bluuebunny/crossref_metadata_2025 huggingface dataset:
Stable Pb isotope signals in the Arctic: does the general background exist?
Authors: Astray Blanca , Chrastný Vladislav , Šípková Adela
Published: February 2023

The crucial historical milestone, phasing out leaded gasoline, has rapidly affected atmospheric Pb's concentration and isotope composition. Distant Arctic localities, often without significant industrial contamination sources, can be influenced by foreign transport. For instance, Greenland is affected by Eurasian and Canadian sources in spring and summer, and North American sources in autumn and winter.Using snow samples, we chose three Arctic/Subarctic localities of Svalbard, Greenland, and Iceland to study the Pb stable isotope signals from the atmosphere. To learn more about possible sources of Pb pollution, we also processed local rock and fuel samples.We filtrated the melted snow to analyze the solid snow particles and the dissolved Pb pool in the snow. The Pb isotope composition in the solid particles was more related to the rock samples in Iceland and Greenland. Signals from rock samples in Greenland are less radiogenic than those we found in Icelandic rocks. In Svalbard, the solid particles are enriched with coal content which is still mined at this locality. In filtrates, the signals from fuel (gasoline/diesel) Pb are present, which indicates that the local sources of car and snowmobile traffic are a significant source of Pb in this area. In Greenland, we also found extremely radiogenic signals in filtrate snow samples. The origin of this source would be more likely related to distant sources by transboundary pollution transfer.  From our data, we conclude that several local and distant sources of Pb exist in pristine Arctic and Subarctic localities. Fuel seems to be the predominant source in Nuuk, while other sources, such as coal, are significant in Iceland and Svalbard, even in areas of higher local traffic.
Evaluation of sediment control due to notches of mountainous river
Authors: Tseng Chih-Ming , Chen Yie-Ruey , Tseng Jen-Yen
Published: February 2023

Upstream of notches in mountainous rivers reveal backwater effect and velocity decreasing characteristics. The sediment transport in the upstream of reach with notches is therefore affected by the plane morphological characteristics. The upstream reach could possibly play a role of sediment control section for temporary sediment trapping and mitigation similar like check dam. In this study, we used the DTM of difference (DoD) method to perform four multi-temporal high-resolution DTMs during 2009 to 2021 to obtain the quantitative terrain elevation variance of river channels in five notch regions. The research results show that during Typhoon Morakot, the sediment control in notch area no. 1 can reach more than 20%. From 2012 to 2018, the control effect of sediment in notch regions no. 1, 2 and 4 is more than 14%. Overall, the notches no. 1 and 2 are the main sediment control areas, and the area of notch number 3 is limited in the amount of sediment due to the small contraction ratio of notch; the area of the notch number 4 and 5 is the secondary sediment control area, because the notch area 5 both the area and the contraction degree of the notch are smaller than those in area 4, and the control effect of sediment is more significant in area 4. Therefore, if we can make good implementation of the natural morphological features combined with the engineering structures to improve the effect of sediment regulation and control, it can be used as a reference for formulating watershed management strategies.
Do Emergent Constraints on Carbon Cycle Feedbacks hold in CMIP6?
Authors: Schlund Manuel , Zechlau Sabrina , Cox Peter , Friedlingstein Pierre , Eyring Veronika
Published: February 2023

Emergent constraints help to better understand Earth system processes in a changing climate and to constrain future climate projections. Here, we analyze the robustness of two previously found emergent constraints on carbon cycle feedbacks using models from the Coupled Model Intercomparison Project (CMIP) of Phases 5 and 6. First, an emergent constraint on the carbon-climate feedback is evaluated, which is found to be robust regarding the choice of model ensemble. For the combined CMIP5 and CMIP6 ensembles, the sensitivity of tropical land carbon uptake to tropical warming is constrained to −37 ± 14 GtC/K. Second, we analyze an emergent constraint on the carbon-concentration feedback. This emergent constraint (originally derived from the CMIP5 models) is not evident in the CMIP6 ensemble. This is in part because the historical increase in the amplitude of the CO2 seasonal cycle is more accurately simulated in CMIP6, such that the models are all now close to the observational constraint.
Supporting operational water management and policy making through scale-specific approaches
Authors: Uhlenbrook Stefan , Mishra Sulagna , Silva Vara Luis Roberto , Korhonen Johanna , Otieno Washington , Kim Hwirin
Published: February 2023

Societies, economies and ecosystems depend on sustainable and resilient hydrological services provided by in-tact hydrological systems and processes. These services are defined by the inter-dependencies of various drivers of which land use and land cover changes (LULC) as well as climate change are increasingly dominating, often leading to degraded hydrological services and altered ecosystem dynamics with different levels of societal and economic impacts.Increasing and more frequent hydrological extremes (floods and droughts) and reduced water availability for various users and uses, often accompanied with increasing water demands, require effective operational water management. Therefore, in-depth knowledge of hydrological processes and their links to LULC, climate changes and other human interventions as well as tools are required to guide water management and policy decisions, such as, increasing water storage in grey and/or green infrastructure, caps on water consumption, or ecosystem restoration. This presentation reviews key processes and introduces the Hydrological Status and Outlook System (HydroSOS) and related assessment and reporting approaches to inform decision and policy-making. Therefore, a scale-specific approach is suggested in which LULC, water use and hydrological processes are embedded in a larger systems approach (including natural and human systems) to guide operational management and policies.
Holocene fire-vegetation history and its relationship with climate and human activity revealed by lake sediments from eastern Tianshan
Authors: Zhao Yongtao , Miao Yunfa , Jia Xin , Li Yuan , Li Haiming , Dong Weimiao , Zhao Jiaju , Wang Xuelian , Cao Xianyong , An Chengbang
Published: February 2023

To distinguish how climatic and human factors influence Holocene fire dynamics in arid, westerlies-dominated areas of Central Asia, we examined micro-charcoal and pollen records in well-dated sediment cores from Balikun lake, eastern Tianshan region, Central Asia. Our results show that vegetation biomass primarily controlled the suborbital-time-scale fire dynamics, with an increasing trend of fire intensity from the early to late Holocene. Evidence for substantial anthropogenic influence on fires is mainly related to the expansion of prehistoric agriculture during ~3.6-2.2 cal kyr BP in our study area. These human activities caused a departure from “natural” background fire levels that vary with climate change.In contrast, the human-linked fire peak in the nearby Hexi Corridor, which lies in Asian summer monsoon dominated regions of eastern China, occurred before ~3.6 cal kyr BP. This may reflect differences in the timing and sequence of cultural development under regions dominated by different circulation patterns. The weakening of the Asian summer monsoon after ~3.6 cal kyr BP likely promoted the Hexi Corridor population to migrate to eastern Tianshan, as evidenced by the similar pottery from eastern Tianshan to those of the Siba culture (4.0-3.5 cal kyr BP) that originated from the Hexi Corridor. This migration facilitated the formation of the westward cultural exchange route known as the “Painted Pottery Road”, enhancing regional human activity and causing an increase of fires in eastern Tianshan.
Understanding the combined effects of ozone pollution and climate change on crop yield and nutritional quality
Authors: Emberson Lisa , Bland Sam , Pande Pritha , Cook Jo , Booth Nathan , Pandey Divya
Published: February 2023

Ozone pollution and climate change are extremely likely to threaten future crop production in important agricultural regions around the World with the Mediterranean, South and East Asia and mid-West US being particularly at risk with implications for food security. Modelling methods used to assess risk of ozone pollution have developed in recent years away from empirical approaches based on dose-response relationships towards more process-based models. The DO3SE-Crop model has developed from an ozone deposition and effects model (having used flux-response relationships to assess damage) to a crop model capable of assessing the effect of ozone on photosynthesis and carbon allocation. Working within the AgMIP-ozone activity, DO3SE-Crop has been calibrated and evaluated against experimental ozone fumigation datasets for wheat cultivars from Spain (Mediterranean Europe), China and India and is able to assess the influence of climate variables on crop growth and yield as well as the effect of ozone on instantaneous photosynthesis and senescence. We find that the ozone effect on senescence is the primary determinant for yield loss in wheat. We are further developing the model to assess ozone effects on nutritional quality since we know that ozone is an important limiter of translocation of nitrogen to the grains. The establishment of DO3SE-Crop will allow assessments of the future impacts resulting form the combined effects of ozone and climate change on supply and nutritional aspects of food security. Importantly, this can include an assessment of the yield improvements between current and near- to mid-term future conditions for a range of adaptation options proposed for wheat in response to climate change including management of irrigation, growing season and development of new varieties from crop breeding with targeted physiological traits such as enhanced gas exchange and improved water use efficiency.
Magnetic Reconnection as the Driver of the Solar Wind
Authors: Raouafi Nour E. , Stenborg Guillermo , Seaton Dan B. , Wang Haimin , Wang Jason , DeForest Craig E. , Bale Stuart D. , Drake James F. , Uritsky Vadim M. , Karpen Judith T. , DeVore Carl R. , Sterling Alphonse C. , Horbury Timothy S. , Harra Louise K. , Bourouaine Sofiane , Kasper Justin C. , Kumar Pankaj , Phan Tai D. , Velli Marco
Published: February 2023

We present an overview of EUV solar observations showing evidence for ubiquitous small-scale jetting activity (i.e., a.k.a. jetlets) driven by magnetic reconnection that might be the primary driver of the solar wind at its source. The jetlets, like the solar wind and the heating of the coronal plasma, are omnipresent throughout the solar cycle. Each event arises from small-scale reconnection of opposite polarity magnetic fields producing a short-lived jet of hot plasma and Alfvén waves into the corona. The discrete nature of the jetlets leads to intermittent outflows from the corona, which homogenize as they propagate away from the Sun and form the solar wind. This discovery establishes the importance of small-scale magnetic reconnection in solar and stellar atmospheres in understanding ubiquitous phenomena such as coronal heating and solar wind acceleration. Based on previous analyses linking the switchbacks to the magnetic network, we also argue that these new observations might provide the link between the magnetic activity at the base of the corona and the switchback solar wind phenomenon. These new observations need to be put in the bigger picture of the role of magnetic reconnection and the diverse form of jetting in the solar atmosphere.
The MAESTRO Spectrophotometer on Canada’s SCISAT satellite: Advances in data processing and improved data products
Authors: McElroy C. Thomas , Walker Kaley A. , Drummond James R. , Zou Jiansheng , Jeffery Paul S.
Published: February 2023

The ACE-FTS and MAESTRO instruments have now been operating on the Canadian Space Agency’s SCISAT satellite as the Atmospheric Chemistry Experiment (ACE) for nearly 20 years.  The ACE satellite is approximately 1 m in diameter and 1 m deep and has a mass of 150 kg.  The Measurement of Aerosol in the Stratosphere and Troposphere Retrieved by Occultation (MAESTRO) spectrophotometer continues to measure ozone, water vapour and aerosol in the stratosphere and upper troposphere.  Like the ACE‑FTS, MAESTRO delivers results from nearly 30 occultation measurements per day, but with a higher vertical resolution of just over 1 km over a range as large as 5 to 40 km as meteorological conditions allow.  It measures from 500 nm to 1000 nm with a resolution of 1 to 2 nm.  The instrument design and performance will be briefly discussed and the algorithms developed to process the data and deal with peculiarities in the performance of the satellite will be described. Significant progress has been made recently in improving the retrievals that has resulted in improved accuracy and a larger number of successful retrievals at lower altitudes.  A new dataset with these improvements will be available for other researchers.  Some examples which illustrate the improvements will be presented.The ACE satellite was funded by the Canadian Space Agency (CSA) and launched by NASA. The CSA funds the MAESTRO data processing.  Environment Canada (EC) partly funded the construction of the MAESTRO instrument. 
Evaluation of CORDEX-CORE RCMs in representing BioClim variables for mosquito distribution models in Mediterranean regions
Authors: Bangelesa Freddy , Merkenschlager Christian , Hertig Elke , Paeth Heiko
Published: February 2023

An adequate representation of the distribution of mosquitoes transmitting vector-based diseases under future climate change conditions is essential to estimate the occurrence of those diseases in areas such as the Mediterranean. For this purpose, species distribution models are used to establish a statistical relationship between recent and future environmental conditions and the spread of species. The 19 BioClim variables have been widely used to drive these models because they represent key features (e.g. hot, cold, dry, humid) of different temporal dimensions (quarter or month). The scientific community has paid less attention to the difficulties that arise when using BioClim variables, including how well the climate model can reproduce them. This study intended to assess the skill of 10 different high-resolution regional climate models (RCMs) of the Coordinated Regional Climate Downscaling Experiment’s CORE initiative that represent BioClim variables in Mediterranean regions. The skill analysis was implemented using the metrics of spatial correlation, spatial standard deviation and the mean absolute percentage error. The result reveals that REGCM4 and REMO15 are the best-performing RCMs in terms of standard deviation and the mean absolute percentage error, and RACMO and CCLM4 are the best-performing RCMs in terms of spatial correlation. The result shows that temperature-based BioClim variables are better represented by the majority of RCMs compared to precipitation models. A huge uncertainty remains when it comes to the representation of quarter-based variables. Hence, future studies should be focused on improving the representation of BioClim variables, especially those related to precipitation, by applying appropriate bias correction techniques. The best-performing RCMs of this study will be used to derive different species distribution models of Anopheles mosquitoes over the Mediterranean regions to estimate the future distribution of vector-based diseases.
Effectiveness of a Mobile Chlorine Gas Generator as a Treatment for Biofouling in Relief Wells
Authors: Smith Clint , Martinez-Guerra Edith , Thomas Catherine , Atwain Fahmi , Fisher Andmorgan , Diaz Lluberes Ilea , Simrall Kie , Dees Jillian , Goodrich James , Daniels Kurtis
Published: February 2023

Dams and levees are a critical component of the contingency plans required to provide sufficient potable water to support the population during episode of droughts. However, microbial growth and subsequent encrustation that builds on the relief wells have been shown to build unwanted pressure within dams and levees when left untreated. This biofouling can lead to malfunctions of the wells, especially in dams that are under stress from drought-induced low water levels. Oxalic acid has been used as the most common alternative to alleviate hydrostatic pressures when encrusted biofouling occurs. The Water on Wheels (WOW) Cart Relief Well Sustainment (RWS) system was designed to function as a more cost-efficient and targeted alternative by allowing the use of a portable chlorine generator. It electrochemically converts sodium chloride to sodium hypochlorite, in a controlled and monitored manner, allowing for the use of either chlorine gas or chlorine gas dissolved in water. The Grenada Dam is a man-made dam that supplies Mississippi, as well as a habitat to various local species. A previous study in the area showed how the effects of drought and biofouling altered the coastline and performance of the dam, affecting the local ecosystem and water supply. Scheduled treatments in this area are conducted to upkeep the dam, as well as monitor the water levels that might indicate a rapidly emerging drought event. Various relief wells in the Grenada Dam region were treated using either oxalic acid or the chlorine produced by the WOW Cart RWS system alternatively. Initial field test results have shown that the WOW cart system reduces the microbial growth just as effectively as current conventional methods of treatment, while minimizing the associated costs. When tested against oxalic acid, it was found that the relief wells treated with the cart reported no detected level of growth for a lesser cost and adequately relieved the pressure on the relief wells to allow proper water-flow and usage. Therefore, the WOW cart provides an easier and more efficient alternative to maintain the functionality and ecosystem of the dam, making it readily prepared for any dry spell that might affect the area. Future studies will be developed to determine Standard Operating Procedures (SOP) that will focus on treatment time and condition.
FTICR-mass spectrometry reveals shifts in plant-microorganism interactions over time
Authors: Rai Akanksha , Lange Markus , Lechtenfeld Oliver , Gleixner Gerd
Published: February 2023

A plethora of experimental studies manipulating plant diversity have shown a positive effect of biodiversity on ecosystem functions (aboveground biomass, microbial biomass etc.), which strengthens over time. Tightening of the interactions between plant and soil microorganisms over time is considered to be one of the mechanisms responsible for the observed strengthening of the biodiversity-ecosystem functioning (BEF) relationship. Belowground plant-microorganism interactions occur via the exchange of molecules present in the dissolved organic matter (DOM). Hence, an untargeted ultrahigh resolution mass spectrometric analysis of DOM provides an opportunity to understand the mechanisms of interaction between plants and microorganisms in soil. To investigate if and how plants-soil interactions changed over time, we took advantage of the highly replicated DBEF experiment of the Jena Experiment (JE) (Roscher et al., 2004, Vogel et al., 2019). In this experiment, the duration of plant-soil interactions (“history”) and the respective effects of plant diversity on ecosystem functioning were manipulated. Here, we analyzed the water extractable organic matter fraction of topsoil (WEOM; analogous to DOM in this study) using online nano solid phase extraction FTICR-mass spectrometry. While the molecular composition of the WEOM was not impacted by soil history, plant diversity effect differs among the soil history treatments. Specifically, plant diversity had a significant impact on the molecular composition of WEOM in treatments with plant and soils history. In addition, the molecular composition of WEOM in this treatment held a large number of molecular formulae that significantly correlated with plant diversity. This suggests that the strengthening of the biodiversity-ecosystem functioning over time is reflected in the WEOM molecular composition. Thus, the molecular composition of WEOM potentially provides insight into the mechanism underlying the strengthening of biodiversity-ecosystem functioning.  Roscher, C., Schumacher, J., Baade, J., Wilcke, W., Gleixner, G., Weisser, W. W., ... & Schulze, E. D. (2004). The role of biodiversity for element cycling and trophic interactions: an experimental approach in a grassland community. Basic and Applied Ecology, 5(2), 107-121.Vogel, A., Ebeling, A., Gleixner, G., Roscher, C., Scheu, S., Ciobanu, M., ... & Eisenhauer, N. (2019). A new experimental approach to test why biodiversity effects strengthen as ecosystems age. In Advances in ecological research (Vol. 61, pp. 221-264). Academic Press.
Ag-IoT application for Vital Monitoring of Plant Ecophysiological Data and Soil Parameters
Authors: Asgharinia Shahla , Lembo Micaela , Eramo Vanessa , Forniti Roberto , Renzi Francesco , Valentini Riccardo , Botondi Rinaldo
Published: February 2023

Ag-IoT systems enable a data pipeline for modern agricultural production. Using Ag-IoT technologies, growers can make better management decisions by leveraging the real-time field data while researchers could utilize these data to answer key scientific questions. Here, we designed a flexible microprocessor-based platform, called TreeTalker, to monitor in real-time plant sap flow rate via thermal approaches. TreeTalker has an onboard spectrometer to collect data in near infrared and visible areas using 12 bands from 450 to 860 nm. Moreover, TreeTalker collects microclimate data (air temperature and air relative humidity) as well as soil moisture and temperature measurement. Sap flow and soil moisture measurements are the main tools to understand the plant water demand for precision irrigation and water-energy efficiency. In this study, 9 TreeTalker units are mounted on Soreli Kiwifruit trees in the Lazio region, Italy. The site is divided into three clusters with different irrigation regimes, 100, 80 and 60 %, respectively. The first objective of this study was to apply new algorithms for sap flow measurement considering the heating and cooling phases of the heat flow curve at the same time and secondly, a compare of phenological and ecohydrological trends of trees under full and deficit irrigation systems. Data captured was used to analyze the correlation between fruit quality, productivity, health, and fertility of trees with ecophysiological parameters under different irrigation systems. The result of continuous monitoring for one growing season in 2022 revealed that sap flow function based on cooling phase data has higher accuracy than heating phase due to independency to the zero-flux condition as well as semi-theoretical flow index. Given sap flow results, plants with the full irrigation system have ∼ 1.3 to 3 times greater sap flow rate than plants with deficit irrigation regimes. Kiwi peak water demand occurred in July coinciding with max VPD confirming maximum sap flow rates between each irrigation regime. A variation between the 80% and 60% irrigation regimes, ∼ 4 to 15 %, is linked to slight differences in sap flow rates and is most prominent in the early part of the growing season. Considering fruit quality data, kiwifruit trees with full irrigation showed lower acidity, and higher Vitamin C concentration while sugar concentrations were noticeably lower. Our results suggest that the 80% irrigation schedule achieves the optimum water energy efficiency as well as reaching optimum fruit quality conditions. This finding requires validation via continued monitoring over successive seasons and irrigation regimes. The revolution in the Internet of trees offers a promising new big data solution for assessing optimal conditions for fruit tree agricultural production considering future and potential water scarcity scenarios.
Fog and low-level stratus characteristics at the airport of Lviv from surface observations
Authors: Khomenko Inna , Hustenko Oleksii
Published: February 2023

Fog and low-level stratus have been recognised as a hazardous weather phenomenon leading to several losses in time, money and even human life above all in aviation but also in other forms of transportation, such as navigation and land transportation. The forecast of low-level stratus and fog is one of the most difficult issues of aviation meteorology due to spatial and temporal variability of their characteristics and high dependence on local conditions. So, weather observations can be used for statistical dependencies of fog/low-level stratus characteristics on numerical model outputs.To study fog and low-level stratus characteristics occurring at the airport of Lviv, Ukraine, three-hourly meteorological observations in the period of 2010-2020 are used. Applying a statistical approach annual, seasonal and diurnal distribution of fog and low stratus and their frequency distribution associated with various meteorological parameters are obtained.It was shown that at the airport of Lviv low-level stratus more frequently (60% of all cases) forms in the November-December-January-February period, whereas in July and August it is least frequently observed (less than 5% of all cases). Distribution of the fog observations with respect to months also is inhomogeneous. Fog mainly forms from October to January (56% of all cases) with the maximum (19%) in November. From March to September fog happen rarely with minimum in June (3% of all cases). No distinct diurnal cycle of the low-level stratus occurrence can be revealed from the data, however low-level stratus more frequently occurs during the nighttime and in morning. As opposed to low-level stratus for fog the highest frequency is observed in the hours before sunrise, while when the day sets in, frequencies are declining and increasing at night.Low-level stratus is the most commonly associated with surface temperatures of 0.0 to +8.0°С and relative humidity of 80 to 95% (32% of all cases), by comparison with 35% of all fog cases observed at temperatures of 0.0 to +6.0°С and relative humidity of 96 to 100%.In all seasons of the year, the highest frequency of low-level stratus (from 35 to 40% of all cases) is in interval of 3...4 m/s, whereas fog is the most frequently observed in calm weather (from 37 to 77% of all cases). In autumn and winter, both under low-level stratus and fog, surface wind is characterized by high occurrence frequency of west, north-west (around 25% of low-level stratus cases and 10% of fog cases) and south, south-east (around 30% of all cases) directions. In spring and summer, north, north-west and west directions are most frequently reported in low-level stratus cases (47% of low-level stratus cases in spring and 69% in summer). For fog in spring and summer the same wind directions are typical (18% of fog cases in spring and 10% in summer). However, it should be noticed that in spring the east direction is often observed for both fog and low-level stratus. 
Environmental Vulnerability Assessment of Anthropogenic Droughts in Regulated Basins
Authors: Mehran Ali , AghaKouchak Amir
Published: February 2023

Man-made local water supply infrastructure (in particular reservoirs) affects future water availability because it is built specifically to cope with climatic extremes. A system with multiple reservoirs, and therefore more local resilience, will be less vulnerable to climatic change and variability compared to a system with limited local capacity to cope with extremes. Therefore, different regions will see different water availability changes depending on their local infrastructure and capacity to cope with variability or adapt to change. The key questions that are studied in this proposal is the extent and intensity of environmental impact of the water stress. To address the question, this study proposes a multidisciplinary framework that integrates top-down (local inflows) and bottom-up (historical water use categories) factors to quantify the human induced water stress in each reservoir and the overall impact on the system’s resilience (water availability). The human induced water stress in regulated basins (with multiple reservoirs) is tracked by assessing the historical water use categories, which are later used to develop hypothetical water demand scenarios for near-future water stress assessment. Recent studies have shown that by changing water use policies, the system builds up resilience to cope with water stress. Our study explores reservoirs with multiple basins and tracks the policy changes impact on the system regarding the reservoirs orientation in the basin. Furthermore, this study tracks the environmental impact of the socioeconomic drought condition in regulated basins and highlights the changes due to water use policies.
AVISO+: what’s new on the reference portal in satellite altimetry?
Authors: Mertz Françoise , Germineaud Cyril , Soudarin Laurent , Rosmorduc Vinca , Schgounn Catherine , Birol Florence , Niño Fernando , Guinle Thierry
Published: February 2023

AVISO (Archiving, Validation and Interpretation of Oceanographic Satellite data) is a service set up by the French spatial agency, CNES (Centre National d'Etudes Spatiales) to process, archive and distribute data and derived products from satellite missions. Its web portal AVISO+ (www.aviso.altimetry.fr) is the entry point to freely access more than 40 products from CNES and CTOH (Center for Topographic studies of the Ocean and Hydrosphere) not only for ocean-oriented applications but also for hydrology, coastal, biology and sea ice applications. In addition, the website proposes information (handbooks, use cases, outreach material, etc.) to discover the products and their use. New operational (or demonstration) products are regularly added to the AVISO+ catalogue. In 2022, the catalogue has been for instance enriched with several along-track and gridded SSALTO/DUACS experimental products, simulated SWOT Sea Surface Heights, costal products of Sea Level Anomaly (X-TRACK L2P), the Floating Sargassum detection index and climate indicators for the ocean heat content and earth energy imbalance. In 2023, new versions of the models produced by CNES and CLS for the Mean Sea Surface (MSS CNES-CLS 2022) and for the Mean Dynamic Topography (MDT CNES-CLS 2022) will be available for AVISO+ users, as well as the upcoming SWOT oceanographic products. A visualization tool will also be available online to discover the AVISO+ products, including the KaRIn measurements of the SWOT mission over the oceans. An overview of these new AVISO+ products will be presented.
Selective dissolution of calcite in a bacterial habitat environment
Authors: Kobatake Hidekazu , Inoue Haruhiko
Published: February 2023

It has been well known that the activity of bacteria causes a promoting crystallization in the natural environment. On the other hand, it has been pointed out that bacteria activity also plays a role in the dissolution of crystals, and the microscopic observation showed that the inhibition of the bacteria affects the pit formation to promote the dissolution of calcite[1]. The authors found a grope of bacteria, which promotes the dissolution process of calcite. We isolated bacteria from calcite-enriched soil and examined their calcite-degrading activity.To understand the role of bacteria in the dissolution process, In the experiments, the cleavage surface of the calcite was exposed to the culture fluid of the bacteria for 4 days to investigate the effect of bacteria on the calcite dissolution. The surface morphology of the calcite was investigated using an optical microscope and scanning electron microscope after the dissolution experiment in the culture fluid with bacteria.The calcium ion concentration in the culture fluid of Streptomyces was one-third of control, Escherichia coli DH5a, indicating the promoting the dissolution process of calcite. The surface observation of the calcite surface, which has been exposed in the culture fluid of bacteria shows the etch pits, which were formed during the dissolution process.Differing from the previous study, [1] the shape of the etch pits showed a rounded and asymmetric shape and deviated from the rectangular, which reflects the symmetry of the surface. These etch pits were formed accompanied by the bacteria colony. And the bacteria colony was formed along the cleavage step on the calcite surface. These observations infer that the inhabitation of the bacteria and the dissolution of the calcite are related to each other and the effect of the surface activity of calcite in the dissolution process could be larger by the biological activity.Reference[1] A. Luettge and P.G. Conrad, Direct observation of microbial inhibition of calcite dissolution, App. Env. Micr (70) 2004
Moisture Seasonality as a Differential Driver of Modeled Forest Distribution during the Pennsylvanian
Authors: Matthaeus William , White Joseph , Macarewich Sophia , McElwain Jennifer , Wilson Jonathan
Published: February 2023

Environmental restriction of forest distribution may be specific to the eco-physiological limits of era-appropriate plants. Accounting for major limiting factors in deep time will improve understanding of ecosystems dominated by extinct plants, surface processes, and Earth System function. Major plant taxa associated with Earth’s penultimate icehouse (the late Paleozoic ice age [LPIA]) are thought to have been limited by moisture seasonality based on evidence from fossil and geological records. We apply recently described methodologies­—climate modeling and ecosystem-process modeling—to simulate global arboreal vegetation in the late Paleozoic ice age. We will compare the intensity of modeled moisture seasonality with plant performance of major late Paleozoic plant taxa. Using National Center for Atmospheric Research’s Community Earth System Model version 1.2 (CESM) simulations, varying pCO2, pO2, and ice extent for the Pennsylvanian, and fossil-derived leaf C:N, maximum stomatal conductance, specific conductivity, and stem physiological limitations for several major Carboniferous plant groups, we will simulate global ecosystem processes at a 2-degree resolution with Paleo-BGC. We hypothesize that moisture seasonality patterns across Pangea will interact with modeled era-appropriate taxa—based on stem hydraulic hysteresis and leaf water limitations—to impact arboreal plant growth and forest cover. The simulated function of era-appropriate stem and leaf trait combinations may provide a mechanistic link to drought-tolerance evolution in lineages like the coniferophytes that persist across global ecological upheavals.
Exploring Europa, Jupiter’s Ocean World: A View from Earth
Authors: Blankenship Donald D. , Young Duncan A. , Chan Kristian , Wolfenbarger Natalie S. , Gerekos Christopher , Steinbrügge Gregor B.
Published: February 2023

Europa Subsurface Studies: The Europa Clipper is a NASA mission to study Europa, the ice-covered moon of Jupiter characterized by a global sub-ice ocean overlying a silicate mantle, through a series of fly-by observations from a spacecraft in Jovian orbit. The science goal is to “explore Europa to investigate its habitability”. The Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) is one of the primary instruments of the scientific payload. REASON is an active dual-frequency (9/60 MHz) instrument led by the University of Texas Institute for Geophysics (UTIG). It is designed to achieve multi-disciplinary measurements to investigate subsurface waters and the ice shell structure (Sounding), the surface elevation and tides (Altimetry), near-surface physical properties (Reflectometry), and the ionospheric environment including plume activity (Plasma/Particles). REASON will play a critical role in achieving the mission’s habitability driven science objectives, which include characterizing the distribution of any shallow subsurface water, searching for an ice-ocean interface and evaluating a broad spectrum of ice-ocean-atmosphere exchange hypotheses. Terrestrial Analogs: The development of successful measurement approaches and data interpretation techniques for exploring Europa and understanding its habitability will need to leverage knowledge of analogous terrestrial environments and processes. Towards this end, we are investigating, and considering for future investigations, a range of terrestrial radio glaciological analogs for hypothesized physical, chemical, and biological processes on Europa and present airborne data collected with the UTIG/University of Kansas dual-frequency radar system over a variety of terrestrial targets relevant to Europa’s potential exchange processes and habitability.  These targets include water filled fractures, brine rich ice, subglacial lakes, accreted marine ice, and ice roughness ranging from porous ice regolith (firn) to extensive crevasse fields. Our goal is to provide context for understanding and optimizing the observable signature of these processes in future radar data collected at Europa with implications for its habitability.
Deep Georeferencing of WWII Aerial Reconnaissance Images
Authors: Karel Wilfried
Published: February 2023

This work is on the automated, photogrammetric orientation of World War II aerial reconnaissance images. For these near-nadir images, the footprint centers are known beforehand with an accuracy of a few hundred meters, together with coarse image scales and nominal focal lengths, but without image rotations. Since their overlap is typically small or absent, the approach orients the images one after another. A novel rotation-invariant, end-to-end CNN image feature matcher finds homologous points both in an aerial image and in an iteratively refined detail of a present-day orthophoto map, initially extracted according to the given metadata. This results in automatically determined ground control points whose heights are interpolated in a likewise present-day terrain model, and which serve to estimate image orientations in a bundle adjustment. The image orientation quality is assessed by projecting manually observed ground control points into image space and comparing them to their likewise manually observed image positions. Hundreds of images of various scales are evaluated, featuring cloud and snow cover, long cast shadows, dust, and scratches. Despite the large gap in time between the aerial and reference data sets and respectively large changes on the ground and in appearance, the approach results in an RMSE of manual ground control points of less than 1mm for over 60% of the images.
Erosion-tectonic Sandbox Models of the Structural and Fluvial Evolution of Transpressional Systems
Authors: Conrad Ethan , Reitano Riccardo , Faccenna Claudio
Published: February 2023

Many analog transpression studies focus on the structural development of the system without including the effects of surface processes. Considering the high number of transpressional systems globally, the lack of these studies restricts our ability to representatively constrain, interpret, and model the crust and surface through time. Here, we present a new set of analog models to investigate how tectonic and surface processes at transpressive plate boundaries interact to shape topography. Experiments were conducted in a 2 × 1 × 0.5 m plexiglass box, with ends left open for drainage. Inside the box, we fix a plexiglass board cut to 20º obliquity to the sidewall. A mylar sheet is pulled under the board, forming a velocity discontinuity between the fixed board and the moving sheet. We load the board–sheet set up with a ~5 cm thick package of the experimental material (cf. CMII in Reitano et al., 2020, doi: 10.5194/esurf-8-973-2020 at 20 wt. % H20). Surface processes are initiated using commercial misting nozzles aligned with the trend of the wedge. We used a laser scanner to generate digital elevation models incrementally throughout the models and cameras (1 min photo intervals) for particle image velocimetry analysis. Here we focus on three experiments that we conducted using this system across various rainfall and convergence settings. Two tests represent end member CR# (the ratio between convergence and rainfall rate) settings. The third is a dry reference model. By analyzing these models, we attempt to identify the potential feedback between drainage and fault networks to explain morphological differences between experimental wedges with high, low, and no erosion. In all experiments, a bivergent wedge forms, and strain partitioning broadly evolves following previously established models. We find that erosion may influence the structural evolution of transpressional mountain belts leading to accelerated strike-slip partitioning. We also highlight how incision along main structures may localize exhumation in the system. We apply this model to assist in understanding uplift, deformation, and erosion patterns in natural transpressional systems, including the central Transverse Ranges of the San Andreas, the Merida Andes of Venezuela, and the Central-Western Cordillera of Colombia.
Status and current considerations on carbon farming in selected European countries
Authors: Hönle Susanna , Heidecke Claudia
Published: February 2023

There is the expectation that carbon farming can contribute significantly to climate change mitigation by both sequestering carbon from the atmosphere and preventing the release of additional CO2-emissions from the soil. While it seems uncontroversial that measures to improve soil carbon provide many additional ecological benefits, it is rather challenging to integrate carbon farming activities into the existing climate policy frameworks. Apart from the usual concerns about the robustness of monitoring, reporting and verification (MRV) and the permanence of the carbon farming result there are other unresolved questions regarding additionality, double-claiming and double-counting when combining state-based action with voluntary carbon markets, where private schemes sell their carbon-credits to companies for the offsetting of their emissions.Within the scope of the EJP-Soil sub-project Road4Schemes our objective was to examine the current state of carbon farming policies in 9 European countries (including Switzerland and Turkey as non-EU members). Having collected questionnaires both at the level of policy makers and at the level of experts on national greenhouse gas inventories, we are able to make a first assessment of the relevance of carbon farming as a climate mitigation strategy in the individual countries, the reportability of different measures in national climate reporting and the role of private initiatives in achieving scalable climate change mitigation effects. It is furthermore of interest to compare countries’ policy approaches for enhancing carbon farming and integrating the different stakeholders and actors. In this way, this study aims to contribute to the current discussion on the potentials and obstacles of using carbon farming for climate mitigation.
Navigating the Coevolution of Land Use Changes and Agricultural Technologies to Achieve Sustainability: An Agent-based Study of Policy Influences
Authors: Zeng Yongchao , Shi Yingying , Fu Hua
Published: February 2023

Land use changes have a significant impact on both the economy and the environment. The competitive behaviors of land managers, influenced by policy and agricultural technology, play a crucial role in shaping the patterns of land use changes. However, it is challenging for a model to couple these three dynamic factors that reflect the heterogeneous, dynamic, and interactive features of land use complex systems while keeping sufficient interpretability for informing policymakers. This research is intended to overcome this challenge by building an agent-based model according to the framework of Competition for Resources between Agent Functional Types (CRAFTY), and integrating it with the dynamics of agricultural technology progress and a policymaker agent that can impose a compound influence on the incentives to different land manager typologies by weighting the marginal utility of multiple agricultural services resulting from the trade-off between economic growth and sustainability. The numeric experiments demonstrate that a complementary effect is captured between different agricultural technologies; the progress of agricultural technology in an arbitrary agricultural service considered in this model is both economically and environmentally beneficial; agricultural technology progress can give policymakers more flexibility to set up protected areas aiming at environmental protection while mitigating damaging the economic growth. The results imply that it is conducive to maintaining redundancy in agricultural productivity to increase the land use system’s robustness to external disturbances.
Retrodicting flow of the early Cenozoic mantle: perspectives from an adjoint modelling approach
Authors: Ghelichkhan Siavash , Bunge Hans-Peter , Oeser Jens
Published: February 2023

Convection in the mantle provides the primary forces that shape the long wavelength structure of the Earth's surfacethrough dynamic topography. These forces have long been known as the cause of key events in the Cenozoic era: thetermination of large-scale marine inundation in North America in the Palaeocene, the late Tertiary rise of Africarelative to other continents and the long-wavelength tilting of Australia since the late Cretaceous. It is anoverarching goal in geodynamics to construct reliable models that can retrodict (make predictions about the past)these key events correctly. This year marks the 20th anniversary since the introduction of adjoint modelling as apowerful method to retrodict mantle flow. Using the adjoint method, various datasets are assimilated to optimizedynamic earth models by deriving the necessary gradient information. Here we explore a suite of eight high-resolution(about 670 million finite elements), compressible, global mantle flow retrodictions going back to 50 Ma. Ourretrodictions involve the dynamic effects from an upper mantle low-viscosity zone, assimilate a past plate-motionmodel for the tangential surface velocity field, probe the influence of two different present-day mantle stateestimates derived from seismic tomography, and acknowledge the rheological uncertainties of dynamic Earth modelsby taking in four different realizations for the radial mantle viscosity profile, two of which were publishedpreviously. The retrodictions show for the first time that key Cenozoic events emerge jointly as part of globalCenozoic mantle flow histories. We show that the retrodicted mantle flow histories are sensitive to the present-daymantle state estimate and the rheological properties of the Earth model, meaning that this input information istestable with inferences gleaned from the geological record. Retrodictions allow one to track material back intime from any given sampling location, making them potentially useful, for example, to geochemical studies. Ourresults call for improved estimates of non-isostatic vertical motion of the Earth’s surface — provided, forinstance, by basin analysis, seismic stratigraphy, landform studies, thermochronological data or the sedimentationrecord — to constrain the recent mantle flow history and suggest that mantle flow retrodictions may yield synergiesacross different Earth science disciplines.