Current Intensification Research Articles

Bridging the gap between an isolated nanochannel and a communicating multipore heterogeneous membrane

To bridge the gap between single and isolated pore systems to multipore systems, such as membranes and electrodes, we studied an array of nanochannels with varying interchannel spacing that controlled the degree of channel communication. Instead of treating them as individual channels connected in parallel or an assembly like a homogeneous membrane, this study resolves the pore-pore interaction. We found that increased channel isolation leads to current intensification, whereas at high voltages electroconvective effects control the degree of communication via suppression of the diffusion layer growth.

Natural powers: from the bio-economy to the eco-economy and sustainable place-making

The current intensification of efforts to develop post-carbon solutions to the global food/energy security problems is developing a highly contested policy/technology/production/consumption arena. The paper examines how current attempts to resolve these new productivist priorities are embedded in combinations of sustainability, security, sovereignty and resource governance concerns. These concerns are coming together with the new contested framings of the bio-economy and the eco-economy. The framings hold different implications for social and spatial development. The paper argues that it is important to apply and connect a critical ‘post normal’ sustainability science approach to developing the place-making properties of the eco-economy model, as well as examining the implications of the wider and more dominant bio-economic framing. The analysis shows that to achieve synergies between sustainability, security, sovereignty and effective resource governance, a more place-based eco-economic model needs to be progressed.

Observed geomagnetic induction effect on Dst-related magnetic observations under different disturbance intensities of the magnetospheric ring current

Based on the spherical harmonic expansion of geomagnetic disturbance observed on the mid-latitude surface of the Earth, external and internal field separation is conducted in which the external component is magnetic disturbance caused by the magnetospheric ring current and the internal component is that raised by the correspondingly induced currents within the Earth. The objectives are to evaluate the influences of the induced internal field on the surface magnetic observations and to reveal the response performance of internal geomagnetic induction under different strengths of magnetospheric ring current fluctuations for better understanding of the disturbance storm time (Dst) index variations. The results show that the ratio of the internal component to surface observation does not remain constant in storm time. During the main phase of the storm, the ratio variation follows the pattern of logarithmic growth with storm evolution up to the top value at the Dst-minimum; then, the ratio slowly decreases in the long recovery phase. Multiple small logarithmic growths are superimposed on the traces of internal ratios, corresponding to temporary ring current intensification during the storm main phase and amplifying the effect of this intensification on surface magnetic observations. With the intensification of magnetospheric storms from the level of (−200 nT, − 100 nT) to (−300 nT, − 200 nT) and (−500 nT, − 300 nT) classified with the Dst-minimum, the top value of the ratio averaged for each storm group in the superposed epoch analysis method increases from the value of 0.295 ± 0.014 to 0.300 ± 0.016 and 0.308 ± 0.015, respectively. It is demonstrated that the geomagnetic induction exceeds the linear relation with the intensification of the external field, which is physically reasonable and coincident with the Faraday’s law of induction. Due to the effects of high induction of the oceans and lateral heterogeneity of electric conductivity distribution in the upper mantle of the Earth, the geomagnetic induction and its contribution to surface geomagnetic disturbance vary significantly among observatories. This factor should be considered in the research of magnetospheric current systems.

The assessment of the impact of oil palm and rubber plantations on the biotic and abiotic properties of tropical peat swamp soil in Indonesia

Current intensification of agricultural activities in Indonesia has led to increased use of tropical peat swamp forests for agriculture. Ideally, peat swamp ecosystems should not be disturbed as they provide essential services such as soil erosion control, ecosystem stabilization and moderation of climate and energy fluxes as well as reducing carbon emission and conserving biodiversity. In this study, agricultural land from Giam Siak Kecil–Bukit Batu Biosphere Reserve in Indonesia was evaluated to assess the impact of oil palm (burning and without burning) and rubber (5–10 and >40 years old) plantations on soil properties through comparisons with soils from a natural forest (NF). Substantial changes in the physico-chemical properties of soils from both plantations were observed including significant reductions in soil organic matter (4–18%) and water holding capacity (22–53%), but an increase in bulk density (ρb) (0.08–0.17 g cm−3). A significant increase in bacterial biomass was also observed following conversion of the NF to plantation (p<0.05). However, the oil palm plantation (OPP) (without burning) showed reduced microbial activities and the lowest Shannon diversity values (2.90) compared to other samples. Community-level physiological profiling showed impaired community function only in soils from the OPP but higher CO2 exchange rates in most plantation soils. Soils from the rubber plantation (RP) were less impaired in terms of their natural function and therefore RPs appeared to be more suitable for sustainable agricultural use than OPP.

Depositional characteristics and processes of alongslope currents related to a seamount on the northwestern margin of the Northwest Sub-Basin, South China Sea

This study infers, from 2D seismic data, the presence of a seamount-related deep-water contourite depositional system, located on the northwestern margin of the Northwest Sub-Basin of the South China Sea. Alongslope aligned erosive features and contourite drifts developed in water depths between 1000 and 1500 m on the present seafloor. A moat formed north of the seamount as a result of bottom current intensification after being deflected by an obstacle morphology, indicating a major eastward flowing current. Due to the Coriolis deflection, an elongated-mounded drift developed to the north of the moat and a modest plastered drift to the south (onlapping the north side of the seamount). Bottom currents away from the seamount are less or minimally intensified, generating contourite channels and furrows over the drift to the north of the moat. Combined with the known oceanographic setting, the bottom currents could belong to the anticyclonic South China Sea Intermediate Water circulation. From the seismic data, the architecture of contourite deposits during progressive burial of the seamount is documented. The first appearance of contourite channels in seismic Unit 1 is inferred to be the onset of the contourite depositional system, which could be traced back to the early Late Miocene. The following aggradational pattern of this system, from the base of seismic Unit 2 onwards, indicates relatively enhanced and stable South China Sea Intermediate Water circulation occurring on the northwestern margin of the northern South China Sea. Subsequently, the behaviour and depositional processes of bottom currents upstream and downstream the seamount are discussed. The depositional model suggests that a complex contourite channel system will replace the former moat-drift system once the seamount is buried. Finally, our findings may provide new challenges for investigating the South China Sea Cenozoic palaeoceanography, which are helpful to understand the sedimentary dynamic processes related to the South China Sea deepwater circulation. (C) 2014 Elsevier B.V. All rights reserved.

Introduction to the special section on Sun‐Earth system response to extreme solar and seismic events

Introduction to the special section on Sun‐Earth system response to extreme solar and seismic events

Forced reconnection in the near magnetotail: Onset and energy conversion in PIC and MHD simulations

Using two‐dimensional particle‐in‐cell (PIC) together with magnetohydrodynamic (MHD) simulations of magnetotail dynamics, we investigate the evolution toward onset of reconnection and the subsequent energy transfer and conversion. In either case, reconnection onset is preceded by a driven phase, during which magnetic flux is added to the tail at the high‐latitude boundaries, followed by a relaxation phase, during which the configuration continues to respond to the driving. The boundary deformation leads to the formation of thin embedded current sheets, which are bifurcated in the near tail, converging to a single sheet farther out in the MHD simulations. The thin current sheets in the PIC simulation are carried by electrons and are associated with a strong perpendicular electrostatic field, which may provide a connection to parallel potentials and auroral arcs and an ionospheric signal even prior to the onset of reconnection. The PIC simulation very well satisfies integral entropy conservation (intrinsic to ideal MHD) during this phase, supporting ideal ballooning stability. Eventually, the current intensification leads to the onset of reconnection, the formation and ejection of a plasmoid, and a collapse of the inner tail. The earthward flow shows the characteristics of a dipolarization front: enhancement of Bz, associated with a thin vertical electron current sheet in the PIC simulation. Both MHD and PIC simulations show a dominance of energy conversion from incoming Poynting flux to outgoing enthalpy flux, resulting in heating of the inner tail. Localized Joule dissipation plays only a minor role.

Anxious Settler Belonging: Actualising the Potential for Making Resilient Postcolonial Subjects

When I arrived in Aurukun, west Cape York, it was the heat that struck me first, knocking city pace from my body, replacing it with a languor familiar to my childhood, although hea more northern. Fieldwork brings with it its own delights and anxieties. It is where I feel competent and incompetent, where I am most indebted and thankful for the generosity kindness of strangers. I love the way “no-where” places quickly become somewhere and some to me. Then there are the bodily visitations: a much younger self haunts my body. At time adult self abandons me, leaving me nothing but an awkward adolescent: clumsy, sweaty, too m body, too white, too urban, too disconnected or unable to interpret the social rules. My body in that this is not my home, but home for Wik and Wik Way people. Flailing about unmoored from socio-cultural system that I take for granted, and take comfort from – and I draw sustena Anxiety circles, closes in on me, who grows distant and unsure, fragmented. Misusing Deborah Rose, I’m tempted to say I’m separated from my nourishing terrain. Indeed it can feel like nation (not the country) slipped out from under my feet.

Intensification of Geostrophic Currents in the Canada Basin, Arctic Ocean

Abstract Continuous sampling of upper-ocean hydrographic data in the Canada Basin from various sources spanning from 2003 through 2011 provides an unprecedented opportunity to observe changes occurring in a major feature of the Arctic Ocean. In a 112-km-radius circle situated near the center of the traditional Beaufort Gyre, geopotential height referenced to 400 dbar increased by about 0.3 gpm from 2003 to 2011, and by the end of the period had increased by about 65% from the climatological value. Near the edges of the domain considered, the anomalies in dynamic height are much smaller, indicating steeper gradients. A rough dynamic topography constructed from profiles collected between 2008 and 2011 shows the center of the gyre to have shifted south by about 2° in latitude, along the 150°W meridian. Geostrophic currents are much stronger on the periphery of the gyre, reaching amplitudes 5–6 times higher than climatological values at grid points just offshore from the Beaufort and Chukchi shelf slopes. Estimates of residual buoy drift velocity after removing the expected wind-driven component are consistent with surface geostrophic currents calculated from hydrographic data. A three-decade time series of integrated ocean surface stress curl during late summer near the center of the Beaufort Gyre shows a large increase in downward Ekman pumping on decadal scales, emphasizing the importance of atmospheric forcing in the recent accumulation of freshwater in the Canada Basin. Geostrophic current intensification appears to have played a significant role in the recent disappearance of old ice in the Canada Basin.

The Black Sea level trends from tide gages and satellite altimetry

Obtained are the estimates of the Black Sea level trends for the period of 1992–2005 as derived from the tide-gage and satellite altimetry data. An estimated rate of the mean sea level rate calculated from the averaged altimetry data is 7.6 ± 0.3 mm/year that is by 2–3 times higher than the estimates for the previous periods. Such high values of the trend are evidently associated with the sea level variability features at the 10-year temporal scale. The Black Sea level trend is characterized by the high spatial variability: it amounts to 8–9.5 mm/year in the coastal areas of the Black Sea basin that exceeds the trend in the deep-water part by 1.5–2 times (4.5–6 mm/year). Such distribution is an effect of the cyclonic Rim Current intensification. Based on the difference in the sea level trends obtained from in-situ and altimetry measurements, the velocity of the vertical crustal motion is estimated for the Ukrainian coastal stations of the Black Sea.

Geometry of duskside equatorial current during magnetic storm main phase as deduced from magnetospheric and low-altitude observations

Abstract. We present the results of a coordinated study of the moderate magnetic storm on 22 July 2009. The THEMIS and GOES observations of magnetic field in the inner magnetosphere were complemented by energetic particle observations at low altitude by the six NOAA POES satellites. Observations in the vicinity of geosynchronous orbit revealed a relatively thin (half-thickness of less than 1 RE) and intense current sheet in the dusk MLT sector during the main phase of the storm. The total westward current (integrated along the z-direction) on the duskside at r ~ 6.6 RE was comparable to that in the midnight sector. Such a configuration cannot be adequately described by existing magnetic field models with predefined current systems (error in B &gt; 60 nT). At the same time, low-altitude isotropic boundaries (IB) of &gt; 80 keV protons in the dusk sector were shifted ~ 4° equatorward relative to the IBs in the midnight sector. Both the equatorward IB shift and the current strength on the duskside correlate with the Sym-H* index. These findings imply a close relation between the current intensification and equatorward IB shift in the dusk sector. The analysis of IB dispersion revealed that high-energy IBs (E &gt; 100 keV) always exhibit normal dispersion (i.e., that for pitch angle scattering on curved field lines). Anomalous dispersion is sometimes observed in the low-energy channels (~ 30–100 keV). The maximum occurrence rate of anomalous dispersion was observed during the main phase of the storm in the dusk sector.

Variability of Air-Sea CO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; Fluxes and Dissolved Inorganic Carbon Distribution in the Atlantic Basin: A Coupled Model Analysis

The biogeochemical dynamics of carbon in the ocean is a subject of fundamental interest to environmental studies. In this context, we have implemented a ten year run of the Brazilian Earth System Coupled Ocean-Atmosphere Model (BESM-OA2.3) integrated with TOPAZ biogeochemical model for the Atlantic basin. The modeled ΔpCO2 for the tropical Atlantic shows very clearly a high dominance of positive fluxes, that is, the CO2 fluxes are sea-to-air throughout the tropical region and for both winter and summer periods. In the mid-latitudes regions negatives fluxes (air-to-sea) were observed for both seasons. An exception to this pattern is an extensive negative tongue on the latitude 10N. The occurrence of this negative ΔpCO2 tongue region in the Tropical Atlantic is highly correlated to negative Evaporation-Precipitation values during this season. In the northern hemisphere (NH) summer the negative values of ΔpCO2 in the tropical Atlantic region are concentrated in the adjacent zone of the Amazon river mouth due to the North Equatorial Counter Current intensification. This process favors the formation of a carbon sink in the adjacent region of the Amazon river mouth. Model results show lowest values of dissolved inorganic carbon (DIC) in a surface layer (100 - 150 m). Highest DIC values are observed in deeper layers and concentrated in an equatorial band. The chlorophyll bloom in equatorial zones was well represented by the model. These blooms are the result of equatorial upwelling that brings the high concentration tongues of DIC present in the equatorial band towards the euphotic zone. This is the first published paper about the BESM-OA2.3 integrated with TOPAZ. The presented results suggest that this modeling system is able to reproduce the main regional carbon dynamics features of the mid-latitude/tropical Atlantic.

Mesoscale eddies in the northeastern Pacific tropical‐subtropical transition zone: Statistical characterization from satellite altimetry

Mesoscale eddies in the northeastern Pacific tropical‐subtropical transition zone (16°N–30°N; 130°W–102°W) are analyzed using nearly 18 years of satellite altimetry and an automated eddy‐identification algorithm. Eddies that lasted more than 10 weeks are described based on the analysis of 465 anticyclonic and 529 cyclonic eddy trajectories. We found three near‐coastal eddy‐prolific areas: (1) Punta Eugenia, (2) Cabo San Lucas, and (3) Cabo Corrientes. These three areas are located in places where the coastal morphology changes abruptly and strong surface current intensification occurs at some phase of the seasonal cycle. Although mesoscale eddies in these areas have been previously reported, this study provides their first statistically supported characterization. Punta Eugenia showed the highest eddy production (with more cyclones generated), followed by Cabo Corrientes (also with more cyclones) and Cabo San Lucas (with more anticyclones). Cabo Corrientes eddies showed the highest mean values in propagation speed, swirling speed and eddy kinetic energy, whereas Punta Eugenia eddies showed the lowest values. Cyclonic eddies increased their distance traveled and duration from south to north; in contrast anticyclonic eddies increased from north to south. In average, anticyclones tend to travel faster than cyclones in all the subregions. These long‐lived eddies were mainly nonlinear and therefore can redistribute coastal waters relatively far into the open ocean. The peaks in the seasonal signal of eddy generation can be associated with the peaks in the strength of the offshore currents and/or in the Coastal Upwelling Index. No clear relationship could be established between El Niño events and eddy generation.

The global financial crisis and health equity: toward a conceptual framework

In this article, we identify pathways that link the global financial crisis to health equity. We distinguish between direct and indirect channels of influence, and develop a conceptual model that builds on the literature analyzing the impacts of globalization on social determinants of health. The most pertinent direct pathways discussed are economic contraction, health budget cutbacks, rise in unemployment, and qualitative transformations of health systems. We also outline how other indirect channels of influence are likely to affect health equity, including cutbacks to welfare programs, labor market transformations, the emergence of an ideological climate conducive to austerity politics, and reductions in official development assistance. We conclude by suggesting that the current intensification of neoliberal policy implementation is likely to undermine health equity, and that a different path toward economic recovery is required to ensure equitable access to health care.

Transformative learning in troubling times: investing in hope

PurposeThe purpose of this paper is to disenchant advocates of sustainability of the current form of capitalism and to argue that under current intensification of globalisation of economic and political efforts, “privilege” and “alienation” might be relocated/rearranged/redistributed but that the basic dynamic will remain constant. The very poor and vulnerable appear to be treated as collateral damage by capitalist practices reified as “The Market” and which we have personified as “The Master”.Design/methodology/approachThe authors draw on the metaphor of subaltern studies to amplify their call for further discussion. Portraying the economic system as The (ruthless) Master invites further conversation about complicity or subjugation and invites reflection on alternatives to associated agency.FindingsThe Master's powers are amplifying globally. He continues to demand sacrifices. The most recent demand comes in the call for the protection of his economy at the expense of those to be most affected by climate change. These sacrifices are to be enacted by the willing high priests, the compliant, and the ignorant. Their sacrificial lambs are those who are forcibly harnessed to a system that exploits them, who become dependent on that system for survival, and who may be summarily dismissed when their “usefulness” is deemed diminished. The paper is here concerned with the people whose alternatives are reduced or destroyed and with the tolerance of this destruction of lives and livelihoods by an enabling population.Research limitations/implicationsThis paper is an invitation to continued conversation, not a research paper in the positivist sense. The paper may be viewed as an experiment to see how far alternative perspectives can flourish in the academy and in our classrooms, boardrooms, and cafeterias. Conversations are posited as a means of change – of self and society.Practical implicationsThis paper invites practitioners and academics to engage with critical self‐reflection as a necessary aspect for transformational learning and leadership. The extent to which positivists models of knowing prevail, papers more exploratory of diverse ontologies may be diminished or dismissed with significant implications for the enhancement or depletion of (intellectual and spiritual) diversity.Social implicationsThe attractiveness of “sustainability” discourses are a mixed blessing. They may be generated to unsettle and used to transform ways of knowing and being that have led to the current crises facing humanity. The proffered remedies for these crises may also enable The Master to become better informed and more able to assimilate those who criticise. A subaltern position would make this less likely.Originality/valueThe value of an amplified subaltern voice lies in the honing of more critical insights and thus the discovery of not only more creative technical solutions to issues of sustainability and justice but the co‐creation of covenants that may generate a form of human and environmental flourishing beyond the Wealth of Corpor‐Nations.

3가크롬 이온의 전착 반응에 용액 산도 및 유기물 첨가제가 미치는 영향 연구

The effect of solution acidity and organic additives, polyethylene glycol (PEG), on the trivalent chromium electroplating was systematically investigated in the view point of electroreduction of trivalent chromium ions and solution stability. It was found that solution acidity controlled at pH 2.5 showed the widest current range for bright electrodeposits in the presence of PEG additives, which reduced the local current intensification at high current densities. Through complex interaction between PEG additives and hydrogen ion, that is, solution acidity, electrode potential was moved in the negative direction in the bulk solution, while it shifted in the positive when electric potential was scanned. In conjunction with electrochemical quartz crystal microbalance (EQCM), it was found that PEG additives had a role in promoting the electron transfer to trivalent chromium ion complexes in bulk solution and their adsorption at the electrode surface as well as interfering with hydrogen ion reduction process below pH 2.5. The PEG additives developed the nodular morphology during electroreduction of trivalent chromium ions with the increase of solution acidity and enhanced its current efficiency by maintaining the consumption of complexant, formic acid, at low speed.

Insulin intensification for people with type 2 diabetes: a practical approach

Background: Type 2 diabetes is a progressive disorder and with time, it is appropriate for insulin therapy to be initiated in the majority of people. Insulin is commonly initiated with once-daily basal insulin. However, when glycaemic control becomes unsatisfactory despite the introduction of basal insulin, no clear guidelines exist for intensifying the insulin regimen. In this article we aim to provide a clinician’s approach to both the optimisation of the basal insulin dose, and strategies to intensify insulin therapy. Methods: An expert consensus panel, consisting of the authors, was convened to review the current practice of insulin intensification in people with type 2 diabetes and to develop a pragmatic algorithm for clinicians. The panel reviewed the published literature on the use of insulin in clinical practice, the evidence for different intensification strategies, and the potential impact of patient-related factors on insulin choices. Results: Insulin intensification should only be considered after the basal insulin dose has been optimised. This is achieved by taking into account basal and prandial (pre and post) blood glucose levels, individualised target HbA1c, and dietary factors. If optimal basal insulin together with oral medications is not sufficient to reach glycaemic targets, the next step is to introduce a basal plus 1 regimen or switch to twice-daily premixed insulin. Each has advantages and disadvantages and existing guidelines do not emphasise or support any particular regimen. Therefore, it is important to individualise the choice according to the individual’s needs. A practical algorithm has been developed to help clinicians choose an appropriate second-line regimen. Conclusion: As beta-cell failure progresses in people with type 2 diabetes, basal insulin regimens need to be optimised and then intensified when necessary to maintain agreed glycaemic targets.

Critiquing Child-Centred Pedagogy to Bring Children and Early Childhood Educators into the Centre of a Democratic Pedagogy

Child-centred pedagogy is both an enduring approach and a revered concept in Western-based teacher preparation. This article weaves together major critiques of child-centred pedagogy that draw on critical feminist, postmodernist and post-structural theories. These critiques have particular relevance for conceptualizing what it can mean to be, and what it takes to become, an early childhood professional. The construct of the female early childhood professional is particularly important with the current intensification of the teacher as a technician and the increasing numbers in the workforce from racialized groups who may face social inequities. The construction of the individualized child and its parallel denial of the influences of gender, ethnicity and class on who a child becomes are equally important. Drawing upon the work of reconceptualist scholars, some preliminary ways will be proposed in which we can theorize and reconstruct children and early childhood professionals at the centre of a pedagogy that is a democratic space for all.

A Retreat in a South Korean Buddhist Monastery. Becoming a Lay Devotee Through Monastic Life

AbstractIn South Korea, the distance between Buddhist monastics and lay devotees tends to reduce as monasteries and temples multiply in urban areas. Even the remote mountain monasteries have broadened their access to lay visitors. Nowadays monastic and lay Buddhists have more occasions to meet than before and the current intensification of their relationships brings important redefinitions of their respective identities. This paper explores how far this new spatial proximity signifies a rapprochement between monastic and lay Buddhists. Through an ethnographic approach and a participant observation methodology I focus on a one-week retreat for laity in a Buddhist monastery dedicated to meditation. This case study examines the ambiguous goal of this retreat programme that combined two aims: initiating lay practitioners to the monastic lifestyle and the practice of kanhwa son meditation; and establishing a group of lay supporters affiliated to the temple. This temporary monastic experience was directed towards an intense socialisation of the participants to the norms and values of an ascetic lifestyle, blurring some aspects of the border between lay and monastic practices of Buddhism. However, this paper suggests that this transitory rapprochement contributed to both challenge and strengthen the distinction between the renouncers (ch'ulga) and the householders (chaega).

Dynamics of North American sector ionospheric and thermospheric response during the November 2004 superstorm

We present a study of ionospheric and thermospheric response during a November 9–10, 2004 major geomagnetic storm event (DsT ∼−300 nT). We utilize the North American sector longitude chain of incoherent scatter radars at Arecibo, Millstone Hill, and Sondrestrom, operating as part of a coordinated international mesosphere/lower thermosphere coupling study experiment. Total electron content (TEC) determinations from global positioning system (GPS) ground receivers, ground magnetometer traces from the Canadian CANOPUS array, Defense Meteorological Satellite Platform (DMSP) topside data, and global convection patterns from the SuperDARN radar network are analyzed to place the detailed radar data in proper mesoscale context. The plasmaspheric boundary layer (PBL) expanded greatly in the dusk sector during ring current intensification to span more than 25° of magnetic latitude, reaching as far south as 30° invariant latitude. Strong sub-auroral polarization stream velocities of more than 1 km/s were accompanied by large upwards thermal O+ fluxes to the overlying magnetosphere. The large PBL expansion subsequently exposed both Millstone Hill and Sondrestrom to the auroral convection pattern, which developed a complex multicell and reverse convection response under strongly northward IMF conditions during a period of global interplanetary electric field penetration. Large traveling atmospheric and ionospheric disturbances caused significant neutral wind and ion velocity surges in the mid-latitude and tropical ionosphere and thermosphere, with substorm activity launching equatorward neutral wind enhancements and subsequent mid-latitude dynamo responses at Millstone Hill. However, ionosphere and thermosphere observations at Arecibo point to significant disturbance propagation modification in the post-dusk sector PBL region.