bluuebunny/crossref_metadata_2025 huggingface dataset:
A 13,500 year speleothem record from southeastern Alaska
Authors: Wilcox Paul , Spötl Christoph , Edwards Lawrence , Honkonen Jessica
Published: February 2023

Under Anthropocene warming, Alaska is one of the fastest warming regions on Earth. To place this warming in better context, it is important to extend a high-resolution paleoclimate record throughout the Holocene. However, few such records exist in Alaska, with the majority limited to low-resolution lake sediment studies. Here, we provide a continuous, precisely dated, and high-resolution speleothem record that extends from modern-day to 13,500 yr BP. This represents the first Holocene speleothem record from Alaska, and sheds light on important paleoclimate changes at this high-latitude location. We find that the speleothem oxygen isotope record is largely controlled by changes in the tropical Pacific Ocean, with a significant mean state shift change occurring after ~1970 CE. The mean state shift at ~1970 CE has no similar anolog during the 13,500 year speleothem record, and we attribute the shift to anthropogenic forcing.
Comparison of discontinuity occurrence in ozone data in selected reanalyses
Authors: Krizan Peter
Published: February 2023

The aim of this poster is to compare the discontinuity occurrence in the ozone data from the following reanalyses: ERA-5, MERRA-2 and JRA-55. We use the ozone concentration data from all layers between 500 hPa and 1 hPa in the period 1980-2020 in January. We also compute the total ozone content between these layers by vertical integration of ozone profile. We search for discontinuities also in this content.    This is important topic, because the presence of discontinuities influences the values of trends and their significance. Discontinuities arise from the changing in the assimilation procedure, introducing new observation to the reanalyse, and changing of data quality.  There are dates which the occurrence of discontinuities is expected in: 2004- transition from SBUV to EOS Aura data and 2015-  the 4.2 MLS data were started to use instead of version 2.2. We search for discontinuities in the following classes of extremity: 1st, 10th, 25th, 50th,75th,90th and 99th percentile as well as the mean. Ozone data with high occurrence of the discontinuities is not suitable for trend analyses.
A new 24/7 operational workflow in agro-meteorology, based on the coupled WRF/SEBAL models
Authors: Nikfal Amirhossein , Karimi Mohammadamin , Pashapour Salar , Vazifedoust Majid , Khorani Masoumeh , Khosravi Tabrizi Amirmahdi , Noory Hamideh , Rezvani Mohammad , Toofaninejad Zahra
Published: February 2023

Water scarcity is regarded as a primary issue in many dry climates, with significant impacts on food security and national developments. Since agricultural irrigation accounts for most of water consumption worldwide, providing a water management system is critical to cope with water stress and its challenges. Agricultural water management is an interdisciplinary task, dealing with meteorological and environmental factors. In this work, we have established a 24/7 operational system to simulate those land surface variables, associated with evapotranspiration, biomass growth, and water deficit, using the Surface Energy Balance Algorithm for Land (SEBAL). SEBAL simulates the energy balance, using satellite data in shortwave and thermal bands, as well as soil and meteorological data (wind speed, humidity, etc).This workflow consists of 3 interconnected units: WRF model, Python implementation of the SEBAL model (pySEBAL), and a web-based management panel for the visualization, reanalysis, and publishing the results. The WRF model is run in a daily basis for 36 hours, starting from 12:00 UTC, to provide the meteorological data for the next day. At the next stage, the simulated WRF data after some required processing (converting formats and units of files andvariables, etc.) will be incorporated as input data into the SEBAL model. The key data for the SEBAL model is the “Visible Infrared Imaging RadiometerSuite” (VIIRS) real-time data over the Suomi satellite, which is received automatically after tracking the satellite and picking the appropriate data files for download. SEBAL outputs include some of the variables with key role in agricultural water management, such as actual and potential evapotranspiration, biomass production and deficit, albedo, NDVI, etc, with a resolution of 375m over Iran.The third section of the operational system is a web-based panel, consisting of an open-source server to share and edit the SEBAL outputs. An open-source database management system for the client- based analysis of the SEBAL outputs, and an open-source JavaScript library for displaying the maps of the SEBAL outputs in web browsers.
Optimization of a classification scheme for Arctic wetlands to support carbon and energy flux upscaling
Authors: Ivanova Kseniia , Goeckede Mathias
Published: February 2023

Wetlands play an important role in the carbon balance of the Arctic. All wetland types are characterized by an individual combination of hydrological conditions, soils, vegetation cover, etc. These characteristics influence their feedback with current and future climate conditions, and therefore also their greenhouse gas exchange processes. While most climate models distinguish only one or two types of wetlands, biogeographical approaches define at least ten types of wetlands in the Arctic.Improving the representation of wetland ecology in carbon upscaling studies in the Arctic requires finding the balance between the diversity of wetlands, including their variability in responses to climate forcing, and the information that is commonly available to represent them in modelling frameworks. On the one hand, a larger number of classes allows a more precise description of the conditions and characteristics of the fluxes within each class. On the other hand, more classes also mean less information per class, and thus more gaps that need to be interpolated.To support the development of a refined classification scheme, we first built a database on Arctic wetland characteristics, including measured carbon pools and fluxes, based on the available information from published studies. Our database covers the period 1988 – 2019, with observations for all seasons available. Most data was taken from flux chamber studies, since this technique allows to resolve the highly heterogeneous mosaic of landcover, environmental conditions, vegetation and consequently GHG fluxes that characterize large fractions of the Arctic. For all plots, general (coordinates, time of measurements, etc.), physical (pH, vegetation composition, water table, etc.) site characteristics and CH4 and CO2 fluxes were collected. However, for some of these parameters, data coverage turned out to be too sparse to complete analyses. For example, permafrost depth, pH, and water table level cover only 45, 15 and 34% of all available plots. To improve this situation, remotely-sensed data was included, allowing to equally cover all measurement points, albeit often with less accuracy.Based on statistical processing using agglomerative hierarchical cluster analysis, we divided all observations into wetland categories based on their CO2 and CH4 flux signatures and the response to dominant environmental factors. We present the most successful classifications for different total numbers of classes, allowing to base the choice of scheme on the information that is available for a specific modelling study.
Climatology and trends derived from columnar aerosol measurements in Cluj-Napoca, Romania.
Authors: Radovici Andrei , Stefanie Horatiu , Mereuta Alexandru , Camarasan Horia , Botezan Camelia , Costin Dan , Ajtai Nicolae
Published: February 2023

It is well known that in the climate and air quality studies, the monitoring process of aerosols and their temporal evolution is very important as they generate a significant impact on meteorology, air quality, climate, and human and ecosystem health. In this study, we present an overview of aerosol optical and microphysical properties over Cluj-Napoca, Romania- based on more than 12 years of observations from a Cimel sun-photometer operating in the framework of AErosol RObotic NETwork (AERONET) and part of the Aerosol, Clouds and Trace Gases Research Infrastructure (ACTRIS). This site is located in the north-western part of Romania and contributes to AERONET with sun photometer observation since 2010. As the atmosphere in the region is characterized by a mixture of aerosols from multiple sources: urban/industrial (dominant) biomass burning, Saharan dust, etc., this study aims to present the aerosol trends and the temporal variation of their properties based on long-term observations. The analysis highlighted that the aerosol load over the area is characterized by high inter-annual and seasonal variation of AOD due to variation of local sources and long-range transport. The same variability was observed for the Ångström Exponent, suggesting the presence of aerosols of different sizes. The methods used in this study can be extended to other stations for identifying the long-term variability of aerosols.
An integrated analysis of land-atmosphere interaction processes over landscapes of grassland, gravel and water in Lake Nam Co basin
Authors: Wang Binbin , Ma Yaoming , Shi Xingdong , Sun Lijun
Published: February 2023

Lake Nam Co is the third largest lake over the Tibetan Plateau and shows significant influences on the forming and the dvelopement of regional-scale weather and climate. In this study, an integrated analysis of land-atmosphere interaction processes (including meteorological variables, land-atmosphere water, heat and CO2 flux exchange) is introduced based on in situ measurements of meteorological variables and eddy covariance fluxes over land surfaces of grassland, gravel and water surfaces. The meteorological variables measured at 20 m height of two planetary boundary layer towers in the island and over the grass land indicate that: (1) the air temperature is warmer in the island than that over the surrounding grass land during the open water season and air humidity in the island are all higher in the island than those at the surrounding grass land, with difference values of 0.6-0.7 g m-3 during monsoon seasons (June to October) and 0.1-0.3 g m-3 during other months. (2) the measured water, heat and CO2 flux over the water and the grassland show significant differences, where the lake acts as a significant carbon sink during ice-forming periods and the monthly LE over the water surface are obviously higher than those at the grass land and gravel surface. Our results demonstrate that spatial heterogeneity of meteorologival variables and lake-atmosphere water, heat and CO2 flux exist in Lake Nam Co basin, which may show hints for other lake catchment research worldwidely.
Giant impacts and the origin and evolution of continents
Authors: Johnson Tim , Kirkland Christopher , Lu Yongjun , Smithies Hugh , Brown Michael , Hartnady Michael
Published: February 2023

Earth is the only planet known to have continents, although how they formed and evolved is not well understood. Using the oxygen isotope compositions (SIMS) of dated magmatic zircon, we show that the Pilbara Craton in Western Australia, Earth’s best-preserved Archaean (4.0–2.5 Ga) continental remnant, was built in three stages. Stage 1 zircons (3.6–3.4 Ga) form two age clusters with one-third recording submantle δ18O, indicating crystallization from evolved magmas derived from hydrothermally-altered basaltic crust similar to that in modern-day Iceland. Shallow melting is consistent with giant meteor impacts that typified the first billion years of Earth history. Giant impacts provide a mechanism for fracturing the crust and establishing prolonged hydrothermal alteration by interaction with the globally extensive ocean. A giant impact at around 3.6 Ga, coeval with the oldest low-δ18O zircon, would have triggered massive mantle melting to produce a thick mafic–ultramafic nucleus. A second low-δ18O zircon cluster at around 3.4 Ga is contemporaneous with spherule beds that provide the oldest material evidence for giant impacts on Earth. Stage 2 (3.4–3.0 Ga) zircons mostly have mantle-like δ18O and crystallized from parental magmas formed near the base of the evolving continental nucleus. Stage 3 (<3.0 Ga) zircons have above-mantle δ18O, indicating efficient recycling of supracrustal rocks. That the oldest felsic rocks formed at 3.9–3.5 Ga, towards the end of the so-called late heavy bombardment, seems unlikely to be a coincidence.
The study of remobilization of static blocks present on the terrain due to rockfall impact: a comparative assessment of rockfall hazard in Manikaran, NW Himalaya, India
Authors: Dhiman Raj Kiran , Bourrier Franck , Thakur Mahesh
Published: February 2023

Manikaran town of Kullu district, Himachal Pradesh, NW Himalaya, India is a famous hotspot for hot springs, ancient Ram Mandir, and Gurudwara Sahib, which makes it a major tourist attraction. Over the past years, the number of tourists visiting Manikaran to explore the hot springs and ancient temples has increased exponentially. One major rockfall event occurred in Manikaran town in August 2015, destroying the four-story Gurudwara building, killing nearly 10 people, and injuring 15 people sleeping in the Gurudwara’s Sarai. Manikaran and surrounding areas witness rockfall activity every monsoon. These past events and the attraction of tourists to this place make it a very risky zone that needs to be studied closely. In this study, a holistic approach comprising geological field investigation, geomorphic mapping, field-based rockfall dataset (rock shape and volume), generation of high-resolution digital elevation model (DEM) using RTK-DGPS, and numerical modelling using open-source software SICONOS was conducted. During field investigations, it was found that the August 2015 rockfall event was not only a result of a single rock block affecting the Gurudwara. Instead, the main rockfall source block triggered the chain of rockfall events by remobilizing the static blocks present on the surface of the runout path of the moving block. A novel rockfall propagation model was developed by incorporating the rock-rock interaction using the rigid body approach in SICONOS software to complement the real August 2015 rockfall event in Manikaran. A comparative rockfall hazard assessment was conducted by comparing the rockfall trajectory simulation with and without static blocks present on the slope. Consequently, two different scenarios of rockfall simulations were generated for Manikaran such that realistic rockfall events can be captured for predicting future rockfall hazards in Manikaran. This study considers for the first time the role of static blocks present on the surface in rockfall propagation models and has potential applications across a wide range of rockfall-prone areas, especially those where large static rock blocks are found in the run-out path of moving rock blocks during rockfalls.
Landslide Susceptibility and Resilience Changing Climate– for the Case in Taiwan
Authors: Shou Keh-Jian
Published: February 2023

Due to the impact of climate change, the increasing frequency of extreme rainfall events, with concentrated rainfalls, commonly cause landslide hazard in the mountain areas of Taiwan. The extraordinary rainfall behavior is critical for the landslide hazard, therefore, it certainly affects the landslide resilience as well.This study employs rainfall frequency analysis together with the atmospheric general circulation model (AGCM) downscaling estimation to understand the temporal rainfall trends, distributions, and intensities in the adopted study area in Central Taiwan. Beside the landslide susceptibility, the landslide resilience was quantitatively defined and analyzed. The upstreams of Tachia River, Wu River, and Chuoshui River were adopted as the study area. The results of predictive landslide susceptibility and resilience analysis can be applied for risk prevention and management in the study area.
Disentangling the impact of co-varying changes in soil moisture, vapor pressure deficit, and temperature on plant carbon and water relations
Authors: Grossiord Charlotte
Published: February 2023

Recent decades have been characterized by increasing temperatures worldwide, resulting in an exponential climb in vapor pressure deficit (VPD). Heat and VPD have been identified as increasingly important drivers of plant functioning in terrestrial biomes and are significant contributors to recent drought-induced tree mortality. Despite this, few studies have isolated the physiological response of plants to high VPD, heat, and soil drought, thus limiting our understanding and ability to predict future impacts on terrestrial ecosystems. I will present diverse experimental approaches to disentangle atmospheric and soil drivers of plant functions across scales. I will further discuss recent findings suggesting that high temperature and VPD can lead to a cascade of impacts, including reduced photosynthesis, foliar overheating, and higher risks of hydraulic failure, independently of soil moisture changes.
Two regimes of inter-basin interactions between the Atlantic and Pacific Oceans on interannual timescales
Authors: Park Jae-Heung , Yeh Sang-Wook , Kug Jong-Seong , Yang Young-Mean , Jo Hyun-Su , Kim Hyo-Jeong , An Soon-Il
Published: February 2023

Understanding the inter-basin interactions between the Atlantic and Pacific Oceans is of great concern due to their substantial global climatic implications. By analyzing observational reanalysis datasets (1948-2020), we found that there are two regimes in Atlantic–Pacific inter-basin interactions: (i) the Pacific-driven regime, and (ii) the Atlantic-driven regime. In the Pacific-driven regime before the mid-1980s, the El Niño-Southern Oscillation (ENSO) in winter effectively drives the primary mode of sea surface temperature anomaly (SSTA) in the tropical Atlantic (i.e., NTA mode) in boreal spring. The NTA mode has a meridional contrast of SSTA along the Atlantic Intertropical convergence zone due to the ENSO effect, similar to the Atlantic Meridional Mode. Whereas, in the Atlantic-driven regime after the mid-1980s, the ENSO effect on the NTA becomes remarkably weaker, so that the NTA mode is featured with a SSTA monopole. Notably, the NTA mode without the meridional contrast of SSTA is capable of modulating an ENSO event. Our analyses of the latest climate models participating in the Coupled Model Intercomparison Project (CMIP) phases 6 support the hypothesis that the two regimes engendered by the Atlantic-Pacific inter-basin interactions are likely due to natural variability.
Digital zenith camera VESTA and vertical deflection test site measurement results
Authors: Varna Inese , Zarins Ansis , Rubans Augusts
Published: February 2023

Digital zenith camera (DZC) VESTA (VErtical by STArs) was developed at the University of Latvia and has achieved an accuracy of 0.1 arcseconds.Currently, a detailed analysis of optimal measurement conditions and potential error sources of DZC VESTA is performed. This study focuses on:testing various parameters of DZC VESTA measurement session: session length, image binning, exposure time;
effect of external conditions: average number of observed stars, temperature, humidity, pressure, wind speed, sky, microseismic;
a significant error source is atmospheric anomalous refraction at the zenith - the amplitudes of the observed zenith coordinate fluctuations reach several arcseconds, and the final vertical deflection (VD) values have amplitudes of approximately 0.2-0.5 arcseconds during the overnight session.
For measurement purpose, a test site with 4 points at a 50x50 meter distance was established and measurements there were started in May 2021. Moreover, it is planned to continue measurements at least for 2 years (till May 2023) to obtain vertical deflection time series at all 4 points of the test site, 1.9 years of regular measurements are completed so far. Several overnight measurement sessions were performed with two adjacent DZCs to investigate anomalous refraction. Preliminary analysis results of VD test site measurements will be presented.This research has been supported by the European Regional Development Fund activity “Post-doctoral Research Aid”, project No.1.1.1.2/VIAA/4/20/
Understanding the climate impacts of the Asian Summer Monsoon with in-situ observations of aerosol microphysical properties in the upper troposphere and lower stratosphere
Authors: Williamson Christina , Simone Dylan , Brock Charles , Lyu Ming , Brown Matthew , Ziemba Luke , Kim Joowan , Campos Teresa , Ullmann Kirk , Pan Laura
Published: February 2023

The Asian monsoon anticyclone transports aerosol and gas phase pollutants from the boundary layer to the upper troposphere and lower stratosphere, from whence they are transported out over the Western Pacific by eddy shedding. This significantly increases aerosol loading in the upper troposphere and maintains a layer of aerosol in the lowermost stratosphere with important implications for climate and stratospheric chemistry. Models show large spread in the spatial distribution and microphysical properties of aerosols transported by the Asian monsoon, and the chemical and radiative effects remain uncertain.In August 2022 we measured aerosol size distributions in Asian summer monsoon outflow from two aircraft, the NCAR GV and NASA WB57, as part of the Asian Summer Monsoon Chemical Climate Impacts Project (ACCLIP). On both aircraft we operated a Nucleation Mode Aerosol Size Spectrometer (NMASS, a custom battery of 5 condensation particle counters) and a modified Ultra-High Sensitivity Aerosol Spectrometer (an optical particle counter from Droplet Measurement Technologies) to measure size distributions from 3 to 1500 nm at 1 Hz time resolution.Here we use these data together with concurrently measured trace gases and reactive gases, and cloud properties, to quantify the transport of primary aerosol by the monsoon system, and the formation of secondary aerosol in the monsoon outflow. We show that new particle formation occurs in the upper troposphere in monsoon outflow and investigate its relation to lofting of condensable vapours and wet scavenging of larger aerosols by deep convection. We use data taken in the upper troposphere and lower stratosphere of the NASA Atmospheric Tomography Mission (ATom) to compare aerosol microphysical properties in the summer monsoon outflow with those in less anthropogenically influence air.
Copernicus for Urban Resilience in Europe: Final results from the CURE project
Authors: Chrysoulakis Nektarios , Ludlow David , Mitraka Zina , Somarakis Giorgos , Khan Zaheer , Lauwaet Dirk , Hooyberghs Hans , Feliu Efrén , Navarro Daniel , Feigenwinter Christian , Holsten Anne , Soukup Tomas , Dohr Mario , Marconcini Mattia , Holt Andersen Birgitte
Published: February 2023

A major challenge for the urban community is the exploitation of Earth Observation intelligence in managing in the multidimensional nature of urban sustainability towards enhancing urban resilience, particularly in relation to the challenges of climate change. This study presents the ways in which the H2020 funded project CURE (Copernicus for Urban Resilience in Europe) synergistically exploited Copernicus Core Services to develop cross-cutting applications supporting urban resilience. CURE provided the urban planning community with spatially disaggregated environmental intelligence at a local scale, as well as a proof-of-concept that urban planning and management strategies development enhancing the resilience of cities can be supported by Copernicus Core Services. Here, we demonstrate the technical operational feasibility of an umbrella cross-cutting system on urban resilience, consisting of 11 specific applications. These use Copernicus core products from at least two services each as main input information, reflect the main urban sustainability dimensions and are relevant to user needs, which were identified based on a strong stakeholders’ engagement. As a result, CURE is built on Data and Information Access Services (DIAS), as a system integrating these cross-cutting applications, capable of supporting downstream services across Europe, enabling its incorporation into operational Copernicus products portfolio in the future and also addressing its economic feasibility. For more information on CURE: http://cure-copernicus.eu
Understanding the thermal history of the North Aquitaine platform: implications on vertical motion and karstification
Authors: Ortiz Alexandre , Husson Eglantine , Barbarand Jocelyn , Lasseur Eric , Briais Justine
Published: February 2023

The Lower Cretaceous corresponds, in northwestern Europe, to a period of significant extension with the rifting of the Bay of Biscay and its eastern prolongation, the Parentis Basin. This basin has a long history of rifting and several important discontinuities between the uppermost Jurassic and the Albian (at the top of the Jurassic, top of the Barremian and at the Aptian-Albian boundary). North of this basin i.e. the Aquitaine Platform, the sedimentation is very patchy, the few known Lower Cretaceous deposits suggest continental conditions during this period. Preliminary work carried out on some deep boreholes located on the Aquitaine platform reconstructed temperatures by thermochronology (apatite fission track on Triassic and Permian samples). The preliminary results show that these samples are not in equilibrium with the current sedimentary thickness taking into account a conventional geothermal gradient (35°/km). All these samples then show a significant cooling, from uppermost Jurassic to lower Cretaceous, consistent with a regional erosional event. This preliminary work leads us to make two hypothesis:-        The deposition of an upper Jurassic/lower Cretaceous sedimentary thickness that was then eroded from the Aptian. This hypothesis is in agreement with study carried out further east (French Massif Central) but not with the first order sedimentary outcropping characterization on the Aquitaine platform.-        The high palaeotemperatures recorded are controlled by an increase in the geothermal gradient (a gradient of 50°/km must be considered) during the Upper Jurassic and Lower Cretaceous. This model does not consider the deposition and the erosion of a thick Cretaceous cover. This hypothesis is difficult to explain over such large area without significant crustal thinning.These two-hypothesis lead to very different palaeogeographical situations and to very different vertical displacement. The answer to these questions is a key to understand the periods of karstification of the Jurassic carbonate platform and therefore to have a better knowledge of the water reservoir. We presented in this work the results of an integrated study. The results are based on a combination of field study and the interpretation of subsurface data (boreholes and seismic). A wide range of methods has been applied to this dataset (sedimentology, sequence stratigraphy, well correlation, isotopic and geochemical analysis of carbonate, sand and clay, thermochronology, heavy mineral, U/Pb zircon, organic geochemistry).
Extreme Birkeland currents are more likely during geomagnetic storms on the dayside of the Earth
Authors: Coxon John , Chisham Gareth , Freeman Mervyn , Forsyth Colin , Walach Maria-Theresia , Murphy Kyle , Vines Sarah , Anderson Brian
Published: February 2023

We combine methods to identify substorms and geomagnetic storms into a single, novel method that identifies four categories: quiet times, storm only, substorm only, substorms in storms. We employ Birkeland current density data from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) between 2010–2017 and use our new combined identification method to sort data in this range into one of the four categories. We then subsample such that each category comprises the same number of data, in order that each category behaves statistically similarly. We then examine the large global behaviour of each category for the first time. We find that the mean current density is larger during substorms and its standard deviation is larger during geomagnetic storms. We assess the kurtosis and variance of the underlying distributions, and determine that the kurtosis is far higher during geomagnetic storms than during substorms. We use the survival function to quantify the probability of current densities above set thresholds and find that current densities which are above a low threshold are more likely during substorms, but that extreme currents are far more likely during geomagnetic storms. We shift the data into an adaptive coordinate system defined by the boundary between Regions 1 and 2 Birkeland current and demonstrate that extreme currents are most likely to flow within Region 2 current during geomagnetic storms. This is consistent with the literature on geomagnetic storms driving extreme behaviour, but unexpected in a paradigm of the current systems in which Region 1 current is generally larger.
Tracking global urban green space trends
Authors: Falchetta Giacomo , Hammad Ahmed T.
Published: February 2023

Urban green space - the presence of vegetation-covered area within cities' boundaries - is an increasingly relevant indicator for evaluating sustainable cities. This is because besides providing a set of local services such as mitigating the urban heat island effect and reducing the impact of extreme precipitation events, urban green space has been widely associated with increasing well-being of urban dwellers. Here we present a global analysis of recent trends in urban green space based on modelling of multi-spectral satellite imagery data to reproduce street-based vegetation presence indicators. We estimate local to continental trends over the 2016-2022 period and estimate global scale (considering a large set of the most populated cities) urban green space change statistical trends. We examine heterogeneities in the direction and magnitude of trends across cities and regions, while also analysing within-city inequalities. Our analysis provides an updated picture of urban green space across world cities and an open-source and open data-driven, spatially cross-validated approach to assess changes in near-real-time.
State of a challenge – Third annual review
Authors: Zagoni Miklos
Published: February 2023

We announced a public challenge at the EGU 2020 General Assembly against CMIP6 models predicting an increase of downward longwave radiation (DLR) in the range of 10 – 40 Wm-2 during the 21st century as a result of human greenhouse gas emissions. We based our challenge on observed facts, supported by long-known but rarely referred theoretical constraints. 22 years of CERES data show +0.11 Wm-2/decade increase in DLR, equivalent to +0.36 Wm-2 increase (+0.06 °K) until 2050 (in contrast to IPCC AR6, predicting +2 Wm-2/decade).Supporting our prediction, we repeat here the deduction of the constraint equations, and control them on the recently available data sets. — Our best tool the compute the transfer of radiation in the atmosphere is Schwarzschild’s (1914) equation; its early, two-stream form is given in Schwarzschild (1906, Eq. 11), appropriate for global-mean energy flow computations. The equation consists of three terms; the difference of the second and first terms gives the net radiation at the surface as constrained to half of the outgoing longwave radiation (OLR), independently of the optical depth.  In the literature it was observed early (Emden 1913) that there is a discontinuity at the surface in radiative equilibrium, balanced by the turbulent fluxes in radiative-convective equilibrium. The formula for this net radiation is given for example in the textbook of Goody (1964, Atmospheric radiation: theoretical basis); repeated by Houghton (1977, Eq. 2.13), graphically represented in Chamberlain (1979, Fig. 1.4); and verified by the data (without explicitly describing the equation) of Hartmann (1994, pp. 61-63) within 0.3 Wm-2. The equation is verified by the CERES EBAF Ed2.8 (16 years of clear-sky global mean data) within 0.6 Wm-2. We use the second term of Schwarzschild (1906, Eq.11) with a particular optical depth of τ = 2 to compute the total energy absorption (and emission) at the surface, verified by the same satellite data product within the same difference (0.6 Wm-2) in the clear-sky annual global mean. — We created the all-sky versions of these two equations by introducing longwave cloud radiative effect (LWCRE), and justified the four individual equations on the most recent 22 years of CERES EBAF Edition 4.1 global mean data within ±3 Wm-2; while the mean bias of the four equations together is 0.0007 Wm-2. These equations form the boundary conditions of every valid climate prediction.Reference:Zagoni, M.: Challenging CMIP6 model predictions, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1, https://doi.org/10.5194/egusphere-egu2020-1 
Diggability field survey for the assessment of the most suitable site for a clandestine homicide grave
Authors: Somma Roberta
Published: February 2023

In criminal cases of clandestine homicide graves, the criminal behavior and mental map of an offender may be influenced by several geographical, botanical, and geological features. Among these factors, diggability assumes for a concealer a predominating role in the concealment act because an easy and efficient digging of a hole requires that the ground is diggable. The diggability (the ease and efficiency with which soils and sediments may be dug and reinstated in a grave) may vary from very easy to difficult, and forensic geologists may qualitatively and relatively evaluate it by using a T-metal bar for offensive and defensive search purposes. Results of a diggability survey were processed in the GIS platform, reconstructing contour maps, Inverse Distance Weighting, Kriging, and Thin Plate Spline with Tension maps of a crime scene. The interpolation of the data by Thin Plate Spline with Tension rendered the best results. The diggability survey demonstrated that the pit fell in a suitable area for concealment, being one of the easiest diggable and thick sectors of the search area.
Theoretical examination of non-summer daytime boundary layer height variability over coastal-mountain-valley topography: the case of central Israel
Authors: Berkovic Sigalit
Published: February 2023

The center of Israel presents relatively simple vertical topographical cross-section: The eastern Mediterranean coast on the west, Judea and Samaria mountain in the center and the deep steep Jordan valley on the east.To the best of our knowledge, the variability of the boundary layer height (BLH) over Israel during the non-summer period was not investigated. This work presents climatological examination of the daytime BLH variability during non-summer months according to WRF simulations with 3 km horizontal resolution during 5 years. The monthly average BLH above the mountain peak and its easterly slope is found to be lower than that over the coastal area (1-2.5 .vs. 2-3 km) during the winter months, November-February, while during the rest of the year (except March) the situation is reversed.In order to track the mechanism responsible for the reduction of the BLH over the mountain peak area during winter, an examination of the BLH variability during 10-13 UTC was performed. Accordingly, events with relatively weak pressure gradients and weak (< 5 m/s) easterly flow were found to be responsible for minimal BLH (< 350 m). The synoptic pressure during these events is characterized by ridge from the south in the middle troposphere (500 hPa) and central Red Sea Trough or high to the east or to the north of Israel next to the surface. Fohn winds which locally reduce the humidity and enhance the temperature due to subsidence flow over the eastern slope of the valley and the western slope of the mountain. In such cases, the mild synoptic pressure gradients are responsible for the maintenance of the local cooling over the mountain peak. The advection of hot air to the mountain peak is limited and therefore relatively stable thermal stability is obtained over the mountain peak and its eastern slope.
Processes controlling the South American Monsoon response to Climate Change
Authors: Chadwick Robin , Garcia-Franco Jorge , Alves Lincoln
Published: February 2023

CMIP6 future climate projections consistently show a drying trend during the onset of the South American monsoon, which has the potential for large ecological and societal impacts in this region. This trend is also present in a high-resolution regional convection-permitting simulation over the South American domain. Here, the processes responsible for this drying trend are examined using a number of idealised experiments and analysis techniques. The main driver is shown to be remote sea surface temperature (SST) warming - rather than local radiative or plant physiological responses to increased CO2 - with both large-scale uniform SST warming and patterned regional warming playing important roles. The role of uniform SST warming on the South American monsoon onset is examined in more detail using a moist static energy budget approach, building on hypotheses from a previous single model study. The atmospheric circulation response to patterned SST warming is examined using a local overturning circulation partioning technique, allowing a link between the South American monsoon region and specific regions of ocean warming to be identified.
A Re-examination of Temporal Variations in Intermediate-Depth Seismicity
Authors: Wimpenny Sam , Craig Tim , Marcou Savvas
Published: February 2023

Changes in the frequency of intermediate-depth (60–300 km) earthquakes in response to static stress transfer can provide insights into the mechanisms of earthquake generation within subducting slabs. In this presentation, we will demonstrate that global and regional earthquake catalogues from Japan and northern Chile show that both aftershock productivity, and the changes in the frequency of intermediate-depth earthquakes around the timing of major megathrust slip, support the view that faults within the slab are relatively insensitive to static stress transfer on the order of earthquake stress drops. We interpret these results to suggest the population of faults within the slab are much further from their failure stress than is typical for shallow faults, and that the mechanism that enables faults to rupture at the high confining pressures within slabs is likely to be spatially heterogeneous over length-scales of a few tens of kilometres. We suggest dehydration-related weakening mechanisms can best account for this heterogeneity.
Silver stable isotopic ratios determined in contaminated soils
Authors: Vaněk Ales , Vaňková Maria , Mihaljevič Martin , Ettler Vojtěch
Published: February 2023

Silver isotopic fractionation(s) during metallurgical processes (or other high-T processes) and its fate in mining- and smelter-affected environments, Ag-contaminated soils/sediments remain entirely unknown. Regarding the Ag-ore processing (roasting/smelting technologies), it can be assumed that, similarly to other isotopic systems (e.g., Tl and Cu), the isotopically lighter Ag (enriched in 107Ag) enters the smelter emissions (fly ash), and isotopically heavier Ag (enriched in 109Ag) remains in the residual metal phase. Our preliminary data from the Ag-contaminated soils around a former primary Ag-smelter at Příbram (Czech Rep.) indicate an apparent variability of ε109Ag within soil profiles. The identified ε109Ag values presented for the forest soil profile (Fig. 1) recorded ~0 in the organic horizon (O), ~0-+1 in the organo-mineral horizons (A1 and A2), and up to +7 in the mineral horizon (B). This finding suggests both the isotopically-lighter Ag fraction present in the topsoil (Fig. 1), as well as enhanced 107Ag release during high-T smelting operations, i.e., relative to geogenic Ag (local ore). However, the question that clearly remains to date is to which degree the alteration/chemical processes in soil could have produced the Ag isotopic fractionation and which type of mechanisms (e.g. Ag(I)→Ag0) could represent the key geochemical controls.Fig. 1 An example of vertical evolution of Ag isotopic signatures (ε109Ag, relative to the NIST SRM 978a Ag standard) and Ag concentrations in a forest soil profile, ~1 km away from a former primary Ag-smelter (Příbram, Czech Rep.). The Ag isotopic data are assigned an estimated error of ±0.7 ε109Ag (2sigma), which is based on our long-term reproducibility of multiple separate analyses (n = 6) of NIST SRM 2782 (Industrial Sludge) (Vaněk et al., unpublished data).
Palaeoclimate evolution on Titan after episodic massive methane outgassing simulated by a global climate model
Authors: Tokano Tetsuya , Lorenz Ralph D.
Published: February 2023

Titan's palaeoclimate after the onset of the putative last major methane outgassing event 700 Myr ago is simulated by a global climate model. If the atmosphere was methane-depleted prior to outgassing, outgassed methane initially causes warming due to increased greenhouse effect. Further outgassing leads to methane snowfall, which in turn cools the troposphere and surface by an ice-albedo feedback and thereby initiates a lengthy ice age. Formation of ice sheets begins in the polar region, but with increasing methane inventory the entire globe is eventually covered by surface methane frost as thick as 100 m, with local accumulation on elevated terrains. Among various time-dependent input parameters the methane inventory by far exerts the greatest control over the climate evolution. As Titan's climate transitions from a dry state via a partially ice-covered state to a globally ice-covered state, the circulation and precipitation pattern change profoundly and the tropospheric temperature further decreases. Globally ice-covered snowball Titan is characterized by weak meridional circulation, weak seasonality and widespread snowfall. Frost ablation begins after the end of outgassing due to photochemical destruction of atmospheric methane. It is conceivable that Titan's polar seas resulted from melting of the polar caps within the past 10 Myr and subsequent drainage to the polar basins. Surface methane frost could only melt when the frost retreated to the polar region, which led to global warming by lowering of the surface albedo at low latitudes and increased greenhouse effect.
A DSS for the dynamical assessment and mapping of the groundwater vulnerability: the pesticide and the nitrate fate tools
Authors: Bancheri Marialaura , Acutis Marco , Botta Marco , Fusco Francesco , Langella Giuliano , Lezzi Daniele , Perego Alessia , Basile Angelo
Published: February 2023

This work presents two web-based, freely-available dynamical tools for the assessment and the mapping of the groundwater vulnerability to both pesticides and nitrate, within the geospatial Decision Support system (s-DSS) LandSupport (www.landsupport.eu).The pesticide fate tool simulates the transport of reactive solutes, i.e., pesticides, and maps the percentage of pollutant mass that reaches the groundwater depth within a user defined time-interval. The tool is based on the extended transfer function model (TFM-ext) and its main inputs are: the soil and, eventually, the vadose zone physical and hydrological properties, the climate, the groundwater table depth, the investigated crop and its management (sowing and harvesting dates, pesticides doses and time of application).The nitrate fate tool simulates the crop growth dynamics and assess the transport of nitrate through the unsaturated zone till the groundwater table depth. The output maps represent the number of years for the arrival to the groundwater of the 50% of the mass of nitrate leachate from the root zone. The tool is based on the coupling of the dynamical crop-growth ARMOSA model and of the TFM-ext model and its main inputs are: the type of crop and/or crop-rotation and related managements (tillage, irrigation, fertilization and residues), the soil physical and hydrological properties, the climate and the groundwater table depth.Eventually, both tools were extended using the COMPSs programming framework that allows to parallelize the execution of multiple model runs.The work presents the implementations of both tools for different case studies across three European regions (Campania Region-IT, Marchfeld Region-AT, Zala County-HU), characterized by different spatial scales, pedo-climatic conditions and land-use, showing some examples of applications in support of local farmers, public authorities and environmental planners for the Water, Pesticides and Nitrate Directive applications.
Transdisciplinary knowledge integration and embracing of uncertainty with Bayesian Belief Networks in water management
Authors: Müller Laura , Döll Petra
Published: February 2023

Climate change alters the water cycle, which makes adaptation in water management necessary. The interdisciplinarily coordinated transdisciplinary project KlimaRhön aimed at developing adaptation strategies in water management in the UNESCO biosphere reserve Rhön in Central Germany. Experts agree that scientific and stakeholders’ knowledge should be involved to develop adaptation strategies, which requires good integration tools.To identify adaptation strategies in the participatory process of the project KlimaRhön, we integrated the knowledge of hydrologists, sociologists and stakeholders while embracing uncertainty with a Bayesian Belief Network. For this, sociologists introduced that the acceptance of relevant actors is needed to implement adaptation measures and hydrologists introduced a range of potential future changes in groundwater recharge. In the first workshops of the participatory process, the stakeholders jointly identified possible adaptation measures. In the last workshops, we focused on two adaptation measures, which are 1) the protection of springs taking into account pasture water supply and 2) the fusion of small water suppliers in a region, and planned to find strategies to stimulate their implementation. For this, the stakeholders identified the relevant actors whose acceptance to implement those adaptation measures is needed. Then, the stakeholders identified and weighted factors that influence the acceptance of the relevant actors to implement the respective adaptation measure. This knowledge was then integrated in two Bayesian Belief Networks (for two adaptation measures) and a suitable communication of the Bayesian Belief Networks, which also focused on the communication of the embraced uncertainty, was developed. In the last workshop in the participatory process, the Bayesian Belief Networks were presented to the stakeholders and discussed. In the presentation, the stakeholders could explore which combinations of factors can enhance the acceptance of the relevant actors for the adaptation measure and thus the probability that they implement it for different degrees of climate change impacts.The conditional probability tables for the Bayesian Networks were derived directly from the stakeholder weightings. Thus, stakeholders did not need to fill out conditional probability tables, which would have been difficult for most of them, and time-consuming. Bayesian Belief Networks show the uncertainty of possible future conditions through the many possible combinations of factors, which might have enhanced the understanding of stakeholders for the need of flexible adaptation strategies. The stakeholders appreciated the good overview of the many interdependencies and their influence on the acceptance of the relevant actors to implement the adaptation measure. In this contribution, we present our integration approach, the Bayesian Belief Networks, its communication as well as its evaluation by the stakeholders. 