bluuebunny/crossref_metadata_2025 huggingface dataset:
Corporate social responsibility reporting by South African mining companies: Evidence of legitimacy theory
Authors: Dube S. , Maroun W.
Published: April 2018

This paper offers evidence on the relevance of legitimacy theory for explaining changes in the frequency of corporate social responsibility (CSR) disclosures by South African platinum mining companies following violent strike action during 2012 at Marikana. The results show that all of the South African platinum mining companies provide additional information dealing specifically with the strike taking place at Marikana. This is more pronounced for the company directly involved in the incident. The research also finds evidence of a reaction to the social event by other companies in the South African Platinum Industry which alter the nature and extent of general CSR disclosures to maintain legitimacy. In this way, the study offers evidence in support of the relevance of legitimacy theory for explaining changes in CSR reporting. The findings of this study complement existing research which has ignored the South African market. Although there has been some work on legitimacy theory in the context of environmental disclosure by South African companies, the study is the first to examine a significant social event using legitimacy theory as the frame of reference.
A supply chain management model to optimise the sorting capability of a ‘third party logistics’ distribution centre
Authors: Yadavalli V. S.S. , Balcou C.
Published: April 2018

In this paper, the process flow within a high-end 3PL distribution centre is studied in order to determine the optimal split between the parcel size categories moved within the system. The article considers the application of an optimisation (MIQP) model with a corresponding discrete event simulation model to validate the authenticity of the solution. The study assumes that the current process flow and layout of the centre remains fixed; the entering and exiting routes to and from the centre and the centre itself are located optimally within the network and the models have base times of one and seven days respectively. Performance measures have been analysed through utilization states of equipment and labour, queue contents versus time and average throughput times of each of the parcel categories. The findings in this paper can create a positive trigger for improvement within the distribution centre as equipment and labour can be downsized to decrease costs and improve safety and benefit the company through the alignment of a network of distribution centres that each applies modified relevant versions of the modelling logic conveyed in this paper.
Cultural intelligence: Concepts and definition statements
Authors: Solomon A. , Steyn R.
Published: April 2018

The rapid rate of globalisation is increasingly exposing both individuals and organisations to situations of cultural heterogeneity in which they are expected to function optimally. The cultural intelligence research programme has consequently experienced increased impetus with the result that a broad array of insights now exists. Organising such information will facilitate the assimilation thereof by both business representatives and scholars. Accordingly, this review sought to situate the cultural intelligence literature in terms of the concept and definition statement elements of the general body of scientific knowledge framework. A systematic literature review followed by content analysis was performed. Concepts were crystallised through a fusion of the key words whilst the definition statements were examined to detect elements of both uniqueness and commonality. Despite a large volume of key words existing across the material, remarkably only a limited number of concepts were identified: accomplishment, culture, expatriates, experience, fit, intelligence, motivation, supervision and training. Whilst the definition statements of cultural intelligence have evolved to include, amongst others, its dimensions, the range of culture types it exists in relation to, the categories of persons that may demonstrate it and the conditions in which it could be exhibited, they mostly remain predicated upon the initial expositions.
Do not feed the predators
Authors: De Jager P. , De Kock F. , Van der Spuy P.
Published: April 2018

This study investigates the prevalence and characteristics of papers published in popular predatory journals by South African academics in economic and management sciences. Our aim is to raise awareness and to deepen understanding of the predatory publishing phenomenon. We collected 728 recent (2013 to mid-2016) articles with South African authors in five popular in the field journals classified as ‘potential, possible, or probable predatory’ according to Beall’s list. Our data shows that publishing in these predatory journals is widespread across authors and universities. However, the data also shows that most of the authors only published once in these journals, suggesting that they perhaps mistakenly perceived the journals as being legitimate research outlets. We found evidence of low-quality publishing by the journals in our data, consistent with deficient peer review and copy editing processes. Thus, low-quality publishing was evident from spelling and grammar mistakes in the titles of articles, publishing the same paper twice in the same journal, so-called ‘salami slicing’, and the publishing of an article already published in another journal.
Psychological well-being and perceived financial performance: An SME perspective
Authors: Farrington S. M.
Published: April 2018

Psychological well-being is influenced by the “surrounding contexts of people’s lives” and has consistently been found to be associated with positive outcomes. Given the turbulent surrounding contexts facing SME owners in South Africa, the primary objective of this study was to investigate their level of psychological well-being and to establish the influence thereof on the financial performance of their businesses. A survey using a structured questionnaire was used to gather the necessary data. The population consisted of all owners of SMEs operating within the borders of the Eastern Cape province of South Africa. Criterion and convenience sampling were used and questionnaires were administered by field workers. In total 495 questionnaires were useable for statistical analysis. Scale validity and reliability was assessed, descriptive statistics calculated and Pearson’s product moment correlations established. Multiple regression analysis was undertaken to investigate the hypothesised relationships. The results show that the participating SME owners have high levels of positive psychological well-being and that their businesses are performing financially. The results also suggest that the more SME owners display the attributes associated with environmental mastery, self-acceptance and autonomy, the more likely their SMEs are to perform financially.
The effect of industry nuances on the relationship between corporate governance and financial performance: Evidence from South African listed companies
Authors: Tshipa Jonty , Brummer Leon M. , Wolmarans Hendrik , Du Toit Elda
Published: April 2018

Background: Premised on agency, resource dependence and stewardship theories, the study investigates empirically the existence of industry nuances in the relationship between corporate governance and financial performance of companies listed in the Johannesburg Stock Exchange. Aims: The main objective of the study is to understand the relationship between internal corporate governance and company performance from the perspective of three distinct economic periods, as well as industry nuances, cognisant of endogeneity issues. Setting: South Africa, as an emerging African market, offers an interesting research context in which the corporate governance and financial performance nexus can be examined empirically. Method: A sample of 90 companies from the five largest South African industries, covering a 13-year period from 2002 to 2014 (1170 firm-year observations) was examined with three estimation approaches. Results: Two key trends emerged from this study. First, the relationship between corporate governance and company performance differed from industry to industry. Second, the association between corporate governance and company performance also changes during steady and non-steady periods, which is an indication that the nexus is driven by the state of the global economy and the type of the industry. Conclusion: Evidence from the study suggests that companies should be allowed to optimise rather than maximise their corporate governance options. This finding questioned the approach of the recently published King IV Code of Good Corporate Governance, which requires Johannesburg Stock Exchange-listed companies to ‘apply and explain’ as opposed to ‘apply or explain’ as pronounced by King III Code of Good Corporate Governance.
The onset of instability in first-order systems
Authors: Lerner Nicolas , Nguyen Toan T. , Texier Benjamin
Published: April 2018

We study the Cauchy problem for first-order quasi-linear systems of partial differential equations. When the spectrum of the initial principal symbol is not included in the real line, i.e., hyperbolicity is violated at initial time, the Cauchy problem is strongly unstable in the sense of Hadamard. This phenomenon, which extends the linear Lax–Mizohata theorem, was explained by G. Métivier [Contemp. Math. 368, 2005]. In the present paper, we are interested in the transition from hyperbolicity to non-hyperbolicity, that is, the limiting case where hyperbolicity holds at initial time, but is violated at positive times: under that hypothesis, we generalize a recent work by N. Lerner, Y. Morimoto and C.-J. Xu [Amer. J. Math. 132 (2010)] on complex scalar systems, as we prove that even a weak defect of hyperbolicity implies a strong Hadamard instability. Our examples include Burgers systems, Van der Waals gas dynamics, and Klein–Gordon–Zakharov systems. Our analysis relies on an approximation result for pseudo-differential flows, proved by B. Texier [Indiana Univ. Math. J. 65 (2016)].
A stable, polynomial-time algorithm for the eigenpair problem
Authors: Armentano Diego , Beltrán Carlos , Bürgisser Peter , Cucker Felipe , Shub Michael
Published: April 2018

We describe algorithms for computing eigenpairs (eigenvalue-eigenvector pairs) of a complex

n \times n

matrix

A

. These algorithms are numerically stable, strongly accurate, and theoretically efficient (i.e., polynomial-time). We do not believe they outperform in practice the algorithms currently used for this computational problem. The merit of our paper is to give a positive answer to a long-standing open problem in numerical linear algebra.

A short professional video explaining the article can be found here: .
A climatology of polar stratospheric cloud composition between 2002 and 2012 based on MIPAS/Envisat observations
Authors: Spang Reinhold , Hoffmann Lars , Müller Rolf , Grooß Jens-Uwe , Tritscher Ines , Höpfner Michael , Pitts Michael , Orr Andrew , Riese Martin
Published: April 2018

Abstract. The Michelson Interferometer for Passive Atmospheric
Sounding (MIPAS) instrument aboard the European Space Agency (ESA) Envisat satellite operated from
July 2002 to April 2012. The infrared limb emission measurements provide
a unique dataset of day and night observations of polar stratospheric clouds
(PSCs) up to both poles. A recent classification method for PSC types in infrared (IR)
limb spectra using spectral measurements in different atmospheric window
regions has been applied to the complete mission period of MIPAS. The method
uses a simple probabilistic classifier based on Bayes' theorem with a strong
independence assumption on a combination of a well-established two-colour
ratio method and multiple 2-D probability density functions of brightness
temperature differences. The Bayesian classifier distinguishes between solid
particles of ice, nitric acid trihydrate (NAT), and liquid droplets of
supercooled ternary solution (STS), as well as mixed types. A climatology of MIPAS PSC occurrence and specific PSC classes has been
compiled. Comparisons with results from the classification scheme of the
spaceborne lidar Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP)
on the Cloud-Aerosol-Lidar and Infrared Pathfinder Satellite Observations
(CALIPSO) satellite show excellent correspondence in the spatial and
temporal evolution for the area of PSC coverage (APSC) even for each
PSC class. Probability density functions of the PSC temperature, retrieved
for each class with respect to equilibrium temperature of ice and based on
coincident temperatures from meteorological reanalyses, are in accordance
with the microphysical knowledge of the formation processes with respect to
temperature for all three PSC types. This paper represents unprecedented pole-covering day- and nighttime
climatology of the PSC distributions and their composition of different
particle types. The dataset allows analyses on the temporal and spatial
development of the PSC formation process over multiple winters. At first
view, a more general comparison of APSC and AICE retrieved from
the observations and from the existence temperature for NAT and ice
particles based on the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis temperature data shows the high potential
of the climatology for the validation and improvement of PSC schemes in
chemical transport and chemistry–climate models.
The influence of internal variability on Earth's energy balance framework and implications for estimating climate sensitivity
Authors: Dessler Andrew E. , Mauritsen Thorsten , Stevens Bjorn
Published: April 2018

Abstract. Our climate is constrained by the balance between solar energy absorbed by the Earth and terrestrial energy radiated to
space. This energy balance has been widely used to infer equilibrium climate sensitivity (ECS) from observations of
20th-century warming. Such estimates yield lower values than other methods, and these have been influential in pushing down
the consensus ECS range in recent assessments. Here we test the method using a 100-member ensemble of the Max Planck Institute Earth System Model
(MPI-ESM1.1) simulations of the period 1850–2005 with known forcing. We calculate ECS in each ensemble member using
energy balance, yielding values ranging from 2.1 to 3.9 K. The spread in the ensemble is related to the central
assumption in the energy budget framework: that global average surface temperature anomalies are indicative of anomalies
in outgoing energy (either of terrestrial origin or reflected solar energy). We find that
this assumption is not well supported
over the historical temperature record in the model ensemble or more recent satellite observations. We find that framing
energy balance in terms of 500 hPa tropical temperature better describes the planet's energy balance.
The Influence of HCl on the Evaporation Rates of H2O over Water Ice in
the Range 188 to 210 K at small Average Concentrations
Authors: Delval Christophe , Rossi Michel J.
Published: April 2018

Abstract. The evaporation flux Jev(H2O) of H2O from HCl-doped typically 1.5 μm or so thick vapor-deposited ice films has been measured in a combined quartz crystal microbalance (QCMB) – residual gas mass spectrometry (MS) experiment. Jev(H2O) has been found to show complex behaviour and to be a function of the average mole fraction χ(HCl) of HCl in the ice film ranging from 6 × 1014 to 3 × 1017 molecule cm−2 s−1 at 174–210 K for initial values χ0(HCl) ranging from 5 × 10−5 to 3 × 10−3 at the start of the evaporation. The dose of HCl on ice was in the range of 1 to 40 formal monolayers and the H2O vapor pressure was independent of χ(HCl) within the measured range and equal to that of pure ice down to 80 nm thickness. The temporal dependence of Jev(H2O) was correlated with (a) the evaporation range rb/e as the ratio of Jev(H2O) just before HCl-doping of the pure ice film and Jev(H2O) after observable HCl desorption towards the end of film evaporation, and (b) the remaining thickness dD below which Jev(H2O) decreases to less than 85 % of pure ice. The time dependence of Jev(H2O) from HCl-doped ice films suggests two limiting data sets, one associated with the occurrence of a two-phase pure ice/crystalline HCl hydrate binary phase (set A), and the other with a single phase amorphous HCl/H2O binary mixture (set B). The measured values of Jev(H2O) may lead to significant evaporative life-time extensions of HCl - contaminated ice cloud particles under atmospheric conditions, regardless of whether the structure corresponds to an amorphous or crystalline state of the HCl/H2O aggregate.
Analyzing the turbulence in the Planetary Boundary Layer by the synergic use of
remote sensing systems: Doppler wind lidar and aerosol elastic lidar
Authors: de Arruda Moreira Gregori , Guerrero-Rascado Juan Luís , Benavent-Oltra Jose Antonio , Ortiz-Amezcua Pablo , Román Roberto , Esteban Bedoya-Velásquez Andrés , Bravo-Aranda Juan Antonio , Olmo-Reyes Francisco Jose , Landulfo Eduardo , Alados-Arboledas Lucas
Published: April 2018

Abstract. The Planetary Boundary Layer (PBL) is the lowermost region of troposphere and endowed with turbulent characteristics, which can have mechanical or thermodynamic origins. Such behavior gives to this layer great importance, mainly in studies about pollutant dispersion and weather forecasting. However, the instruments usually applied in studies about turbulence in the PBL have limitations in spatial resolution (anemometer towers) or temporal resolution (aircrafts). In this study we propose the synergetic use of remote sensing systems (microwave radiometer [MWR], Doppler lidar [DL] and elastic lidar [EL]) to analyze the PBL behavior. Furthermore, we show how some meteorological variables such as air temperature, aerosol number density, vertical wind, relative humidity and net radiation might influence the PBL dynamic. The statistical moments of the high frequency distributions of the vertical velocity, derived from DL and of the backscattered coefficient derived from EL, are corrected by two methodologies, namely first lag and −2/3 correction. The corrected profiles present small differences when compare against the uncorrected profiles, showing low influence of noise and the viability of the proposed methodology. Two case studies were analyzed in detail, one corresponding to a well-defined PBL and another one corresponding to a situation with presence of a Saharan dust lofted aerosol layer and clouds. In both cases the results provided by the different instruments are complementary, thus the synergistic use of the different systems allow us performing a detailed monitoring of the PBL.
Satellite-derived sulphur dioxide (SO2) emissions from the 2014–2015 Holuhraun eruption (Iceland)
Authors: Carboni Elisa , Mather Tamsin A. , Schmidt Anja , Grainger Roy G. , Pfeffer Melissa A. , Ialongo Iolanda
Published: April 2018

Abstract. The six-month-long 2014–2015 Holuhraun eruption was the largest in Iceland for 200 years, emitting huge quantities of sulphur dioxide (SO2) into the troposphere, at times overwhelming European anthropogenic emissions. Weather, terrain and latitude, made continuous ground-based or UV satellite sensor measurements challenging. Infrared Atmospheric Sounding Interferometer (IASI) data, is used to derive the first time-series of daily SO2 mass and vertical distribution over the eruption period. A new optimal estimation scheme is used to calculate daily SO2 fluxes and average e-folding time every twelve hours. The algorithm is used to estimate SO2 fluxes of up to 200 kt per day and a minimum total SO2 erupted mass of 4.4 ± 0.8 Tg. The average SO2 e-folding time was 2.4 ± 0.6 days. Where comparisons are possible, these results broadly agree with ground-based near-source measurements, independent remote-sensing data and model simulations of the eruption. The results highlight the importance of high-resolution time-series data to accurately estimate volcanic SO2 emissions.
Haze in Singapore – Source Attribution of Biomass Burning from Southeast Asia
Authors: Hansen Ayoe Buus , Chong Wei Ming , Kendall Emma , Chew Boon Ning , Gan Christopher , Hort Matthew Craig , Lee Shao-Yi , Witham Claire Suzanne
Published: April 2018

Abstract. This paper presents a study of haze in Singapore caused by biomass burning in Southeast Asia over the six year period from 2010 to 2015, using the Lagrangian dispersion model, NAME. The major contributing source regions are shown to be Riau, Peninsular Malaysia, South Sumatra, and Central and West Kalimantan. However, we see differences in haze concentrations and variation in the relative contributions from the various source regions between monitoring stations across Singapore, as well as on an inter-annual timescale. These results challenge the current popular assumption that haze in Singapore is dominated by emissions/burning from only Indonesia. It is shown that Peninsular Malaysia is a large source for the Maritime Continent off-season biomass burning impact on Singapore. As should be expected, the relatively stronger southeast monsoonal winds that coincide with increased biomass burning activities in the Maritime Continent create the main haze season from August to October (ASO), which brings particulate matter from several and varying source regions to Singapore. In contrast, atypical haze episodes in Singapore are characterised by atypical weather conditions, ideal for biomass burning, and emissions dominated by a single source region (for each event). The two most recent atypical haze events in mid 2013 and early 2014 have different source regions, whereas a different set of five regions dominate as major contributing source regions for most of the recent ASO haze seasons. Haze in Singapore varies across year, season, and location it is influenced by local and regional weather, climate, and regional burning. The study shows that even across small scales, such as in Singapore, variation in local meteorology can impact concentrations of particulate matter significantly, and emphasises the importance of the scale of modelling both spatially and temporally.
Aerosol distribution in the northern Gulf of Guinea: local anthropogenic sources, long-range transport and the role of coastal shallow circulations
Authors: Flamant Cyrille , Deroubaix Adrien , Chazette Patrick , Brito Joel , Gaetani Marco , Knippertz Peter , Fink Andreas H. , de Coetlogon Gaëlle , Menut Laurent , Colomb Aurélie , Denjean Cyrielle , Meynadier Rémi , Rosenberg Philip , Dupuy Regis , Schwarzenboeck Alfons , Totems Julien
Published: April 2018

Abstract. The complex vertical distribution of aerosols over coastal southern West Africa (SWA) is investigated using airborne observations and numerical simulations. Observations were gathered on 2 July 2016 offshore of Ghana and Togo, during the field phase of the Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa project. The aerosol loading in the lower troposphere includes emissions from coastal cities (Accra, Lomé, Cotonou and Lagos) as well as biomass burning aerosol and dust associated with long-range transport from Central Africa and the Sahara, respectively. Our results indicate that the aerosol distribution is impacted by subsidence associated with zonal and meridional regional scale overturning circulations associated with the land-sea surface temperature contrast and orography over Ghana and Togo. Numerical tracer release experiments highlight the dominance of aged emissions from Accra on the observed pollution plume loadings over the ocean. The contribution of aged emission from Lomé and Cotonou is also evident above the marine boundary layer. Lagos emissions do not play a role for the area west of Cotonou. The tracer plume does not extend very far south over the ocean (i.e. less than 100 km from Accra), mostly because emissions are transported northeastward near the surface over land and westward above the marine atmospheric boundary layer. The latter is possible due to interactions between the monsoon flow, complex terrain and land-sea breeze systems, which support the vertical mixing of the urban pollution. This work sheds light on the complex – and to date undocumented – mechanisms by which coastal shallow circulations distribute atmospheric pollutants over the densely populated SWA region.
Multiday haze in the East Asia:
Transport and chemical aging of hygroscopic particles
Authors: Lim Yong Bin , Seo Jihoon , Kim Jin Young , Turpin Barbara J.
Published: April 2018

Abstract. East Asian countries (Korea and China) have been experiencing exceedingly high concentrations of particulate matter (PM) that threatens health and potentially alters climate. However, the formation of East Asian PM is poorly understood. Furthermore, during the winter high PM concentrations at Seoul, Korea often occurs via the combination of the transport of Chinese haze through the prevailing Westerlies and the local formation at Seoul, and this complicates the PM formation. A severe multiday haze event occurred at Seoul during February 24–28, 2014, and the synoptic meteorological conditions suggest the combination the transport and the local formation (Seo et al., 2017). PM at Seoul and Deokjeok Island during this haze period was sampled and analyzed. Deokjeok Island provides background for Seoul PM since it is upwind and emission free. We hypothesize that transported PM from China (PM at Deokjeok Island) is hygroscopic (thus contains water due to high RH) and undergoes multiphase photochemical aging at Seoul. To validate our hypothesis, we conducted smog chamber experiments. In a humid smog chamber, photochemistry of NOx initiates hygroscopic growth of particles and aerosol liquid water in turn facilitates aqueous chemistry forming organonitrates and oligomers. This multiphase chemistry provides chemical insights of chemical aging during a haze event in East Asia. NOx effects on photochemical aging of particles are substantial. Even a few ppb of NOx form nitrates in aerosol liquid water, and acidify neutral particles. NOx reduction is not likely to be an effective strategy for nitrate- and acidity-related health.
Automated enclosure and protection system for compact solar-tracking spectrometers
Authors: Heinle Ludwig , Chen Jia
Published: April 2018

Abstract. A novel automated enclosure for protecting solar-tracking atmospheric instruments was designed, constructed, and successfully tested under various weather conditions. A complete automated measurement system, consisting of a compact solar-tracking Fourier transform infrared (FTIR) spectrometer (EM27/SUN) and the enclosure, has been deployed in central Munich to monitor greenhouse gases since 2016 and withstood all critical weather conditions, including rain, storms, and snow. It provided ground-based measurements of column-averaged concentrations of CO2, CH4, O2, and H2O throughout this time.The enclosure protects the instrument from harmful environmental influences while allowing open-path measurements in sunny weather. The newly developed and patented cover, a key component of the enclosure, permits unblocked solar measurements while reliably protecting the instrument. This enables dynamic decision regarding taking measurements, and thus increases the number of data samples. This enclosure leads to a fully automated measurement system, which collects data whenever possible without any human interaction. In the long term, the enclosure will provide the foundation for a permanent greenhouse gas monitoring sensor network.
Agrometeorological services for smallholder farmers in West Africa
Authors: Tarchiani Vieri , Camacho José , Coulibaly Hamidou , Rossi Federica , Stefanski Robert
Published: April 2018

Abstract. Climate variability and change are recognised as a major threat for West
African agriculture, particularly for smallholder farmers. Moreover,
population pressure, poverty, and food insecurity, are worsening the
vulnerability of production systems to climate risks. Application of Climate
Services in agriculture, specifically Agrometeorological Services, is
acknowledged as a valuable innovation to assist decision-making and develop
farmers' specific adaptive capacities. In West Africa, the World
Meteorological Organisation and National Meteorological Services deployed
considerable efforts in the development of Agrometeorological Services.
Nevertheless, the impacts of such services on West African farming
communities are still largely unknown. This paper aims to delineate the
added value of agrometeorological services for farmers within the
Agriculture Innovation System of Mauritania. The results of this
quali-quantitative assessment demonstrate that farmers use
agrometeorological information for a variety of choices: making strategic
choice on the seed variety and on the geographical distribution of plots,
choosing the most appropriate planting date, better tuning crop development
cycle with the rhythm of the rains and choosing favourable periods for
different cultural operations. Globally, the effects of all these good practices can be summarized by an
increase of crops productivity and a decrease of cropping costs (including
opportunity cost) in terms of inputs and working time.
Impact of salinity on element incorporation in two benthic foraminiferal species with contrasting magnesium contents
Authors: Geerken Esmee , de Nooijer Lennart Jan , van Dijk Inge , Reichart Gert-Jan
Published: April 2018

Abstract. Accurate reconstructions of seawater salinity could provide valuable
constraints for studying past ocean circulation, the hydrological cycle and
sea level change. Controlled growth experiments and field studies have shown
the potential of foraminiferal Na ∕ Ca as a direct salinity proxy.
Incorporation of minor and trace elements in foraminiferal shell carbonate
varies, however, greatly between species and hence extrapolating calibrations
to other species needs validation by additional (culturing) studies. Salinity
is also known to impact other foraminiferal carbonate-based proxies, such as
Mg ∕ Ca for temperature and Sr ∕ Ca for sea water carbonate
chemistry. Better constraints on the role of salinity on these proxies will
therefore improve their reliability. Using a controlled growth experiment
spanning a salinity range of 20 units and analysis of element composition on
single chambers using laser ablation-Q-ICP-MS, we show here that Na ∕ Ca
correlates positively with salinity in two benthic foraminiferal species
(Ammonia tepida and Amphistegina lessonii). The Na ∕ Ca
values differ between the two species, with an approximately 2-fold higher
Na ∕ Ca in A. lessonii than in A. tepida, coinciding
with an offset in their Mg content (∼ 35 mmol mol−2 versus
∼ 2.5 mmol mol−1 for A. lessonii and A. tepida, respectively). Despite the offset in average Na ∕ Ca values, the
slopes of the Na ∕ Ca–salinity regressions are similar between these two
species (0.077 versus 0.064 mmol mol−1 change per salinity unit). In
addition, Mg ∕ Ca and Sr ∕ Ca are positively correlated with salinity
in cultured A. tepida but show no correlation with salinity for
A. lessonii. Electron microprobe mapping of incorporated Na and Mg
of the cultured specimens shows that within chamber walls of A. lessonii, Na ∕ Ca and Mg ∕ Ca occur in elevated bands in close
proximity to the primary organic lining. Between species, Mg banding is
relatively similar, even though Mg content is 10 times lower and that
variation within the chamber wall is much less pronounced in A. tepida. In addition, Na banding is much less prominent in this species than
it is in A. lessonii. Inter-species differences in element banding
reported here are hypothesized to be caused by differences in
biomineralization controls responsible for element uptake.
QUAL-NET, a high temporal-resolution eutrophication model for large hydrographic networks
Authors: Minaudo Camille , Curie Florence , Jullian Yann , Gassama Nathalie , Moatar Florentina
Published: April 2018

Abstract. To allow climate change impact assessment of water quality in river systems, the scientific community lacks efficient deterministic models able to simulate hydrological and biogeochemical processes in drainage networks at the regional scale, with high temporal resolution and water temperature explicitly determined. The model QUALity-NETwork (QUAL-NET) was developed and tested on the Middle Loire River Corridor, a sub-catchment of the Loire River in France, prone to eutrophication. Hourly variations computed efficiently by the model helped disentangle the complex interactions existing between hydrological and biological processes across different timescales. Phosphorus (P) availability was the most constraining factor for phytoplankton development in the Loire River, but simulating bacterial dynamics in QUAL-NET surprisingly evidenced large amounts of organic matter recycled within the water column through the microbial loop, which delivered significant fluxes of available P and enhanced phytoplankton growth. This explained why severe blooms still occur in the Loire River despite large P input reductions since 1990. QUAL-NET could be used to study past evolutions or predict future trajectories under climate change and land use scenarios.
Carbonate system distribution, anthropogenic carbon and
acidification in the Western Tropical South Pacific (OUTPACE 2015
transect)
Authors: Wagener Thibaut , Metzl Nicolas , Caffin Mathieu , Fin Jonathan , Helias Nunige Sandra , Lefevre Dominique , Lo Monaco Claire , Rougier Gilles , Moutin Thierry
Published: April 2018

Abstract. The western tropical South Pacific was sampled along a longitudinal 4000 km transect (OUTPACE cruise, 18 Feb., 3 Apr. 2015) for measurement of carbonates parameters (total alkalinity and total inorganic carbon) between the Melanesian Archipelago (MA) and the western part of the South Pacific gyre (WGY). This manuscript reports this new dataset and derived properties: pH on the total scale (pHT) and the CaCO3 saturation state with respect to calcite (Ωcal) and aragonite (Ωara). We also estimate anthropogenic carbon (CANT) distribution in the water column using the TrOCA method (Tracer combining Oxygen, inorganic Carbon and total Alkalinity). Along the OUTPACE transect, CANT inventories of 37–43 mol m−2 were estimated with higher CANT inventories in MA waters (due to a deeper penetration of CANT in the intermediate waters) than in the WGY waters although highest CANT concentrations were detected in the sub-surface waters of WGY. By combining our OUTPACE dataset with data available in GLODAPv2 (1974–2009), temporal changes in oceanic inorganic carbon were evaluated. An increase of 1.3 to 1.6 µmol kg−1 a−1 for total inorganic carbon in the upper thermocline waters is estimated whereas CANT increases of 1.1 to 1.2 µmol kg−1 a−1. In the MA intermediate waters (27 kg m−3 < σθ < 27.2 kg m−3) an increase of 0.4 µmol kg−1 a−1 of CANT is detected. Our results suggest a clear progression of ocean acidification in the western tropical South Pacific with a decrease of the oceanic pH of up to −0.0027 a−1 and a shoaling of the saturation depth for aragonite of up to 200 m since the pre-industrial period.
Understanding the Australian Monsoon change during the Last Glacial Maximum with multi-model ensemble
Authors: Yan Mi , Wang Bin , Liu Jian , Zhu Axing , Ning Liang
Published: April 2018

Abstract. The response of Australian monsoon to the external forcings and the relative mechanisms during the Last Glacial Maximum (LGM) is investigated by multi-models in CMIP5/PMIP3. Although the annual mean precipitation over Australian monsoon region decreases, the annual range, or the monsoonality, is enhanced. The precipitation increases in early austral summer and decreases in austral winter, causing the annual range or monsoonality to amplify. The decreased precipitation in austral winter has a large contribution to the strengthened monsoonality. It is primarily caused by the weakened upward motion, although the reduced water vapor has also a moderate contribution. The weakened upward motion in austral winter is induced by the enhanced land–sea thermal contrast, which intensifies the divergence over northern Australia. The increased Australian monsoon rainfall in early summer is an integrated result of the positive effect of local dynamic processes (enhanced moisture convergence) and the negative effect of thermodynamics (reduced moisture content). The enhanced moisture convergence is caused by two factors: the strengthened northwest–southeast thermal contrast between the cooler Indochina–western Indonesia and the warmer northeastern Australia, and the east–west sea surface temperature gradients between the warmer western Pacific and cooler eastern Indian Ocean, both due to the alteration of land–sea configuration arising from the sea level drop. The enhanced Australian monsoonality in LGM is caused by the local processes rather than the large scale dynamics, which should be taken into account when investigating its future change under global warming. Our findings may also explain why proxy records indicate different changes in Australian monsoon precipitation during the LGM.
The Global Streamflow Indices and Metadata Archive (GSIM) – Part 2: Quality control, time-series indices and homogeneity assessment
Authors: Gudmundsson Lukas , Do Hong Xuan , Leonard Michael , Westra Seth
Published: April 2018

Abstract. This is Part 2 of a two-paper series presenting the Global Streamflow Indices
and Metadata Archive (GSIM), which is a collection of daily streamflow
observations at more than 30 000 stations around the world. While Part 1 (Do
et al., 2018a) describes the data collection process as well as the
generation of auxiliary catchment data (e.g. catchment boundary, land cover,
mean climate), Part 2 introduces a set of quality controlled time-series
indices representing (i) the water balance, (ii) the seasonal cycle,
(iii) low flows and (iv) floods. To this end we first consider the quality of
individual daily records using a combination of quality flags from data
providers and automated screening methods. Subsequently, streamflow
time-series indices are computed for yearly, seasonal and monthly resolution.
The paper provides a generalized assessment of the homogeneity of all
generated streamflow time-series indices, which can be used to select time
series that are suitable for a specific task. The newly generated global set
of streamflow time-series indices is made freely available with an digital
object identifier at https://doi.pangaea.de/10.1594/PANGAEA.887470 and
is expected to foster global freshwater research, by acting as a ground truth
for model validation or as a basis for assessing the role of human impacts on
the terrestrial water cycle. It is hoped that a renewed interest in
streamflow data at the global scale will foster efforts in the systematic
assessment of data quality and provide momentum to overcome administrative
barriers that lead to inconsistencies in global collections of relevant
hydrological observations.
Identification of stable areas in unreferenced laser scans for automated geomorphometric monitoring
Authors: Wujanz Daniel , Avian Michael , Krueger Daniel , Neitzel Frank
Published: April 2018

Abstract. Current research questions in the field of geomorphology focus on the impact
of climate change on several processes subsequently causing natural hazards.
Geodetic deformation measurements are a suitable tool to document such
geomorphic mechanisms, e.g. by capturing a region of interest with
terrestrial laser scanners which results in a so-called 3-D point cloud. The
main problem in deformation monitoring is the transformation of 3-D point
clouds captured at different points in time (epochs) into a stable reference
coordinate system. In this contribution, a surface-based registration
methodology is applied, termed the iterative closest proximity algorithm
(ICProx), that solely uses point cloud data as input, similar to the
iterative closest point algorithm (ICP). The aim of this study is to
automatically classify deformations that occurred at a rock glacier and an
ice glacier, as well as in a rockfall area. For every case study, two epochs
were processed, while the datasets notably differ in terms of geometric
characteristics, distribution and magnitude of deformation. In summary, the
ICProx algorithm's classification accuracy is 70 % on average in
comparison to reference data.
Flood-Related Extreme Precipitation in Southwestern Germany: Development of a
Two-Dimensional Stochastic Precipitation Model
Authors: Ehmele Florian , Kunz Michael
Published: April 2018

Abstract. Various application fields, such as insurance industry risk assessments for the design of flood protection systems, require reliable precipitation statistics in high spatial resolution, including estimates for events with high return periods. Observations from point stations, however, lack of spatial representativeness, especially over complex terrain, and do not reliably represent the heavy tail of the distribution function. This paper presents a new method for stochastically simulating precipitation fields based on a linear theory of orographic precipitation and additional functions that consider synoptically driven rainfall and embedded convection in a simplified way. The model is initialized by various statistical distribution functions describing prevailing atmospheric conditions, such as wind vector, moisture content, or stability, estimated from radiosonde observations for a limited sample of the 200 strongest rainfall events observed. The model is applied for the stochastic simulation of heavy rainfall over the complex terrain of Southwest Germany. It is shown that the model, despite its simplicity, yields reliable precipitation fields. Differences between observed and simulated rainfall statistics are small, being in the order of only ±10 % for return periods of up to 1000 years.
Microbial community changes induced by Managed Aquifer Recharge activities: Linking hydrogeological and biological processes
Authors: Barba Carme , Folch Albert , Gaju Núria , Sanchez-Vila Xavier , Carrasquilla Marc , Grau-Martínez Alba , Martínez-Alonso Maira
Published: April 2018

Abstract. Managed Aquifer Recharge (MAR) is a worldwide used technique to increase the availability of water resources. We study how MAR modifies microbial ecosystems, and its implications for enhancing biodegradation processes to eventually improve groundwater quality. We compare soil and groundwater samples taken from a MAR facility located in NE Spain during recharge (with the facility operating continuously for several months) and after four months of no recharge. The study demonstrates a strong correlation between soil and water microbial prints with respect to sampling location along the mapped infiltration path. In particular, managed recharge practices disrupt groundwater ecosystems by modifying diversity indices and the composition of microbial communities, indicating that infiltration favors the growth of certain populations. Analysis of the genetic profiles showed the presence of nine different bacterial phyla in the facility, revealing high biological diversity at the highest taxonomic range. In fact, the microbial population patterns under recharge conditions agree with the Intermediate Disturbance Hypothesis. Moreover, DNA sequence analysis of excised DGGE band patterns revealed the existence of indicator species linked to MAR, most notably Dehalogenimonas sp., Nitrospira sp. and Vogesella sp. Our real facility multidisciplinary study (hydrological, geochemical and microbial), involving soil and groundwater samples, support that MAR is a naturallybased, passive, and efficient technique with broad implications for the biodegradation of pollutants dissolved in water.
A SMAP-Based Drought Monitoring Index for the United States
Authors: Sadri Sara , Wood Eric F. , Pan Ming
Published: April 2018

Abstract. Since April 2015, NASA's Soil Moisture Active Passive (SMAP) mission has monitored near-surface soil moisture, mapping the globe between the latitude bands of 85.044° N/S in 2–3 days depending on location. SMAP Level 3 passive radiometer product (SPL3SMP) measures the amount of water in the top 5 cm of soil except for regions of heavy vegetation (vegetation water content >4.5 kg/m2) and frozen or snow covered locations. SPL3SMP retrievals are spatially and temporally discontinuous, so the 33 months offers a short SMAP record length and poses a statistical challenge for meaningful assessment of its indices. The SMAP SPL4SMAU data product provides global surface and root zone soil moisture at 9-km resolution based on assimilating the SPL3SMP product into the NASA Catchment land surface model. Of particular interest to SMAP-based agricultural applications is a monitoring product that assesses the SMAP near-surface soil moisture in terms of probability percentiles for dry and wet conditions. We describe here SMAP-based indices over the continental United States (CONUS) based on both near-surface and root zone soil moisture percentiles. The percentiles are based on fitting a Beta distribution to the retrieved moisture values. To assess the data adequacy, a statistical comparison is made between fitting the distribution to VIC soil moisture values for the days when SPL3SMP are available, versus fitting to a 1979–2017 VIC data record. For the cold season (November–April), 57 % of grids were deemed to be consistent between the periods, and 68 % in the warm season (May–October), based on a Kolmogorov–Smirnov statistical test. It is assumed that if grids passed the consistency test using VIC data, then the grid had sufficient SMAP data. Our near-surface and root zone drought index on maps are shown to be similar to those produced by the U.S. Drought Monitor (from D0-D4) and GRACE. In a similar manner, we extend the index to include pluvial conditions using indices W0-W4. This study is a step forward towards building a national and international soil moisture monitoring system, without which, quantitative measures of drought and pluvial conditions will remain difficult to judge.
Technical note: rectifying systematic underestimation of the specific energy required to evaporate water into the atmosphere
Authors: Kowalski Andrew S.
Published: April 2018

Abstract. Not all of the specific energy consumed when evaporating water into the atmosphere (λ) is due to the latent heat of vaporization (L). What L represents is the specific energy necessary to overcome affinities among liquid water molecules, neglecting the specific work done against atmospheric pressure (p) when water expands in volume (V) from liquid to gas (pV work). Here, in the one-dimensional context typifying micrometeorology, the pV work done in such an expansion is derived based on the Stefan flow velocity at the surface boundary, yielding a simple function of the virtual temperature; additionally, an empirical formula is provided that approximates λ quite accurately over a useful range of environmental conditions. Neglect of this pV work term has caused a systematic 3–4 % underestimation of λ, and to some extent inhibited closure of the surface energy balance.