bluuebunny/crossref_metadata_2025 huggingface dataset:
Debris-cover on glaciers in the Austrian Alps. Regional patterns, Changes and Significance.
Authors: Otto Jan-Christoph , Fleischer Fabian , Junker Robert , Hölbling Daniel
Published: March 2021

Debris cover on glaciers is an important component of glacial systems as it influences climate-glacier dynamics and thus the lifespan of glaciers. Increasing air temperatures, permafrost thaw, as well as rock faces freshly exposed by glacier downwasting results in increased rockfall activity and debris input into the glacier system. In the ablation zone, negative mass balances result in an enhanced melt-out of englacial debris to the glacier system. Glacier debris cover thus represents a signal of climate warming in mountain areas. To assess the temporal development of debris on glaciers of the Eastern Alps, Austria, we mapped debris cover on 255 of the more than 800 glaciers using Landsat data at three time steps between 1996 and 2015. We applied a ratio-based threshold classification technique using existing glacier outlines. The debris cover evolution was subsequently compared to glacier changes. Glacier and glacier catchment characteristics have been analysed using GIS techniques and statistics in order to investigate potential reasons for debris cover change.

Across the Austrian Alps debris cover increased by more than 10% between 1996 and 2015 while glaciers retreated significantly in response to climate warming. Debris cover distribution shows regional variability with some mountain ranges being characterised by mean debris cover on glaciers of up to 75%. We also observed a general rise of mean elevation of debris cover on glaciers in Austria. Debris cover distribution and dynamics are highly variable due to topographic, lithological and structural settings that determine the amount of debris delivered to and stored in the glacier system. Lower relative debris cover is observed on glaciers with higher mean and maximum elevation. Additionally, glaciers with increased mean slope, as well as catchments with large areas of steep slopes and a high elevation range of these slopes tend to show higher debris cover. Both parameters indicate that the influence of the steep rockwalls in the glacier catchment is a first order control on debris cover at regional scale. We can also show that catchments with a high percentage of potential permafrost distribution contain glaciers with a higher relative debris cover.

Despite strong variation in debris cover, all glaciers investigated melted at increasing rates. We conclude that the retarding effects of debris cover on the mass balance and melt rate of Austrian glaciers is strongly subdued compared to other mountain areas. The study indicates that if this trend continues many glaciers in Austria may become fully debris covered in the future. However, since debris cover seems to have little impact on melt rates in the study area it will therefore not lead to a prolonged existence of debris-covered ice compared to clean ice glaciers.
Effects of chlorine chemistry combined with Heterogeneous N2O5 reactions on PM2.5 and Ozone formation in China
Authors: Yang Xiajie , Wang Qiaoqiao , Yang Ning , Ma Nan , Zheng Junyu , Huang Xiaofeng , Hu Weiwei
Published: March 2021

Heterogeneous reactivity of N2O5 on Cl-containing aerosols can produce nitric acid (HNO3) and nitryl chloride (ClNO2), which is a critical parameter in assessing O3 variation, nitrate production, and chloride activation. In this study, we used the GEOS-Chem to quantify the effects of chlorine chemistry on fine particulate matter (PM2.5) and O3 formation across China, with comprehensive anthropogenic chlorine emissions (HCl + Cl2 + particulate Cl-). We extended GEOS-Chem to include the heterogeneous reactions of N2O5 and assess the impact of different parameterizations of uptake coefficient of N2O5(γ(N2O5)), and ClNO2 yield (Φ(ClNO2)). Observation from three representative sites in the north, east and south China were selected to assess the model performance with regard to particulate chloride. With the addition of anthropogenic chlorine emissions, model bias in particulate chloride decreased from -79.10% to -39.64% (Dongying), -60.55% to -34.14% (Shenzhen), and -77.53% to -39.97% (Gucheng), respectively. The results show that N2O5-ClNO2 chemistry can reduce the concentration of NO3- and NH4+, but increase the concentration of SO42- slightly, consequently leading to a reduction in the concentration of PM2.5 in China(0.5 μg/m3 on average and 1.8 μg/m3 on haze days). On the other hand, the monthly average O3 MDA8 concentration in China increased by up to 2 ppbv(8 ppbv on haze days), which is mainly due to the increase of OH concentration associated with the photolysis of ClNO2.
Spatio-temporal effects on extreme precipitation in the coastal areas of southeast China
Authors: Qian Weikang , Sun Xun
Published: March 2021

Extreme precipitation is considered to be one of the natural disasters with greatest impact on human society, leading to floods and debris flows. To better understand the spatio-temporal effects on extreme precipitation, and to predict the intensity of extreme precipitation ahead in different return periods, this study focus on quantifying both climate and spatial effects on the intensity of extreme precipitation in coastal areas of southeast China, considering different weather system. A hierarchical Bayesian model with generalized extreme value distribution (GEV) is applied to maximum daily precipitation through 94 stations in study area from 1964 to 2013 in JAS. Tropical cyclone (TC) and non-TC influenced extreme precipitation are analyzed separately. Climate and spatial effects are introduced through regression models associating parameter values in GEV with different covariates, such as climate indices and distance to coastline. It was observed that SST anomaly in North Pacific, SLP anomaly above North India Ocean are found to be the main climate indices that influence extreme precipitation in coastal areas of southeast China. Using SST, we can predict the intensity of extreme precipitation in different return period at 6-month lag. Extreme precipitation was found to decrease as distance to coastline increase. In addition, different performances of extreme precipitation along with distance to coastline were found among various subregions and weather systems.
Making informed use of observations and climate models to advance understanding of past and future sea ice changes
Authors: Massonnet Francois
Published: March 2021

Polar Regions are viewed by many as "observational deserts", as in-situ measurements there are indeed scarce relative to other regions. The increasing availability of satellite observations does not entirely solve the problem, due to persistent uncertainties in the derived products. Climate models have been instrumental in completing the big picture, but they are themselves subject to errors, some of which are systematic. How to take advantage of the respective strengths of observations and models, while minimizing their respective weaknesses?  To illustrate this point, I will discuss how recent advances in data assimilation, model evaluation, and numerical modeling have enabled progress on addressing important questions in polar research, such as: what are the causes of the recent Antarctic sea ice variability? What might the future of Arctic sea ice look like? How to improve the skill of seasonal sea ice predictions? How should the existing observational network be improved at high latitudes? What are the priorities in terms of modeling? By running through these cases, I will provide support for the emerging hypothesis that "the whole is greater than the sum of its parts": treating observations and climate models as two noisy instances of the same, unknown truth, gives access to answers that would not have been possible using each source separately.
Combining rainfall thresholds and field monitoring data for development of LEWS.
Authors: Bulzinetti Maria Alexandra , Abraham Minu Treesa , Satyam Neelima , Pradhan Biswajeet , Segoni Samuele
Published: March 2021

Landslide Early Warning Systems (LEWS) can provide enough time to take necessary precautions before the occurrence of landslides and can reduce the risk associated with it. Deriving empirical rainfall thresholds is the conventional approach in developing regional scale LEWS, but the major drawback of this approach is the relatively high number of false alarms. In this study, a prototype method for LEWS is proposed by combining rainfall thresholds and field monitoring data from MicroElectroMechanical Systems (MEMS) units that integrate a tilt sensor, a soil moisture meter and a real-time wireless transmitter. The study was conducted in the Kalimpong district of West Bengal, India. Tilt sensors were installed at different locations on unstable slopes of Kalimpong since July 2017 and the observations from July 2017 to August 2020 were used to enhance the performance of the existing rainfall thresholds.

During this period, both rainfall thresholds and tilt meters, when used separately, systematically overestimated landslide hazard, producing high false alarm rates. However, it was found that using a decisional algorithm that combines both approaches can reduce the false alarms and improve the overall efficiency of the system from 84 % (based on rainfall thresholds) to 92 % (combined method). The prototype LEWS is found to be promising to be developed as an operational LEWS capable to issue alerts with a lead time of 24 h. 

The method is simple and can be easy exported to other sites with historical rainfall and landslide data and a network of slope monitoring sensors. Cost of installation of a large number of sensors is a major concern for developing countries like India, hence a cost-effective approach is used in this study: the use of MEMS sensors along with empirical rainfall thresholds is thus a simple and economical approach for the prediction of landslide events.
A new approach for improving representation of boreal forest phenology in land surface models
Authors: Majasalmi Titta , Rautiainen Miina
Published: March 2021

In a boreal region, terrestrial vegetation carbon balance is controlled by vegetation phenology, which steers photosynthesis, respiration, and biomass turnover processes. In the absence of a full mechanistic understanding of environmental processes controlling vegetation phenology (i.e. senescence, dormancy, chilling), empirically-based models are often applied. These models are typically based on greenness proxies (obtained from satellite data) with fixed amplitude thresholds (e.g. of 15%, 50%, 90%) to determine timings of different phenological events. Yet, it is not known how well those percentiles correspond with the timings of events such as the green-up and the senescence. Especially in the boreal region, estimating timings of different phenological events across large spatial scales remains challenging due to the lack of sufficient ground validation data representative of both forest tree canopy and forest understory species compositions, which are both observed by a satellite sensor. From the land surface modeling perspective, there is a need to develop methods to improve the mapping of phenological events for prudent prediction of the land vegetation-atmosphere interactions under different future climates. In this study, we developed a new approach for calibrating boreal forest greenness amplitude thresholds which indicate timings of different phenological transitions in satellite data. The new approach to calibrate satellite-based greenness thresholds was demonstrated using boreal Finland as a case study area (60-70 N°). Using the approach, we computed satellite-based phenological events and compared them to ground reference data on temperature from a network of meteorological stations across Finland. We also investigated the effects of using different phenological events or ground reference temperature data on estimated growing season length. Results showed that while the standard greenness amplitude threshold values corresponded fairly well with the growing season start, the autumn phenology was not well captured by the standard greenness amplitude threshold values, which has direct impact on growing season length. Based on our data, boreal conifer forest senescence (default is 90%) corresponds with the timing of greenness amplitude of ~45%, while boreal conifer forest dormancy (default is 15%) corresponds with the timing of reaching greenness amplitude of ~0%. The approach allows flexible application across spatial scales (i.e. point or grid) and different satellite sensors, and may be combined with any land cover product, and it provides a meaningful linking between surface temperature data and seasonal reflectance measured by satellite sensors.
Soil microbiome from postmining ecosystems from Kabardino-Balkaria, Russia
Authors: Gladkov Grigory , Kimeklis Anastasiia , Tembotov Rustam , Kichko Arina , Andronov Evgeny , Abakumov Evgeny
Published: March 2021

The soil microbiome is critical to the restoration of soils , destroyed by human activity. The dynamics of changes in the soil microbiome was investigated from the two overgrown gravel-sand quarry dumps in the North Caucasus (Kabardino-Balkaria, Russia). Samples were taken in the quarries of contrasting soil types (Calcareous Chernozem and Umbric Gleyic soils) under the various types of reclamation. Samples were taken from 10 points from a quarry with meadow soil and from 11 points from the Chernozem. The 16S ssu gene libraries were sequenced from soil DNA.The difference in microbiomes between the control points and the points where the soil is restored was statistically significant. The disturbed Gleyic soil is characterized by an increase in the representatives of Acidobacteria, for Chernozem of the genera Niastella, Ramlibacter, Microvirga. On the Umbric  Gleyic soil without reclamation, significant heterogeneity was shown, in contrast to Chernozem with different types of reclamation. In different soil types, the response of the soil microbiome to soil restoration was significantly different, which in turn should influence the choice of the strategy for the restoration of anthropogenically diturbed soils.
Net surface heat fluxes and Meridional Overturning Circulations
Authors: Bell Mike , Hyder Pat , Jonathan Twm , Johnson Helen , Marshall David , Storkey David , Wood Richard
Published: March 2021

The geographical patterns of the annual mean net surface heat fluxes (NSHF) simulated by the HadGEM3 GC3.1 coupled atmosphere-ocean models are shown to agree well with the CDEEP analyses. The patterns for the coarse resolution (N96O1) and high resolution (N512O12) simulations are shown to be similar (except near the “cold pool of death”). We argue that they can be interpreted relatively simply in terms of (a) regions of net surface heating where Ekman pumping provides a supply of cold water at the sea surface and (b) regions of net cooling where boundary currents have taken warm water poleward. We extend the simple models of Gnanadesikan (1999), Nikurashin & Vallis (2011) and Bell (2015) for the mid-depth Meridional Overturning Circulation (MOC) to a simple model describing the upper and mid-depth MOC cells. As a first step in investigating whether these ideas simulate the model circulations “realistically”, we show that in the HadGEM3 Pacific Ocean, time-variations in the annual and zonal mean NSHF within 5o of the equator are well correlated (r2=0.6) with those in the annual and zonal mean wind stress along the equator. Finally we explore a warm, salty wedge of water next to the eastern boundary in the north Atlantic N96O1 pre-industrial simulations and interpret its northward heat transport in terms suggested by Bell (2015).     

This work is distributed under the Creative Commons Attribution 4.0 License. This licence does not affect the Crown copyright work, which is re-usable under the Open Government Licence (OGL). The Creative Commons Attribution 4.0 License and the OGL are interoperable and do not conflict with, reduce or limit each other.
Geochemical and micropaleontological evidence of the Messinian Salinity Crisis preconditioning phase in the West Alboran Basin  
Authors: Bulian Francesca , Kouwenhoven Tanja J. , Sierro Francisco J. , Krijgsman Wout
Published: March 2021

The Messinian Salinity Crisis (MSC), still highly discussed within the scientific community, affected the Mediterranean Sea between 5.97 and 5.33 Ma and led to the deposition of huge evaporite accumulations both in its marginal and deep basins. During this profound palaeoecological change, the connections between the Atlantic Ocean and Mediterranean Basin were extremely reduced or even non-existing creating an environment where evaporation was dominant. However, the isolation from the global ocean was not a sudden change but most probably a stepwise process. At 7.17 Ma the first signs of restriction are visible in the sedimentological and micropaleontological records all over the Mediterranean.

Particularly, several Italian, Greek and Cypriot locations register a reduced deep water marine ventilation to the sea floor since 7.17 Ma ago as reflected in the higher abundance of benthic low oxygen foraminifer species, indicators of stressed conditions like Bolivinia spp., Bulimina aculeata, Uvigerina peregrina. In these locations, the start of the progressive Mediterranean isolation coincides with the beginning of a more regular occurrence or even the first appearance of sapropel levels which further confirms the increasingly adverse conditions and increasingly dysoxygenated bottom waters. On the other hand, apart from the first opal-rich deposits in the Sorbas basin (Southern Spain) and the Messadit section (North-East Morocco), evidence from the Western Mediterranean is lacking and no studies have focused so far on the 7.17 Ma event.

In this view, we conducted a detailed benthic foraminifer and stable isotope study of West Alboran Sea Site 976 before and after the 7.17 Ma event. This new record highlights the imprint that the early Atlantic-Mediterranean gateway restriction had on the Mediterranean sedimentological record, in a location proximal to the Messinian Gateways. Here, even if anoxic bottom water conditions were never reached, the benthic foraminifer association, paired with the benthic foraminifer carbon isotope record suggest a perturbation of the bottom water circulation and a decrease in bottom water oxygen levels starting ~7.17 Ma. In addition, a comparison of Western-Eastern Mediterranean records enabled us to make assumptions regarding the Mediterranean scale circulation before and after the 7.17 Ma event.
A microstructure-based parameterization of the effectivetransverse isotropic elasticity tensor of snow, firn, and porous ice
Authors: sundu kavitha , Loewe Henning
Published: March 2021

Effective elastic properties of snow, firn, and porous ice are key for
various applications and influenced by ice volume fraction and
different types of anisotropy. The geometrical anisotropy of the ice-matrix created by temperature gradient metamorphism in low-density
snow and firn and the crystallographic anisotropy commonly created
upon deformation in high-density, porous ice. Towards a quantitative-distinction of the impact of the different anisotropies on elasticity,
we derived a parametrization for the effective elasticity tensor over
the entire range of volume fractions as a function of density and
geometrical anisotropy. We employed FEM simulations on 395 X-ray
tomography microstructures of Lab, Alpine, Arctic, and Antarctic
samples. We employed an empirical two-parameter modification of the
anisotropic Hashin Shtrikman bounds to obtain a closed-form
parametrization accounting for density, anisotropy, and the correct
limiting behavior for bubbly ice. We compare our prediction to
previous parametrizations derived in limited density regimes and we
utilize the Thomson parameter to compare the geometrical-elastic
anisotropy to the crystallographic-elastic anisotropy of
monocrystalline ice. Our results suggest that a coupled treatment of
geometrical and crystallographic effects would be beneficial for a
careful interpretation of acoustic measurements in deep firn.
Spatiotemporal zonation of the Freiberg Ag-Pb-Zn-(Cu) epithermal system
Authors: Swinkels Laura , Schulz-Isenbeck Jan , Frenzel Max , Gutzmer Jens , Burisch Mathias
Published: March 2021

The Freiberg district, located in the eastern part of the Erzgebirge, Germany, hosts one of the largest series of epithermal polymetallic vein deposits in Europe. The present study aims to decipher mineralogical and geochemical zoning on the vein- and district-scale and to constrain the underlying ore-forming processes. Detailed petrographic investigations, geochemical analyses and fluid inclusion studies are carried out on several vertical vein profiles within the Freiberg district in order to develop a district-scale metallogenic model. Five different mineral associations related to Permian magmatic-hydrothermal activity have been recognized within the Freiberg epithermal vein system exhibiting a distinct district-scale and vein-scale zonation. The central part of the Freiberg district is dominated by sphalerite-pyrite-quartz and galena-quartz±carbonate associations with a mean silver grade of 769 g/t (n=65). Similar base metal-rich assemblages also predominate the deepest vein intersections (>300 m below ground level) in the peripheral sectors of the Freiberg District. Vein infill at intermediate depth and peripheral positions in the district is, in contrast, dominated by a sphalerite-Ag-sulfides-carbonate association. This association is marked by an abundance of carbonate gangue and significantly higher silver grades (mean = 4800 g/t; n=25). Veins in the shallowest and most peripheral parts (depth <150 m b.g.l.) of the Freiberg district are dominated by a Ag-sulfide-quartz association with a mean Ag concentration of 4900 g/t (n= 56). Silver is mainly hosted by sulfosalts and fahlore but significant concentrations may also be associated to Ag-sulfide inclusions in galena. Even shallower, the veins comprise a stibnite-quartz association with distinctly low Ag contents (410 g/t Ag, n=4). Fluid inclusions related to the various associations yield consistent salinities in the range of 0.1 to 6.0 % eq. w(NaCl). The homogenization temperature, however, progressively decreases from about 320°C for quartz associated with proximal sphalerite-pyrite-quartz mineralization, down to ~170°C for quartz related to distal Ag-sulfide-quartz association. The general formation of the Freiberg epithermal veins is related to the continuous evolution of a magmatic-hydrothermal system in time and space. Silver deposition is most likely triggered by boiling and associated cooling and volatile-loss, which results in a distinct carbonate horizon (typically at ~500 m depth b.g.l. for peripheral parts) with significantly elevated Ag grades (sphalerite-Ag-sulfides-carbonate association).
Generation and seasonal variability of eddy kinetic energy in the central Indian Ocean
Authors: Shapiro Georgy I. , Gonzalez-Ondina Jose Maria
Published: March 2021

The breakthrough in our knowledge of ocean eddies came with the results of the POLYGON-67 experiment in the central Indian Ocean carried out in January-April 1967 (see Koshlyakov et al, 2016). It was the first direct and unambiguous observation that proved an earlier hypothesis by V. B. Shtockman of the existence of mesoscale eddies in open ocean, not only next to strong jet-stream currents. Now it is well known that the currents in open ocean are almost everywhere dominated by meso-scale eddies also known as synoptic eddies (Robinson, 1983). POLYGON-67 experiment covered a rectangle bounded by 10-15°N and 63-66.5°E. The purpose of this work is to analyse the seasonal variability of meso-scale eddy activity in the area covered by POLYGON-67 using a modern and comprehensive data set produced by an operational data assimilation model over a period from 1998 to 2017.

The 20-year long eddy resolving reanalysis of velocity fields in the Indian Ocean allows the study of seasonal variability, dynamics and generating mechanisms of eddy kinetic energy (EKE) in the tropical Indian Ocean, including the area covered by the original survey of POLYGON-67. In contrast to some other areas of the World Ocean, the EKE seasonality shows two maxima, the large one in April and the secondary one in October. The main mechanism of EKE generation is the barotropic instability which is evidenced by high correlation between EKE and enstrophy of large-scale currents, representing the strength of horizontal shear. It is found that the main contributor to the EKE variability within POLYGON-67 area is the advection of EKE across the boundaries during January-October, while the local generation has a comparable magnitude during August-December. The direction and strength of surface currents is consistent with the monsoon wind pattern in the area.

References

Koshlyakov, M.N., Morozov, E.G., and Neiman, V.G., 2016. Historical findings of the Russian physical oceanographers in the Indian Ocean. Geoscience Letters, 3:19; doi:10.1186/s40562-016-0051-6

Robinson, A.R. (Ed), 1983. Eddies in Marine Science. Springer, ISBN 978-3-642-69003-7, 612p.
How do different wind forcing products impact the zonal current variability in the tropical Atlantic?
Authors: Burmeister Kristin , Schwarzkopf Franziska U. , Biastoch Arne , Brandt Peter , Lübbecke Joke F. , Inall Mark
Published: March 2021

The upper wind-driven circulation in the tropical Atlantic plays a key role in the basin wide distribution of water mass properties and affects the transport of heat, freshwater, and biogeochemical components like oxygen or nutrients. It is an important component of the Atlantic climate system and the marine ecosystems. Hence, it is crucial to improve our understanding of its long-term variability which largely relies on model simulations due to sparse observational data coverage in earlier periods. In this study the impact of two different wind forcing products on the tropical Atlantic zonal current field is studied in a high-resolution ocean general circulation model. The first forcing product is the Coordinated Ocean-Ice Reference Experiments (CORE) v2 dataset covering the period 1948 to 2009 (Griffies et al., 2009). It has a horizontal resolution of 2°x2° and temporal resolution of 6-hours. The second forcing product is the new JRA55-do surface dataset (Tsujino et al., 2018). This dataset stands out due to its high horizontal (~55 km) and temporal resolution (3 h) which now covers the entire observational period (1958 to present).

While CORE simulations had difficulties to realistically simulate off-equatorial zonal currents in the tropical Atlantic, in model simulations forced with JRA55-do preliminary results show a clearly improved structure of the equatorial current system. In this study, the used CORE simulation tends to overestimate the strength and vertical extend of the zonal currents especially north of the equator compared to the here used JRA55-do simulation and observations. This might be due to the low resolution of the CORE forcing which cannot resolve smaller scale wind stress and wind stress curl structures.

Furthermore, the CORE wind forcing exhibit suspicious multidecadal wind variability (He et al., 2016) which presumable impacts the multidecadal variability of the simulated wind-driven circulation in the tropical Atlantic. Here, largest differences of zonal wind stress anomalies (up to ~0.03 N m-2) between both forcing products occur north of the equator between 30°-10°W before 1990. CORE shows stronger eastward wind stress anomalies between 1958 and 1970 and stronger westward wind stress anomalies between 1970 and 1990. How this impacts the variability of the equatorial current system is investigated in this study.
An improved method for extracellular enzyme assays in paddy soil: a comparative study under aerobic and anaerobic conditions
Authors: Wang Chaoqun , Dorodnikov Maxim , Blagodatskaya Evgenia , Dippold Michaela
Published: March 2021

Soil enzymes produced by microorganisms and plants are very sensitive to the variations in microclimate, e.g. aeration, and respond quickly to the induced changes. The majority of the enzyme assays are conducted under normal (temperature and air) conditions irrespectively of the origin of the environmental samples. However, it remains unclear how conditions of assays may affect results in anaerobic systems. In the present study, we have clarified this key gap in current methods by measuring the kinetics of phosphatase, β-glucosidase, and leucine aminopeptidase in paddy soil under aerobic and anaerobic conditions by means of a glovebox. Specifically, we quantified Vmax and Km in soil from three compartments in a rhizobox (top bulk (2-5 cm), rhizosphere, and bottom bulk (15-18 cm)) during rice growth. We demonstrate that the activities of three tested enzymes were significantly lower under aerobic conditions compared to anaerobic conditions at three consecutive dates of rice growth. Lower Vmax values for phosphatase in top bulk soil and rhizosphere soil and β-glucosidase in top bulk soil, rhizosphere soil, and bottom bulk soil confirmed that aerobic conditions limited enzyme activities. For leucine aminopeptidase, although the difference in Vmax values between anaerobic and aerobic conditions was not significant, the values always increased under anaerobic conditions compared to aerobic conditions. Compared with anaerobic conditions, the Km values for phosphatase under aerobic conditions decreased by 10.11-22.78%. The maximum difference in the Km values for β-glucosidase and leucine aminopeptidase between aerobic and anaerobic conditions was 30.93% and 40.53%, respectively. We conclude that enzyme activities of samples taken from the anaerobic or low-redox environment have to be assayed under anoxic conditions to avoid 10-40% underestimation (for Vmax) due to suppression by oxygen.
Form-based recommendations for pedestrian level thermal comfort in compact neighbourhoods – A case study in Glasgow
Authors: Maharoof Nusrath , Emmanuel Rohinton , Thomson Craig
Published: March 2021

In light of climate change as well as challenges associated with urban liveability, many cities are now focusing on outdoor spaces as an extension of living spaces.  Aligned with this, the Glasgow city development plan aims to achieve a healthy and high-quality compact city that supports sustainable development in times of climate change.  However, overheating associated with climate change as well as urban heat island requires planners to identify the thermal comfort consequences of decisions to enhance outdoor living in urban neighbourhoods. Yet, the lack of performance data often hinders planners’ ability to propose guidelines for the health and wellbeing of city dwellers.  In particular, the relationship between compact urban form and heat stress needs to explored.

In this paper, we explore the thermal performance of neighbourhoods based on vertical and horizontal density parameters that are amenable with planning control. We develop graphic tools for the analysis of neighbourhood thermal performance at street level.  We demonstrate mechanisms to integrate the tool into the planning process of City Centre development in Glasgow by way of thermal comfort guidelines to enhance the liveability of an existing streetscape as well as proposed new developments within pre-determined neighbourhood forms.
Optimising solar park design and management to boost pollinator abundance
Authors: Blaydes Hollie , Armstrong Alona , Whyatt Duncan , Potts Simon , Gardner Emma
Published: March 2021

Solar photovoltaics (PV) is projected to become the dominant renewable, with much capacity being installed as ground-mounted solar parks. Land use change for solar can affect ecosystems across various spatial scales and solar parks offer a unique opportunity for ecological enhancement. One compelling potential benefit put in practice by the solar industry is management for insect pollinators. Specifically, solar parks can provide refuge for pollinators through the provision of suitable habitat, potentially contributing to halting and reversing widespread declines recorded in a number of pollinator groups. There is scope to both manage and design solar parks for pollinators, but understanding is limited. Using a combination of GIS and a process-based pollinator model, we explore how solar park size, shape and management could affect ground-nesting bumblebee abundance inside solar parks and surrounding landscapes in the UK. We show that within solar parks, the floral resources provided by different management practices is a key factor affecting bumblebee abundance, but the impacts are dependent on landscape context. In comparison, solar park size and shape have a lesser impact. Moreover, the effects of both solar park management and design extend into the surrounding landscape, affecting bumblebee abundance up to 1 km away from the solar park. If designed and managed optimally, solar parks therefore have the potential to boost local pollinator abundance and pollination services to surrounding land. Our results demonstrate how incorporating biodiversity into solar park design and management decisions could benefit groups such as pollinators and contribute to the wider environmental sustainability of solar parks.
Rise and fall of projected vegetation primary production resilience to climate variability
Authors: Zampieri Matteo , Grizzetti Bruna , Toreti Andrea
Published: March 2021

The SDGs recognize the importance of ensuring conservation, restoration and sustainable use of terrestrial ecosystems and their services and strengthening the resilience and adaptive capacity to climate-related hazards. Vegetation primary production is the main function of terrestrial ecosystems providing food and other services to society. Agricultural production is a main source of employment, livelihood and income for a large portion of population, especially in developing countries.

Anticipating the changes in vegetation primary production resilience – the plant capacity to cope with disturbances and shocks including such as those related to climate variability and extremes – is therefore critical to understand and project ecosystems’ responses to global change and the impacts on the related ecosystem services, to support mitigation actions, and to define proper adaptation plans. However, the estimation of resilience is not straightforward.

Here, we applied a recently proposed resilience metrics – the annual production resilience indicator (Zampieri et al. 2019, 2020) – to quantify the changes in vegetation gross primary production (GPP) resilience computed from a large ensemble of state-of-the-art CMIP6 Earth System Model (ESM) simulations.

Our results indicate that climate change mitigation is necessary to significantly reduce the risk of losing terrestrial ecosystems production resilience. In the ‘Sustainability (Taking the Green Road)’ and ‘Middle of the Road’ scenarios considered here (ssp126 and ssp245), the areas where vegetation shows increasing GPP resilience (mainly boreal, African and Indian monsoon regions) are wider than the areas with decreasing resilience. The situation drastically reverses in the ’Fossil-fuel Development (Taking the Highway)’ scenario (ssp585), mostly because the increase of GPP interannual variability outbalances the mean GPP increase due to the CO2 fertilization effect in this high greenhouse gases’ emission scenario. 

To raise social awareness, identify adaptation plans, but especially to stimulate mitigation efforts, we analyse and discuss the gains and losses of vegetation GPP resilience for each World country. Among the larger countries, Brazil is exposed to the highest risk of losing vegetation GPP resilience, especially in the higher emission scenario.

This study explores the linkages between future climate, associated changes in resilience of global vegetation gross primary production, and the mitigation pathways that society can undertake to conserve and restore ecosystems and their services, on which human well-being depends.
Impact of aerosols on the future Euro-Mediterranean climate: results from the CORDEX FPS-Aerosol
Authors: Nabat Pierre , Somot Samuel , Corre Lola , Katragkou Eleni , Li Shuping , Mallet Marc , van Meijgaard Erik , Pavlidis Vasileios , Pietikäinen Joni-Pekka , Soerland Silje , Solmon Fabien
Published: March 2021

The Euro-Mediterranean region is subject to numerous and various aerosol loads, which interact with radiation, clouds and atmospheric dynamics, with ensuing impact on regional climate. However up to now, aerosol variations are hardly taken into account in most regional climate simulations, although anthropogenic emissions have been dramatically reduced in Europe since the 1980s. Moreover, inconsistencies between regional climate models (RCMs) and their driving global model (GCM) have recently been identified in terms of future radiation and temperature evolution, which could be related to the differences in aerosol forcing. 
The present study aims at assessing the role of aerosols in the future evolution of the Euro-Mediterranean climate, using a specific multi-model protocol carried out in the Flagship Pilot Study "Aerosol" of the CORDEX program. This protocol relies on three simulations for each RCM: a historical run (1971-2000) and two future RCP8.5 simulations (2021-2050), a first one with evolving aerosols, and a second one with the same aerosols as in the historical period. Six modeling groups have taken part in this protocol, providing nine triplets of simulations. The analysis of these simulations will be presented here. First results show that the future evolution of aerosols has a significant impact on the evolution of surface radiation and surface temperature. In addition RCM runs taking into account the evolution of aerosols are simulating climate change signal closer to the one of their driving GCM than those with constant aerosols.
On the ability of Sentinel-1 backscatter to detect soil moisture and vegetation changes caused by irrigation fluxes over the Po River Valley (Italy)
Authors: Modanesi Sara , Massari Christian , Gruber Alexander , Brocca Luca , Lievens Hans , Morbidelli Renato , De Lannoy Gabrielle
Published: March 2021

Worldwide, the amount of water used for agricultural purposes is rising because of an increasing food demand. In this context, the detection and quantification of irrigation is crucial, but the availability of ground observations is limited. Therefore, an increasing number of studies are focusing on the use of models and satellite data to detect and quantify irrigation. For instance, the parameterization of irrigation in large scale Land Surface Models (LSM) is improving, but it is still characterized by simplifying assumptions, such as the lack of dynamic crop information, the extent of irrigated areas, and the mostly unknown timing and amount of irrigation. Remote sensing observations offer an opportunity to fill this gap as they are directly affected by, and hence potentially able to detect, irrigation. Therefore, combining models and satellite information through data assimilation can offer a viable way to quantify the water used for irrigation.

The aim of this study is to test how well modelled soil moisture and vegetation estimates from the Noah-MP LSM, with or without irrigation parameterization in the NASA Land Information System (LIS), are able to mimic in situ observations or to capture the signal of high-resolution Sentinel-1 backscatter observations in an irrigated area. The experiments were carried out over select sites in the Po river Valley, an important agricultural area in Northern Italy. To prepare for a data assimilation system, Level-1 Sentinel-1 backscatter observations, aggregated and sampled onto the 1 km EASE-v2 grid, were used to calibrate a Water Cloud Model (WCM) using simulated soil moisture and Leaf Area Index estimates. The WCM was calibrated with and without activating an irrigation scheme in Noah-MP. Results demonstrate that the use of the irrigation scheme provides the optimal calibration of the WCM, confirming the ability of Sentinel-1 to track the impact of human activities on the water cycle. Additionally, a first data assimilation experiment demonstrates the potential of Sentinel-1 backscatter observations to correct errors in Land Surface Model (LSM) simulations that are caused by unmodelled or wrongly modelled irrigation.
Isotopic constraints on the tropospheric carbonyl sulfide budget
Authors: Kamezaki Kazuki , Hattori Shohei , Yoshida Naohiro
Published: March 2021

Carbonyl sulfide (OCS), the most abundant sulfur-containing gas in the ambient atmosphere, possesses great potential for tracer of the carbon cycle. Sulfur isotopic composition (34S/32S ratio, δ34S) on OCS is a feasible tool to evaluate the OCS budget. We applied the sulfur isotope measurement for the tropospheric OCS cycle and distinguished OCS sources from oceanic and anthropogenic emissions.

 

Here, we present a developed measurement system of δ34S of OCS and the result of latitudinal (north-south) observations of OCS within Japan using the method. The OCS sampling system was carried to three sampling sites in Japan: Miyakojima (24°8’N, 125°3’E), Yokohama (35°5’N, 139°5’E), and Otaru (43°1’N, 141°2’E). The observed δ34Sof OCS ranging from 9.7 to 14.5‰ reflects the tropospheric OCS cycle. Particularly in winter, latitudinal decreases in δ34Svalues were found to be correlated with increases in OCS concentrations, resulting in an intercept of (4.7 ± 0.8)‰ in the Keeling plot approach. This trend suggests the transport of anthropogenic OCS emissions from the Asian continent to the western Pacific by the Asian monsoon outflow.

 

The estimated background δ34S of OCS in eastern Asia is consistent with the δ34S of OCS previously reported in Israel and the Canary Islands, suggesting that the background δ34S of OCS in the Northern Hemisphere ranges from 12.0 to 13.5‰. Our constructed sulfur isotopic mass balance of OCS revealed that anthropogenic sources, not merely oceanic sources, account for much of the missing source of atmospheric OCS. This sulfur isotopic constraint on atmospheric OCS is an important step together with isotopic characterizations and analysis using a chemical transport model, will enable detailed quantitative OCS budget and estimation of gross primary production.
Timescales of continental subduction: Constraints from ultrahigh-pressure metapelites in the Western Gneiss Region, Norway
Authors: March Samantha , Tamblyn Renée , Hand Martin , Carvelho Bruna , Clark Chris
Published: March 2021

The Western Gneiss Region (WGR), Norway is an archetypal continental ultrahigh-pressure (U)HP terrane with an extensive metamorphic history, recording the subduction and subsequent exhumation of continental crust to depths exceeding 120 km. The vast bulk of past work within the WGR has focused on mafic eclogites. In this study, data from rare garnet-kyanite metapelites in (UHP) domains of the WGR is presented. U–Pb geochronology and trace element compositions in zircon, monazite, apatite, rutile and garnet were acquired, and P–T conditions were calculated by mineral equilibria forward modelling and Zr-in-rutile thermometry. The Ulsteinvik metapelite defines a prograde path that traverses through ~600–710 °C and ~11–14 kbar. Minimum peak conditions are ~750 °C and ~2.9 GPa in an inferred garnet-kyanite-coesite-omphacite-muscovite-rutile-quartz-H2O assemblage. Plagioclase-biotite-quartz intergrowths developed after omphacite-phengite-rutile breakdown on the early retrograde path, followed by cordierite-spinel-plagioclase symplectites after garnet-kyanite-biotite, defining a retrograde P–T point at ~740 °C and ~7 kbar. Late Ordovician-Early Silurian (~470–440 Ma) zircon and rutile age data in Ulsteinvik pre-dates the major Scandian UHP subduction episode in the WGR, interpreted as recording early Caledonian subduction within the Blåhø nappe. Monazite and apatite U-Pb geochronology and trace element data suggest exhumation occurred at ~400 Ma. The Fjørtoft metapelite is a constituent of the Blåhø nappe. Minimum peak P–T conditions are ~1.8 GPa and ~750 °C, with poor peak mineral fidelity attributed to extensive retrograde deformation. Negative Eu anomalies in ~423 Ma monazite suggest retrograde conditions were reached [RJT1] by ~423 Ma. Ulsteinvik and Fjørtoft may have experienced pre-Scandian subduction together within the Blåhø nappe, but record dissimilar histories after this. Two potential scenarios are presented: (1) Ulsteinvik resided within the mantle for 20 million-years longer than Fjørtoft during Scandian subduction, or (2), the samples were exhumed at different times during pre-Scandian subduction of the Blåhø nappe. The preservation of prograde zoning within Ulsteinvik garnets precludes a long-term residence within the mantle and suggests the latter option. In this scenario, the subducting Blåhø nappe experienced a degree of slab tear and partial underplating of the upper plate during the early stages of continental underthrusting. Discrete pieces may have later reattached to the lower plate at different times, partially exhumed, and then subducted to mantle-depths during the Scandian.
Practical Estimation of Minimum Night Flow in Water Distribution Networks: Large-scale Application to the City of Patras in Western Greece
Authors: Serafeim Athanasios V. , Karathanasi Irene , Kokosalakis George , Deidda Roberto , Langousis Andreas
Published: March 2021

Abstract

In the present work we develop and test a non-parametric statistical methodology to obtain point estimates of Minimum Night Flow (MNF) in Water Distribution Networks (WDNs). The methodology constitutes a simplified version of the approach of Serafeim et al. (2021) for confidence interval estimation of background losses in WDNs, that simultaneously analyzes all night flow measurements, producing robust estimates independent of the nominal resolution of the available data.

In addition to being simpler to apply and computationally more efficient, the developed method can be applied to any WDN independent of its size, age and overall condition, its  specific geometric characteristics (intensity of altimetry, average diameter etc.), inlet/operating pressures, and the nominal resolution of the flow data.

The effectiveness of the method is tested via a large-scale application to the WDN of the City of Patras in western Greece, which consists of 79 Pressure Management Areas (PMAs) with more than 700 km of pipeline grid. To do so, we use flow data at 1 min temporal resolution, provided by the Municipal Enterprise of Water Supply and Sewerage of the City of Patras, for the 4-month winter period from 01 November 2018 – 28 February 2019, which are progressively averaged to coarser temporal resolutions, in an effort to test the sensitivity of the developed method to the nominal resolution of the data.  

The obtained point estimates of MNF are assessed on the basis of the confidence intervals obtained by the approach of Serafeim et al. (2021), highlighting the accuracy and robustness of a simple non-parametric approach in providing MNF point estimates at a minimum of effort.

Acknowledgements

The research work was supported by the Hellenic Foundation for Research and Innovation (H.F.R.I.) under the “First Call for H.F.R.I. Research Projects to support Faculty members and Researchers and the procurement of high-cost research equipment grant” (Project Number: 1162).

References

Serafeim, A.V., G. Kokosalakis, R. Deidda, I. Karathanasi and A. Langousis, (2021) Probabilistic Estimation of Minimum Night Flow in Water Distribution Networks: Large-scale Application to the City of Patras in Western Greece (submitted).