The Crypto Market Ecosystem has emerged as the most profound application of blockchain technology in finance. This textbook adopts an integrated approach, linking traditional functions of the current ...financial system (payments, traded assets, fundraising, regulation) with the respective functions in the crypto market, in order to facilitate the reader in their understanding of how this new ecosystem works.
The book walks the reader through the main features of the blockchain technology, the definitions, classifications, and distinct characteristics of cryptocurrencies and tokens, how these are evaluated, how funds are raised in the cryptocurrency ecosystem (ICOs), and what the main regulatory approaches are. The authors have compiled more than 100 sources from different sub-fields of economics, finance, and regulation to create a coherent textbook that provides the reader with a clear and easily understandable picture of the new world of encrypted finance and its applications.
The book is primarily aimed at business and finance students, who already have an understanding of the basic principles of how the financial system works, but also targets a more general readership, by virtue of its broader scope and engaging and accessible tone.
Arctic warming leading to reduced summertime sea-ice is likely to lead to increased local shipping especially along the Northeast Passage near the northern coasts of Norway and Russia, which are ...shorter than the traditional southerly routes. Here, the regional chemistry-transport model WRF-Chem is used to examine the effects of shipping emissions on levels of air pollutants and deposition fluxes over the Barents Sea both for present-day and future conditions, based on a high growth scenario. Present-day shipping emissions are found to have already substantial effects on ozone concentrations, but limited effects on sulphate and nitrate aerosols. Predicted future changes in ozone are also important, particularly in regions with low nitrogen oxide concentrations, and results are sensitive to the way in which diversion shipping is distributed due to non-linear effects on photochemical ozone production. Whilst modest future increases in sulphate and nitrate aerosols are predicted, large enhancements in dry deposition of sulphur dioxide and wet deposition of nitrogen compounds to the Barents Sea are predicted. Such levels of future nitrogen deposition would represent a significant atmospheric source of oceanic nitrogen affecting sensitive marine ecosystems.
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•Research highlight 1: Arctic shipping releases large amounts of aerosols and ozone over the Barents Sea.•Research highlight 2: Arctic shipping will substantially increase nitrogen and sulphur deposition.•Research highlight 3: Future ozone increases are sensitive to spatial extent of shipping diversion routes.
We introduce and evaluate aerosol simulations with the global aerosol–climate model ECHAM6.3–HAM2.3, which is the aerosol component of the fully coupled aerosol–chemistry–climate model ECHAM–HAMMOZ. ...Both the host atmospheric climate model ECHAM6.3 and the aerosol model HAM2.3 were updated from previous versions. The updated version of the HAM aerosol model contains improved parameterizations of aerosol processes such as cloud activation, as well as updated emission fields for anthropogenic aerosol species and modifications in the online computation of sea salt and mineral dust aerosol emissions. Aerosol results from nudged and free-running simulations for the 10-year period 2003 to 2012 are compared to various measurements of aerosol properties. While there are regional deviations between the model and observations, the model performs well overall in terms of aerosol optical thickness, but may underestimate coarse-mode aerosol concentrations to some extent so that the modeled particles are smaller than indicated by the observations. Sulfate aerosol measurements in the US and Europe are reproduced well by the model, while carbonaceous aerosol species are biased low. Both mineral dust and sea salt aerosol concentrations are improved compared to previous versions of ECHAM–HAM. The evaluation of the simulated aerosol distributions serves as a basis for the suitability of the model for simulating aerosol–climate interactions in a changing climate.
During the last 30 years, significant effort has been made to improve air quality through legislation for emissions reduction. Global three-dimensional chemistrytransport simulations of atmospheric ...composition over the past 3 decades have been performed to estimate what the air quality levels would have been under a scenario of stagnation of anthropogenic emissions per capita as in 1980, accounting for the population increase (BA1980) or using the standard practice of neglecting it (AE1980), and how they compare to the historical changes in air quality levels. The simulations are based on assimilated meteorology to account for the yearto- year observed climate variability and on different scenarios of anthropogenic emissions of pollutants. The ACCMIP historical emissions dataset is used as the starting point. Our sensitivity simulations provide clear indications that air quality legislation and technology developments have limited the rapid increase of air pollutants. The achieved reductions in concentrations of nitrogen oxides, carbon monoxide, black carbon, and sulfate aerosols are found to be significant when comparing to both BA1980 and AE1980 simulations that neglect any measures applied for the protection of the environment. We also show the potentially large tropospheric air quality benefit from the development of cleaner technology used by the growing global population. These 30-year hindcast sensitivity simulations demonstrate that the actual benefit in air quality due to air pollution legislation and technological advances is higher than the gain calculated by a simple comparison against a constant anthropogenic emissions simulation, as is usually done. Our results also indicate that over China and India the beneficial technological advances for the air quality may have been masked by the explosive increase in local population and the disproportional increase in energy demand partially due to the globalization of the economy.
Emission inventories (EIs) are vital for air quality modeling. Specific research goals often require modifying EIs from diverse data sources, demanding significant code development. In this study, we ...utilized and further developed the High Elective Resolution Modeling Emission System version three for Global and Regional domains (HERMESv3_gr). This user-friendly processing system was adapted for generating EIs compatible with the Chemistry Transport Model Tracel Model 5 Massive Parallel (TM5-MP). The results indicate that HERMESv3_gr is capable of generating EIs with negligible biases (10−7 relative differences) for TM5-MP, showcasing its effectiveness. We applied HERMESv3_gr to integrate the EI Regional Emission inventory in Asia (REAS) into the global EI Community Emission Data System (CEDS). Comparison of model results using CEDS alone and the integrated EI against measurement data for various pollutants globally revealed small improvements for carbon monoxide (1%) ethane (1–2%), and nitrogen oxide (2%) and larger for propane (5–7%). Ozone in the northern hemisphere improved by about 2% while in the southern hemisphere improvements of 5% could be observed. Our findings highlight the importance of carefully considering the effects of EI integration for accurate air quality modeling.
Pituitary adenylate cyclase-activating polypeptide (PACAP) regulates plasticity in brain systems underlying arousal and memory and is associated with posttraumatic stress disorder (PTSD). Research in ...animal models suggests that PACAP modulates entorhinal cortex (EC) input to the hippocampus, contributing to impaired contextual fear conditioning. In PTSD, PACAP is associated with higher activity of the amygdala to threat stimuli and lower functional connectivity of the amygdala and hippocampus. However, PACAP-affiliated structural alterations of these regions have not been investigated in PTSD. Here, we examined whether peripheral PACAP levels were associated with neuronal morphology of the amygdala and hippocampus (primary analyses), and EC (secondary) using Neurite Orientation Dispersion and Density Imaging.
Sixty-four (44 female) adults (19 to 54 years old) with DSM-5 Criterion A trauma exposure completed the Clinician-Administered PTSD Scale (CAPS-5), a blood draw, and magnetic resonance imaging. PACAP38 radioimmunoassay was performed and T1-weighted and multi-shell diffusion-weighted images were acquired. Neurite Density Index (NDI) and Orientation Dispersion Index (ODI) were quantified in the amygdala, hippocampus, and EC. CAPS-5 total score and anxious arousal score were used to test for clinical associations with brain structure.
Higher PACAP levels were associated with greater EC NDI (
= 0.0099,
= 0.032) and lower EC ODI (
= -0.0073,
= 0.047), and not hippocampal or amygdala measures. Neither EC NDI nor ODI was associated with clinical measures.
Circulating PACAP levels were associated with altered neuronal density of the EC but not the hippocampus or amygdala. These findings strengthen evidence that PACAP may impact arousal-associated memory circuits in PTSD.
In this paper, we present the implementation and evaluation of the
aerosol microphysics module SALSA2.0 in the framework of the
aerosol–chemistry–climate model ECHAM-HAMMOZ. It is an alternative
...microphysics module to the default modal microphysics scheme M7 in
ECHAM-HAMMOZ. The SALSA2.0 implementation within ECHAM-HAMMOZ is evaluated
against observations of aerosol optical properties, aerosol mass, and size
distributions, comparing also to the skill of the M7 implementation. The
largest differences between the implementation of SALSA2.0 and M7 are in the
methods used for calculating microphysical processes, i.e., nucleation,
condensation, coagulation, and hydration. These differences in the
microphysics are reflected in the results so that the largest differences
between SALSA2.0 and M7 are evident over regions where the aerosol size
distribution is heavily modified by the microphysical processing of aerosol
particles. Such regions are, for example, highly polluted regions and regions
strongly affected by biomass burning. In addition, in a simulation of the
1991 Mt. Pinatubo eruption in which a stratospheric sulfate plume was formed,
the global burden and the effective radii of the stratospheric aerosol are
very different in SALSA2.0 and M7. While SALSA2.0 was able to reproduce the
observed time evolution of the global burden of sulfate and the effective
radii of stratospheric aerosol, M7 strongly overestimates the removal of
coarse stratospheric particles and thus underestimates the effective radius
of stratospheric aerosol. As the mode widths of M7 have been optimized for
the troposphere and were not designed to represent stratospheric aerosol, the
ability of M7 to simulate the volcano plume was improved by modifying the
mode widths, decreasing the standard deviations of the accumulation and coarse
modes from 1.59 and 2.0, respectively, to 1.2 similar to what was observed
after the Mt. Pinatubo eruption. Overall, SALSA2.0 shows promise in improving
the aerosol description of ECHAM-HAMMOZ and can be further improved by
implementing methods for aerosol processes that are more suitable for the
sectional method, e.g., size-dependent emissions for aerosol species and size-resolved wet deposition.
Anthropogenic nitrogen (N) emissions to the atmosphere have increased significantly the deposition of nitrate (NO
) and ammonium (NH
) to the surface waters of the open ocean, with potential impacts ...on marine productivity and the global carbon cycle. Global-scale understanding of the impacts of N deposition to the oceans is reliant on our ability to produce and validate models of nitrogen emission, atmospheric chemistry, transport and deposition. In this work, ~2900 observations of aerosol NO
and NH
concentrations, acquired from sampling aboard ships in the period 1995 - 2012, are used to assess the performance of modelled N concentration and deposition fields over the remote ocean. Three ocean regions (the eastern tropical North Atlantic, the northern Indian Ocean and northwest Pacific) were selected, in which the density and distribution of observational data were considered sufficient to provide effective comparison to model products. All of these study regions are affected by transport and deposition of mineral dust, which alters the deposition of N, due to uptake of nitrogen oxides (NO
) on mineral surfaces. Assessment of the impacts of atmospheric N deposition on the ocean requires atmospheric chemical transport models to report deposition fluxes, however these fluxes cannot be measured over the ocean. Modelling studies such as the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP), which only report deposition flux are therefore very difficult to validate for dry deposition. Here the available observational data were averaged over a 5° × 5° grid and compared to ACCMIP dry deposition fluxes (ModDep) of oxidised N (NO
) and reduced N (NH
) and to the following parameters from the TM4-ECPL (TM4) model: ModDep for NO
, NH
and particulate NO
and NH
, and surface-level particulate NO
and NH
concentrations. As a model ensemble, ACCMIP can be expected to be more robust than TM4, while TM4 gives access to speciated parameters (NO
and NH
) that are more relevant to the observed parameters and which are not available in ACCMIP. Dry deposition fluxes (CalDep) were calculated from the observed concentrations using estimates of dry deposition velocities. Model - observation ratios, weighted by grid-cell area and numbers of observations, (R
) were used to assess the performance of the models. Comparison in the three study regions suggests that TM4 over-estimates NO
concentrations (R
= 1.4 - 2.9) and under-estimates NH
concentrations (R
= 0.5 - 0.7), with spatial distributions in the tropical Atlantic and northern Indian Ocean not being reproduced by the model. In the case of NH
in the Indian Ocean, this discrepancy was probably due to seasonal biases in the sampling. Similar patterns were observed in the various comparisons of CalDep to ModDep (R
= 0.6 - 2.6 for NO
, 0.6 - 3.1 for NH
). Values of R
for NH
CalDep - ModDep comparisons were approximately double the corresponding values for NH
CalDep - ModDep comparisons due to the significant fraction of gas-phase NH
deposition incorporated in the TM4 and ACCMIP NH
model products. All of the comparisons suffered due to the scarcity of observational data and the large uncertainty in dry deposition velocities used to derive deposition fluxes from concentrations. These uncertainties have been a major limitation on estimates of the flux of material to the oceans for several decades. Recommendations are made for improvements in N deposition estimation through changes in observations, modelling and model - observation comparison procedures. Validation of modelled dry deposition requires effective comparisons to observable aerosol-phase species concentrations and this cannot be achieved if model products only report dry deposition flux over the ocean.
Abstract
Terrestrial vegetation emits vast amounts of monoterpenes into the atmosphere, influencing ecological interactions and atmospheric chemistry. Global emissions are simulated as a function of ...temperature with a fixed exponential relationship (β coefficient) across forest ecosystems and environmental conditions. We applied meta-analysis algorithms on 40 years of published monoterpene emission data and show that relationship between emissions and temperature is more sensitive and intricate than previously thought. Considering the entire dataset, a higher temperature sensitivity (β = 0.13 ± 0.01 °C
−1
) is derived but with a linear increase with the reported coefficients of determination (R
2
), indicating that co-occurring environmental factors modify the temperature sensitivity of the emissions that is primarily related to the specific plant functional type (PFT). Implementing a PFT-dependent β in a biogenic emission model, coupled with a chemistry – climate model, demonstrated that atmospheric processes are exceptionally dependent on monoterpene emissions which are subject to amplified variations under rising temperatures.
This work documents and evaluates the tropospheric
gas-phase chemical mechanism MOGUNTIA in the three-dimensional chemistry
transport model TM5-MP. Compared to the modified CB05 (mCB05) chemical
...mechanism previously used in the model, MOGUNTIA includes a detailed
representation of the light hydrocarbons (C1–C4) and isoprene, along with a
simplified chemistry representation of terpenes and aromatics. Another
feature implemented in TM5-MP for this work is the use of the Rosenbrock
solver in the chemistry code, which can replace the classical Euler backward
integration method of the model. Global budgets of ozone (O3), carbon
monoxide (CO), hydroxyl radicals (OH), nitrogen oxides (NOx), and
volatile organic compounds (VOCs) are analyzed, and their mixing ratios are
compared with a series of surface, aircraft, and satellite observations for
the year 2006. Both mechanisms appear to be able to satisfactorily represent
observed mixing ratios of important trace gases, with the MOGUNTIA chemistry
configuration yielding lower biases than mCB05 compared to measurements in
most of the cases. However, the two chemical mechanisms fail to reproduce
the observed mixing ratios of light VOCs, indicating insufficient primary
emission source strengths, oxidation that is too fast, and/or a low bias in the
secondary contribution to C2–C3 organics via VOC atmospheric oxidation.
Relative computational memory and time requirements of the different model
configurations are also compared and discussed. Overall, the MOGUNTIA scheme
simulates a large suite of oxygenated VOCs that are observed in the
atmosphere at significant levels. This significantly expands the possible
applications of TM5-MP.
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