bluuebunny/crossref_metadata_2025 huggingface dataset:
Variability Changes in the Tropical Atlantic in CMIP6
Authors: Sobral Verona Laura , Silva Paulo , Wainer Ilana , Khodri Myriam
Published: March 2022

Climate variability in the Tropical Atlantic is complex and significantly different than that in the Pacific. A strong ocean-atmosphere coupling is present, sea surface temperature (SST) variability in this region impacts the hydroclimate of the surrounding continents and influences the meridional displacement of the Intertropical Convergence Zone (ITCZ).  We observe a decrease in the variability of the Tropical Atlantic after 1970 in both CMIP6 models and observations. Most of the Tropical Atlantic interannual variability is explained by equatorial and meridional modes. The Atlantic Zonal Mode (AZM) characterizes an equatorial cold tongue. The Atlantic Meridional Mode (AMM) represents an interhemispheric SST anomaly gradient.  Both modes respond to positive ocean-atmosphere feedback: the Bjerkens Feedback controls most of the dynamics underlying the AZM; and a thermodynamic feedback amplifies the AMM, the WES (wind-evaporation-SST) feedback .

            The observed winds relaxation after 1970 in both the equatorial Atlantic region and in the Tropical Northern Atlantic (TNA) plays a role in the decrease of Tropical Atlantic variability, for each mode predominant season. With respect to the AZM, a widespread warming trend is observed in the equatorial Atlantic accompanied by a weakening trend of the trade winds. This drives a weakening in the Bjerkens Feedback by deepening the thermocline in the eastern equatorial Atlantic and increasing the thermal damping. Even though individually the TNA and Tropical South Atlantic (TSA) show increased variability, the observed asymmetric warming in the Tropical Atlantic and relaxed northeast trade winds after the 70s play a role in decreasing the AMM variability. This configuration leads to positive WES feedback, increasing further the TNA SST, preventing AMM from changing phases as before 1970.

            Associated with SST, trade wind trends and decreased Tropical Atlantic variability, the African Sahel shows a positive precipitation trend. The southwest wind anomaly (trade wind relaxation) over the Tropical North Atlantic carries more humidity into the Sahel region, therefore increasing precipitation. As a consequence of the observed trends and decreased variability especially in the AMM, the ITCZ tends to shift northward, which acts on maintaining the increased precipitation over the Sahel.
Shifting baselines revisited: Exploring pre-industrial climate and human impacts on marine ecosystems (Q-MARE, 2022–2025)
Authors: Agiadi Konstantina
Published: March 2022

Marine ecosystems are deteriorating worldwide, but scientific monitoring postdates the industrial revolution, leading to a distorted image of the pristine state of the world’s oceans. The Q-MARE working group of PAGES brings together scientists from vastly different disciplines, historians, archaeologists, paleontologists and ecologists to explore pre-industrial baselines and understand the true magnitude and rate of change induced by modern anthropogenic activities, including climate change, specifically biodiversity loss and the sustainability of ecosystems and societies. How did climate and human activities affect marine ecosystems in the pre-industrial Holocene and the Pleistocene? When did humans start having a significant impact on the marine environment? How can data from different sources be combined to inform environmental conservation targets and model marine ecosystems? Through our activities, we aim to determine the state and gaps of knowledge around these questions, but also to inform policy-makers and the public.
A Fractal Approach to Evaluate Biological Soil Crust in Arid and Semiarid Ecosystems
Authors: Florentino Adriana , Ospina Abelardo , Tarquis Ana María
Published: March 2022

Biological soil crusts (BSC) are an integral part of dryland ecosystems and  They are intimate association between soil particles and diverse microorganism, including cyanobacteria, algae, lichen and bryophites, which live on the uppermost millimeters of soil. The successional stage of BSCs cause changes in soil surface conditions such as soil stability, soil aggregate stability and roughness, and affects some ecosystem processes including nutrient cycling, erosion, runoff, water retention and increase carbon secuestration.
Fractal dimension can be associated with the roughness of a surface represented by a digital image. Because surface roughness is so related to scale and to BSCs successional stage, a fractal analysis is worth pursuing and it would give realistic results. In order to differentiate the successional stages of  BSCs in quantity, we determined several fractal parameters in a series of different developmental BSCs in a tropical semiarid region of Venezuela. A progressive  classification of soil crust type from incipient crust through various BSCs successional stages were selected in two semiarid ecosystems (Quibor and Ojo de agua) in the Quibor Depression, Venezuela. This study focus on characterize the development stage of the BSC based on Fractal image analysis.
To this end, grayscale images of different biological soil crust at different successional stages were taken, each image corresponding to an area of 12.96 cm2 with a resolution of 1024x1024 pixels. For each image lacunarity and fractal dimension through the differential box counting method were  calculated, using the software ImageJ/Fraclac. Fractal dimension and lacunarity could be good descriptors of BSCs successional stages, and could be very useful in a further exploration of the link between the BSCs successional stages and other soil properties.
Persistent discrepancies between observed and modeled trends in the tropical Pacific
Authors: Seager Richard , Cane Mark , Henderson Naomi
Published: March 2022

The trends over recent decades in tropical Pacific sea surface and upper ocean temperature are examined in observations, an ocean reanalysis and the latest models from the Coupled Model Intercomparison Project Six and the multimodel Large Ensembles archive.  Comparison is made using three metrics of SST trend - the east-west and north-south sea surface temperature (SST) gradients and a pattern correlation for the equatorial region - as well as change in thermocline depth.  It is shown that the latest generation of models persist in not reproducing the observed SST trends as a response to radiative forcing and that the latter are at the far edge or beyond the range of modeled internal variability.  The observed combination of thermocline shoaling and lack of warming in the equatorial cold tongue upwelling region is similarly at the extreme limit of modeled behavior.  The persistence over the last century and a half of the observed trend towards an enhanced east-west SST gradient, and in four of five observed datasets to an enhanced equatorial north-south SST gradient, is also at the limit of model behavior. It is concluded that it is extremely unlikely that the observed trends are consistent with modeled internal variability.  Instead, the results support the argument that the observed trends are a response to radiative forcing in which an enhanced east-west SST gradient and thermocline shoaling are key and that the latest generation of climate models continue to be unable to simulate this aspect of climate change.
CliMetLab and Pangeo use case: Machine learning data pipeline for sub-seasonal To seasonal prediction (S2S)
Authors: pinault florian , Spring Aaron , Vitart Frederic , Raoult Baudouin
Published: March 2022

As machine learning algorithms are being used more and more prominently in the meteorology and climate domains, the need for reference datasets has been identified as a priority. Moreover, boilerplate code for data handling is ubiquitous in scientific experiments. In order to focus on science, climate/meteorology/data scientists need generic and reusable domain-specific tools. To achieve these goals, we used the plugin based CliMetLab python package along with many packages listed by Pangeo.  

Our use case consists in providing data for machine learning algorithms in the context of the sub-seasonal to seasonal (S2S) prediction challenge 2021. The data size is about 2 Terabytes of model predictions from three different models. We experimented with providing data in multiple formats: Grib, NetCDF, and Zarr. A Pangeo recipe (using the python package pangeo_forge_recipes) was used to generate Zarr data (relying heavily on xarray and dask for parallelisation). All three versions of the S2S data have been stored on an S3 bucket located on the ECMWF European Weather Cloud (ECMWF-EWC). 

CliMetLab aims at providing a simple interface to access climate and meteorological datasets, seamlessly downloading and caching data, converting to xarray datasets or panda dataframes, plotting data, feed them into machine learning frameworks such as tensorflow or pytorch. CliMetLab is open-source and still a Beta version (https://climetlab.readthedocs.io). The main target platform of CliMetLab is Jupyter notebooks. Additionally, a CliMetLab plugin allows shipping dataset-specific code along with a well-defined published dataset. Taking advantage of the CliMetLab tools to minimize the boilerplate code, a plugin has been developed for S2S data as a companion python package of the dataset.
Air temperature variability inside crevasses in the accumulation area of a maritime glacier in the Southern Alps, New Zealand
Authors: Purdie Heather , Zawar-Reza Peyman , Schumacher Benjamin , Katurji Marwan , Bealing Paul
Published: March 2022

In mountain regions around the world, crevasses in glacier accumulation areas undergo cycles of burial and re-exposure between one melt season and the melt season that follows. However, climate warming is extending the length of the ablation season meaning that crevasses are now exposed at the glacier surface for longer.  An analysis of air temperature inside crevasses in the accumulation area of a maritime glacier has found that air temperature inside crevasses can at times be higher than the overlying air temperature. Here we combine measurements of air temperature and wind-speed from inside crevasses with adjacent meteorological data to demonstrate that open crevasses trap incoming shortwave radiation and have complex relationships with wind shear. Results show that crevasse morphology influences warming with the effect more pronounced at wider (more open) crevasses. This highlights the potential of crevasses to enhance glacial melt by acting as heat source through positive radiative and sensible heat feedback. Therefore we hypothesis that energy balance models that treat glacier accumulation areas as smooth surfaces will be underestimating snow melt and possibly overestimating mass balance on alpine glaciers. 
The economic value of ensemble numerical weather forecasts combined with remote sensing data and hydrological modeling for irrigation scheduling: an application to Southern Italy
Authors: Pelosi Anna , Battista Chirico Giovanni , Falanga Bolognesi Salvatore , De Michele Carlo , D'Urso Guido
Published: March 2022

The use of numerical weather prediction (NWP) outputs in hydrological modeling combined with remote sensing data for forecasting irrigation water demand in the short-medium term, has becoming one of the key actions adopted in precision farming for decreasing water and energy consumptions in the long-term perspective of sustainability.

In the last decades, ensemble prediction systems (EPS) have been developed to support operational decision-making processes in many environmental fields. Unlike traditional deterministic forecasts where the numerical weather prediction model is run only once, in EPS the NWP model is run several times from very slightly different initial conditions and perturbed model parameters, to produce an ensemble of forecasts that are used to account for uncertainty in initial atmospheric conditions and NWP model errors. Moreover, in recent years, limited area ensemble prediction systems (LEPS) have been developed as dynamic regional downscaling of global ensemble prediction systems, opening new opportunities for the application of weather forecasts in agriculture and water resource management. Indeed, high resolution probabilistic forecasting may allow water irrigation managers to set-up agrometeorological advisory services based on a more reliable risk analysis.

This study exploits the potential economic benefit (i.e., economic value) related to the use of an ensemble numerical weather prediction model, such as COSMO-LEPS (20 members, 7 km of spatial horizontal resolution) for irrigation scheduling at farm scale in Southern Italy, by combining its outputs with high resolution satellite images in the visible and near infrared wavelengths for crop parameter estimations. An adaptive ensemble Kalman filter is employed for bias correcting weather forecasts by assimilating ground based meteorological variables. Then, a bucket model for soil-vegetation-atmosphere modeling is implemented for providing spatial and temporal estimates of crop water requirements and irrigation schedules along with their predictive uncertainty.
Co-located ice core and sediment core records reveal climate-warming induced acceleration of mercury inputs to Lake Hazen, Nunavut, Canada
Authors: Lehnherr Igor , Lemire Danielle , Criscitiello Alison , Young Cora , Serbu Jessica , De Silva Amila , Kirk Jane , Varty Stephanie
Published: March 2022

Mercury (Hg) is a globally dispersed contaminant that can bioaccumulate and biomagnify in food-webs. This research uses a unique combination of measurements in an ice core and a sediment core collected within the same watershed (Lake Hazen, Nunavut, Canada) to determine how the relative importance of Hg inputs from atmospheric and terrestrial sources has changed over the last century. Hg accumulation in Lake Hazen sediment began increasing dramatically in the mid- 1990s, exhibiting a decoupling from atmospheric sources (as estimated from the ice core record), due to the increased importance of remobilized terrestrial Hg inputs to Lake Hazen. Increasing glacier melt and permafrost thaw slumping have increased the delivery of catchment Hg, via glacial rivers, into Lake Hazen. These results show that climate change is likely to slow the recovery of glacierized Arctic watersheds from Hg contamination, countering the anticipated benefit from recent international efforts to reduce anthropogenic Hg emissions.
Ancient steroids: Human faecal signals and environmental data from a Holocene sediment record of the Yagour Plateau, High Atlas, Morocco
Authors: Cornelissen Henk , Lupien Rachel , Fletcher William , Hughes Philip , Bell Benjamin , Rhoujjati Ali , Ewague Abdelhadi , Fink David
Published: March 2022

The analysis of steroids (stanols and stanols compounds) preserved within Holocene sediment records represents a novel approach to establish past periods of human and herbivore occupation in the Atlas mountains of Morocco. These organic compounds are faecally produced by omnivorous and ruminant mammals; the concentrations and ratios of the compounds are used in this study as proxies for past dynamics of human presence. In this study, stanol analysis is employed in tandem with multiproxy sedimentological, palaeoecological and geochronological data of a lake-margin sediment core to evaluate Holocene human presence around the high-elevation wetland system of the Yagour Plateau, in the High Atlas mountains (31.31°N, 7.60°W, 2460 m.a.s.l.). The site is a vital resource for modern pastoral communities, providing fodder for livestock during seasonal dry periods. Cultural institutions known as Agdals regulate access to this wetland and have been established since early-historic times at least. The Yagour Plateau is well-known for its remarkable abundance of undated petroglyphs, which may relate to the territorial delineation of these Agdals. However, direct dating of archaeological remains is rare and the timing of human presence on the High Atlas rangelands is not well known. Information gained on the dynamics of human presence of remote, high-elevation sites in the High Atlas may be helpful in improving the understanding of the relationships between Holocene climatic, anthropogenic and ecological signals. Here, we present new data from 25 stanol samples spanning the last 13 kyr, complemented by two multiproxy records that include pollen, charcoal and non-pollen palynomorphs. The temporal context of these proxy records is underpinned by high-resolution age-depth radiocarbon chronology. We observe elevated stanol ratios from 6.2 cal ka BP to modern times, likely indicating intermittent human presence on the plateau since the Mid-Holocene. High coprostanol concentrations between 4.9 to 4.0 cal ka BP are similar to modern levels and indicate peak human presence. Faecal biomarkers match well with pollen-based anthropogenic indicators, particularly Plantago pollen abundance. This study supports a significant human presence on the Yagour Plateau from the Mid-Holocene onwards, contributing to the study of long-term human presence and climate dynamics in a sensitive mountain region at the boundary of the Atlantic and Saharan climate systems.
The RUHM framework for rapid rating curve uncertainty estimation: comparison to power-law methods and potential using drone-derived data
Authors: Westerberg Ida , Mansanarez Valentin , Lyon Stephen , Lam Norris
Published: March 2022

Climate change, together with other natural and anthropogenic drivers lead to changes in streamflow patterns that are now occurring with increasing frequency. At the same time traditional streamflow monitoring methods are time-consuming and costly so that it typically takes many years of significant field efforts to establish reliable streamflow data for a new location or for stations with major temporal changes to the stage—discharge relation. To provide timely and reliable streamflow data to tackle these changes to the hydrological regime and their impacts on society’s water management requires new cost-effective monitoring methods that can rapidly produce data with low uncertainty. Hydraulically modelled rating curves are a promising alternative to traditional power-law methods as they need much fewer calibration gaugings, but they are associated with additional uncertainty sources in the hydraulic knowledge and these need to be assessed.
We present the Rating curve Uncertainty estimation using Hydraulic Modelling (RUHM) framework which was developed to rapidly estimate rating curves and their uncertainty. The RUHM framework combines a one-dimensional hydraulic model with Bayesian inference to incorporate information from both hydraulic knowledge and the calibration gauging data. In this study we compare RUHM and the Bayesian power-law method BaRatin in application to a Swedish site using nine different gauging strategies associated with different costs. We compare results for the two methods in terms of accuracy, cost and time required for establishing rating curves. 
We found that rating curves with low uncertainty could be modelled with fewer gaugings for RUHM compared to BaRatin. As few as three gaugings were needed with RUHM if these gaugings covered low and medium flows, whereas high flow gaugings were not necessary. This makes the RUHM method both cost effective and time efficient as low and medium flows occur more frequently than high flows. When using all gaugings (i.e., a high-cost gauging strategy), the uncertainty for RUHM and BaRatin was similar. The results for this Swedish site show that hydraulic rating curve uncertainty estimation is a promising tool for quickly estimating rating curves and their uncertainties. Finally, we discuss the potential of using RUHM together with drone-derived data to make field efforts even more efficient.
Exploring links between precipitation extremes and land use types through the UK Convection-Permitting Model
Authors: Chun Kwok Pan , Fan Pingyu , He Qing , Dieppois Bastien , Danaila Luminita , Quinn Nevil , Klaus Julian , Toker Emir , Yetemen Omer
Published: March 2022

Precipitation extremes are commonly linked with land use types. The UKCP18 Convection-Permitting Model (CPM) Projections at 5km high resolution simulation provide opportunities to investigate probable relationships between precipitation extremes and land use types. Changes in the duration and severity of extreme precipitation events can be linked to landscape characteristics, which affect the risk of rapid and local hydrological hazards.

Based on publicly accessible data and a standard approach, Local Climate Zones (LCZs) provide coherent descriptions of the form and function of urban landscapes. From the World Urban Database and Access Portal, the LCZ is used to translate relevant land attributes to urban canopy parameters for climate and weather modelling applications at appropriate scales. Using the Severn River Basin as a case study, we use LCZ data to calculate urban fractions to investigate the roles of urban land types to the extreme distribution parameters.

In conjunction with the LCZ data, the Corine Land Cover (CLC) and the Moderate Resolution Imaging Spectroradiometer (MODIS) datasets are used to benchmark how future changes in rainfall intensities and seasonal patterns might be related to land use. The results are used to generate possible hypotheses to run different CPM models based on the LCZ data.

Based on these findings, we present a novel land-use-based approach for water hazard management addressing hydrological risk connected to regional climate resilience. For management authorities and infrastructure owners, precipitation extreme risk related to land use is critical for their long-term investment planning. The proposed methodology would be advantageous to many UK water regulators and stakeholders in generating more informative precipitation extreme estimations based on land use, for the high greenhouse gas emissions scenario RCP8.5.
Weathering of soil parent material controls quantity and quality of soil organic carbon in alpine ecosystems
Authors: Moser Maria , Doetterl Sebastian , Griepentrog Marco
Published: March 2022

In the global carbon cycle, organic matter in soils represents the major terrestrial pool of carbon, storing roughly twice the amount of carbon as do the atmosphere and vegetation combined. However, under changing environmental conditions, it remains unclear whether soils act as sources or sinks of carbon. Especially soils in alpine ecosystems are subject to undergo changes in their soil organic carbon (SOC) stocks. To disentangle the possible effects of climate change on SOC stocks in alpine environments, the factors which contribute to SOC stabilization have to be known and understood. Recent studies indicated the importance of soil physicochemical parameters governed by weathering of parent material.

To attain a better understanding of how parent material may influence SOC stabilization in alpine ecosystems, five alpine sites in Europe with varying parent material (i.e., Dolomite, Flysch, Gneiss, Greenschist, and Marl) were investigated. Similar climatic conditions, aspect, and slope allowed to analyze the impact of different parent materials on SOC stocks. The geochemical composition of the parent material and the soil, exchangeable cations and effective cation exchange capacity, pH, pedogenic oxides, soil texture, organic carbon and nitrogen contents, and SOC fractions were determined for all soil horizons (i.e., Oh, Ah, Bv, and Cv). The following SOC fractions were physically separated: unprotected, coarse particulate organic carbon (>250 µm), SOC occluded in microaggregates (53 – 250 µm), and SOC in the silt and clay fraction (<53 µm), which is assumed to be predominantly protected via minerals. Linear and non-linear models were computed in order to distill the relative importance of the geochemical parameters on SOC concentrations in the bulk soil (SOCbulk) and the silt and clay fraction (SOCs+c).

Preliminary findings point at the importance of soil depth, texture, and organically complexed oxides as these parameters were found to be among the best predictors for SOCbulk. The concentrations of poorly crystalline aluminum, magnesium, and exchangeable manganese gained importance when predicting SOCs+c. These results align with previous research which has shown the influence of pedogenic oxides on SOC stabilization, Furthermore, the significance of soil depth supports the increasing call of soil scientists to take the entire soil profile into account when analyzing SOC dynamics since large amounts of carbon are stored at depth below the commonly analyzed first 30 cm.
Interpreting recent landslide events in Campania Region (Southern Italy) by using innovative approaches
Authors: Rianna Guido , Reder Alfredo
Published: March 2022

The study is aimed at verifying the reliability of the ERA5 reanalysis in reproducing histories of soil water fluxes exchanges (in terms of precipitation and evapotranspiration) leading to landslide events that actually occurred in Campania Region (Southern Italy). In the specific, the investigation deals with landslide events affecting pyroclastic covers result of repeated eruptions of Vesuvius and Campi Flegrei over the course of millennia. Indeed, for many events occurred in the last years, it is hard to retrieve continuous and reliable atmospheric data provided by weather stations in the vicinity of the affected slopes. Under such constraints, it could be difficult to identify the weather patterns triggering the events and then how they could vary in a climate change perspective. To deal with these issues, the fifth generation of atmospheric reanalysis made available by European Centre for Medium-Range Weather Forecasts (ECMWF) can represent a valuable support. ERA5 and its downscaling ERA5land return hourly data with an horizontal resolution of respectively 31km and 9 km over the entire globe. The data are available since Fifties and they are continuously updated with a delay of only 5 days for ERA5 and few months for ERA5land. Well-documented test cases over Campania Region for which long datasets of atmospheric data and details about the landslide events are available, are exploited to assess the capabilities of ERA5 reanalysis in reproducing antecedent and triggering soil water fluxes exchanges histories. Then, strengths and potential gaps are identified and thoroughly explained to permit a reliable adoption of the datasets.
Climate-driven deterioration of long-life, long-linear geotechnical infrastructure
Authors: Brooks Helen , Stirling Ross , Blake Anthony , Holmes Jessica , Yu Zelong , Watlet Arnaud , Whiteley James , Briggs Kevin , Smith Alister , Hughes Paul , Smethurst Joe , Chambers Jonathan , Dixon Neil
Published: March 2022

Long-life, long linear geotechnical assets such as road, rail and flood embankments provide vital transport and flood defence infrastructure. Slope failures can close transport networks and cause delays, or can reduce the protection provided against flood hazards. This creates huge economic cost and can cause a risk to life for those using affected transport networks or resident on the floodplain. Where emergency repair is needed, the estimated cost of this is 10 times that of scheduled maintenance making effective asset management an industry priority (Glendinning et al., 2009).

However, projected climatic changes pose a threat to the stability of these assets. The most recent IPCC report highlighted projected future changes to temperatures and rainfall. These climatic changes alter the natural cycles of wetting and drying experienced by assets, which results in deterioration of asset performance. Deterioration can occur due to a variety of processes, including crack formation and propagation, downslope plastic strain accumulation and geochemical or mineralogical changes. These ultimately influence the strength, stiffness, permeability and water retention of the soil, which can often mean the construction standard of the asset is not maintained (Stirling et al., 2021).

The ACHILLES project aims to improve understanding of how these processes occur and how they may be affected by projected climatic change. Here, we introduce three large-scale field monitoring sites, including a purpose-built trial embankment, flood embankment and highway cutting. These assets are heavily instrumented to measure soil deformation, soil hydrology and local weather conditions, amongst others. Data from these sites are analysed to further understand deterioration processes and inform future design, construction, monitoring and management of these earthworks. We will discuss key insights from this project, including implications for stakeholders.

References:

Glendinning S, Hall J, Manning L (2009) Asset-management strategies for infrastructure embankments. Proc Inst Civ Eng Eng Sustain 162:111–120

Stirling RA, Toll DG, Glendinning S, Helm PR, Yildiz A, Hughes PN, Asquith JD. Weather-driven deterioration processes affecting the performance of embankment slopes. Géotechnique 2021, 71(11), 957-969.
The potential of crowdsourced personal weather stations for hydrological forecasting in a Dutch lowland catchment
Authors: Brauer Claudia , Lammerts Romy , de Vos Lotte , Overeem Aart
Published: March 2022

Accurate and real-time available rainfall data are indispensable for flood forecasting and warning. Crowdsourced personal weather stations have a high spatiotemporal resolution (in our case 9 km2 and 5 min) and are available in near-real-time, but are prone to errors. In this study, we (1) assessed the accuracy of rainfall observations from personal weather stations in a Dutch lowland catchment (Oude IJssel, 1210 km2) and (2) used these PWS data as input to a rainfall-runoff model (WALRUS) to assess their potential for discharge forecasting.

 

The catchment-averaged rainfall depths measured by personal weather stations slightly overestimated the reference with a bias of only 0.03 mm, which is much lower than the underestimation of the real-time available (unadjusted) radar product (-0.16 mm). Quality control of PWS did not reduce the bias, but time series varied less and correlated better with the reference. For individual stations, quality control reduced the bias with 11% while retaining 85% of the data.

 

Discharge simulations using quality-controlled personal weather stations (NSE=0.98, using simulations with gauge-adjusted radar rainfall data as reference) were better than before quality control (NSE = 0.95) and much better than the real-time available (unadjusted) radar product (NSE=0.70).

 

To conclude, rainfall data from personal weather stations are suitable for real-time hydrological applications, especially after quality control.

 
AusGeochem: an Australian AuScope Geochemistry Network data platform for laboratories and their users
Authors: Prent Alexander M. , Boone Samuel C. , Dalton Hayden , Gréau Yoann , Florin Guillaume , Kohlmann Fabian , Theile Moritz , Noble Wayne , Hodgekiss Sally-Ann , Ware Bryant , Philips David , Kohn Barry , O’Reilly Suzanne , Gleadow Andrew , McInnes Brent , Rawling Tim
Published: March 2022

Over the last two years, the Australian AuScope Geochemistry Network (AGN) has developed AusGeochem in collaboration with geoscience-data-solutions company Lithodat Pty Ltd. This open, cloud-based data platform (https://ausgeochem.auscope.org.au) serves as a geo-sample registry, with IGSN minting capability, a geochemical data repository and a data analysis tool. With guidance from experts in the field of geochemistry from a number of Australian institutions, and following international standards and best practices, various sample and geochemistry data models were developed that align with the FAIR data principles. AusGeochem is currently accepting data of SIMS U-Pb as well as of fission track and (U-Th-Sm)/He techniques with LA-ICPS-MS U-Pb and Lu-Hf, 40Ar/39Ar data models under development. Special attention is paid to the implementation of streamlined workflows for AGN laboratories to facilitate ease of data upload from analytical sessions. Analytical results can then be shared with users through AusGeochem and where required can be kept fully confidential and under embargo for specified periods of time. Once the analytical data on individual samples are finalized, the data can then be made more widely accessible, and where required can be combined into specific datasets that support publications.
Loop blocking (“tiling”) in NEMO
Authors: Calvert Daley , Bell Mike , Mele Francesca , Epicoco Italo , Masson Sebastien , Glover Maff , Madec Gurvan
Published: March 2022

NEMO is an example of a memory-bound code, where computational performance is limited by memory bandwidth due to intensive main memory access. This can be mitigated by more efficient use of the memory hierarchy, ensuring that data is held in fast low-level cache for as long as possible. Loop blocking or “tiling” is one way of achieving this, by partitioning loops so that data access is divided into smaller blocks that fit into cache.

This optimisation technique has been applied to several numerical ocean models, including MITgcm, ROMS and CROCO. We describe an implementation of tiling in the NEMO 4.2 release candidate and its performance in realistic global configurations.

The MPI domain is partitioned horizontally (over latitude and longitude) by modifying DO loop bounds and local working array declarations. A DO loop at the time-stepping level iterates over the tiles asynchronously. Lateral boundaries use an extended halo (two points wide instead of one) so that MPI communications can be suppressed when the tiling is active. Tiling has so far been implemented in the active tracer, vertical diffusion and dynamical code sections of NEMO.

Tiling of the longitudinal axis always results in a loss of performance while tiling of the latitudinal axis can perform very well, reducing the execution time of individual code sections by up to 40% in ORCA2 simulations. However, this is offset against the cost of additional calculations due to the two-point halo, which increases the execution time of individual code sections by up to 15%. Additionally, the number of calculations is proportional to the number of tiles, further reducing potential performance gains from the tiling. This can be mitigated by removing halo calculations where possible.

Overall tiling performance in ORCA025 is significantly worse compared to ORCA2. This is because a greater proportion of time is spent in code that is not tiled (75% in ORCA025 vs 45% in ORCA2) and because the performance of some tiled code is worse. Tiling in the vertical, as well as the horizontal, not only recovers the performance of this tiled code but improves it beyond that in the ORCA2 simulations.
Analysis of Self-Potential signals due to cable bacteria over different conductivity structures
Authors: Upadhyay Akanksha , Madsen Line Meldgaard , Christiansen Anders Vest , Damgaard Lars Riis
Published: March 2022

Cable bacteria are multicellular microorganisms that are capable of long distance electron transport (LDET) along their length. This electron transport is the result of oxidation of hydrogen Sulfide (H2S) in the sulfidic sediment layer where electrons are conducted up through cable filament aided by cell-to-cell transfer in the oxic layer thus reducing oxygen by gaining electrons. Cable bacteria behave as dipoles where anaerobic zones interfere with oxic zones for example oil/tar pollution site and can generate enough natural SP fields as a function of redox mechanism that can be measured on the surface. This study focuses on the theoretical analysis of Self-Potential (SP) signals resulting due to the presence of dipole current source under different conductivity structures in the subsurface. To investigate the behavior of SP signals, four different types of forward models are synthesized by varying resistivity of subsurface layers and changing the depth of the dipole beneath the surface. The dipole has a default current density of 20 mA/m2. In the first model, a rectangular pollution patch carrying a dipole of the same shape is placed between two homogeneous layers where the top layer resistivity is swept from 10-1000 ohm-m while keeping the resistivity of bottom layer constant. In the second model, the pollution patch is placed between an inhomogeneous layer with low, intermediate, and high resistivity contrasts and a homogeneous layer. In this model, half of the patch lies in lower conducting region whereas the other part is in the high conductivity region. The third model is an extension of the second one, where the inhomogeneous layer is sandwiched between two homogeneous layers. In the last model, the pollution patch was moved beneath the surface to a depth where the SP signal cannot be observed at the surface. In this model, the depth is observed for three different pollution sources with current density values equal to 2, 20 and 200 mA/m2 respectively. The results showed that SP anomaly caused by the patch when the conductivity of upper layer is high is smaller as compared to the anomaly due to the less conducting upper layer. Next two models with inhomogeneous layer, correlate well with the first model showing high SP anomaly caused by dipole when it is present in the lower conducting region and low values when in high conducting region. Fourth model demonstrates when the depth of pollution patch is increased beneath the surface, SP signal decreases and is not observed beneath a depth of around 10 m, even when the source has current density value as high as 200 mA/m2. This study explicitly demonstrates the behavior of SP anomaly and will help in improved interpretation of SP technique where inhomogeneity will be present beneath the surface.
Impact cratering into water-covered targets on Mars
Authors: Sokolowska Aleksandra , Thomas Nicolas , Wünnemann Kai
Published: March 2022

Mars is a cold dry planet, yet there is ample evidence for fluvial activity on its past surface, including sediments suggestive of shallow lakes, which paints a different picture for the Martian past climate. Mars is also heavily cratered, and some of those craters may have resulted from impact cratering into water-covered targets. Distinguishing between water-overed and dry surface at the time of the impact is the topic of this project. We approach this problem from the theoretical point of view and use a shock physics code iSALE capable of simulating different materials with various strength and damage models. This hydrocode is widely used in impact physics and has been extensively tested against laboratory experiments. We realise several impact scenarios with varied rheology, as well as sizes of projectiles and impact angles, in particular water-covered (simulated paleolake), water ice-rich and dry targets. We discuss the theoretical effects of the presence of surface water on the morphology and dynamics of impact sites (both craters and ejecta). Distinguishing between these scenarios can aid the interpretation of remote sensing observations, and open a possibility of using a new independent observable to study the past climate of Mars.
Ten new insights in climate science 2021 – a horizon scan
Authors: Martin Maria A.
Published: March 2022

Since 2017, the 10 new insights in climate science (10NICS, https://10insightsclimate.science/) annually summarize a set of the most critical aspects of Earth’s complex climate system – including physical, biogeochemical and socioeconomic/sociocultural dimensions.

Here we set the context of the 10NICS series as a joint project between Future Earth, the Earth League and the World Climate Research Programme (WCRP), and briefly visit each of the ten insights from the 2021 edition (Martin et al., 2021):  (1) the options to still keep global warming below 1.5 °C; (2) the impact of non-CO2 factors in global warming; (3) a new dimension of fire extremes forced by climate change; (4) the increasing pressure on interconnected climate tipping elements; (5) the dimensions of climate justice; (6) political challenges impeding the effectiveness of carbon pricing; (7) demandside solutions as vehicles of climate mitigation; (8) the potentials and caveats of nature-based solutions; (9) how building resilience of marine ecosystems is possible; and (10) that the costs of climate change mitigation policies can be more than justified by the benefits to the health of humans and nature.

The 10NICS topics are not intended to form a comprehensive scientific assessment. Intentionally limited to 10, each insight is succinct and does not try to cover entire fields.

Martin, M. A., Alcaraz Sendra, O., Bastos, A., Bauer, N., Bertram, C., Blenckner, T., … Woodcock, J. (2021). Ten new insights in climate science 2021: a horizon scan. Global Sustainability, 4(e25), 1–20. https://doi.org/10.1017/sus.2021.25
Climate change adaptation digital twin to support decision making
Authors: Kontkanen Jenni , Manninen Pekka , Doblas-Reyes Francisco , Niemelä Sami , Stevens Bjorn
Published: March 2022

Climate change will have far reaching impacts on human and natural systems during the 21st century. To increase the understanding of the present and future climate impacts and build resilience, improved Earth system modelling is required. The European Commission Destination Earth (DestinE) initiative aims to contribute to this by developing high precision digital twins (DTs) of the Earth. We present our solution to a climate-change adaptation DT, which is one of the two DTs developed during the first phase of DestinE. The objective of the climate change adaptation DT is to improve the assessment of the impacts of climate change and different adaptation actions at regional and national levels over multi-decadal timescales. This will be achieved by using two storm- and eddy-resolving global climate models, ICON (Icosahedral Nonhydrostatic Weather and Climate Model) and IFS (Integrated Forecasting System). The models will be run at a resolution of a few km on pre-exascale LUMI and MareNostrum5 supercomputers, which are flagship systems of the European High Performance Computing Joint Undertaking (EuroHPC JU) network. Following a radically different approach, climate simulations will be combined with a set of impact models, which enables assessing impacts on different sectors and topics, such as forestry, hydrology, cryosphere, energy, and urban areas. The end goal is to create a new type of climate simulations, in which user requirements are an integral part of the workflow, and thus adaptation solutions can be effectively deployed.
Inferring the hydration of downgoing oceanic crust and lithospheric mantle from intermediate-depth earthquakes and outer rise faulting patterns
Authors: Sippl Christian , Geersen Jacob , Harmon Nick
Published: March 2022

It is commonly assumed that intermediate-depth seismicity is in some way linked to dehydration reactions inside subducting oceanic lithosphere. There is growing evidence that the hydration state of an oceanic plate is controlled by its structure and degree of faulting at the outer rise, but we do not yet have a quantitative understanding of this relationship.

Double seismic zones offer the possibility of investigating changes in oceanic-plate hydration not only along strike but also with depth beneath the slab surface. To quantify the impact of oceanic-​plate structure and faulting on slab hydration and intermediate-depth seismicity, with a focus on the genesis of double seismic zones, we correlate high-resolution earthquake catalogs and seafloor maps of ship-based bathymetry for the northern Chilean and Japan Trench subduction zones. The correlations show only a weak influence of oceanic-plate structure and faulting on seismicity in the upper plane of the double seismic zone, which may imply that hydration is limited by slow reaction kinetics at low temperatures in the oceanic crust 5–7 km below the seafloor and by the finite amount of exposed wall rock in the outer-rise region. These factors seem to limit hydration even if abundant water is available.

Seismicity in the lower plane is, in contrast, substantially enhanced where deformation of the oceanic plate is high and distributed across intersecting faults. This likely leads to an increase in the volume of damaged wall rock around the faults, thereby promoting the circulation of water to mantle depths where serpentinization is faster due to elevated temperatures. Increased lower-plane seismicity around the projection of subducting oceanic features such as seamounts or fracture zones to depth may also be caused by enhanced faulting around these features. Our results provide a possible explanation for the globally observed presence of rather homogeneous upper-plane seismicity in double seismic zones as well as for the commonly patchy and inhomogeneous distribution of lower-plane seismicity.
The Effect of Calcium and Magnesium Ions on CO2 Convective Dissolution and Carbonate Precipitation
Authors: Knoll Pamela , De Wit Anne
Published: March 2022

The reduction of carbon dioxide concentration in the atmosphere has become an important objective to diminish the predicted exponential increase in global temperatures. A promising long-term solution is carbon capture, and sequestration (CCS), whereby CO2 is injected into saline aquifers containing high concentrations of divalent cations leading to the mineralization of carbonate salts. These precipitation reactions provide a potential long-term solution for storing and preventing reentry of this greenhouse gas into the atmosphere. Our study aims to understand the influence of the initial host solution composition on CCS. Using two glass plates separated by a thin gap (~1 mm), we steadily inject CO2 gas above an alkaline aqueous solution of either calcium chloride and/or magnesium chloride and monitor the convective uptake of CO2 and subsequent mineralization into calcium carbonate (e.g., calcite, aragonite, and vaterite), magnesium carbonate (e.g., hydromagnesite), or calcium magnesium carbonate (e.g., dolomite). The buoyancy-driven convective dynamics from the dissolution of CO2 is monitored using schlieren imaging techniques. In addition, a pH indicator in the initial metal salt solution shows its acidification from the continuous uptake of CO2. The mineral products are analyzed using X-ray diffraction, Raman spectroscopy and scanning electron microscopy to determine the composition, crystal structure, and crystal habit.
Numerical investigations on different possible generating mechanisms for the tsunami following the January 15 2022 Hunga Tonga-Hunga Ha’apai eruption
Authors: Armigliato Alberto , Angeli Cesare , Gallotti Glauco , Tinti Stefano , Zanetti Martina , Zaniboni Filippo
Published: March 2022

The Hunga Tonga-Hunga Ha’apai eruption of January 15 2022 was the culminating event of a sequence of seismic and volcanic events starting back in December 2021. The January 15 eruption manifested itself above the sea level with a number of phenomena, including the generation of a convective column ascending well into the stratosphere, pyroclastic flows travelling over the sea surface, an atmospheric pressure wave recorded by several instruments around the globe, and a tsunami, that represents the main focus of this study.

The tsunami that followed the eruption was observed both in the near-field and in the far-field, propagating across the entire Pacific Ocean and causing damage and loss of lives as far as Peru. In the near-field (Tonga archipelago) it is trickier to distinguish the damage induced by the impact of the eruption and the tsunami waves.

It is still not clear what the main generating mechanism for the ensuing tsunami was. In this contribution, several different hypotheses are investigated, adopting simplified models ranging from the submerged volcanic edifice collapse to the phreatomagmatic explosion and to the atmospheric pressure wave that was recorded across the entire globe. The propagation of the tsunami is simulated numerically with both non-dispersive and dispersive codes. Different spatial scales and resolutions are adopted to check the relative weight of the different generating mechanisms in the near- and in the far-field. Tentative conclusions are drawn by comparing the simulated results with the available experimental data in terms of tide-gauge records and near-field coastal impact.