bluuebunny/crossref_metadata_2025 huggingface dataset:
Source to Sea: the relationship between carbon and iron in mid-latitude fjord sediments
Authors: Kellock Celeste , Smeaton Craig , Shah Nadeem , Austin William , Schroeder Christian
Published: March 2022

Mid-latitude fjords have recently been identified as important environments for carbon storage. This research highlights the importance of the lateral transport of carbon from land to sea as we assess the influence of catchment land use (primarily forestry) on carbon transport and sediment carbon burial. Establishing the influence of land use, specifically forestry, on coastal biogeochemical cycling is particularly important if afforestation is to help mitigate climate change impacts, and to better understand the impact of deforestation. The relationship between carbon and iron in fjord sediments is the focus of this study. We provide insights into carbon and iron coupling in a mid-latitude fjord. Here we show the variability of carbon burial, and how this is influenced by terrestrial inputs and iron speciation in fjord sediments. We use bulk organic carbon and elemental data, isotopic analysis, Mössbauer spectroscopy and chemical extractions to better understand the relationship between carbon and iron. Observed decreases in organic carbon from the upper to lower basin are influenced by the input of terrestrial material. Organic carbon is up to three times higher in the upper basin and terrestrial organic carbon is ~20% higher in comparison to the lower basin of the fjord. The strength of the reactive iron signal is found to vary vertically (with depth, over time) and laterally (from upper – lower basin) within this fjord. Results highlight that there is a changing relationship between iron and carbon within this system. Understanding land-sea controls on coastal carbon transport and burial is crucial during this period of climate change.
Amazon mega-flood naratives from large ensemble simulations – are they unseen or unrealistic?
Authors: Kelder Timo , Wanders Niko , van der Wiel Karin , Marjoribanks Tim , Slater Louise , Wilby Rob , Prudhomme Christel
Published: March 2022

Large ensemble simulations can be exploited to generate larger data samples than the observed record and consequently better assess the likelihood of rare events. Such simulations have the potential to inform storylines of ‘unseen’ flood episodes, i.e., that are more extreme than those seen in historical records. This method has, for example, been used to improve design levels of storm-surges in the river Rhine and to anticipate rainfall extremes over the UK. However, adequate evaluation of simulated ‘unseen’ events is a complex task.
Here, we showcase simulated Amazonian mega-floods from the combination of global climate model EC-Earth and global hydrological model PCR-GLOBWB. We introduce a three-step procedure to assess the realism of these mega-floods based on the model properties (step 1), as well as the statistical features (step 2) and physical credibility of the simulation (step 3). For the Amazon example, we find that the unseen floods were the result of an unrealistic bias correction of precipitation. 
We reflect on the different types of models that can be used to generate large sample sizes, and discuss the difference between storylines from large ensembles as compared to targeted model experiments to identify mega-floods. We conclude that understanding the driving mechanisms of unseen events may guide future research by uncovering key model deficiencies. They may also play a vital role in helping decision makers to anticipate unseen impacts by detecting plausible drivers. 
Enhancing planetary imagery with the holistic attention network algorithm
Authors: Maxheimer Denis , Markonis Ioannis , Jan Masner , Vojtech Curin , Jan Pavlik , Anezina Solomonidou
Published: March 2022

The recent developments in computer vision research in the field of Single Image Super Resolution (SISR)

can help improve the satellite imagery data quality and, thus, find application in planetary exploration.

The aim of this study is to enhance planetary surface imagery, in planetary bodies that there are

available data but in a low resolution. Here, we have applied the holistic attention network (HAN)

algorithm to a set of images of Saturn’s moon Titan from the Titan Radar Mapper instrument in its

Synthetic Aperture Radar (SAR) mode, which was on board the Cassini spacecraft. HAN can find

correlations among hierarchical layers, channels of each layer, and all positions of each channel, which

can be interpreted as an application and intersection of previously known models. The algorithm used

in our case-study was trained on 5000 grayscale images from HydroSHED Earth surface imagery dataset

resampled over different resolutions. Our experimental setup was to generate High Resolution (HR)

imagery from eight times lower resolution (x8 scale). We followed the standard workflow for this

purpose, which is to first train the network enhancing x2 scale to HR, then x4 scale to x2 scale, and

finally x8 scale to x4 scale, using subsequently the results of the previous training. The promising results

open a path for further applications of the trained model to improve the imagery data quality, and aid

in the detection and analysis of planetary surface features.
Future changes of East Asian cyclones in the CMIP5 models
Authors: Lee Jaeyeon , Hwang Jaeyoung , Son Seok-Woo , Gyakum John
Published: March 2022

Future changes of extratropical cyclones (ETCs) over East Asia are investigated using the models participating in the fifth phase of the Coupled Model Intercomparison Project (CMIP5). To quantify ETC frequency, intensity, and genesis changes in a warming climate, the objective tracking algorithm is applied to the CMIP5 models which provide 6-hourly wind data with no missing values in the high-terrain region. The historical simulations reasonably well capture the spatial distribution of ETC properties, except for noticeable biases in, and downstream of, the high-terrain regions. Such biases are particularly pronounced in the models with a coarse spatial resolution and a smooth topography which weakens lee cyclogenesis. The best five models, which show better performance for historical simulations than other models, are used to evaluate the possible changes of East Asian ETCs under the RCP8.5 scenario. These models project a reduced cyclogenesis in the leeward side of the Tibetan Plateau, and over East China Sea and western North Pacific in the late 21st century, resulting in a reduced ETC frequency from the east coast of China to the western North Pacific. The ETC intensity also shows a hint of weakening over the North Pacific. These ETC property changes are largely consistent with an enhanced static stability and a reduced vertical wind shear in a warming climate. This result indicates that the local baroclinicity, instead of increased moisture content, plays a critical role in determining the future changes of East Asian ETCs.
Impact of the extratropical cyclone over the North Pacific on the onset of Sudden Stratospheric Warming: A case study of 2021
Authors: Cho Hyeong-Oh , Kang Min-Jee , Son Seok-Woo , Hong Dong-Chan , Kang Joonsuk M.
Published: March 2022

The role of the midlatitude cyclone on the onset of January 2021 sudden stratospheric warming (SSW) is examined by conducting a set of numerical model experiments. The control simulation initialized on 26th December 2020, 10 days before the SSW onset, successfully reproduces the spatio-temporal evolution of SSW. Since this event is preceded by the developing cyclone over the North Pacific, its impact is tested by initializing the model without cyclonic anomaly, over the North Pacific (20°–80°N, 110°E–160°W) from 1000 hPa to 150 hPa. The potential vorticity inversion technique is used to modify the initial condition. This perturbed simulation shows much weaker polar-vortex deceleration than the control simulation resulting in no distinct SSW onset. Such a difference is attributable to the fact that constructive linear interference between the climatological wave and the North Pacific cyclone is reduced in the perturbed simulation. It weakens the upward propagation of wavenumber one into the stratosphere, thereby reducing the breaking of the planetary-scale waves in the polar stratosphere.
Hydrologic response to climate change: A case from a high-mountain river basin
Authors: Baniya Rupesh , Regmi Ram Krishna , Talchabhadel Rocky , Sharma Sanjib , Panthi Jeeban , Ghimire Ganesh R , Bista Sunil , Thapa Bhesh Raj
Published: March 2022

Water resources in the Himalayan region are highly exposed and vulnerable to climate variability and climate change. We investigate the potential impact of climate change on hydroclimatic extremes and spatiotemporal distribution of water balance components of the Himalayan river basin, taking the Tila River Basin of Nepal as a test site. This study integrates CMIP6 climate model outputs with a semi-distributed hydrologic model to produce streamflow projections. We analyze climate change impact in three timeframes: near (2026-2050), mid (2051-2075), and far (2076-2100) future under SSP 245 and SSP 585 scenarios. Results showed that the projected change in precipitation, evapotranspiration, and water yield is as high as 50%, 45%, and 75%, respectively. Both low and high flows are projected to increase under future climate scenarios. High altitude regions, with dominant snow- and glacier-covered areas, are more vulnerable to climate change impact. Our results are of practical importance for planners and decision-makers to formulate adaptation strategies under a changing climate.
Do Large Earthquakes along Major Faults Synchronize in Time?
Authors: Sopaci Eyup , Özacar Atilla Arda
Published: March 2022

The triggering mechanism of earthquakes and their synchronization in time and space can be considered the two sides of the same coin. Our previous studies on earthquake triggering reveal sensitive parameters affecting the triggering mechanism using simple spring slider systems. We pursue our previous analyses by considering a simulation set-up for synchronizing three strong asperity patches on a vertically oriented strike-slip fault with initial slip heterogeneity separated by barriers and strong creeping regions at the edges. This analogy intends to explore earthquake synchronization in time and mimic observed sequences of large earthquakes that ruptured most of the North Anatolian Fault within short time intervals. Using the quasi-dynamic and full-dynamic pseudo-spectral Fast Fourier Transform (FFT) method, we apply a periodic fault model governed with Rate-and-State Friction (RSF) law embedded in a 2.5D continuum. Simulation results so far using the quasi-dynamic approach revealed that the earthquake synchronization is mainly affected by direct velocity effect parameters, barrier dimension/properties, and RSF law (aging and slip law), particularly the weakening terms. Lower direct velocity effect parameters, state evolutions with a stronger weakening term such as slip law, and shorter barrier lengths promote better synchronization. In this respect, we observed fast, slow, or no synchronization depending on the parameter sets. It is also worth noting that slip localizes in the continuum at small critical slip distances, which cannot be inferred from simple 1D models, suggesting the size dependence. In order to minimize inherent non-uniqueness and uncertainties, the same set-up will also be simulated with the full-dynamic approach in which wave-mediated stress transfer is taken into account, and the long-term earthquake histories will be correlated with case-specific simulations.
The short-to medium-to long-term effects of bench terrace construction for planting eucalypt trees on soil water repellency
Authors: Martins Martinho A S , González-Pelayo Oscar , Machado Ana I , Simões Liliana B , Ben-Hur Meni , Keizer Jan J
Published: March 2022

The establishment of monospecific eucalypt plantations has increased considerably over the last half-century. At present, eucalypts are the tree species that are planted most widely across the world, and the common practice of soil mobilization prior to their planting has been associated with negative effects on soil functions such as nutrient and water cycling, carbon sequestration, soil erosion control and soil biodiversity conservation. In Central Portugal, the construction of bench terraces for eucalypt plantations areas has become increasingly common on steep terrain. Bench terrace construction implies the mobilization of large quantities of topsoil and, hence, elevated installation costs that are justified by the advantages in planting, fertilizer application, mechanical and agrichemical weed control and, ultimately, salvage logging and extraction of wood and logging residues. Although terraces are a traditional soil and water conservation technique, the hydrological impacts of bench terracing for forest plantations have been poorly studied. The use of heavy machinery in forests has been reported to increase soil compaction and bulk density and, thereby, decrease soil infiltration capacity and increase runoff generation. At the same time, the flat sections of bench terraces will increase not only infiltration of rainfall but also re-infiltration of run-on, for example from the adjacent risers or diverted forest tracks. In the case of eucalypt plantations, (re-)infiltration patterns may be strongly affected by soil water repellency (SWR), as eucalypts have been widely associated with strong to extreme SWR, especially during dry periods. This study aimed to quantify the short- to long-term impacts of bench terrace construction on SWR in eucalypt plantations along a chrono-sequence. To this end, SWR was measured in-situ, using the Methanol droplet (MED) test, for four different periods of time-since-terracing, i.e. 0, 5, 10 and 17 years after terracing. For each of these periods, three pairs of nearby terraced and non-terraced eucalypt plantations were studied, giving a total of 24 study sites. The MED measurements were done during the dry summer of 2020 (in plain covid-19 crisis conditions). The results showed clear differences in SWR between terraced and non-terraced eucalypt plantations. The median SWR was extreme in all non-terraced sites (MED classes 7 to 8) as opposed to highly variable at the terraced sites, ranging from wettable to strong (MED classes 0 to 6). In the case of the terraced sites, the time elapsed since terrace construction had a major impact. The median SWR was very wettable immediately as well as 5 years after terracing, while it was moderate and strong water repellent 10 and 17 years after terracing.
Linkage between chemical erosion and human-induced vegetation pattern during the late Holocene period
Authors: Samanta Anupam , Tripathy Gyana Ranjan , Panchang Rajani , Nath B Nagender , Bhushan Ravi , Bharti Nisha
Published: March 2022

Geochemistry of marine sediments serves as a reliable proxy for past continental erosion patterns. Available studies on paleo-erosion although have evaluated the impact of natural factors (climate, vegetation, basin slopes) on erosion rates, the impact of anthropogenic forces on the land surface processes has received limited attention. Recognizing this, major and trace elemental compositions of a sediment core (SSK40/GC06) from the eastern Arabian Sea have been investigated to reconstruct the temporal change in erosional pattern, if any, during the late Holocene period. The chronology of the core has been established using the AMS-14C age of foraminifera samples. The SSK40/GC06 sediments are mostly clayey to silty in nature, with minimal change in size with depth. Depth profiles of Al-normalized elemental ratios and patterns of rare earth elements point to an insignificant change in relative sediment contributions from the major provenances. In contrast, temporal trends of multiple weathering indices show a significant increase in chemical erosion since ~ 1600 yr BP to the present. Past climatic and sedimentary records show no major change in the southwest monsoon regime during this period. However, existing studies based on sedimentary records from peninsular India show a synchronous rise in the C4 vegetation, which possibly is linked to human-induced agricultural practices. This increase of C4 vegetation with shallow root systems may erode young soils more efficiently, which in turn expose fresh minerals for chemical weathering in basins. The observed trends, along with available past vegetation records, show a strong linkage between chemical erosion and anthropogenic activity.
A relatively pristine C-like component in the eastern Anatolian asthenosphere
Authors: Aktağ Alican , Sayit Kaan , Peters Bradley J. , Furman Tanya , Rickli Jörg
Published: March 2022

Eastern Anatolia (Eastern Turkey) resides in the Alpine-Himalayan orogenic belt and hosts the Eastern Anatolian Volcanic Province (EAVP), one of the volumetrically most important volcanic provinces within the circum-Mediterranean region. Previous studies have revealed that the predominant portion of EAVP is composed of the products of the sub-continental lithospheric mantle (SCLM) metasomatized during subduction of the Neo-Tethyan slab. The wide distribution of the lithospheric signatures in EAVP lavas has led to the availability of a large number of geochemical information regarding the regional SCLM in eastern Anatolia. In contrast, the nature of the asthenospheric mantle of eastern Anatolia remains poorly constrained due to scarcity of the asthenosphere-derived melts and lack of detailed information on the source components it comprises. Hence, this study aims primarily to put constraints on the chemical nature of asthenosphere beneath eastern Anatolia by a detailed characterization of its end-members.  

In this study, we provide new trace element and Sr-Nd-Hf-Pb isotope data from Quaternary Elazığ volcanism. This volcanism, entirely represented by mafic alkaline basaltic rocks, is one of the most recent members of EAVP, and its chemistry provides compelling evidence for a predominate asthenosphere origin. Modellings suggest that these mafic volcanics are largely free of crustal assimilation; their geochemical signatures, hence, closely reflect their source regions. Their trace element and Sr-Nd-Hf-Pb isotope systematics are consistent with derivation from an asthenospheric mantle source domain containing approximately 70% recycled oceanic lithologies with the characteristics of the C-like mantle component. However, minor contributions from depleted component (DM; ca. 20%) and an enriched component representing metasomatically modified SCLM (ca. 10%) are also needed to explain their total range of isotope data. With these findings, we propose that the C-like material is dispersed within the asthenosphere, and has mixed with the depleted mantle matrix beneath eastern Anatolia. The SCLM domains, on the other hand, occur as detached pods, following the lithospheric delamination in the region. Having triggered by the extensional dynamics during Quaternary, upwelling of the hot asthenosphere resulted in the melting of the C-DM and SCLM domains. Subsequently, the C-DM melts interacted with the SCLM-type melts, eventually generating the Elazığ volcanism.
A visual approach for water quality monitoring within the CrowdWater project
Authors: Blanco Ramírez Sara , van Meerveld Ilja , Seibert Jan , Scheller Mirjam , Schwarzenbach Franziska
Published: March 2022

CrowdWater is a citizen science project that uses a mobile phone application (app) to collect hydrological data. The project aims to develop and test methods for hydrological measurements that do not require sensors. So far, the app is used to collect data about stream water levels, the state of intermittent streams, soil moisture, and plastic pollution. The app can also be used to record general characteristics of streams, such as the color, the presence of fish and other living beings, or water pollution.

Perhaps without realizing it, many people make visual water quality assessments for their daily decisions. Based on visual aspects of the water, people decide whether the water is suitable for swimming or drinking. This presents an opportunity to explore the potential of a visual approach through citizen science-based water quality observations. Water color and clarity are one of the most frequently used indicators for the visual assessment of water quality. Remote sensing studies have shown that water color is changing in many areas, which suggests that it is useful to characterize visual water quality aspects throughout time and to relate these to perceptions of water quality and how this affects water use. However, most of the time this perception is not just based only on the current characteristics of the water but also on local environmental knowledge, such as the presence of outlets that discharge waste water or sewage overflows, the water quality in the past, etc.

This presentation will describe the visual approach for water quality that fits within the CrowdWater philosophy of not using any sensors so that observations can be made by anyone at any place. We will also present a first evaluation of the method. This includes discussing how consistent people are in their assessment of water color and whether they can assess differences in water color over time or between sites.
Distribution of soil carbon stock in a forested wetland in the semiarid region of India: implications for climate change mitigation
Authors: Deval Kundan , Joshi Pawan Kumar
Published: March 2022

Climate change mitigation strategies require long time removal and storage of carbon; thus, enhancing soil carbon stock is an appealing way to increase carbon sink potential and control emissions owing to associated ecosystem benefits. Understanding soil organic carbon (SOC) stock in the semiarid landscape is vital for natural based climate solutions and mechanisms. The carbon stock in soil represents 25% of the potential of natural climate solutions and wetlands have around 72% mitigation potential for soil carbon. Wetlands have a very complex natural system and provide a potential sink of atmospheric carbon. Particularly the role of wetlands in arid and semiarid lands has become vital as they not only provide a water source and livelihood options to the local community but also play an important role in maintaining ecosystem services. However, only limited studies have been conducted to assess the roles and potentials of wetlands in carbon sequestration in a semiarid region. The geospatial technologies provide a cost-effective and more accurate estimation of SOC stock in these ecosystems. The SOC distribution in wetland ecosystems and their carbon sequestration potential studies are crucial to understanding the global carbon budget. The present study area Keoladeo National Park is an ecologically important forested wetland situated in semiarid India with a heterogeneous landscape. Current research work illustrated a hybrid interpolation method for estimating the distribution of soil carbon in different vegetation type/land cover (VT/LC) using point survey data (prepared after laboratory test) with remote sensing. The map prepared has given satisfactory results with more than 80 present accuracy. SOC distribution data were collected from 130 plots from both the surface (0-15 cm) and subsurface soil (15-30 cm) covering all the 15 VT/LC classes. SOC was found to be significantly related to VT/LC type and water availability. The spatial distribution of SOC shows a wide range with an average value of around 1.5%; the seasonal distribution shows an increased amount of carbon in pre monsoon season and a high amount of carbon in the surface soil. The concentration of SOC (around 2.5%) has been observed to be more in wetland and grassland soils in both the seasons that cover about 13% and 27% area of the park, respectively. SOC stock management in this region is vital in observing the local community needs, which is mainly dependent on the park for livestock food. Further geospatial analysis of soil carbon stock potential will add value to the study. Synergising climate change mitigation strategies and community requirements are needed to enhance vulnerable communities' benefits. 

Keywords: Soil carbon, semiarid region, remote sensing, climate change mitigation.
S3M Italy: a real-time, open-source cryospheric-forecasting chain for applications on a large scale 
Authors: Avanzi Francesco , Gabellani Simone , Delogu Fabio , Silvestro Francesco , Puca Silvia , Toniazzo Alexander , Giordano Pietro , Falzacappa Marco , Ratto Sara , Stevenin Hervè , Cardillo Antonio , Cremonese Edoardo , Morra di Cella Umberto
Published: March 2022

Monitoring the state of the cryosphere in real time is a key to improved risk and water resources management, especially in a warming climate. All around the world, this goal is achieved through forecasting chains combining models with in-situ and remote-sensing measurements. Here, we discuss lessons learned while developing S3M Italy, one such chain delivering hourly estimates of snow water equivalent, density, snow and glacier melt, and bulk liquid water content across the Italian territory (300k+ km2, 200 m resolution, 1.5 hour turnaround). S3M Italy includes downloaders to ingest input data from automatic weather stations, spatialization tools to convert these data into weather-input maps, blending routines for deriving daily snow-covered-area maps from ESA Sentinel 2, NASA MODIS, and EUMETSAT H-SAF products, mapping algorithms based on multilinear regressions for assimilating on-the-ground snow-depth data, as well as algorithms to manage parallelized runs and then mosaic model outputs. S3M Italy has been developed to support decisions by the Italian Civil Protection Agency and is fully open source, not only in terms of underlying models (https://github.com/c-hydro/s3m-dev), but also in terms of all pre-processing routines (https://github.com/c-hydro/fp-hyde, https://github.com/c-hydro/fp-s3m). 
Temporal deformation in the Hellisheiði geothermal field and its adjacent Húsmúli injection field explained by poroelastic modelling
Authors: Ducrocq Cécile , Heimisson Elías Rafn , Geirsson Halldór , Árnadóttir Thóra , Axelsson Gudni , Hjörleifsdóttir Vala , Drouin Vincent
Published: March 2022

Crustal deformation allows us to monitor and understand critical properties of exploited geothermal systems around the world. The Hellisheiði high-temperature geothermal field (in 2011: 303MWe and 133MWth) in SW Iceland has been previously studied using Global Navigation Satellite Systems (GNSS) and Interferometry Synthetic Aperture Radar (InSAR) data between 2011 and 2015. These studies characterized the subsidence rate related to the extraction of fluids in the Hellisheiði area, as well as a 4-month uplift at the start of injection of geothermal fluids in the Húsmúli area. This uplift was accompanied by significant seismicity culminating with two ML >3.5 earthquakes felt in the surrounding region.

We carry out further analysis of GNSS and InSAR data between 2011 and 2019 that show a total of three uplift events, separated by periods of subsidence or little deformation in the Húsmúli area. The deformation episodes seem to correlate with heightened seismic activity despite the continued decrease of injected mass flow rate in the original injection boreholes.

Here we use a finite element poroelastic model (COMSOL Multiphysics) to relate the extraction and injection of the adjacent Hellisheiði and Húsmúli areas to the ground deformation within the same time span. We assume that the boreholes can be represented by three point-injector sources: one of negative mass flow rate in Hellisheiði, and two of positive mass flow rates in (west and east) Húsmúli. The three sources are necessary to explain the deformation observed between 2011 and 2019. The poroelastic model presents insights into the temporal response of geothermal systems from extraction/injection, changes in exploitations and variability in permeability all of which induce heightened strain and stress in the fractured Húsmúli region. We investigate if poroelastic effects may be responsible for triggering transient earthquake swarms and to what degree poroelasiticy can explain the spatially and temporally complex uplift and subsidence. We suggest this study offers new insights into the Hellisheiði geothermal system that are transferable to geothermal systems around the world.
Recognising cold-based glaciation in the rock record: striated bedrock surfaces of the > 540 million year old Luoquan Formation of China
Authors: Vandyk Thomas , Chen Xiaoshuai , Wang Yuchong , Yang Zhenrui , Kuang Hongwei , Liu Yongqing , Wu Guanghui , Li Meng , Davies Bethan J. , Shields Graham A. , Le Heron Daniel P.
Published: March 2022

When preserved from deep time glaciation, subglacially striated bedrock surfaces allow the interpretation of past ice characteristics that are often elusive from the study of sediments alone. Salient amongst these is the thermal regime, which has a profound influence upon ice behaviour and consequent sediment erosion, transport and deposition. Typically, striated bedrock surfaces are linked to ice at its pressure-temperature melting point, indicating a locally warm-based thermal regime. Conversely, a cold-based thermal regime is defined by ice frozen to the substrate and is linked to minimal erosion. Cold-based erosional forms have been identified in Antarctica but their recognition is next to impossible if imprinted upon a surface previously or subsequently affected by warm-based erosion (e.g. striation). In the ancient record this is especially problematic, as it is typically only through the recognition of characteristic warm-based features that a surface can be confirmed as subglacial at all. Consequently, it is likely that there is an observational bias in the rock record toward warm-based over cold-based ice. This study, through careful geomorphologic analysis of unusually well preserved striated surfaces of the North China Craton from the Ediacaran Period (c. 635 – 540 Ma), presents rare examples that record dominant cold-based and more limited warm-based erosion on the same subglacial surface. It is hoped that this approach may benefit other workers interested in identifying cold-based as well as the more obvious warm-based subglacial conditions from the record of deep time glaciation.
Recognizing the effect of modern and paleo bottom currents across deep-marine basins: insights from sedimentological and geophysical data across the Western Gap and Josephine Seamount (NE Atlantic)
Authors: Urazmuratova Zarina , Bashirova Leila , Kuleshova Liubov , Glazkova Tatiana , Rikhman Mark , Kazakova Diana , Rodrigues Sara
Published: March 2022

We present geophysical and sedimentological data acquired during the 59th cruise of the P/V Akademik Ioffe (September – October 2021) from the eastern North Atlantic. Two sediment cores AI-59022 and AI-59027 were recovered southwest of the Western Gap entrance sill (water depth 4872 m) and from the western slope of the Josephine seamount (water depth 3282 m), respectively.  The collected data is valuable for reconstructions of the Pleistocene to Holocene sedimentary record and recognizing the influence of near-bottom currents on sediment deposition in the study areas.

Using high-resolution sub-bottom profiling, sediment waves (up to 50 m in amplitude) were found southwest of the entrance sill of the Western Gap. The presence of ripples and scours north of this sill also indicate elevated bottom current velocities in the gap which is in agreement with direct current velocity measurements (30 cm/s). Given that temperatures of <2 °C, which are characteristic of the AABW (Morozov et al., 2010), were recorded by CTD profiling near the seafloor, it is possible that AABW has played a significant role in shaping the sedimentary and morphological features in the Western Gap.

On the western slope of the Josephine seamount, a contourite drift intercalated with mixed features was identified, characterized by multiple, continuous sub-parallel reflections.  High-resolution sub-bottom profiling has also allowed us to identify a distinct erosional furrow at 1410 m (water depth). The depth of this feature corresponds to the present depth of the Mediterranean Outflow Water and may be related to the erosive passage of MOW currents.

The sponge species Pheronema carpenter was also observed on the western slope of the Josephine seamount. This species is typically associated with areas of high productivity, and possibly with regions of enhanced bottom tidal currents which promote the resuspension of organic matter. Thus, the presence of this sponge indicates elevated near-bottom hydrodynamic activity in the Josephine seamount area.

The dataset across the western slope of the Josephine seamount was supported by an IO RAS state assignment (№0128-2021-0012), whereas the study in the Western Gap was financed by RFBR (№20-08-00246).
Effect of aerosols on ecosystem productivity: a double-edged sword in climate change
Authors: Hari Manoj , Tyagi Bhishma
Published: March 2022

Rapid climate change exerts a burden on terrestrial primary productivities, which perturb the carbon budget. Being an atmospheric pollutant, a high load of aerosols dampens/overweigh the diffuse radiation; likewise, optimal aerosol load upsurges diffuse radiation and enhance plant photosynthesis (Net Primary Productivity; NPP). This cascading effect is inevitable for understanding the enviro-climate feedbacks, backing which, the present study is framed for multiple ecosystems of India using MODIS products with Carnegie-Ames Stanford Approach (CASA) model. The sensitivity of NPP to aerosol loading was analysed on a decadal scale, isolated for 2001 – 2020. The analysis revealed that, for the Indian scenario, when the overall AOD was greater than 42% above the threshold, i.e., relatively more than 0.81, it cribs NPP. Contrastingly, NPP was influenced when the AOD was at 14% (0.32). The analysis highlighted that the maximum NPP for the forest ecosystems was observed when AOD was 0.38, and the growth persisted with higher AOD until 0.51. In contrast, the agroecosystem's NPP growth was restricted at 0.59, and maximum growth was observed with 0.49. Even though agroecosystems indicated the maximum NPP growth with higher AOD, the fertilisation effects were comparatively lower than the forest ecosystem due to the consistent, intense AOD load over the croplands (especially over the Indo Gangetic Pain belt). This indicated that the vegetational adaptiveness in the agrosystems to the effect of aerosol was weaker than the forest-based ecosystems. Presumably, anthropogenic interventions in cropland management (biomass burning) may also have steered the sensitivity responses of NPP. Based on the analysis, the presented study elucidates the need for considering the intricating aerosol effects on ecosystem productivity in projecting the Indian terrestrial carbon cycle under changing climate.

Keywords: Aerosol; CASA; India; Net primary productivity; Radiative forcing; Terrestrial carbon cycle
Multi-hazard risk assessment of critical infrastructure at the global scale
Authors: Nirandjan Sadhana , Koks Elco , de Moel Hans , Verschuur Jasper , Wing Oliver , Aerts Jeroen , Ward Philip
Published: March 2022

Critical infrastructures (CI) play an essential role in the day-to-day functioning of societies and economies. They refer to the array of physical assets required for the operation of the complex infrastructure network, which include energy grids, waste systems, and transportation networks. At the same time, impacts of natural hazards highlight the importance of improving our understanding on the natural hazard risk to these infrastructures. CI have evolved in large interconnected networks, whereby disruption of one asset may quickly propagate into widespread consequences – even outside an exposed area. The disruption of the services provided by CI have large potential to seriously hamper the daily activities of societies and economies that depend on them, as well as the recovery in the aftermath of an disruptive event.

To date, however, scientific literature on the potential global asset damages to CI induced by multi-hazards remain limited. Modelling assessments that combine information on hazard intensities and extents, exposure of infrastructure and the vulnerability of these exposed assets are crucial to improve our understanding of infrastructure that are directly at risk to multi-hazards. In this study, we provide first global estimates of multi-hazard risk to CI systems under current climate conditions. To this end, we assess: (1) the global exposure of CI to coastal and fluvial flooding, cyclones, earthquakes and landslides; and (2) quantify the potential asset damages as a consequence of these multi-hazards.

We represent the infrastructure network by seven overarching CI systems: energy, transportation, telecommunication, water, waste, education and health. A total of 42 infrastructure types (e.g. hospitals, power towers, wastewater treatment plants) are selected from OpenStreetMap (OSM) and categorized under these overarching CI systems. The high-detailed spatial data for infrastructure is combined with hazard data to derive the exposure of infrastructure to the various hazards. Moreover, we develop a vulnerability database for critical infrastructure based on the current body of literature to translate the exposure into asset damages.   

It is urgently needed to build robust and resilient infrastructure, so that they are able to cope with current and future natural hazards. Therefore, risk information should systematically be included for infrastructure planning, and the protection of the most vulnerable and critical assets needs to be improved. Limiting the direct impact of natural hazards on exposed assets will result in economic and social benefits that go beyond direct infrastructure damage.
Multi-scalar association between large-scale climatic pattern and droughts in India 
Authors: Valiya Veetil Sidhan , Singh Sarmistha
Published: March 2022

Extreme meteorological events, such as droughts, are strongly influenced by large-scale climatic oscillations. Since India is one of the most drought-prone countries, comprehensive knowledge of the teleconnection of the climatic oscillations is very helpful towards developing precise drought prediction models. For evaluating the association between climatic indices and drought indices, the interdependency among the climatic oscillation time series has not been addressed well in previous studies. Hence in this study, an elaborate analysis is done in a time-frequency space using the variants of wavelet analysis such as Wavelet Coherence Analysis (WCA), Multiple Wavelet Coherence Analysis (MWCA), and wavelet reconstruction method. The study has used Five major climatic oscillations namely El Niño Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), Atlantic Multidecadal Oscillation (AMO), Indian Ocean Dipole (IOD), and Equatorial Indian Ocean Oscillation (EQUINOO), and a PET-based drought index, called Standardized Precipitation Evapotranspiration Index (SPEI) at four time-scales. The results from the analysis show that the interannual variability (2-4 years) of Indian droughts are primarily influenced by ENSO while the drought variability at 4–8-year time scale is influenced by the combined effect of PDO and EQUINOO. Similarly, the interdecadal variability (16-32 years) of Indian drought is dominantly influenced by PDO and IOD. AMO has not shown any significant association at any scale. Moreover, the droughts in Northwest and North Central India are strongly influenced by climatic oscillations. Further, the teleconnection pattern doesn’t significantly vary with the different timescale of drought. The study will help the hydrologists to enhance the understanding of the connection between climatic oscillations and Indian droughts and thereby better prepare for the impending droughts.
Toward a three-dimensional tomographic model of the Pacific upper mantle with full resolution and uncertainties
Authors: Latallerie Franck , Zaroli Christophe , Lambotte Sophie , Maggi Alessia
Published: March 2022

Tomographic models suffer from unevenly distributed noisy data and therefore have complicated resolution and uncertainties that can hinder their interpretation. Using linear Backus & Gilbert inversion, it is possible to obtain tomographic models with resolution and uncertainties in a single step. Using such a method, we aim to produce a three-dimensional tomographic model of the Pacific upper mantle from surface-wave data. To linearise the forward problem, we use finite-frequency theory to describe the sensitivity of surface-wave phase-delays to the three-dimensional shear-wave velocity. We build a data-base of phase-delay measurements for surface-waves that cross the Pacific Ocean. We estimate the data uncertainties caused by measurement errors using a multitaper technique and those caused by poor knowledge of the seismic source and crust by a Monte-Carlo method. Using the Backus & Gilbert approach, the phase-delay dataset, and the data uncertainty estimates, we obtain a model of the shear-wave velocity of the Pacific upper mantle together with its three-dimensional resolution and uncertainties. These allow us to discuss, using robust statistical arguments, the existence and the three-dimensional organisation of structures we expect to see in the Pacific upper mantle, such as plume-like upwellings or small-scale sub-lithospheric convections.
The role of tropical waves in the genesis of tropical cyclone Seroja
Authors: Latos Beata , Peyrillé Philippe , Lefort Thierry , Flatau Maria , Flatau Piotr , Baranowski Dariusz , Florida Nelly , Permana Donaldi , Szkółka Wojciech
Published: March 2022

In this study, we have examined meteorological drivers that led to the genesis of tropical cyclone Seroja. Developing over the Maritime Continent and in April 2021, it brought historic flooding and landslides to southern Indonesia, East Timor and Western Australia’s Mid West region. Seroja was the first tropical cyclone to have a significant impact on Indonesian land.

We have shown that the genesis of tropical cyclone Seroja in the region of Timor and Suvu Seas was associated with enhanced Equatorial Convection on March 27, 2021 which was preceded by warm sea surface anomalies (SSTs) in that region. The Equatorial Convection was related to Madden-Julian Oscillation (MJO) mode: it developed on the leading edge of MJO where SSTs were high. We have also investigated the role of tropical waves in the development of tropical cyclone Seroja. The interaction between convectively coupled equatorial Rossby wave and three convectively coupled Kelvin waves embedded within the larger-scale envelope of the MJO, provided a supportive environment for this extreme event. The Equatorial Convection that eventually became tropical cyclone Seroja moved southwest, boosted by environmental cyclonic vorticity associated with Rossby Wave. Each of the three Kelvin Waves that arrived over the Maritime Continent had a unique contribution in this event; structuring the convection, winds and precipitation patterns.
hydroPASS: a newly developed R package to go through the regional calibration of distributed catchment models
Authors: Pesce Matteo , Viglione Alberto , von Hardenberg Jost , Tarasova Larisa , Basso Stefano , Merz Ralf
Published: March 2022

Large scale hydrological modelling requires the estimation of model parameters across a variety of different environments. To deal with this issue, robust parameter estimation procedures, able to exploit observed patterns of climate and geomorphological characteristics, must be considered. This contribution presents hydroPASS, a newly developed R package available in GitHub, which automatically implements the PArameter Set Shuffling (PASS) method in around 100 catchments over North-Western Italy. This was developed and tested for SALTO (SAme Like The Others) model, but in principle is valid for every distributed or semi-distributed catchment model. In particular, the package contains the function to run SALTO model (Fortran code), the function for PASS application (R code) and functions for data pre-processing and post-processing (R codes). To ease the repeatability and reproducibility of experiments, examples are provided with full documentation. An example of how to use PASS for the regional calibration of other models (e.g., TUW model), is also provided. From the source package, installation packages have been built for Windows, Linux and Mac operating systems and can be freely downloaded from GitHub.
Validation of the Arctic water and energy cycles in CMIP6 with consistent observation-based estimates
Authors: Winkelbauer Susanna , Mayer Michael , Haimberger Leopold
Published: March 2022

This contribution focuses on the Arctic water budget, including its atmospheric, terrestrial, and oceanic components. Oceanic volume fluxes through the main Arctic gateways are calculated, using data from the CMEMS Global Reanalysis Ensemble Product (GREP), and compared to water input to the ocean from atmosphere and land. For this purpose, we use various state-of-the-art reanalyses, including the European Centre for Medium Range Weather Forecast's (ECMWF) latest products ERA5 and ERA5-Land and evaluate them against available satellite (e.g., GRACE) and in-situ river discharge observations.

To obtain a consistent estimate of all physical terms, we combine the most credible estimates of the individual budget terms and perform a variational optimization to obtain closed water budgets on annual and seasonal scales. This up-to-date estimate of the Arctic water cycle is subsequently used to validate historical runs from the Coupled Model Intercomparison Project Phase 6 (CMIP6). Modelled water budget components are analyzed concerning their annual means, seasonal cycles and trends and compared to our observationally constrained data. Results suggest that there remain large uncertainties in the simulation of the Arctic water cycle of the recent decades.

Furthermore, we choose a similar approach to validate the coupled energy budget in CMIP6 models, including oceanic heat transports through the Arctic gateways (where mooring-derived oceanic heat transports are available), atmospheric energy transports and vertical energy fluxes at the surface and top-of-the-atmosphere, as well as Arctic Ocean heat storage.

This assessment helps to understand model biases in typically analyzed quantities such as sea ice extent or volume. It also provides physically based metrics for detecting outliers from the model ensemble which can help to reduce spread in future projections of Arctic change.