Radio Emissions from Electrical Activity in Martian Dust Storms

2020 ◽  
Author(s):  
Walid Majid
Keyword(s):  
Electric Fields ◽  
Large Scale ◽  
Electric Activity ◽  
Electrical Circuit ◽  
Dust Storms ◽  
Deep Space ◽  
Electrostatic Discharges ◽  
Human Exploration

<p>Dust storms on Mars are predicted to be capable of producing electrostatic fields and discharges, even larger than those in dust storms on Earth.  There are three key elements in the characterization of Martian electrostatic discharges: dependence on Martian environmental conditions, event rate, and the strength of the generated electric fields.  The detection and characterization of electric activity in Martian dust storms has important implications for habitability, and preparations for human exploration of the red planet. Furthermore, electrostatic discharges may be linked to local chemistry and plays an important role in the predicted global electrical circuit.</p><p> </p><p>Because of the continuous Mars telecommunication needs of NASA’s Mars-based assets, the Deep Space Network (DSN) is the only facility in the world that combines long term, high cadence, observing opportunities with large sensitive telescopes, making it a unique asset worldwide in searching for and characterizing electrostatic activity from large scale convective dust storms at Mars. We will describe a program at NASA’s Madrid Deep Space Communication Complex that has been carrying out a long-term monitoring campaign to search for and characterize the entire Mars hemisphere for powerful discharges during routine tracking of spacecraft at Mars on an entirely non-interfering basis. The ground-based detections will also have important implications for the design of a future instrument that could make similar in-situ measurements from orbit or from the surface of Mars, with far greater sensitivity and duty cycle, opening up a new window in our understanding of the Martian environment.</p>

scholarly journals Topophilia, Placemaking, and Boundary Work

2022 ◽  
Vol 6 (GROUP) ◽  
pp. 1-33
Author(s):  
Janghee Cho ◽  
Samuel Beck ◽  
Stephen Voida
Keyword(s):  
Large Scale ◽  
Methodological Approach ◽  
Work Practice ◽  
Small Scale ◽  
Work From Home ◽  
Humanistic Geography ◽  
Working From Home ◽  
Long Term Impact

The COVID-19 pandemic fundamentally changed the nature of work by shifting most in-person work to a predominantly remote modality as a way to limit the spread of the coronavirus. In the process, the shift to working-from-home rapidly forced the large-scale adoption of groupware technologies. Although prior empirical research examined the experience of working-from-home within small-scale groups and for targeted kinds of work, the pandemic provides HCI and CSCW researchers with an unprecedented opportunity to understand the psycho-social impacts of a universally mandated work-from-home experience rather than an autonomously chosen one. Drawing on boundary theory and a methodological approach grounded in humanistic geography, we conducted a qualitative analysis of Reddit data drawn from two work-from-home-related subreddits between March 2020 and January 2021. In this paper, we present a characterization of the challenges and solutions discussed within these online communities for adapting work to a hybrid or fully remote modality, managing reconfigured work-life boundaries, and reconstructing the home's sense of place to serve multiple, sometimes conflicting roles. We discuss how these findings suggest an emergent interplay among adapted work practice, reimagined physical (and virtual) spaces, and the establishment and continual re-negotiation of boundaries as a means for anticipating the long-term impact of COVID on future conceptualizations of productivity and work.

scholarly journals Structural geology and geophysics as a support to build a hydrogeologic model of granite rock

Solid Earth ◽  
2016 ◽  
Vol 7 (3) ◽  
pp. 881-895 ◽  
Author(s):  
Lurdes Martinez-Landa ◽  
Jesús Carrera ◽  
Andrés Pérez-Estaún ◽  
Paloma Gómez ◽  
Carmen Bajos
Keyword(s):  
Structural Geology ◽  
Large Scale ◽  
Preferential Flow ◽  
Three Dimensional ◽  
Pumping Test ◽  
Discrete Elements ◽  
Flow Paths ◽  
Preferential Flow Paths

Abstract. A method developed for low-permeability fractured media was applied to understand the hydrogeology of a mine excavated in a granitic pluton. This method includes (1) identifying the main groundwater-conducting features of the medium, such as the mine, dykes, and large fractures, (2) implementing this factors as discrete elements into a three-dimensional numerical model, and (3) calibrating these factors against hydraulic data . A key question is how to identify preferential flow paths in the first step. Here, we propose a combination of several techniques. Structural geology, together with borehole sampling, geophysics, hydrogeochemistry, and local hydraulic tests aided in locating all structures. Integration of these data yielded a conceptual model of the site. A preliminary calibration of the model was performed against short-term (< 1 day) pumping tests, which facilitated the characterization of some of the fractures. The hydraulic properties were then used for other fractures that, according to geophysics and structural geology, belonged to the same families. Model validity was tested by blind prediction of a long-term (4 months) large-scale (1 km) pumping test from the mine, which yielded excellent agreement with the observations. Model results confirmed the sparsely fractured nature of the pluton, which has not been subjected to glacial loading–unloading cycles and whose waters are of Na-HCO3 type.

scholarly journals Progress in managing the transition from the RS92 to the Vaisala RS41 as the operational radiosonde within the GCOS Reference Upper-Air Network

2019 ◽  
Author(s):  
Ruud J. Dirksen ◽  
Greg E. Bodeker ◽  
Peter W. Thorne ◽  
Andrea Merlone ◽  
Tony Reale ◽  
...  
Keyword(s):  
Measurement Errors ◽  
Large Scale ◽  
Integrated Approach ◽  
Burden Sharing ◽  
Ancillary Data ◽  
Laboratory Characterization ◽  
History Of ◽  
Large Scale Change

Abstract. This paper describes the GRUAN-wide approach to manage the transition from the Vaisala RS92 to the Vaisala RS41 as the operational radiosonde. The goal of the GCOS Reference Upper-Air Network (GRUAN) is to provide long-term high-quality reference observations of upper air Essential Climate Variables (ECVs) such as temperature and water vapor. With GRUAN data being used for climate monitoring, it is vital that the change of measurement system does not introduce inhomogeneities in to the data record. The majority of the 27 GRUAN sites were launching the RS92 as their operational radiosonde, and following the end of production of the RS92 in the last quarter of 2017, most of these sites have now switched to the RS41. Such a large-scale change in instrumentation is unprecedented in the history of GRUAN and poses a challenge for the network. Several measurement programmes have been initiated to characterize differences in biases, uncertainties and noise between the two radiosonde types. These include laboratory characterization of measurement errors, extensive twin sounding studies with RS92 and RS41 on the same balloon, and comparison with ancillary data. This integrated approach is commensurate with the GRUAN principles of traceability and deliberate redundancy. A two-year period of regular twin soundings is recommended, and for sites that are not able to implement this burden sharing is employed, such that measurements at a certain site are considered representative of other sites with similar climatological characteristics. All data relevant to the RS92-RS41 transition are archived in a database that will be accessible to the scientific community for external scrutiny. Furthermore, the knowledge and experience gained about GRUAN's RS92-RS41 transition will be extensively documented to ensure traceability of the process. This documentation will benefit other networks in managing changes in their operational radiosonde systems. Preliminary analysis of the laboratory experiments indicates that the manufacturer's calibration of the RS41's temperature and humidity sensors is more accurate than for the RS92; with uncertainties of

scholarly journals The impact of large-scale afforestation on ecological environment in the Gobi region

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhengyi Yao ◽  
Jianhua Xiao ◽  
Xixi Ma
Keyword(s):  
Inner Mongolia ◽  
Large Scale ◽  
Dust Storms ◽  
Sustainable Growth ◽  
Ecological Environment ◽  
Gravel Layer ◽  
Annual Evaporation ◽  
Strong Winds ◽  
The Impact

AbstractIn recent year, there has been large-scale afforestation in the gobi region of western Inner Mongolia, China. However, this area has low annual precipitation of 35–55 mm, and a high annual evaporation capacity of 3842 mm. Further, water resources in this region are scarce and cannot support the sustainable growth of shrubs. Thus, without effective irrigation, the shrubs cannot survive and ultimately, large-scale afforestation in the gobi region will destroy “black vegetation”. The surface of this area is covered by dense gravel (65.43–82.08%; average of 77.14%) as a result of long-term erosion caused by strong winds. The sediments underlying the gravel layer are rich in sand (60.34–87.51%) and silt (11.26–35.18%). Once the surface gravel layer is destroyed, the underlying sand and silt expose and increase dust supply, and result in increased intensity and frequency of dust storms. Thus, large-scale afforestation in the gobi region is an ecological disaster for these very dry lands.

scholarly journals Managing the transition from Vaisala RS92 to RS41 radiosondes within the Global Climate Observing System Reference Upper-Air Network (GRUAN): a progress report

2020 ◽  
Vol 9 (2) ◽  
pp. 337-355 ◽  
Author(s):  
Ruud J. Dirksen ◽  
Greg E. Bodeker ◽  
Peter W. Thorne ◽  
Andrea Merlone ◽  
Tony Reale ◽  
...  
Keyword(s):  
Measurement Errors ◽  
Large Scale ◽  
Global Climate ◽  
Integrated Approach ◽  
Burden Sharing ◽  
Ancillary Data ◽  
Laboratory Characterization ◽  
History Of

Abstract. This paper describes the Global Climate Observing System (GCOS) Reference Upper-Air Network (GRUAN) approach to managing the transition from the Vaisala RS92 to the Vaisala RS41 as the operational radiosonde. The goal of GRUAN is to provide long-term high-quality reference observations of upper-air essential climate variables (ECVs) such as temperature and water vapor. With GRUAN data being used for climate monitoring, it is vital that the change of measurement system does not introduce inhomogeneities to the data record. The majority of the 27 GRUAN sites were launching the RS92 as their operational radiosonde, and following the end of production of the RS92 in the last quarter of 2017, most of these sites have now switched to the RS41. Such a large-scale change in instrumentation is unprecedented in the history of GRUAN and poses a challenge for the network. Several measurement programs have been initiated to characterize differences in biases, uncertainties, and noise between the two radiosonde types. These include laboratory characterization of measurement errors, extensive twin sounding studies with RS92 and RS41 on the same balloon, and comparison with ancillary data. This integrated approach is commensurate with the GRUAN principles of traceability and deliberate redundancy. A 2-year period of regular twin soundings is recommended, and for sites that are not able to implement this, burden-sharing is employed such that measurements at a certain site are considered representative of other sites with similar climatological characteristics. All data relevant to the RS92–RS41 transition are archived in a database that will be accessible to the scientific community for external scrutiny. Furthermore, the knowledge and experience gained regarding GRUAN's RS92–RS41 transition will be extensively documented to ensure traceability of the process. This documentation will benefit other networks in managing changes in their operational radiosonde systems. Preliminary analysis of the laboratory experiments indicates that the manufacturer's calibration of the RS41 temperature and humidity sensors is more accurate than for the RS92, with uncertainties of <0.2 K for the temperature and <1.5 % RH (RH: relative humidity) for the humidity sensor. A first analysis of 224 RS92–RS41 twin soundings at Lindenberg Observatory shows nighttime temperature differences <0.1 K between the Vaisala-processed temperature data for the RS41 (TRS41) and the GRUAN data product for the RS92 (TRS92-GDP.2). However, daytime temperature differences in the stratosphere increase steadily with altitude, with TRS92-GDP.2 up to 0.6 K higher than TRS41 at 35 km. RHRS41 values are up to 8 % higher, which is consistent with the analysis of satellite–radiosonde collocations.

scholarly journals Structural geology and geophysics as a key to build a hydrogeologic model of granite rock to support a mine

2016 ◽  
Author(s):  
L. Martinez Landa ◽  
J. Carrera ◽  
A. Perez-Estaún ◽  
P. Gomez ◽  
C. Bajos
Keyword(s):  
Structural Geology ◽  
Large Scale ◽  
Preferential Flow ◽  
Three Dimensional ◽  
Pumping Test ◽  
Discrete Elements ◽  
Flow Paths ◽  
Preferential Flow Paths

Abstract. A methodology developed for low permeability fractured media has been applied to understand the hydrogeology of a mine excavated in a granitic pluton. This methodology consists of (1) identifying the main ground water conducting features of the medium, such as the mine, dykes and large fractures, (2) implementing them as discrete elements into a three-dimensional numerical model, and (3) calibrating them against hydraulic data (Martínez-Landa and Carrera, 2005b). The key question is how to identify preferential flow paths in the first step. Here, we propose a combination of several techniques. Structural geology, together with borehole samples, geophysics, hydrogeochemistry and local hydraulic tests aided in locating all structures. Integrating these data yields a conceptual model of the site. A preliminary calibration of the model was performed against short-term (less than a day) pumping tests, which helped in the characterization of some fractures. Their hydraulic properties were then used for other fractures that, according to geophysics and structural geology, belonged to the same families. Model validity was tested by blind prediction of a long-term (4 months) large-scale (1 km) pumping test from the mine, which yielded an excellent agreement with observations. Model results confirm the sparsely fractured nature of the pluton, which has not been subjected to glacial loading-unloading cycles and whose waters are of Na-HCO3 type.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Some applications of electron beam microanalysis techniques in VLSI process evaluation

1983 ◽  
Vol 41 ◽  
pp. 160-161
Author(s):  
Simon Thomas
Keyword(s):  
Integrated Circuits ◽  
Process Evaluation ◽  
Large Scale ◽  
Technology Development ◽  
Analytical Techniques ◽  
Successful Implementation ◽  
Analysis Of Failures ◽  
Characterization Of Materials ◽  
Circuits Vlsi

Trends in the technology development of very large scale integrated circuits (VLSI) have been in the direction of higher density of components with smaller dimensions. The scaling down of device dimensions has been not only laterally but also in depth. Such efforts in miniaturization bring with them new developments in materials and processing. Successful implementation of these efforts is, to a large extent, dependent on the proper understanding of the material properties, process technologies and reliability issues, through adequate analytical studies. The analytical instrumentation technology has, fortunately, kept pace with the basic requirements of devices with lateral dimensions in the micron/ submicron range and depths of the order of nonometers. Often, newer analytical techniques have emerged or the more conventional techniques have been adapted to meet the more stringent requirements. As such, a variety of analytical techniques are available today to aid an analyst in the efforts of VLSI process evaluation. Generally such analytical efforts are divided into the characterization of materials, evaluation of processing steps and the analysis of failures.

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