scholarly journals The carbon dioxide signal from the COVID-19 lock-down

2020 ◽  
Author(s):  
John Reid
Keyword(s):  
Mixed Layer ◽  
Deep Ocean ◽  
Weather Conditions ◽  
Anthropogenic Emissions ◽  
Temporary Reduction ◽  
Local Weather ◽  
Global Carbon ◽  
Insight Into

Abstract Two unintended experiments provide insight into the role of anthropogenic emissions in the global carbon cycle. One was the temporary reduction in emissions during the COVID-19 lock-down. The other was the emission of a radioactive isotope of carbon during the testing of nuclear weapons in the 1950s and the abrupt cessation of these tests in 1963. Together they imply the existence of two distinct reservoirs which exchange carbon with the atmosphere, viz.: the mixed layer and the deep ocean. Exchanges with the former are noisy because they are influenced by sea surface temperature which, in turn, depends on local weather conditions. They completely mask any variations caused by the COVID-19 lock-down. Exchanges with the latter are steady, long-term and uninfluenced by the weather. They result in half the carbon content of the atmosphere and mixed layer being replaced every eleven years.

scholarly journals CO2 dynamics and heterogeneity in a cave atmosphere: role of ventilation patterns and airflow pathways

2021 ◽  
Author(s):  
Lovel Kukuljan ◽  
Franci Gabrovšek ◽  
Matthew D. Covington ◽  
Vanessa E. Johnston
Keyword(s):  
Temporal Variations ◽  
Observation Point ◽  
Spatially Distributed ◽  
Combined Action ◽  
Karst Systems ◽  
The Relationship ◽  
Co2 Dynamics ◽  
Global Carbon

AbstractUnderstanding the dynamics and distribution of CO2 in the subsurface atmosphere of carbonate karst massifs provides important insights into dissolution and precipitation processes, the role of karst systems in the global carbon cycle, and the use of speleothems for paleoclimate reconstructions. We discuss long-term microclimatic observations in a passage of Postojna Cave, Slovenia, focusing on high spatial and temporal variations of pCO2. We show (1) that the airflow through the massif is determined by the combined action of the chimney effect and external winds and (2) that the relationship between the direction of the airflow, the geometry of the airflow pathways, and the position of the observation point explains the observed variations of pCO2. Namely, in the terminal chamber of the passage, the pCO2 is low and uniform during updraft, when outside air flows to the site through a system of large open galleries. When the airflow reverses direction to downdraft, the chamber is fed by inlets with diverse flow rates and pCO2, which enter via small conduits and fractures embedded in a CO2-rich vadose zone. If the spatial distribution of inlets and outlets produces minimal mixing between low and high pCO2 inflows, high and persistent gradients in pCO2 are formed. Such is the case in the chamber, where vertical gradients of up to 1000 ppm/m are observed during downdraft. The results presented in this work provide new insights into the dynamics and composition of the subsurface atmosphere and demonstrate the importance of long-term and spatially distributed observations.

Investment opportunities for student housing in Europe

2018 ◽  
Vol 36 (6) ◽  
pp. 578-584 ◽  
Author(s):  
Nick French ◽  
Geetha Bhat ◽  
Gurpreet Matharu ◽  
Filipe Ortigão Guimarães ◽  
David Solomon
Keyword(s):  
Student Housing ◽  
European Countries ◽  
Content Type ◽  
Market Requirements ◽  
Investment Opportunities ◽  
Property Markets ◽  
Practical Implications ◽  
Insight Into

Purpose The purpose of this paper is to provide an insight into how the demographic of international and home students in the major university cities in three European countries (France, Spain and Germany) offers investors an opportunity to provide students housing. This paper looks at how a mobile and demanding student clientele now demands, well priced, good quality and purpose built accommodation during their studies at University. This offers a good property investment opportunity. Design/methodology/approach This practice briefing is an overview of the demand factors that are creating opportunities in France, Spain and Germany. Findings This paper analyses the link between the under provision of purpose built student housing and an opportunity to develop a long-term cash flow producing investment asset. Practical implications The role of the property developers and investors is to successfully identify trends and demands and provide the assets that meet the market requirements. This paper looks at the meeting point in three major European countries for this latent and, currently, poorly served demand. Originality/value This provides guidance on how investment opportunities develop in non-traditional property markets.

The utility of relationships in the creation and maintenance of an event portfolio

2018 ◽  
Vol 36 (2) ◽  
pp. 260-275 ◽  
Author(s):  
Donna M. Kelly ◽  
Sheranne Fairley
Keyword(s):  
Process Model ◽  
Structured Interviews ◽  
Content Type ◽  
Key Stakeholders ◽  
Strategic Goals ◽  
The Creation ◽  
Practical Implications ◽  
Insight Into

Purpose Event portfolios promote synergies among events and stakeholders within a destination in order to maximise resources. The purpose of this paper is to examine the role of relationships in the creation and maintenance of an event portfolio using the four stages of Parvatiyar and Sheth’s (2000) process model of relationship marketing: formation, management and governance, performance evaluation, and evolution. Design/methodology/approach Nine semi-structured interviews were conducted with tourism and government stakeholders involved in the creation and maintenance of an event portfolio within a single destination. Findings The destination outlined clear strategic goals through an event strategy. An Events Board was established to bring together key stakeholders from tourism, events, and government to oversee the development of an event portfolio. The Events Board gave advice to relevant tourism and government stakeholders on which events they should provide funding. Developing relationships was not a stated objective, but the Events Board realised the importance of relationships to create and maintain the destination’s event portfolio. Long-term funding contracts were used as a mechanism to establish relationships and were an impetus for interaction. Relationships were also maintained through dedicated staff who managed the relationships between the destination stakeholders and the events. Practical implications Understanding factors that contribute to the successful creation and maintenance of event portfolios can inform destination stakeholders who are responsible for generating tourism through events. Originality/value Limited research has examined the creation and maintenance of event portfolios. This study provides insight into the central importance of relationships in creating and maintaining an event portfolio.

scholarly journals Changes in Foliar Functional Traits of S. pyrenaicus subsp. carpetanus under the Ongoing Climate Change: A Retrospective Survey

Plants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 395
Author(s):  
Rosina Magaña Ugarte ◽  
Adrián Escudero ◽  
Daniel Sánchez Mata ◽  
Rosario G. Gavilán
Keyword(s):  
Stomatal Density ◽  
Weather Conditions ◽  
Plant Performance ◽  
Adaptive Plasticity ◽  
Mountain Areas ◽  
Stomatal Size ◽  
Physiological Approach ◽  
Stomatal Traits

The sensitivity of stomatal behavior and patterning (i.e., distribution, density, size) to environmental stimuli, renders them crucial for defining the physiological performance of leaves. Thus, assessing long-term modifications in stomatal traits in conserved specimens arises as a valuable eco-physiological approach to predict how the rising trend of warmer, drier summers could affect plant fitness; particularly in mountain areas already experiencing climate aggravation and lacking the related monitoring schemes like Mediterranean high-mountains. Variations in foliar and stomatal traits were studied in conserved specimens of Senecio pyrenaicus subsp. carpetanus from Sierra de Guadarrama over the past 71 years. Our findings revealed decreasing trends in leaf width, stomatal size, and increasing tendency in stomatal density, all correlated with the recent 30-year climate exacerbation in these mountains. This evidenced a positive selection favoring traits that allow safeguarding plant performance under drier, hotter weather conditions. The significant relation between stomatal traits and climatic variables upholds the role of stomatal patterning in sensing environmental cues in this species, feasibly optimizing physiological responses involved in the growth–water loss trade-off. The transition to smaller, densely packed stomata observed in recent decades could indicate local-adaptive plasticity in this species, enhancing stomatal response, as coarser environmental conditions take place in Sierra de Guadarrama.

scholarly journals Role of Atmospheric Circulations on Haze Pollution in December 2016

2017 ◽  
Author(s):  
Zhicong Yin ◽  
Huijun Wang
Keyword(s):  
Surface Wind ◽  
Weather Conditions ◽  
Gulf Of Alaska ◽  
Surface Wind Speed ◽  
Control Measures ◽  
Anthropogenic Emissions ◽  
Small Surface ◽  
Atmospheric Circulations ◽  
Haze Pollution

Abstract. In the east of China, recent haze pollution has been severe and damaging. In addition to anthropogenic emissions, atmospheric circulations and local meteorological conditions were conductive factors. The number of December haze days over North China and the Huanghuai area has increased sharply since 2010 and was greatest in 2016. During 2016, the most aggressive control measures for anthropogenic emissions were executed from 16–21 December, but the most severe haze pollution still occurred, covering approximately 25 % of the land area of China and lasting for 6 days. The atmospheric circulations must play critical roles. The associated atmospheric circulations that were verified by climatic correlation analysis were a weaker East Asia jet stream in the upper troposphere, a positive phase of the East Atlantic/West Russia pattern in the middle troposphere and conductive local weather conditions (lower PBL, small surface wind speed, and abundant moisture) near the surface. The influence of sea surface temperature near the Gulf of Alaska and the subtropical eastern Pacific, snow cover in western Siberia and associated physical processes on haze pollution are also discussed.

Unravelling some mysteries of porcine respiratory and reproductive syndrome virus (PRRSV) infections: new insights from modelling studies

2009 ◽  
Vol 2009 ◽  
pp. 30-30
Author(s):  
A Doeschl-Wilson ◽  
I Kyriazakis ◽  
L Galina-Pantoja
Keyword(s):  
Immune Response ◽  
Host Immune Response ◽  
Growing Pigs ◽  
Modelling Studies ◽  
Porcine Respiratory ◽  
Insight Into

Porcine reproductive and respiratory syndrome (PRRS) is an endemic pig disease in most European countries, causing respiratory distress, fever and growth reductions in growing pigs and increased litter mortality in sows. The disease is characterised by exceptionally long-term viral persistence within the host, a weak innate host immune response and delayed adaptive host immune response, and large between animal variation in the immune response (Murtaugh et al., 2004). Although numerous in-vitro and in-vivo studies produced valid insight into the fine details of the virus dynamics and its interaction with the host’s immune response, several fundamental questions concerning the role of diverse immune components and host genetics remain unanswered. In this study mathematical models were developed to investigate the role of diverse processes caused by the virus or the immune response on the infection characteristics.

scholarly journals Consequences of acute and long-term removal of neuromodulatory input on the episodic gastric rhythm of the crab Cancer borealis

2015 ◽  
Vol 114 (3) ◽  
pp. 1677-1692 ◽  
Author(s):  
Albert W. Hamood ◽  
Eve Marder
Keyword(s):  
Pattern Generation ◽  
Stomatogastric Nervous System ◽  
Cancer Borealis ◽  
Cycle Frequency ◽  
Motor Behaviors ◽  
Rhythmic Motor ◽  
Insight Into ◽  
Phase Relationships

For decades, the episodic gastric rhythm of the crustacean stomatogastric nervous system (STNS) has served as an important model system for understanding the generation of rhythmic motor behaviors. Here we quantitatively describe many features of the gastric rhythm of the crab Cancer borealis under several conditions. First, we analyzed spontaneous gastric rhythms produced by freshly dissected preparations of the STNS, including the cycle frequency and phase relationships among gastric units. We find that phase is relatively conserved across frequency, similar to the pyloric rhythm. We also describe relationships between these two rhythms, including a significant gastric/pyloric frequency correlation. We then performed continuous, days-long extracellular recordings of gastric activity from preparations of the STNS in which neuromodulatory inputs to the stomatogastric ganglion were left intact and also from preparations in which these modulatory inputs were cut (decentralization). This allowed us to provide quantitative descriptions of variability and phase conservation within preparations across time. For intact preparations, gastric activity was more variable than pyloric activity but remained relatively stable across 4–6 days, and many significant correlations were found between phase and frequency within animals. Decentralized preparations displayed fewer episodes of gastric activity, with altered phase relationships, lower frequencies, and reduced coordination both among gastric units and between the gastric and pyloric rhythms. Together, these results provide insight into the role of neuromodulation in episodic pattern generation and the extent of animal-to-animal variability in features of spontaneously occurring gastric rhythms.

scholarly journals Observation Based Budget and Lifetime of Excess Atmospheric Carbon Dioxide

2021 ◽  
Author(s):  
Stephen E. Schwartz
Keyword(s):  
Mixed Layer ◽  
Atmospheric Carbon Dioxide ◽  
Deep Ocean ◽  
Compartment Model ◽  
Turnover Time ◽  
Atmospheric Co2 ◽  
Anthropogenic Emissions ◽  
Terrestrial Biosphere ◽  
Subsequent Decrease ◽  
Tightly Coupled

Abstract. The global budgets of CO2 and of excess CO2 (i.e., above preindustrial) in the biogeosphere are examined by a top-down, observationally constrained approach. Global stocks in the atmosphere, mixed-layer and deep ocean, and labile and obdurate terrestrial biosphere, and fluxes between them are quantified; total uptake of carbon by the terrestrial biosphere is constrained by observations, but apportionment to the two terrestrial compartments is only weakly constrained, requiring examination of sensitivity to this apportionment. Because of near equilibrium between the atmosphere and the mixed-layer ocean and near steady state between the atmosphere and the labile biosphere, these three compartments are tightly coupled. For best-estimate present-day anthropogenic emissions the turnover time of excess carbon in these compartments to the deep ocean and obdurate biosphere is 67 to 158 years. Atmospheric CO2 over the Anthropocene is accurately represented by a five-compartment model with four independent parameters: two universal geophysical quantities and two, specific to CO2, treated as variable. The model also accurately represents atmospheric radiocarbon, particularly the large increase due to atmospheric testing of nuclear weapons and the subsequent decrease. The adjustment time of excess atmospheric CO2, evaluated from the rate of decrease following abrupt cessation of emissions, is 78 to 140 years, consistent with the turnover time, approaching a long-time floor of 15–20 % of the value at the time of cessation. The lifetime of excess CO2 found here, several-fold shorter than estimates from current carbon-cycle models, indicates that cessation of anthropogenic emissions atmospheric would result in substantial recovery of CO2 toward its preindustrial value in less than a century.

scholarly journals Experiencing climate change: revisiting the role of local weather in affecting climate change awareness and related policy preferences

2021 ◽  
Vol 167 (3-4) ◽  
Author(s):  
Lea Gärtner ◽  
Harald Schoen
Keyword(s):  
Climate Change ◽  
Fixed Effects ◽  
Reference Frames ◽  
Weather Conditions ◽  
Policy Preferences ◽  
Weather Data ◽  
Standard Errors ◽  
Theoretical Argument ◽  
Local Weather

AbstractOver the last few years, climate change has risen to the top of the agenda in many Western democracies, backed by a growing share of voters supporting climate protection policies. To understand how and why these changes came about, we revisit the question whether personal experiences with increasingly unusual local weather conditions affect people’s beliefs about climate change and their related attitudes. We first take a closer look at the theoretical underpinnings and extend the theoretical argument to account for the differential impact of different weather phenomena, as well as the role of prior beliefs and individual reference frames. Applying mixed-effects regressions to a novel dataset combining individual-level multi-wave panel survey data from up to 18,010 German voters collected from 2016 to 2019 with weather data from 514 weather stations, we show that personally experiencing unusual or extreme local weather did not shape people’s awareness of climate change as a political problem or their climate policy preferences in a sustained manner. Even among people who may be considered most likely to exhibit such effects, we did not detect them. Moreover, we demonstrate that the common modeling strategy of combining fixed-effects regression with clustered standard errors leads to severely reduced standard errors and substantively different results. We conclude that it cannot be taken for granted that personally experiencing extreme weather phenomena makes a difference in perceptions of climate change and related policy preferences.

scholarly journals CO2 Dynamics and Heterogeneity in a Cave Atmosphere: Role of Ventilation Patterns and Airflow Pathways

2021 ◽  
Author(s):  
Lovel Kukuljan ◽  
Franci Gabrovsek ◽  
Matthew D. Covington ◽  
Vanessa E. Johnston
Keyword(s):  
Temporal Variations ◽  
Observation Point ◽  
Spatially Distributed ◽  
Combined Action ◽  
Karst Systems ◽  
The Relationship ◽  
Co2 Dynamics ◽  
Global Carbon

Abstract Understanding the dynamics and distribution of CO2 in the subsurface atmosphere of carbonate karst massifs provides important insights into dissolution and precipitation processes, the role of karst systems in the global carbon cycle, and the use of speleothems for paleoclimate reconstructions. We discuss long-term microclimatic observations in a passage of Postojna Cave, Slovenia, focusing on high spatial and temporal variations of pCO2. We show 1) that the airflow through the massif is determined by the combined action of the chimney effect and external winds and 2) that the relationship between the direction of the airflow, the geometry of the airflow pathways, and the position of the observation point explains the observed variations of pCO2. Namely, in the terminal chamber of the passage, the pCO2 is low and uniform during updraft, when outside air flows to the site through a system of large open galleries. When the airflow reverses direction to downdraft, the chamber is fed by inlets with diverse flow rate and pCO2, which enter via small conduits and fractures embedded in a CO2-rich vadose zone. If the spatial distribution of inlets and outlets produces minimal mixing between low and high pCO2 inflows, high and persistent gradients in pCO2 are formed. Such is the case in the chamber, where vertical gradients of up to 1000 ppm/m is observed during downdraft. The results presented in this work provide new insights into the dynamics and composition of the subsurface atmosphere and demonstrate the importance of long-term and spatially distributed observations.

Sign in / Sign up

Export Citation Format

Share Document