bluuebunny/crossref_metadata_2025 huggingface dataset:
THE IMPACT OF HUMAN FREEDOMS ON ECONOMIC GROWTH
Authors: Makrevska Disoska Elena , Shapkova Kocevska Katerina
Published: January 2021

The impact of formal institutions, including rule of law, human rights, and civil liberties on economic growth has been in the focus of the latest research agenda of the new institutional economics due to the current pandemic of the Corona-19 virus. Some limitations are necessary to be imposed to address a pandemic, but this is a real risk of lasting deterioration in basic human freedoms. Increased surveillance, restrictions on free expression and information, and limits on public participation are becoming increasingly common. The present fear is that the authorities worldwide are using the current situation to repress human rights for political purposes. This paper aims to explore the effect of the overall institutional environment, understood as the concept of human freedom, on economic prosperity in different jurisdictions around the world. Human freedom is a general term for personal, civil, and economic freedom and therefore the interconnection with economic growth can be seen in both directions. In our analysis, we use the Human Freedom Index published by the Fraser Institute as a proxy for human freedom. Here, human freedom is understood as the absence of coercive constraint. The index is calculated based on 79 distinct indicators representing different aspects of personal and economic freedom. This analysis seeks to answer several questions. First, we are interested in examining whether there is empirical evidence about the causality between human freedoms and economic growth. Second, we are interested in whether human freedom has a positive impact on growth rates. And third, we are interested in examining the influence of other determinants on economic growth. To test the causality between human freedom and economic growth, we have conducted a Granger causality analysis. The empirical strategy for identification of the possible influence of human freedom to growth rates includes the development of ordinary least squares (OLS) panel regression models for selected economies of the world, or around 174 cross-section units (countries) in the period between 2008 and 2017.
A Survey Paper on Palm Prints Based Biometric Authentication System
Authors: Verma Swati , Mishra Pomona
Published: January 2021

In this paper we are providing an approach for authentication using palm prints. Reliability in computer aided personal authentication is becoming increasingly important in the information-based world, for effective security system. Biometrics is physiological characteristics of human beings, unique for every individual that are usually time invariant and easy to acquire. Palm print is one of the relatively new physiological biometrics due to its stable and unique characteristics. The rich information of palm print offers one of the powerful means in personal recognition.
Audio Watermarking Scheme in MDCT Domain
Authors: Singh Santosh Kumar , Singh Jyotsna
Published: January 2021

In our proposed watermark embedding system, the original audio is segmented into overlapping frames. The psychoacoustic auditory model has been utilized to calculate the global threshold in modified discrete cosine transform domain. The perceptual insignificant locations have been used to insert the appropriately scaled watermark in the transform domain. Blind detection of watermark has been performed. Simulation results indicate that the proposed watermarking system is perceptually transparent and robust against various kind of attacks such as AWGN addition and MP3 compression.
Design of a GSM Cell – Phone based Vehicle Monitoring & Theft Security System
Authors: Dhotre Amol S. , Chandurkar Abhishek S. , Jadhav Sumedh. S.
Published: January 2021

This project will focus on developing an enhancement of the vehicle alarm security system via SMS. The system will manipulate a mobile phone to send SMS (Short Message Service). Even though the SMS can be sent using the features available in the mobile, the objective of this project is to activate the SMS sending by the mobile phone using external program, connected physically to the mobile phone. The study of telecommunication is an interesting field because it involves digital signal processing, signal and systems, programming and more. This inspires people to improvise the technology into daily use. In this project, the technology of telecommunication, to be specific; SMS, is integrated or improvised to the present vehicle security system. Instead of human to human telecommunication, this system creates new entity which is machine to human telecommunication. This system is an upgrading and improving vehicle security system by integrating SMS features to alert vehicle owners whenever intrusion occurs. This project involves hardware and software parts construction and the integration of both parts to create the system. We succeed in achieving the objective and in fact, add another feature to the system which will initiates a call to the owner after sending the SMS. In the end of this project, we will document all the hardware and software development and provide a simulation model of the system. An interfacing mobile is also connected to the microcontroller, which is in turn, connected to the engine. Once, the vehicle is being stolen, the information is being used by the vehicle owner for further processing. The information is passed onto the central processing insurance system which is in the form of the sms, the microcontroller unit reads the sms and sends it to the Global Positioning System (GPS) module and using the triangulation method, GPS module feeds the exact location in the form of latitude and longitude to the user’s mobile. By reading the signals received by the mobile, one can control the ignition of the engine.
RENEWABLE ENERGY BASED AGRICULTURAL ROBOT
Authors: KRISHNA R. , RICHBERT J.ENOCH , JEYAKARAN J. , KIRUBHAKARAN R. , DHINAKAR S.
Published: January 2021

This paper deals with how to mechanize agricultural process through electronic and embedded components. The aim of the paper is to elaborately explain the processes done by the so called robot.
STUDY OF FEASIBILITY OF SIX SIGMA IMPLEMENTATION IN A MANUFACTURING INDUSTRY : A CASE STUDY
Authors: ZAMAN MEHDIUZ , PATTANAYAK SUJIT KUMAR , PAUL ARUN CHANDRA
Published: January 2021

This paper discusses the implementation of Six-sigma methodology in reducing rejection in a welding electrode manufacturing industry. The Six-sigma DMAIC (define– measure – analyse –improve – control) approach has been used to achieve this result. This paper explains the step-by-step approach of Six-sigma implementation in this manufacturing process for improving quality level. This resulted in reduction of rejection, and thus, reduced the Defect Per Million Output (DPMO) from 28356.96 to 1666.67. This had resulted in increasing the sigma level from 3.41 to 4.43, without any huge capital investment. During this study, data were collected on all possible causes and was analysed and thereby conclusions were made. Implementation of Six-sigma methodology has resulted in large financial savings for the industry.
COMPARISON OF VARIOUS NUMERICAL DIFFERENCING SCHEMES IN PREDICTING NON-NEWTONIAN TRANSITION FLOW THROUGH AN ECCENTRIC ANNULUS WITH INNER CYLINDER IN ROTATION
Authors: DEWANGAN SATISH KUMAR , SINHA S.L.
Published: January 2021

Flow through annulus is a widely solved problem in fluid mechanics because of its practical applicability in many areas. In oil well drilling, cuttings generated are of non-Newtonian nature which flows through an eccentric annulus with inner cylinder in rotation, considering the real drilling situations. In the present work, a comparison have been done amongst three differencing schemes, the second order upwind, the Power law scheme and QUICK scheme used in computational fluid dynamics solution algorithms, so as to find the best amongst them to solve transition flow for this case as well as in general. A three dimensional orthogonal hexahedral mesh with suitable boundary conditions & input parameters was taken as computational domain for eccentric annulus. This was solved with standard k-ω turbulence model and SIMPLE algorithm. Results were validated against the published experimental work of J. M. Nouri, et. al [1]. Radial velocity, axial velocity and tangential velocity of fluid were plotted along chosen planes and contours of molecular viscosity as well as turbulence kinetic energy were observed for comparison amongst the solutions obtained by three differencing schemes. Although in most of the cases close agreement have been observed between computational data, but as far as prediction of radial velocity is concerned there was surprising difference amongst the three schemes.
Should sanitation tents be used for prevention of COVID-19 transmission?
Authors: Tan-Lim Carol Stephanie C. , Melendres Jacqueline Michelle D.
Published: January 2021

KEY FINDINGS

There is currently no evidence to support the use of sanitation tents in the prevention of COVID-19 transmission.

• Sanitation tents or disinfection tents have been installed in various areas of the Philippines as a measure to decontaminate individuals and prevent COVID-19 transmission.• The commonly used disinfectant in these tents is diluted household bleach. Others propose to use alcohol or diluted povidone iodine to decontaminate individuals in the tent.• Bleach is an irritant to mucous membranes and loses its antimicrobial effect over time or when exposed to heat and sunlight.• Alcohol is flammable and also causes irritation to mucous membranes.• Povidone iodine may cause skin irritation, chemical pneumonitis when inhaled, and acute kidney injury when systemically absorbed.• There are no completed or ongoing studies on the use of sanitation tents for the prevention of COVID-19 transmission.• To date, there are no guidelines that recommend the use of sanitation tents for prevention of COVID-19 transmission.• The World Health Organization explicitly recommends against spraying alcohol or chlorine all over a person's body due to adverse health effects and the lack of inhibitory activity against viruses that have already entered the body.• The Centers for Disease Control and Prevention note that most environmental protection agency-registered household disinfectants are effective against COVID-19. However, these products are approved for use only on surfaces and not on humans.• The Department of Health guidelines recommend the avoidance of spraying or misting for COVID-19 due to lack of evidence of its efficacy.
TRASPLANTE RENAL EN ECUADOR, PUNTOS CLAVE Y SITUACIÓN ACTUAL.
Authors: Albán Tigre Jorge , Villarreal Juris Andrea , Mora Betancourt Juan , Betancourt Nole Víctor
Published: January 2021

IntroductionKidney transplantation in Ecuador began in 1976, it was limited until 2011, when the Organic Law of Donation and Transplantation of Organs, Tissues and Cells became valid. This is indicated in end-stage renal failure, in adult and pediatric patients; and, compared to peritoneal and renal dialysis, it is less expensive for the health system. In 2015, in Ecuador, at least 30,000 people suffered from end-stage kidney disease; 45% of them could die without treatment. The objective of this study was to determine the current situation in Ecuador regarding kidney transplantation. MethodologyA descriptive, retrospective study. INDOT statistics were reviewed from 2007 to August 2019, to determine the total number of transplants and kidney transplants, type of transplant, effective donors, rate of donors per million population (pmp), transplanted organ rate (pmp), evolution of the national waiting list, survival rate, etc. Results From 2007 to 2019, 6134 transplants were performed: 25.4% renal. Most donors were male (68.1%). The donor rate (pmp) between 2009 and 2019 was 4.2 (SD: ± 2.1). The mean rate of transplanted organs was 8.1 (SD: ± 3.6) (pmp) from 2007 to 2019. In this period 1560 kidney transplants were performed: 83.1% with cadaveric donors (88.1% adults; 11.9% pediatric) and 16.9% with living donors (72.4% adults; 27.6% pediatric). The one-year survival rate after cadaveric and living donor kidney transplantation was 0.94 and 0.97 in adults; and 0.90 and 0.97 in pediatrics, respectively. Currently there are only 5 accredited centers for kidney transplantation in adults and one for pediatric kidney transplantation .ConclusionsKidney transplantation has made significant progress in Ecuador, however, it is still below the World Health Organization (WHO) goal established for the proper management of patients with chronic kidney failure.
Práticas linguísticas em uma escola na região de fronteira Brasil/Paraguai: questões político-linguístico-educacionais de (não) gestão de línguas
Authors: Martiny Franciele Maria , Redel Elisângela , Heck Diana Milena
Published: January 2021

Com base nos estudos desenvolvidos no Grupo de Pesquisa Políticas Linguísticas e Educacionais no Oeste do Paraná, desde 2016, e nos princípios norteadores da gestão de situações de plurilinguismo e translinguagem no âmbito das escolas (CANAGARAJAH, 2004; RAJAGOPALAN, 2013; CAVALCANTI, 1999; SEVERO, 2013; SPOLSKY, 2005, 2016; SHOHAMY, 2006), este texto tem por finalidade apresentar reflexões em torno de um espaço plurilíngue em uma instituição de ensino pública da rede municipal, localizada no Oeste do Paraná, em região de fronteira Brasil/Paraguai. A partir de contato com a direção e com documentos norteadores do educandário, verificou-se a presença de alunos provenientes do Paraguai, falantes de espanhol e guarani, desde 2007, sendo que estes perfazem aproximadamente 10% do total de estudantes anualmente matriculados nos últimos anos. Entretanto, apesar de haver este ambiente sociolinguisticamente complexo, não há (e não houve) qualquer política de acolhimento ou ações de gestão de diferentes línguas no contexto educativo. Nesse sentido, desenvolvemos uma pesquisa qualitativa e interpretativista que analisa o cenário dessa escola municipal, a partir do contato com a direção e com os documentos norteadores do referido educandário, evocando a necessidade de discussões para o fomento de práticas e políticas linguístico-educacionais adequadas a tais situações plurilíngues com ações translíngues e transculturais.
Investigações acerca da validade da psicologia popular: uma abordagem intimista da mente
Authors: Faria Daniel Luporini de
Published: January 2021

No presente trabalho, avaliaremos a validade do discurso ordinário que embasa a psicologia popular. Partindo das análises sobre a linguagem, tal qual pensa Francis Bacon, apresentaremos as idéias de Jerry Fodor, que com seu realismo intencional, procura naturalizar o discurso mentalista. Problematizando as análises de Fodor, avaliaremos, finalmente, a “razão de ser” da psicologia popular, à luz da proposta eliminativista de Paul M. Churchland.
Marginalidade e homoerotismo nas narrativas de Marcelino Freire
Authors: Nascimento Henrique , Soares Alfranio Pedroso
Published: January 2021

As narrativas de Marcelino Freire fazem parte da vasta produção literária brasileira da atualidade. É possível identificar nos personagens, nos ambientes e nos enredos, do autor pernambucano, traços estilísticos recorrentes como a temática da marginalidade e do homoerotismo. Torna-se necessário estabelecer uma análise de tais traços, de forma articulada, a partir de uma comparação entre textos literários e teóricos. Assim, neste trabalho, propomos, a partir da análise literária das narrativas de Marcelino Freire, estabelecer uma articulação entre a literatura marginal e as noções de homoerotismo. Para a análise, destacamos os contos “A volta de Carmen Miranda”, do livro BaléRalé (2003), e “Coração”, do livro Contos Negreiros (2015), bem como o romance Nossos Ossos (2013). Valemo-nos de análise comparativa entre textos literários do autor e, assim, revistamos os conceitos de literatura marginal e periférica a partir dos textos de Rejane Pivetta de Oliveira (2011), Karl Erik Schøllhammer (2009), Jaime Ginzburg (2012), Flora Süssekind (2005). Da mesma forma, retomamos os elementos dos estudos sobre homoerotismo a partir da leitura de Jurandir Freire Costa (1992) e David William Foster (2019). Ao final, pretendemos consolidar, por meio da análise literária comparatista, a relação entre marginalidade e homoerotismo nas narrativas de Marcelino Freire, bem como uma articulação possível para leituras da literatura contemporânea brasileira.
In memoriam Herbert J. Nickel
Authors: Ponce Alcocer María Eugenia
Published: January 2021

Relevancia de este investigador en la historia de la hacienda mexicana y de la historia agraria en México.
Of Monsters and Men: The Aesthetics of the Alt-Right
Authors: Jungen Thari
Published: January 2021

In February 2016, the Institute for Falsification researched the production of fake news in Veles, North Macedonia. Focusing on a specific hoax distributed from Veles via social media, this article analyses the political and aesthetic effects of fake news. It argues that fakes and hoaxes (mis)use established references to renew pre-existing discourses, media techniques, and symbols. The present definition of fakes is therefore insufficient for these practices.
Do Job Coach Effective to PWDs Secured a Job in Malaysia
Authors: MAT RADZI NOOR FATIHAH
Published: January 2021

The right to work has been recognized through artice 23(1) of the Universal Declaration of Human Right 1948. But, opportunity and participation of Person With Disabilities (PWDs) in the workforce is still a challenge in Malaysian context. Various efforts and initiatives have been continuously undertaken to secure inclusion of PWDs in the workforce. Malaysia introduced Supported Employment (SE) through Job Coach programme largely provided by the Department of Social Welfare and other Non-Govermental Organizations (NGOs) focuses on helping PWDs in securing employment in the workplace. This conceptual paper discuss about the effectiveness Job Coach to PWDs enhancing participation in the open job market. Implications of the study to the organisation in particular and to the general public at large are also examined and to be considered in order to ensure PWDs inclusion in the workplace and their well-being could be continuously and effectively promoted.
Introducción a la bibliografía peruana
Authors: Tauro Alberto
Published: January 2021

Estudio de Alberto Tauro sobre introducción a la bibliografía peruana, publicado en la presente edición de Fénix al conmemorarse el primer centenario del nacimiento del historiador y bibliógrafo, don José Toribio Medina (1852-1952).
Adiciones inéditas a "La Imprenta en Lima"
Authors: Toribio Medina José
Published: January 2021

Merced a la gentileza del doctor Guillermo Feliú Cruz, albacea de la vasta obra que la cultura de América debe a José Toribio Medina, publicamos ahora las adiciones inéditas a "La Imprenta en Lima", que el acucioso bibliógrafo reunió durante los últimos lustros de su vida, y en las cuales denota el afecto y la constancia que puso en sus trabajos.
Prontuario del curso de clasificación
Authors: Arbulú Vargas Ricardo
Published: January 2021

Resumen y  anotaciones  del curso de Clasificación dictado por el profesor Ricardo Arbulú Vargas
Libro primero de Cabildos de la ciudad de San Juan de la Frontera de Chachapoyas 2
Authors: Rivera Serna Raúl
Published: January 2021

El objetivo fundamental de la nota, circunscrita a presentar la versión adjunta del Libro de Cabildos de la ciudad de San Juan de la Frontera de Chachapoyas, impide ofrecer un estudio integral o al menos más completo sobre la historia de ciudad de tan especiales características en el orden geográfico, social y económico. Ello no es óbice, sin embargo, para pasar por alto ciertos rasgos que denuncian su prestancia aborigen primero, y mestiza después.
La Escuela Nacional de Bibliotecarios del Perú
Authors: Mackee de Maurial Nelly
Published: January 2021

Recorrido histórico de la Escuela Nacional de Bibliotecarios del Perú. Las primeras Escuelas de Bibliotecarios. .Las Reuniones Americanas de Bibliotecología y la Educación del Bibliotecario. Acción de la Unesco y de la Organización de los Estados Americanos en pro de la educación profesional del Bibliotecario.El primer año de funcionamiento.  Evolución de las asignaturas. Currículum. Profesorado. Alumnado. Admisión.
“Descendencia paralela” en una familia indígena noble del Cuzco
Authors: Zudeima Tom
Published: January 2021

Los documentos aquí presentados forman parte de la comprobación por parte de Don Fernando Puma Orcosupa en el año de 1789 para que se le mantuviese en su condición de indio noble del pueblo de Anta, un pueblo cerca al Cuzco. Él prueba así que es descendiente de un noble Inca que había servidoa los Españoles poco tiempo después de la conquista del Perú. Este noble por su parte habría sido bisnieto del Inca Tupac Yupanqui, abuelo de los IncasHuáscar y Atauhuallpa quienes estaban envueltos en una guerra civil al tiempo de la conquista española (1532) del Perú. El principal interés de estos documentos es que nos dan detalles ---hasta ahora no encontrados en otros documentos todavía-i- sobre linajes de familias nobles indígenas del Cuzco y alrededores, que, como quiero comprobar, expresan ideas indígenas de parentesco, ideas distintas de las españolas.
Notas para un diccionario biográfico de pintores peruanos (1535-1821)
Authors: Rodrígez L. Flor de María
Published: January 2021

Tesis presentada a la Escuela Nacional dc Bibliotecarios, para optar el título de Bibliotecaria, elaborado por Flor de María Rodríguez L.
Rassushin’s precedent: to save a cultural artifact
Authors: Lisitsina Yana
Published: January 2021

Preservation of cultural heritage is a complex task regarded from legislative, professional and sociocultural aspects. It demands a very delicate approach. At the same time, the heritage preservation system in the Russian Federation has a number of problems related to imperfection of the institution of historical and cultural expertise, which allows removing obvious cultural resources from the field of state protection. The civil society can resist such incidents, as evidenced by the case of the Irkutsk architectural and historic monument, Doctor Rassushin’s House (early 20th century).
Industrial architecture of Primorye. Vladivostok, Ussuriysk
Authors: Bazilevich Mikhail , Kradin Nikolai
Published: January 2021

The article presents a systematic picture of the development of industrial architecture of large cities in the south of the Russian Far East in the second half of the XIX - early XX centuries. Using the example of Vladivostok and Ussuriysk, the main features of the architecture of factories and other industrial facilities are identified, due to the specifics of the development of the region and its individual cities. The main types of industrial facilities and the principles of their placement in urban areas are considered.
Facility level measurement of offshore oil and gas installations from a medium-sized airborne platform: method development for quantification and source identification of methane emissions
Authors: France James L. , Bateson Prudence , Dominutti Pamela , Allen Grant , Andrews Stephen , Bauguitte Stephane , Coleman Max , Lachlan-Cope Tom , Fisher Rebecca E. , Huang Langwen , Jones Anna E. , Lee James , Lowry David , Pitt Joseph , Purvis Ruth , Pyle John , Shaw Jacob , Warwick Nicola , Weiss Alexandra , Wilde Shona , Witherstone Jonathan , Young Stuart
Published: January 2021

Abstract. Emissions of methane (CH4) from offshore oil and gas installations are
poorly ground-truthed, and quantification relies heavily on the use of
emission factors and activity data. As part of the United Nations Climate
& Clean Air Coalition (UN CCAC) objective to study and reduce short-lived
climate pollutants (SLCPs), a Twin Otter aircraft was used to survey CH4
emissions from UK and Dutch offshore oil and gas installations. The aims of
the surveys were to (i) identify installations that are significant CH4
emitters, (ii) separate installation emissions from other emissions using
carbon-isotopic fingerprinting and other chemical proxies, (iii) estimate
CH4 emission rates, and (iv) improve flux estimation (and sampling)
methodologies for rapid quantification of major gas leaks. In this paper, we detail the instrument and aircraft set-up for two
campaigns flown in the springs of 2018 and 2019 over the southern North Sea
and describe the developments made in both the planning and sampling methodology
to maximise the quality and value of the data collected. We present example
data collected from both campaigns to demonstrate the challenges encountered
during offshore surveys, focussing on the complex meteorology of the marine
boundary layer and sampling discrete plumes from an airborne platform. The
uncertainties of CH4 flux calculations from measurements under varying
boundary layer conditions are considered, as well as recommendations for
attribution of sources through either spot sampling for volatile organic compounds (VOCs) ∕ δ13CCH4 or using in situ instrumental data to determine
C2H6–CH4 ratios. A series of recommendations for both
planning and measurement techniques for future offshore work within marine
boundary layers is provided.
Evaluation and optimization of ICOS atmosphere station data as part of the labeling process
Authors: Yver-Kwok Camille , Philippon Carole , Bergamaschi Peter , Biermann Tobias , Calzolari Francescopiero , Chen Huilin , Conil Sebastien , Cristofanelli Paolo , Delmotte Marc , Hatakka Juha , Heliasz Michal , Hermansen Ove , Komínková Kateřina , Kubistin Dagmar , Kumps Nicolas , Laurent Olivier , Laurila Tuomas , Lehner Irene , Levula Janne , Lindauer Matthias , Lopez Morgan , Mammarella Ivan , Manca Giovanni , Marklund Per , Metzger Jean-Marc , Mölder Meelis , Platt Stephen M. , Ramonet Michel , Rivier Leonard , Scheeren Bert , Sha Mahesh Kumar , Smith Paul , Steinbacher Martin , Vítková Gabriela , Wyss Simon
Published: January 2021

Abstract. The Integrated Carbon Observation System (ICOS) is a pan-European research infrastructure which provides harmonized and high-precision scientific data on the carbon cycle and the greenhouse gas budget. All stations have to undergo a rigorous assessment before being labeled, i.e., receiving approval to join the network. In this paper, we present the labeling process for the ICOS atmosphere network through the 23 stations that were labeled between November 2017 and November 2019. We describe the labeling steps, as well as the quality controls, used to verify that the ICOS data (CO2, CH4, CO and meteorological measurements) attain the expected quality level defined within ICOS. To ensure the quality of the greenhouse gas data, three to four calibration gases and two target gases are measured: one target two to three times a day, the other gases twice a month. The data are verified on a weekly basis, and tests on the station sampling lines are performed twice a year. From these high-quality data, we conclude that regular calibrations of the CO2, CH4 and CO analyzers used here (twice a month) are important in particular for carbon monoxide (CO) due to the analyzer's variability and that reducing the number of calibration injections (from four to three) in a calibration sequence is possible, saving gas and extending the calibration gas lifespan. We also show that currently, the on-site water vapor correction test does not deliver quantitative results possibly due to environmental factors. Thus the use of a drying system is strongly recommended. Finally, the mandatory regular intake line tests are shown to be useful in detecting artifacts and leaks, as shown here via three different examples at the stations.
Vegetation modulates the impact of climate extremes on gross primary production
Authors: Flach Milan , Brenning Alexander , Gans Fabian , Reichstein Markus , Sippel Sebastian , Mahecha Miguel D.
Published: January 2021

Abstract. Drought and heat events affect the uptake and sequestration of carbon in terrestrial ecosystems. Factors such as the duration, timing, and intensity of extreme events influence the magnitude of impacts on ecosystem processes such as gross primary production (GPP), i.e., the ecosystem uptake of CO2. Preceding soil moisture depletion may exacerbate these impacts. However, some vegetation types may be more resilient to climate extremes than others. This effect is insufficiently understood at the global scale and is the focus of this study.
Using a global upscaled product of GPP that scales up in situ land CO2 flux observations with global satellite remote sensing, we study the impact of climate extremes at the global scale. We find that GPP in grasslands and agricultural areas is generally reduced during heat and drought events. However, we also find that forests, if considered globally, appear in general to not be particularly sensitive to droughts and heat events that occurred during the analyzed period or even show increased GPP values during these events. On the one hand, normal-to-increased GPP values are in many cases plausible, e.g., when conditions prior to the event have been particularly positive. On the other hand, however, normal-to-increased GPP values in forests may also reflect a lack of sensitivity in current remote-sensing-derived GPP products to the effects of droughts and heatwaves. The overall picture calls for a differentiated consideration of different land cover types in the assessments of risks of climate extremes for ecosystem functioning.
The impact of land-fast ice on the distribution of terrestrial dissolved
organic matter in the Siberian Arctic shelf seas
Authors: Hölemann Jens A. , Juhls Bennet , Bauch Dorothea , Janout Markus , Koch Boris P. , Heim Birgit
Published: January 2021

Abstract. Remobilization of soil carbon as a result of permafrost degradation in the drainage basin of the major Siberian rivers combined with higher precipitation in a warming climate potentially increase the flux of terrestrial derived dissolved organic matter (tDOM) into the Arctic Ocean. The Laptev (LS) and East Siberian Seas (ESS) receive enormous amounts of tDOM-rich river water, which undergoes at least one freeze-melt cycle in the Siberian Arctic shelf seas. To better understand how freezing and melting affect the tDOM dynamics in the LS and ESS, we sampled sea ice, river and seawater for their dissolved organic carbon (DOC) concentration and the colored fraction of dissolved organic matter. The sampling took place in different seasons over a period of 9 years (2010–2019). Our results suggest that the main factor regulating the tDOM distribution in the LS and ESS is the mixing of marine waters with freshwater sources carrying different tDOM concentrations. Of particular importance in this context are the 211 km3 of meltwater from land-fast ice from the LS, containing ~ 0.3 Tg DOC, which in spring mixes with 245 km3 of river water from the peak spring discharge of the Lena River, carrying ~ 2.4 Tg DOC into the LS. During the ice-free season, tDOM transport on the shelves takes place in the surface mixed layer, with the direction of transport depending on the prevailing wind direction. In winter, about 1.2 Tg of brine-related DOC, which was expelled from the growing land-fast ice in the LS, is transported in the near-surface water layer into the Transpolar Drift Stream that flows from the Siberian Shelf toward Greenland. The actual water depth in which the tDOM-rich brines are transported, depends mainly on the density stratification of the LS and ESS in the preceding summer and the amount of ice produced in winter. We suspect that climate change in the Arctic will fundamentally alter the dynamics of tDOM transport in the Arctic marginal seas, which will also have consequences for the Arctic carbon cycle.
Drivers of nitrogen and phosphorus dynamics in a groundwater-fed urban catchment revealed by high-frequency monitoring
Authors: Yu Liang , Rozemeijer Joachim C. , Broers Hans Peter , van Breukelen Boris M. , Middelburg Jack J. , Ouboter Maarten , van der Velde Ype
Published: January 2021

Abstract. Eutrophication of water bodies has been a problem causing severe degradation of water quality in cities. To gain mechanistic understanding of the temporal dynamics of nitrogen (N) and phosphorus (P) in a groundwater-fed low-lying urban polder, we applied high-frequency monitoring in Geuzenveld, a polder in the city of Amsterdam. The high-frequency monitoring equipment was installed at the pumping station where
water leaves the polder. From March 2016 to June 2017, total phosphorus (TP), ammonium (NH4), turbidity, electrical conductivity (EC), and water temperature were measured at intervals of less than 20 min. This paper discusses the results at three timescales: annual scale, rain event scale, and single pumping event scale. Mixing of upwelling groundwater (main source of N and P) and runoff from precipitation on pavements and roofs was the dominant hydrological process governing the temporal pattern of the EC, while N and P fluxes from the polder were also regulated by primary production and iron transformations. In our groundwater-seepage controlled catchment, NH4 appeared to be the dominant form of N with surface water concentrations in the range of 2–6 mg N L−1, which stems from production in an organic-rich subsurface. The concentrations of NH4 in the surface water were governed by the mixing process in autumn and winter and were reduced down to 0.1 mg N L−1 during the algal growing season in spring. The depletion of dissolved NH4 in spring suggests uptake by primary producers, consistent with high concentrations of chlorophyll a,
O2, and suspended solids during this period. Total P and turbidity were high during winter (range 0.5–2.5 mg P L−1 and 200–1800 FNU, respectively, where FNU represents Formazin Nephelometric Unit) due to the release of P and reduced iron from anoxic sediment to the water column, where Fe2+ was rapidly oxidized and precipitated as iron oxides which contributed to turbidity. In the other seasons, P is retained in the sediment by sorption to precipitated iron oxides. Nitrogen is exported from the polder to the receiving waters throughout the whole year, mostly in the form of NH4 but in the form of organic N in spring. P leaves the polder mainly during winter, primarily associated with Fe(OH)3 colloids and as dissolved P. Based on this new understanding of the dynamics of N and P in this low-lying urban catchment, we suggested management strategies that may effectively control and reduce eutrophication in urban polders and receiving downstream waters.
Performance of the Adriatic early warning system during the multi-meteotsunami
event of 11–19 May 2020: an assessment using energy banners
Authors: Tojčić Iva , Denamiel Cléa , Vilibić Ivica
Published: January 2021

Abstract. This study quantifies the performance of the Croatian meteotsunami early warning system (CMeEWS) composed of a network of air pressure and sea level observations, a high-resolution atmosphere-ocean modelling suite and a stochastic surrogate model. The CMeEWS, which is not operational due to a lack of numerical resources, is used retroactively to reproduce the multiple events observed in the eastern Adriatic between the 11th and 19th of May 2020. It is found that deterministic simulations largely fail to forecast these extreme events at endangered locations along the Croatian cost mostly due to a systematic northwestward shift of the atmospheric disturbances. Additionally, the use of combined ocean and atmospheric model results, instead of atmospheric model results only, is not found to improve the selection of the transects used to extract the atmospheric parameters feeding the stochastic meteotsunami surrogate model. Finally, in operational mode, the stochastic surrogate model would have triggered the warnings for most of the observed events, but also setting off some false alarms. Due to the uncertainties associated with operational modelling of meteotsunamigenic disturbances, the stochastic approach has thus proven to overcome the failures of the deterministic forecasts and should be further developed.
The role of geochemistry in organic carbon stabilization in tropical rainforest soils
Authors: Reichenbach Mario , Fiener Peter , Garland Gina , Griepentrog Marco , Six Johan , Doetterl Sebastian
Published: January 2021

Abstract. Stabilization of organic carbon in soils (SOC) depends on several soil properties, including the soil weathering stage and the mineralogy of parent material. As such, tropical SOC stabilization mechanisms likely differ from those in temperate soils due to contrasting soil development. To better understand these mechanisms, we investigated SOC dynamics at three soil depths under pristine tropical african mountain forest along a geochemical gradient from mafic to felsic and a topographic gradient covering plateau, slope and valley positions. To do so we conducted a series of soil C fractionation experiments in combination with an analysis of the geochemical composition of soil and a sequential extraction of pedogenic oxides. Relationships between our target and predicting variables were investigated using a combination of regression analyses and dimension reduction. Here, we show that reactive secondary mineral phases drive SOC properties and stabilization mechanisms together with, and sometimes more strongly than, other mechanisms such as aggregation or C stabilization by clay content. Key mineral stabilization mechanisms for SOC were strongly related to soil geochemistry, differing across the study regions. These findings were independent of topography in the absence of detectable erosion processes. Instead, fluvial dynamics and changed hydrological conditions had a secondary control on SOC dynamics in valley positions, leading to higher SOC stocks there than at the non-valley positions. We also detected fossil organic carbon (FOC) at several sites, constituting up to 52.0 ± 13.2 % of total SOC stock in the C depleted subsoil. Interestingly, total SOC stocks for these soils did not exceed those of sites without FOC. Additionally, FOC decreased strongly towards more shallow soil depths, indicating decomposability of FOC by microbial communities under more fertile conditions. Regression analysis showed that variables affiliated with soil weathering, parent material geochemistry and soil fertility, together with soil depth, explained up to 75 % of the variability of SOC stocks and Δ14C. Furthermore the same variables explain 44 % of the variability in the relative abundance of C associated with microaggregates versus free silt and clay associated C fractions However, geochemical variables gained or retained importance for explaining SOC target variables when controlling for soil depth. We conclude that despite long-lasting weathering, geochemical properties of soil parent material leave a footprint in tropical soils that affects SOC stocks and mineral related C stabilization mechanisms. While identified stabilization mechanisms and controls are similar to less weathered soils in other climate zones, their relative importance is markedly different in the investigated tropical soils.
Evaluation of sea-ice thickness from four reanalyses in the Antarctic Weddell Sea
Authors: Shi Qian , Yang Qinghua , Mu Longjiang , Wang Jinfei , Massonnet François , Mazloff Matthew R.
Published: January 2021

Abstract. Ocean–sea-ice coupled models constrained by various observations provide different ice thickness estimates in the Antarctic. We evaluate
contemporary monthly ice thickness from four reanalyses in the Weddell Sea: the German contribution of the project Estimating the Circulation and Climate of
the Ocean Version 2 (GECCO2), the Southern Ocean State Estimate (SOSE), the Ensemble Kalman Filter system based on the Nucleus for European Modelling of the Ocean (NEMO-EnKF) and the Global Ice–Ocean Modeling and Assimilation System (GIOMAS). The evaluation is performed against
reference satellite and in situ observations from ICESat-1, Envisat, upward-looking sonars and visual ship-based sea-ice observations. Compared with
ICESat-1, NEMO-EnKF has the highest correlation coefficient (CC) of 0.54 and lowest root mean square error (RMSE) of 0.44 m. Compared with
in situ observations, SOSE has the highest CC of 0.77 and lowest RMSE of 0.72 m. All reanalyses underestimate ice thickness near the coast of
the western Weddell Sea with respect to ICESat-1 and in situ observations even though these observational estimates may be biased low. GECCO2 and
NEMO-EnKF reproduce the seasonal variation in first-year ice thickness reasonably well in the eastern Weddell Sea. In contrast, GIOMAS ice thickness
performs best in the central Weddell Sea, while SOSE ice thickness agrees most with the observations from the southern coast of the Weddell Sea. In
addition, only NEMO-EnKF can reproduce the seasonal evolution of the large-scale spatial distribution of ice thickness, characterized by the thick
ice shifting from the southwestern and western Weddell Sea in summer to the western and northwestern Weddell Sea in spring. We infer that the thick
ice distribution is correlated with its better simulation of northward ice motion in the western Weddell Sea. These results demonstrate the
possibilities and limitations of using current sea-ice reanalysis for understanding the recent variability of sea-ice volume in the Antarctic.
Continuous in situ measurements of anchor ice formation, growth, and release
Authors: Ghobrial Tadros R. , Loewen Mark R.
Published: January 2021

Abstract. In northern rivers, turbulent water becomes supercooled
(i.e. cooled to slightly below the freezing point) when exposed to freezing
air temperatures. In supercooled turbulent water, frazil (small ice disks)
crystals are generated in the water column, and anchor ice starts to form on
the bed. Two anchor ice formation mechanisms have been reported in the
literature: either by the accumulation of suspended frazil particles, which
are adhesive (sticky) in nature, on the riverbed or by in situ growth of
ice crystals on the bed material. Once anchor ice has formed on the bed, the
accumulation typically continues to grow (due to either further frazil
accumulation and/or crystal growth) until release occurs due to mechanical
(shear force by the flow or buoyancy of the accumulation) or thermal
(warming of the water column which weakens the ice-substrate bond) forcing
or a combination of the two. There have been a number of detailed laboratory
studies of anchor ice reported in the literature, but very few field
measurements of anchor ice processes have been reported. These measurements
have relied on either sampling anchor ice accumulations from the riverbed
or qualitatively describing the observed formation and release. In this
study, a custom-built imaging system (camera and lighting) was developed to
capture high-resolution digital images of anchor ice formation and release
on the riverbed. A total of six anchor ice events were successfully
captured in the time-lapse images, and for the first time, the different
initiation, growth, and release mechanisms were measured in the field. Four
stages of the anchor ice cycle were identified: Stage 1: initiation
by in situ crystal growth; Stage 2: transitional phase; Stage 3: linear
growth; and Stage 4: release phase. Anchor ice initiation due to in situ
growth was observed in three events, and in the remainder, the accumulation
appeared to be initiated by frazil deposition. The Stage 1 growth rates
ranged from 1.3 to 2.0 cm/h, and the Stage 2 and 3 growth rates varied from
0.3 to 0.9 cm/h. Anchor ice was observed releasing from the bed in three
modes: lifting of the entire accumulation, shearing of layers of the
accumulation, and rapid release of the entire accumulation.
Intercomparison of photogrammetric platforms for spatially continuous snow depth mapping
Authors: Eberhard Lucie A. , Sirguey Pascal , Miller Aubrey , Marty Mauro , Schindler Konrad , Stoffel Andreas , Bühler Yves
Published: January 2021

Abstract. Snow depth has traditionally been estimated based on
point measurements collected either manually or at automated weather
stations. Point measurements, though, do not represent the high spatial
variability in snow depths present in alpine terrain. Photogrammetric
mapping techniques have progressed in recent years and are capable of
accurately mapping snow depth in a spatially continuous manner, over larger
areas and at various spatial resolutions. However, the strengths and
weaknesses associated with specific platforms and photogrammetric
techniques as well as the accuracy of the photogrammetric performance on
snow surfaces have not yet been sufficiently investigated. Therefore,
industry-standard photogrammetric platforms, including high-resolution
satellite (Pléiades), airplane (Ultracam Eagle M3), unmanned aerial
system (eBee+ RTK with SenseFly S.O.D.A. camera) and terrestrial (single lens reflex
camera, Canon EOS 750D) platforms, were tested for snow depth mapping in the alpine
Dischma valley (Switzerland) in spring 2018. Imagery was acquired with
airborne and space-borne platforms over the entire valley, while unmanned
aerial system (UAS) and terrestrial photogrammetric imagery was acquired
over a subset of the valley. For independent validation of the
photogrammetric products, snow depth was measured by probing as well as
by using remote observations of fixed snow poles. When comparing snow depth maps with manual and snow pole measurements, the
root mean square error (RMSE) values and the normalized median absolute deviation (NMAD) values were 0.52 and 0.47 m, respectively, for the satellite snow
depth map, 0.17 and 0.17 m for the airplane snow depth map, and 0.16 and
0.11 m for the UAS snow depth map. The area covered by the terrestrial snow
depth map only intersected with four manual measurements and did not generate
statistically relevant measurements. When using the UAS snow depth map as a
reference surface, the RMSE and NMAD values were 0.44 and 0.38 m for the
satellite snow depth map, 0.12 and 0.11 m for the airplane snow depth map,
and 0.21 and 0.19 m for the terrestrial snow depth map. When compared to the
airplane dataset over a large part of the Dischma valley (40 km2), the
snow depth map from the satellite yielded an RMSE value of 0.92 m and an NMAD
value of 0.65 m. This study provides comparative measurements between
photogrammetric platforms to evaluate their specific advantages and
disadvantages for operational, spatially continuous snow depth mapping in
alpine terrain over both small and large geographic areas.
Reconstruction of annual accumulation rate on firn synchronizing H2O2 concentration data with an estimated temperature record
Authors: Travassos Jandyr M. , Martins Saulo S. , Potocki Mariusz , Simões Jefferson C.
Published: January 2021

Abstract. This work deals with two distinct datasets, a well preserved H2O2 concentration data from firn cores at a high deposition location and a temperature time series, estimated from the daily records from four Antarctic stations around the Antarctic Peninsula. With them we have produced a time scale, an ice–core chronology, for the 133  deep borehole DP-07-1 from Plateau Detroit, Antarctic Peninsula. We constructed the chronology through a non-linear pairing transformation of the two series, based entirely on mathematical optimization, compensating the peroxide frequency scaling, reflecting the gradual thinning of the annual firn layers with depth. We resorted to a dynamic time warping algorithm to find an optimal alignment between the two data series, allowing for the thinning of the annual firn layers with depth and the estimation of their original thicknesses at time of deposition. The core chronology spanning from Jan-1980 to Dec-2010 for the borehole reach, a time frame of a mere 30 years period, revealing a fairly stable 11 year average for the accumulation rate of 2.5 m w.e./y.