysis results of surface rupture caused by the earthquake in 2018, it can further confirm the flower structural characteristics of the Milun Fault system. Additionally, it allows for observing other motion features associated with lateral fault movements.
Research on avalanches caused by stability of snow cornices developed by blowing snow
Authors: Yamaguchi Satoru , Ito Yoichi , Tanabe Takahiro , Nishimura Koichi , Adachi Satoru , Sunako Sojiro , Saito Yoshihiko , Okaze Tsubasa , Niiya Hirofumi , Tsunematsu Kae , Nishimori Hiraku
Published: March 2024

Our research is aimed at improving the prediction accuracy of avalanches caused by the stability of snow cornices developed by blowing snow in the Niseko region, one of Japan's international ski resorts. For this purpose, several studies were conducted in cooperation with local authorities and ski resorts in the Niseko region. Specifically, a network of anemometers was installed and a system was developed to estimate areal wind conditions and snow redistribution over the entire mountain area from wind observation data. To validate the developed system, the snow cover distribution over the entire mountain area for two winters was obtained by laser survey using an aircraft. In addition, several portable ultrasonic anemometers were installed on the slopes where snow cornices develop to observe detailed wind conditions, and small LiDAR was used to continuously survey snow cornice development. We sampled snow in the developing snow cornice and analyzed its microstructure using X-ray computed tomography imaging. The presentation presents a first analysis.  
Progress on third glacier inventory of Xinjiang Uygur Autonomous Region (XUAR), northwestern China
Authors: Li Zhongqin , Wang Feiteng , Wang Puyu , Zhan Zexin
Published: March 2024

There are nearly half of the glaciers in China distributed in the Xinjiang Uygur Autonomous Region (XUAR) in northwestern China, where the largest glacierized centers outside polar region are nourished by the highest mountain ranges on earth such as Karakoram, western Kunlun mountains, eastern Pamir and Tianshan etc. Glaciers are water tower in this vast arid land in northwestern China. Up-to-date glacier inventory is highly demanded. Based on the latest glacier inventory compilation techniques including those for the first and second Chinese glacier inventories, we currently compiled the third glacier inventory of XUAR, named as Chinese Glacier Inventory of Xinjiang 2020 (CGI-X2020). Comparing to the second Chinese glacier inventory (CGI-2), three improvement has been made in the CGI-X2020. Firstly, CGI-X2020 is based on a total of 235 scenes Chinese satellite imageries were selected out of 30,000 ：ZY1 (5); ZY3 (59);  GF1 (135); GF2 (1) ; GF7 (2) and GF6 (33) during the period 2018-2021, mainly during 2020 summer, having a resolution better the 2 m, whereas CGI-2 was based on Landsat TM/ETM+ imageries acquired during 2006–09 with a resolution of 30 m. Secondly, the glacier volume (an important parameter of the glacier inventory) was computed by scaling method which was validated by 22 in-suit glacier thickness measurements through GPR cross glacierized region in XUAR by our research team. Thirdly, the debris coverage of the glaciers were better identified on the basis of high-resolution imageries.According to GIX2020, by 2020, there are 24,448 glaciers in XUAR, covering an area of 23,531.65 km2 with a total volume about 1548.80 km3  ; There are 20,586 glaciers with an area smaller than 1km2, but the area and volume occupy only 19.16% and 7.95%. Glacier volume in Tarim basin accounts for 64.72% of that in total river systems; The glacier volume is distributed in Kunlun Mountains, followed by Tien Shan and Karakoram Mountains, respectively; 30.68% and 23.92% of the total glacier volume are distributed in Kashgar and Hotian region, respectively.
Temporal trends and causes of deoxygenation: a comparison of the Northwest Atlantic Shelf and Atlantic Basin
Authors: Nguyen Hung , Siedlecki Samantha , Curchitser Enrique , Stock Charles , Rocha Cesar , Chen Zhuomin , Soares Felipe
Published: March 2024

Oxygen concentrations are of fundamental importance for organisms as well as geochemical cycling in oceans. Since the middle of the 20th century, oxygen concentrations have been declining in the open ocean and the coastal ocean. Located near the intersection of subtropical and subpolar circulation, the northwest Atlantic (NWA) Shelf is sensitive to climate variability. Recent work has been done on regional NWA trends in sea-surface temperature, salinity, and chlorophyll, but the trends and drivers of oxygen in the region have not yet been established. Here, we use World Ocean Database oxygen observations to determine the temporal trend of subsurface oxygen concentrations between 50-100m on the NWA Shelf from 1988 to 2019. We also use a regional NWA ROMS and MOM6 configuration to simulate the historical decadal trends and spatial patterns in dissolved oxygen concentrations over the shelf. Our results indicate a significant decrease of oxygen by 1.542±0.308 µmol/kg/year, which surpasses the established Atlantic basin-wide trend. The greatest subregional oxygen loss occurs on the Scotian Shelf and in the Gulf of St. Lawrence. A detailed analysis revealed that the oxygen trends on the NWA shelf are driven by changes in Apparent Oxygen Utilization (AOU), consistent with the decreased influence of Labrador Current in the region and associated water mass properties. Our model identifies the location of minimum oxygen concentrations occurring both at the bottom but also at midwater column depths in the Mid-Atlantic Bight and Gulf of Maine. Under SSP5-8.5, our dynamically downscaled projection (2014-2098) projects that the bottom oxygen in the NWA Shelf will accelerate relative to the historical period (1980-2014). Diagnosis of the mechanisms behind the future acceleration as well as the mid-water column minimum oxygen pattern using various tools will be presented.
Distribution of geothermal resources in New Zealand: insights from geophysics and numerical modelling
Authors: Pearson-Grant Sophie , Bertrand Edward , Miller Craig , Carson Lucy
Published: March 2024

New Zealand has abundant geothermal resources which produce ~20% of the country’s electricity. Most geothermal systems are located in the geologically complex rifting arc of the Taupō Volcanic Zone (TVZ), along the Australian/Pacific plate boundary. The TVZ is one of the most geothermally active regions on Earth, discharging ~4200 GW of heat through 23 high-temperature systems. Understanding the regional-scale factors influencing the locations of the geothermal systems is important for exploration and sustainable exploitation.There are several intriguing correlations between TVZ geology and geothermal system locations. Over two-thirds of geothermal systems occur near inferred caldera margins. Many geothermal systems rise to the surface beneath topographic lows. Geothermal activity forms two NE-SW trending zones of low resistivity which are separated by the densely faulted and geothermally quiescent Taupo Fault Belt; most of the geothermal systems are not associated with any known major faults. We can gain new insights into these potential relationships by merging increasingly extensive geophysical and geological surveys of the central North Island of New Zealand into numerical flow models.We created generalised numerical models of heat and fluid flow using TOUGH2 software to explore large-scale influences on geothermal circulation in the TVZ. Locations of over half the modelled geothermal systems can be broadly explained by the effects of topographic loading due to water table variations. Locations are further improved when topographic effects are combined with localised heat sources at depth inferred from magnetotelluric models. At three geothermal systems, influences such as more permeable volcano-sedimentary cover or a region of intense faulting that acts as a recharge zone for cold downwelling fluid also seem to be important. Three systems (Ohaaki, Te Kopia and Orakei Korako) cannot be explained with any of our models but are known to be in areas with significant local geological structures, making them interesting targets for future studies.
Mapping Global Lithospheric Mantle Pressure-Temperature Conditions by Machine Learning-Based Thermobarometry
Authors: Ye Chenyang , Qin Ben , Liu Jingao , Huang Shichun , Wang Shunguo , Zhangzhou Johnny
Published: March 2024

Understanding the temperature and pressure within Earth's lithospheric mantle is crucial for comprehending the dynamics of Earth's interior, its geochemical and geophysical properties, as well as their influence on magma formation and the stability of cratons. While traditional mineral-based thermobarometers have provided valuable insights in estimating temperature and pressure, their reliance on specific mineral pairs and reactions limits their global applicability. Furthermore, as a type of high-dimensional data, mineral compositions have complex relationships that are difficult to capture by conventional methods, and these conventional methods are prone to overfitting, which can produce inaccurate results in certain cases. Our work introduces a new method using XGBoost to develop machine learning-based thermometers and barometers. These models are trained on a comprehensive dataset from 985 high-temperature and high-pressure experiments. This approach is designed to fully leverage the potential of high-dimensional data, offering more precise and widely applicable estimations while also preventing overfitting inherent in traditional methods. Comparison between machine learning models and classic thermobarometer reveals that the machine learning models significantly improve the accuracy in predicting temperature and pressure. This improvement can be attributed to the capability of machine learning models in processing the high-dimensional data of mineral pairs. The global application of these machine learning models has enabled a re-evaluation of the mantle's thermal conditions across diverse cratons. Most notably, the depth estimations to the lithosphere-asthenosphere boundary using machine learning thermobarometry typically exceed seismic measurements by approximately 40 km. This discrepancy suggests the presence of melt-bearing zones at the lithosphere-asthenosphere boundary.
Modelling interactions between consecutive floods and channel-floodplain systems in the Lower Yellow River, China
Authors: Li Wei , Zhu Lehong , Hu Peng
Published: March 2024

Consecutive floods combined with hyperconcentrated floods and moderate/low sediment-laden floods have always been observed in the Lower Yellow River (LYR) characterized by complex channel-floodplain systems of alternated meandering and straight segments. Interactions between those floods and sophisticated morphological segments are much more complicated than normal low-sediment laden rivers of relatively simple geometry. In this regard, we numerically investigate the 92.8 consecutive floods in the natural channel-floodplain reach of Xiaolangdi-Jiahetan in the LYR by deploying a 2-D depth-averaged fully coupled morphological model. The major focus includes (1) the unusual phenomenon of downstream peak discharge increase and (2) the different hydro-morphodynamic behaviors between meandering and straight channel-floodplain systems. For the former, the peak discharge increase of hyperconcentrated floods could be satisfactorily reproduced when the effects of bed roughness reduction and bed deformation are considered simultaneously. For the latter, the water-sediment exchange between channels and floodplains is relatively strong in hyperconcentrated floods and exhibits distinct features in meandering and straight segments. The straight one is featured by lateral channel-floodplain diffusion while the meandering one is characterized by the transition from lateral diffusion at the meander apex to streamwise advection. Consequently, the deposition at the meanders (especially on the floodplains) is much larger than that at the straight reach floodplains resulting in a remarkable uneven deposition pattern along the streamwise direction. Key words: Lower Yellow River; Hyperconcentrated floods; Channel-floodplain interactions; Morphological modelling; Sediment transport Acknowledgements: National Natural Science Foundation of China (No. 12272349, 52339005).
Assessment of wetland ecosystem services associated with changing climate and agricultural wetland drainage in a major food producing region
Authors: Whitfield Colin , Cavaliere Emily , Baulch Helen , Clark Robert , Spence Chris , Shook Kevin , Pomeroy John , He Zhihua
Published: March 2024

Agricultural regions worldwide face the dual challenge of producing food for a growing world population while simultaneously reducing the industry’s environmental footprint. The prairie region of western Canada, where more than 40 million ha are used as cropland or pasture, is one of the world’s major food producing regions. This complex landscape provides agroecosystem services associated with these agricultural lands and their millions of depressional wetlands. As a cold region, and one with a highly variable climate which is undergoing strong climate change, agricultural practices continue to evolve. One widely used tool for adaptation to wet periods and to maximize arable land area is to drain wetlands; however, a tradeoff exists between draining wetlands to support expansion of cropland, and conserving wetlands to maintain their valuable ecosystem services. Wetland drainage decisions are often made without identifying impacts to the services these systems provide.We address this gap using a novel assessment to quantify impacts to ecosystem services via wetland drainage in the Canadian prairie landscape, and explore how wetland ecosystem services may be impacted by future climate. Quantifying response of a suite of indicators (median annual flows, total phosphorus export, riparian habitat, dabbling ducks, wetland-associated birds, carbon sequestration) to wetland drainage demonstrated that all respond strongly to the loss of depressional wetlands, but sensitivity varies among the indicators. Median annual flows and phosphorus export respond more strongly than longer return period flows, potentially tripling in magnitude with high levels of wetland loss. Dabbling ducks and wetland-associated bird abundances are even more sensitive, with abundances predicted to decrease by half with loss of as little as 20% of wetland area. As a relatively unique region, where inundated wetland area is highly dynamic both interannually as the system alternates between dry and wet phases, and intra-annually (across seasons), wetland ecosystem services response to climate change is more nuanced. In the Canadian prairie, there appears to be a delicate balance between future warming and changes in precipitation amount that could yield either increases or decreases in wetland area, with wetland ecosystem services anticipated to change accordingly. Our results illustrate the sensitivity of wetland ecosystem services to agroecosystem management and climate change in a major food producing region, highlighting the need to consider the tradeoff between loss of these services and benefits of agricultural expansion. Under a drier future climate, fewer remaining wetlands may both enhance the value of wetland-associated ecosystem services, and temper the demand for wetland drainage. 
Near surface runoff generation in a pre-Alpine headwater catchment
Authors: Gauthier Victor , Leuteritz Anna , van Meerveld Ilja
Published: March 2024

Near-surface flow pathways can be important contributors to runoff in headwater catchments with low conductivity soils. However, the high spatio-temporal variability and connectivity between surface flow and shallow subsurface flow makes it difficult to study these processes. As a result, they are still poorly understood, especially for well vegetated humid catchments. The TopFlow project, therefore, aims to enhance our understanding of the generation and connectivity of overland flow and shallow subsurface flow in a pre-Alpine headwater catchment with low permeability Gleysols.We installed 14 small (1 by 3 m) runoff plots at different topographic locations to cover the range in slope, vegetation, and wetness conditions across the catchment. At each plot, we measured overland flow (including biomat flow) and shallow subsurface flow from the rooting zone during two snow-free seasons. In addition, we collected groundwater, precipitation and soil moisture data. We also installed two larger plots (8 by >10 m), where we collected data during natural rainfall events and sprinkling experiments. Specifically, we conducted experiments to determine the surface flow path lengths and celerity of overland flow and shallow subsurface flow.Overland flow and shallow subsurface flow occurred frequently on most plots (on average for 40% of the 26 rainfall events for which data were collected) but the spatial and temporal variability in overland flow and shallow subsurface flow generation was high. The timing and relative importance of overland flow and subsurface flow varied as well. Runoff ratios increased with increasing soil moisture storage and precipitation, and were generally higher for sites with a higher Topographic Wetness Index. Runoff ratios were sometimes larger than 1, indicating the importance of connectivity between subsurface and surface flow. Flow path lengths and celerity also differed for the plots and can be explained by differences in soil characteristics and wetness conditions. Overall, these results highlight the importance of fast near surface flow pathways for runoff generation and its high spatial and temporal variability.
The Competition Between Anthropogenic Aerosol and Greenhouse Gas Forcing is Revealed by North Pacific Water-mass Changes
Authors: Shi Jia-Rui , Wijffels Susan , Kwon Young-Oh , Talley Lynne , Gille Sarah
Published: March 2024

Modelled water-mass changes in the North Pacific thermocline from CMIP6, both in the subsurface and at the surface, reveal the impact of the competition between anthropogenic aerosols and greenhouse gases (GHGs) over the past 6 decades. The aerosol effect overwhelms the GHG effect during 1950-1985 in driving salinity changes on density surfaces, while after 1985 the GHG effect dominates. These subsurface water-mass changes are traced back to changes at the surface, of which ~70% stems from the migration of density surface outcrops, equatorward due to regional cooling by anthropogenic aerosols and subsequent poleward due to warming by GHGs. Ocean subduction connects these surface outcrop changes to the main thermocline. Both observations and models reveal this transition in climate forcing around 1985 and highlight the important role of anthropogenic aerosol climate forcing on our oceans’ water masses.
Satellite thermal mapping of the lowest surface temperatures in Greenland
Authors: Campbell George , Scambos Theodore
Published: March 2024

Inspired by a recent paper on the lowest observed air temperature in thenorthern hemisphere (AWS observation near Summit Station; Weidner et al., 2021),we will composite Aqua MODIS Land Surface Temperatures (LST, data setMYD11_I2 ver061) over the Greenland Ice Sheet spanning 2003-2023. Our preliminaryanalysis shows LST below 200°K with just part of the data processed. or colderthan -100°F. Using the record-setting AWS station data, we estimate thetemperature inversion between the ~2 meter air temperature and the snow surfaceto adjust the LST satellite measurements.  Greenland shows a similar gradient intemperature between LST ‘skin’ temperature and air temperatures as seen inAntarctica from our earlier research (Scambos et al., 2018).  Lowesttemperatures occur on clear-sky polar nights under calm or nearly calm winds,in general just to the west and northwest of the ice divide. Maps of LST showsmall scale geographic variations that are closely associated with local lows intopography. We infer that this is a result of cold air pooling and furtherchilling of the surface under conditions that maximize radiative heat loss.
Mechanism of Strike-slip Transfer along the East Kunlun Fault in Northern Tibet, China
Authors: Zhang Yueqiao , Jiao Liqing
Published: March 2024

Strike-slip faults of considerable scale play a pivotal role in accommodating crustal deformation resulting from the Cenozoic India-Eurasia collision. The manner in which strike-slip motion is transferred along faults remains a topic of ongoing debate. In this study, we have meticulously compiled millennial strike-slip rates and GPS-derived strike-slip data along the extensive ~1800 km East Kunlun Fault (EKF). Our objective is to discern the slip distribution pattern and evaluate the mode of strike-slip transfer. The findings reveal a segmented pattern of strike-slip activity, characterized by a consistently high strike-slip rate exceeding 10 mm/yr along the central segments. In contrast, the eastern segment exhibits a reduced slip rate, measuring less than 5 mm/yr, and further diminishes to approximately 1 mm/yr along its eastern fault tip zone. Notably, strike-slip drop events occur within the fault bending zone, or in areas where the fault bifurcates, forming a horsetail structure. To complement our observational insights, numerical modeling has been employed to validate that the fault geometry may serve as a crucial controlling factor in the observed variation of strike-slip rates, Additionally, it influences the local stress situation along the fault, further contributing to the earthquake risk along the fault and the associated hazards impacting the local area.
Current Status of Pre-Calibration Techniques for Enhancing the Positional Accuracy of the Agricultural and Forestry Satellite
Authors: Lim Joongbin , Kim Chaeyeon , Son Jong-Hwan , Kim Taejung , RLee Sooahm , Lee Junghee , Kim Kyoungmin , Lee Seunghyun
Published: March 2024

The agricultural and forestry satellite, scheduled for launch in 2025, is a satellite being jointly developed by the Ministry of Science and ICT, the Rural Development Administration, and the Korea Forest Service of South Korea. Prior to its launch, technological developments have been made to ensure the positional accuracy of the agricultural and forestry satellite. For the geometric calibration of the satellite, a total of 4,650 precise image reference points have been established across the Korean Peninsula. These established precise image reference points have been verified to have a positional error of less than 1 meter based on field survey results. Utilizing this, the Rational Function Model (RFM) was corrected, determining the optimal parameters with six coefficients as suitable RFM correction coefficients for the precise geometric establishment of simulated images of the agricultural and forestry satellite. Subsequently, using the Digital Elevation Model for orthorectification, a final positional error of within 1 pixel (less than 5 meters) was confirmed.
Progress and achievement of Tianwen-1 mission
Authors: Geng Yan , Liu Jianjun , Zhang Lihua , Zhang Xiao
Published: March 2024

Tianwen-1 mission is the first in the world to achieve Mars orbiting, landing and roving exploration through a single launch, and has developed technologies for planetary exploration launch and flight, planetary capture control, Mars entry and descent landing, Mars surface roving for Zhurong, scientific payload design and operation, long-distance deep space TT&C communication, etc. The mission has obtained a large number of scientific exploration data, formed a series of basic information such as true color image maps covering Mars surface, and a series of new discoveries such as new evidence of water and wind and sand activities in the Martian Utopia Plain. It enriches mankind's scientific understanding of Mars.The report will introduce the progress and achievements of the Tianwen-1 mission in terms of technological development and scientific discovery.
Summer monsoon transition induced microseisms observed at the South China Sea seabed
Authors: Zhou Yulong , Kong Fansheng , Zhang Han , Liu Zhangju , Ding Weiwei , Li Jiabiao
Published: March 2024

It has long been recognized that complex interactions and energy conversions between the atmosphere-ocean system and the solid Earth can generate strong ambient noise field, known as microseisms which can be detected worldwide. Under the vast majority of circumstances, such seismic energy is believed to be induced by tropical cyclones. Whether unidirectional propagating winds, such as monsoons, can generate microseisms lacks solid seismic evidence. Here we utilize broadband seismic data recorded by seven ocean-bottom seismometers (OBSs) deployed in the South China Sea basin and 17 terrestrial stations to systematically investigate possible influences of the summer monsoon transition on the microseisms. Spectral analyses over time reveal significant seismic energy in the secondary microseisms frequency band (0.1−0.5 Hz) during 18th to 29th May, coinciding with the period of the summer monsoon transition occurring in the South China Sea. Polarization analyses and time-space variation of offshore surface wind field indicate that the source region of the observed secondary microseisms is located at the South China Sea. Given the absence of tropical cyclones during this time, we attribute the observed strong secondary microseisms to the summer monsoon transition. When the near-surface wind field is transformed to be southwest, ocean waves are driven to propagate northeastward and interact with an opposing wave train which represents precursor waves and is reflected by coastlines, generating the secondary microseisms. This study provides solid evidence for a causal link between the monsoon transition and microseisms, highlighting the potential of applying ocean bottom seismic observations for monitoring and characterizing monsoon transition and ocean activities.
Using a novel N-15 natural abundance approach to quantify soil nitrogen transformations in biochar-treated vineyard soils.
Authors: Kingston Kate , Xu Zhihong , Pratt Chris , Mackey Brendan , Petrie Paul , Li Yihan
Published: March 2024

The increased frequency and intensity of climate extremes challenges vineyards to adapt and mitigate to ensure the survival of grape vines (Vitis vinifera) to meet the growing demand for quality wine.  Regenerative Viticulture (RV) is a novel approach with a strong focus on increasing soil carbon (C) stocks to regenerate vineyard soil that is largely degraded and in poor health.  When soil health and fertility is low, this impacts vine health and reduces its ability to fight disease and pests and withstand extreme climatic events. We hypothesised that biochar would increase nitrogen (N) cycling and retention and that these would differ in relation to the distinct physiochemical properties of the two vineyard soils.   Conscious of contributing to a sustainable circular economy, we utilised viticulture industry waste to produce biochar’s to compare with standard pine biochar.  Biochar was produced with three feedstocks at different pyrolysis temperatures, grape marc (475°C), vine pruning (450°C) and pine (600°C).  Soil (0 - 10 cm depth) was collected from under vines from vineyards at the South Burnett (heavy texture) and Granite Belt (sandy texture) regions in Queensland, Australia. We used a novel 15N natural abundance approach in a laboratory incubation experiment to investigate the potential of using biochar, a C-dense material produced by high temperature pyrolysis of organic materials in limited oxygen conditions as a suitable climate smart RV method for vineyard soils.  A short three-day laboratory incubation followed by microdiffusion was conducted to quantify the impacts of the three biochars on N transformations in the two soils.  Soil moisture was controlled at 60% and 90% water holding capacity (WHC) and biochar applied at 0% and 10% (w/w), with samples harvested on incubation days 0 and 3. Preliminary results indicate that in the short term for both experimental soils, biochar stimulated microbial activity, increased N availability and water use efficiency and reduced N loss through denitrification.  The results indicate that fungicides use in vineyards impacted the underlying soil health and microbial communities and influencing N cycling.  For the long term impact, the potential to use biochar for increase biodiversity and ecosystem recovery as a climate smart RV method in vineyards needs to be trialled in the field.  This is to establish the long-term effects of C accumulation and improved N cycling on soil health, biodiversity, vine resilience under extreme natural weather events, and on wine grape quality and quantity.
Effect of Drought and Subsequent Precipitation (2016-2020) on Soil pH, Microbial Biomass, and Plant Nutrient Change in the Semi-Arid Region of Western North Dakota, USA
Authors: Landblom Douglas , Senturklu Songul , Cihacek Larry
Published: March 2024

Drought resulting from extended periods of limited precipitation have a substantial impact on soil pH, microbial biomass, and soil derived nutrients for plant growth. A long-term integrated crop, beef, and soil health research project at the Dickinson Research Extension Center is designed around a no-till diverse multi-crop rotation (spring wheat, cover crop, corn, pea-barley, sunflower). In this crop and animal production system, beef cattle graze the pea-barley, corn, and 13-specie cover crop to document microbial, fungal, and nutrient change over time and space. Precipitation during the first five-year crop rotation was normal to slightly above normal. However, the second five-year rotation was drier than normal resulting in nutrient concentration, reduced microbial biomass, and pH decline. Potential nitrogen mineralization of soil organic matter (SOM) in the crop rotation suggests that 8.4 mg N/kg of soil are mineralized for each 1.0% increase in SOM. The mean SOM content of soils in the study is 3.97%. For rain-fed crops, periods of reduced precipitation inhibit soil nutrient solubilization and translocation that negatively impacts a complex system of soil microbial respiration, fungal activity, plant nutrient supply, crop yield, and animal grazing days. The extent of soil drying in 2017 compared to moist soil in 2019 and somewhat drier soil in the 2020 cropping season will be presented. With drying, soil pH declined as soluble salt became more concentrated resulting in a more acidic condition. Naturally, reduced precipitation contributes to minimized plant and root growth, which contributed to reduced SOM content and nitrogen mineralization. For most of the crops in the diverse crop rotation, the percent of microbial active carbon, organic C : N ratio, and organic N : inorganic N ratio declined. Ward Lab Haney Test results for 24-hour microbial respiration provide measurements of microbial community and organismal diversity. Mean microbial biomass under drought conditions (2017), in the crop rotation, was 1,637 ng/g of soil. With the return to normal precipitation (2019) soil microbial biomass was 4,804 ng/g of soil; a 193.5% increase. While total microbial biomass increased with return to normal precipitation in 2019, arbuscular mycorrhizal fungi (AMF) did not reestablish in sunflower, cover crop, corn, and spring wheat-control, and only slight levels of AMF were measured in the pea-barley and spring wheat-rotation crops. Declining soil pH effects mineral nutrient availability among copper, manganese, zinc, and aluminum. At pH levels less than 5 (strongly acidic), aluminum availability becomes toxic to plants. Drought effected soil pH in this integrated systems research declined 9.5% to a mean crop pH value of 5.95, which at this pH level aluminum is sufficiently hydrated to be non-toxic. Return to normal precipitation (2019) increased the crop rotation pH mean to 6.58.
Role of Land Use Land Cover and Skilful Prediction of Rainfall Using Bias Corrected Ensemble during Extreme Rainfall Event
Authors: Vishwakarma Vijay , Pattnaik Sandeep
Published: March 2024

Extreme rainfall events (ERF) and their associated regimes are among the major catastrophes that have a worldwide impact including India which result in large-scale flooding and immense socio-economic loss. During the southwest monsoon season, these extremes are becoming a frequent norm in the hilly and mountainous regions of the country such as Assam which received one of the most historical ERFs during June 14-17, 2022. The present study investigates the ERF implementing the Weather Research and Forecasting (WRF) model using two different land use and land cover data sets (i.e. ISRO and USGS) and three different sets of physical parameterization schemes (i.e. planetary boundary layer, cumulus, and microphysics) with a lead time up to 96 hours. Further ahead, the performance of rainfall in bias-corrected ensembles (BCE) along with a suite of model ensembles is rigorously quantified up to the district level in terms of its intensity, and distribution. Results suggest that among all the ensembles (E1-E10), USGS (E6 - E10) has underestimated rainfall (140-260 mm/day) compared to ISRO (150-280 mm/day), including the heavy rainfall (HR), very heavy rainfall (VHR), and extremely heavy rainfall (EHR) categories over the upper Assam division (UAD) and lower Assam division (LAD) of Assam throughout the 96 hours. Afterward, rigorous statistical analysis in terms of frequency distribution, Taylor diagram, and benchmark skill scores is carried out to elucidate the model biases for all the ensembles. Throughout the 96 forecast hour, BCE E5(E10) is noted with the distinct realistic(underestimated) representation of model rainfall bias over all the subdivisions of Assam. The findings of the present study encapsulate the critical role of the ensembles of physical parameterization schemes, along with proper LULC, and the BCE approach is required to overcome challenges to improve the skills of ERF, particularly over complex terrains of Indian subcontinent such as Assam.