scholarly journals Sensing earth and environment dynamics by telecommunication fiber-optic sensors: An urban experiment in Pennsylvania USA

2020 ◽  
Author(s):  
Tieyuan Zhu ◽  
Junzhu Shen ◽  
Eileen R. Martin
Keyword(s):  
Urban Areas ◽  
Fiber Optic ◽  
Seismic Monitoring ◽  
Anthropogenic Sources ◽  
Extreme Weather Events ◽  
State University ◽  
Fiber Array ◽  
Near Surface ◽  
Multiple Observations ◽  
One Year

Abstract. Continuous seismic monitoring of the Earth's near surface (top 100 meters), especially with improving the resolution and extent of data both in space and time, would yield more accurate insights about the effect of extreme weather events (e.g. flooding or drought) and climate change on the Earth's surface and subsurface systems. However, continuous long-term seismic monitoring, especially in urban areas, remains challenging. We describe the Fiber-Optic foR Environmental SEnsEing (FORESEE) project in Pennsylvania, United States, the first continuous monitoring distributed acoustic sensing (DAS) fiber array in the Eastern US. This array is made up of nearly 5 km of pre-existing dark telecommunications fiber underneath the Pennsylvania State University Campus. A major thrust of this experiment is the study of urban geohazard and hydrological systems through near-surface seismic monitoring. Here we detail the FORESEE experiment deployment, instrument calibration, and describe multiple observations of seismic sources in the first year. We calibrate the array by comparison to earthquake data from a nearby seismometer and to active-source geophone data. We observed a wide variety of seismic signatures in our DAS recordings: natural events (earthquakes and thunderstorms) and anthropogenic events (mining blasts, vehicles, music concerts, and walking steps). Preliminary analysis of these signals suggest DAS has the capability to sense broadband vibrations and discriminate between seismic signatures of different quakes and anthropogenic sources. With the success of collecting one-year of continuous DAS recordings, we conclude that DAS along with telecommunication fiber will potentially serve the purpose of continuous near-surface seismic monitoring in populated areas.

scholarly journals Sensing Earth and environment dynamics by telecommunication fiber-optic sensors: an urban experiment in Pennsylvania, USA

Solid Earth ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 219-235
Author(s):  
Tieyuan Zhu ◽  
Junzhu Shen ◽  
Eileen R. Martin
Keyword(s):  
Urban Areas ◽  
Fiber Optic ◽  
Seismic Monitoring ◽  
Anthropogenic Sources ◽  
Extreme Weather Events ◽  
State University ◽  
Fiber Array ◽  
Near Surface ◽  
Multiple Observations ◽  
Eastern Usa

Abstract. Continuous seismic monitoring of the Earth's near surface (top 100 m), especially with improved resolution and extent of data both in space and time, would yield more accurate insights about the effect of extreme-weather events (e.g., flooding or drought) and climate change on the Earth's surface and subsurface systems. However, continuous long-term seismic monitoring, especially in urban areas, remains challenging. We describe the Fiber Optic foR Environmental SEnsEing (FORESEE) project in Pennsylvania, USA, the first continuous-monitoring distributed acoustic sensing (DAS) fiber array in the eastern USA. This array is made up of nearly 5 km of pre-existing dark telecommunication fiber underneath the Pennsylvania State University campus. A major thrust of this experiment is the study of urban geohazard and hydrological systems through near-surface seismic monitoring. Here we detail the FORESEE experiment deployment and instrument calibration, and describe multiple observations of seismic sources in the first year. We calibrate the array by comparison to earthquake data from a nearby seismometer and to active-source geophone data. We observed a wide variety of seismic signatures in our DAS recordings: natural events (earthquakes and thunderstorms) and anthropogenic events (mining blasts, vehicles, music concerts and walking steps). Preliminary analysis of these signals suggests DAS has the capability to sense broadband vibrations and discriminate between seismic signatures of different quakes and anthropogenic sources. With the success of collecting 1 year of continuous DAS recordings, we conclude that DAS along with telecommunication fiber will potentially serve the purpose of continuous near-surface seismic monitoring in populated areas.

scholarly journals Impacts of biogenic and anthropogenic emissions on summertime ozone formation in the Guanzhong Basin, China

2018 ◽  
Vol 18 (10) ◽  
pp. 7489-7507 ◽  
Author(s):  
Nan Li ◽  
Qingyang He ◽  
Jim Greenberg ◽  
Alex Guenther ◽  
Jingyi Li ◽  
...  
Keyword(s):  
Urban Areas ◽  
Control Strategies ◽  
Anthropogenic Sources ◽  
Air Pollution Control ◽  
Near Surface ◽  
Source Contributions ◽  
Surface Measurements ◽  
Individual Source ◽  
Guanzhong Basin ◽  
The Impact

Abstract. This study is the first attempt to understand the synergistic impact of anthropogenic and biogenic emissions on summertime ozone (O3) formation in the Guanzhong (GZ) Basin where Xi'an, the oldest and the most populous city (with a population of 9 million) in northwestern China, is located. Month-long (August 2011) WRF-Chem simulations with different sensitivity experiments were conducted and compared with near-surface measurements. Biogenic volatile organic compounds (VOCs) concentrations was characterized from six surface sites among the Qinling Mountains, and urban air composition was measured in Xi'an city at a tower 100 ma.s. The WRF-Chem control experiment reasonably reproduced the magnitudes and variations of observed O3, VOCs, NOx, PM2.5, and meteorological parameters, with normalized mean biases for each parameter within ±21 %. Subsequent analysis employed the factor separation approach (FSA) to quantitatively disentangle the pure and synergistic impacts of anthropogenic and/or biogenic sources on summertime O3 formation. The impact of anthropogenic sources alone was found to be dominant for O3 formation. Although anthropogenic particles reduced NO2 photolysis by up to 60 %, the anthropogenic sources contributed 19.1 ppb O3 formation on average for urban Xi'an. The abundant biogenic VOCs from the nearby forests promoted O3 formation in urban areas by interacting with the anthropogenic NOx. The calculated synergistic contribution (from both biogenic and anthropogenic sources) was up to 14.4 ppb in urban Xi'an, peaking in the afternoon. Our study reveals that the synergistic impact of individual source contributions to O3 formation should be considered in the formation of air pollution control strategies, especially for big cities in the vicinity of forests.

scholarly journals Impacts of Biogenic Emissions on Summertime Ozone Formation in the Guanzhong Basin, China

2018 ◽  
Author(s):  
Nan Li ◽  
Qingyang He ◽  
Jim Greenberg ◽  
Alex Guenther ◽  
Junji Cao ◽  
...  
Keyword(s):  
Urban Areas ◽  
Control Strategies ◽  
Northwest China ◽  
Anthropogenic Sources ◽  
Biogenic Emissions ◽  
Air Pollution Control ◽  
Near Surface ◽  
Source Contributions ◽  
Guanzhong Basin ◽  
The Impact

Abstract. This study is the first attempt to understand the synergistic impact of anthropogenic and biogenic emissions on summertime ozone (O3) formation in the Guanzhong (GZ) basin where Xi’an, the oldest and the most populous city (with a population of 9 million) in the northwest China, is located. Month-long (August 2011) WRF-Chem simulations with different sensitivity experiments were conducted and compared with near-surface measurements. Biogenic volatile organic compounds (VOCs) concentrations were characterized from 6 surface sites among the Qinling Mountains, and urban air composition was measured in the Xi’an city at a tower 100 m above the surface. The WRF-Chem control experiment reasonably reproduced the magnitudes and variations of observed O3, VOCs, NOx, PM2.5 and meteorological parameters, with normalized mean biases for each parameter within ±21 %. Subsequent analysis employed the factor separation approach (FSA) to quantitatively disentangle the pure and synergistic impacts of anthropogenic and/or biogenic sources on summertime O3 formation. The impact of anthropogenic sources alone was found to be dominant for O3 formation. Although anthropogenic particles reduced NO2 photolysis by up to 60 %, the anthropogenic sources contributed 19.1 ppb O3 formation on average for urban Xi’an. The abundant biogenic VOCs from the nearby forests promoted O3 formation in urban areas by interacting with the anthropogenic NOx. The calculated synergistic contribution (from both biogenic and anthropogenic sources) was up to 14.4 ppb in urban Xi’an, peaking in the afternoon. Our study reveals that the synergistic impact of individual source contributions to O3 formation should be considered in the formation of air pollution control strategies, especially for big cities in the vicinity of forests.

Fiber Optics foR Environmental SEnsE-ing (FORESEE) at Pennsylvania State University

2020 ◽  
Author(s):  
Eileen Martin ◽  
Tieyuan Zhu ◽  
Junzhu Shen ◽  
Srikanth Jakkampudi ◽  
Weichen Li ◽  
...  
Keyword(s):  
Fiber Optics ◽  
Urban Areas ◽  
Ambient Noise ◽  
State University ◽  
Source Inversion ◽  
Pennsylvania State University ◽  
Noise Sources ◽  
Fiber Array ◽  
Public College ◽  
Seismic Acquisition

<p>The FORESEE Distributed Acoustic Sensing (DAS) Array records roughly 1/3 terabyte of data per day along 5 kilometers of dark fiber optic telecommunications cable underneath the Pennsylvania State University campus. The campus sits in the Allegheny Mountain region of the US, and our aim is to understand urban hydrology and detection of geohazards (particularly karst features). We have verified a number of features of these data similar to prior urban seismic studies, both in ambient noise and in distant earthquake records, which builds further evidence that dark fiber can be a useful tool for seismology in cities.</p><p>These data also contain a number of new signals not observed on previous dark fiber arrays. We see a stronger response to air waves than prior experiments. For instance, musical bass lines are clearly observed in the 30-100 Hz range during a concert, and we can see the spatial decay of higher versus lower frequencies throughout the array. This is the first dark fiber array in the eastern US, where thunderstorms occur with some frequency, and we have observed clear recordings of ground motion due to thunder. Source inversion of the waveforms throughout the array leads to locations that show reasonable agreement compared to the National Lightning Detection Network. These thunderquake signals could be an important source of broadband energy for seismic imaging in an area with little earthquake seismicity.</p><p>We have performed ambient noise interferometry throughout the array with a variety of pre-processing workflows, but some subsets of the array are strongly affected by nearby sources. With the wide variety of natural and manmade signals in these data, we are working towards further efficient automation to detect repeatable signals that could be used for targeted interferometry, and methods to automate filtering of non-ideal noise sources. As one example of filtering a specific noise, we were surprised the array is able detect the paths of individuals walking along a sidewalk by the fiber. While this array records data on a public college campus, a likely future area of research may include urban areas with a mix of commercial and residential purposes, so we desire tools to remove individual signals as they are recorded. Thus, we have developed a neural network to detect and remove footsteps from data before those data are shared with researchers. To encourage others working on urban seismic acquisition to remove similar signals, we are generalizing these methods for footstep removal to different scales.</p>

scholarly journals Study of Temporal Variations of Equivalent Black Carbon in a Coastal City in Northwest Spain Using an Atmospheric Aerosol Data Management Software

2021 ◽  
Vol 11 (2) ◽  
pp. 516
Author(s):  
María Piñeiro-Iglesias ◽  
Javier Andrade-Garda ◽  
Sonia Suárez-Garaboa ◽  
Soledad Muniategui-Lorenzo ◽  
Purificación López-Mahía ◽  
...  
Keyword(s):  
Data Management ◽  
Black Carbon ◽  
Light Absorption ◽  
Atmospheric Aerosol ◽  
Urban Areas ◽  
Radiative Properties ◽  
Anthropogenic Sources ◽  
Biomass Combustion ◽  
Management Support ◽  
Diurnal Variability

Light-absorbing carbonaceous aerosols (including black carbon (BC)) pose serious health issues and play significant roles in atmospheric radiative properties. Two-year measurements (2015–2016) of aerosol light absorption, combined with measurements of sub-micrometric particles, were continuously conducted in A Coruña (northwest (NW) Spain) to determine their light absorption properties: absorption coefficients (σabs) and the absorption Ångström exponent (AAE). The mean and standard deviation of equivalent black carbon (eBC) during the period of study were 0.85 ± 0.83 µg m−3, which are lower than other values measured in urban areas of Spain and Europe. High eBC concentrations found in winter are associated with an increase in emissions from anthropogenic sources in combination with lower mixing layer heights and frequent stagnant conditions. The pronounced diurnal variability suggests a strong influence from local sources. AAE had an average value of 1.26 ± 0.22 which implies that both fossil fuel combustion and biomass burning influenced optical aerosol properties. This also highlights biomass combustion in suburban areas, where the use of wood for domestic heating is encouraged, as an important source of eBC. All data treatment was gathered using SCALA© as atmospheric aerosol data management support software program.

scholarly journals Microanchored borehole fiber optics allows strain profiling of the shallow subsurface

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cheng-Cheng Zhang ◽  
Bin Shi ◽  
Song Zhang ◽  
Kai Gu ◽  
Su-Ping Liu ◽  
...  
Keyword(s):  
Fiber Optics ◽  
Field Experiments ◽  
Fiber Optic ◽  
Strain Sensing ◽  
Near Surface ◽  
Shallow Subsurface ◽  
Buried Cables ◽  
Capacity Theory ◽  
Confining Pressures ◽  
Strain Determination

AbstractVertical deformation profiles of subterranean geological formations are conventionally measured by borehole extensometry. Distributed strain sensing (DSS) paired with fiber-optic cables installed in the ground opens up possibilities for acquiring high-resolution static and quasistatic strain profiles of deforming strata, but it is currently limited by reduced data quality due to complicated patterns of interaction between the buried cables and their surroundings, especially in upper soil layers under low confining pressures. Extending recent DSS studies, we present an improved approach using microanchored fiber-optic cables—designed to optimize ground-to-cable coupling at the near surface—for strain determination along entire lengths of vertical boreholes. We proposed a novel criterion for soil–cable coupling evaluation based on the geotechnical bearing capacity theory. We applied this enhanced methodology to monitor groundwater-related vertical motions in both laboratory and field experiments. Corroborating extensometer recordings, acquired simultaneously, validated fiber optically determined displacements, suggesting microanchored DSS as an improved means for detecting and monitoring shallow subsurface strain profiles.

scholarly journals Detection of Beta-Lactam-Resistant Escherichia coli and Toxigenic Clostridioides difficile Strains in Wild Boars Foraging in an Anthropization Gradient

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1585
Author(s):  
Laila Darwich ◽  
Chiara Seminati ◽  
Jorge R. López-Olvera ◽  
Anna Vidal ◽  
Laia Aguirre ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Disease Transmission ◽  
Urban Areas ◽  
Carbapenem Resistance ◽  
Anthropogenic Sources ◽  
Health Concern ◽  
Natural Environments ◽  
Beta Lactam ◽  
Wild Boars ◽  
Clostridioides Difficile

Disease transmission among wild boars, domestic animals and humans is a public health concern, especially in areas with high wild boar densities. In this study, fecal samples of wild boars (n = 200) from different locations of the Metropolitan Area of Barcelona were analyzed by PCR to explore the frequency of β-lactamases and extended cephalosporin and carbapenem resistance genes (ESBLs) in Escherichia coli strains and the presence of toxigenic Clostridioides difficile. The prevalence of genes conferring resistance to β-lactam antimicrobials was 8.0% (16/200): blaCMY-2 (3.0%), blaTEM-1b (2.5%), blaCTX-M-14 (1.0%), blaSHV-28 (1.0%), blaCTX-M-15 (0.5%) and blaCMY-1 (0.5%). Clostridioides difficile TcdA+ was detected in two wild boars (1.0%), which is the first report of this pathogen in wild boars in Spain. Moreover, the wild boars foraging in urban and peri-urban locations were more exposed to AMRB sources than the wild boars dwelling in natural environments. In conclusion, the detection of E. coli carrying ESBL/AmpC genes and toxigenic C. difficile in wild boars foraging in urban areas reinforces the value of this game species as a sentinel of environmental AMRB sources. In addition, these wild boars can be a public and environmental health concern by disseminating AMRB and other zoonotic agents. Although this study provides the first hints of the potential anthropogenic sources of AMR, further efforts should be conducted to identify and control them.

scholarly journals Seasonal variation and spatial distribution of carbonaceous aerosols in Taiwan

2010 ◽  
Vol 10 (19) ◽  
pp. 9563-9578 ◽  
Author(s):  
C. C.-K. Chou ◽  
C. T. Lee ◽  
M. T. Cheng ◽  
C. S. Yuan ◽  
S. J. Chen ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Rural Areas ◽  
Urban Areas ◽  
Air Pollutants ◽  
Chemical Properties ◽  
Anthropogenic Sources ◽  
Carbonaceous Aerosols ◽  
Urban Rural ◽  
Southern Taiwan ◽  
Northern Taiwan

Abstract. To investigate the physico-chemical properties of aerosols in Taiwan, an observation network was initiated in 2003. In this work, the measurements of the mass concentration and carbonaceous composition of PM10 and PM2.5 are presented. Analysis on the data collected in the first 5-years, from 2003 to 2007, showed that there was a very strong contrast in the aerosol concentration and composition between the rural and the urban/suburban stations. The five-year means of EC at the respective stations ranged from 0.9±0.04 to 4.2±0.1 μgC m−3. In rural areas, EC accounted for 2–3% of PM10 and 3–5% of PM2.5 mass loadings, comparing to 4–6% of PM10 and 4–8% of PM2.5 in the urban areas. It was found that the spatial distribution of EC was consistent with CO and NOx across the network stations, suggesting that the levels of EC over Taiwan were dominated by local sources. The measured OC was split into POC and SOC counterparts following the EC tracer method. Five-year means of POC ranged from 1.8±0.1 to 9.7±0.2 μgC m−3 among the stations. It was estimated that the POM contributed 5–17% of PM10 and 7–18% of PM2.5 in Taiwan. On the other hand, the five-year means of SOC ranged from 1.5±0.1 to 3.8±.3 μgC m−3. The mass fractions of SOM were estimated to be 9–19% in PM10 and 14–22% in PM2.5. The results showed that the SOC did not exhibit significant urban-rural contrast as did the POC and EC. A significant cross-station correlation between SOC and total oxidant was observed, which means the spatial distribution of SOC in Taiwan was dominated by the oxidant mixing ratio. Besides, correlation was also found between SOC and particulate nitrate, implying that the precursors of SOA were mainly from local anthropogenic sources. In addition to the spatial distribution, the carbonaceous aerosols also exhibited distinct seasonality. In northern Taiwan, the concentrations of all the three carbonaceous components (EC, POC, and SOC) reached their respective minima in the fall season. POC and EC increased drastically in winter and peaked in spring, whereas the SOC was characterized by a bimodal pattern with the maximal concentration in winter and a second mode in summertime. In southern Taiwan, minimal levels of POC and EC occurred consistently in summer and the maxima were observed in winter, whereas the SOC peaked in summer and declined in wintertime. The discrepancies in the seasonality of carbonaceous aerosols between northern and southern Taiwan were most likely caused by the seasonal meteorological settings that dominated the dispersion of air pollutants. Moreover, it was inferred that the Asian pollution outbreaks could have shifted the seasonal maxima of air pollutants from winter to spring in the northern Taiwan, and that the increases in biogenic SOA precursors and the enhancement in SOA yield were responsible for the elevated SOC concentrations in summer.

scholarly journals Temporal–Spatial Patterns of Relative Humidity and the Urban Dryness Island Effect in Beijing City

2017 ◽  
Vol 56 (8) ◽  
pp. 2221-2237 ◽  
Author(s):  
Ping Yang ◽  
Guoyu Ren ◽  
Wei Hou
Keyword(s):  
Relative Humidity ◽  
Urban Areas ◽  
Late Summer ◽  
Beijing City ◽  
Near Surface ◽  
Suburban Areas ◽  
Island Effect ◽  
Different Seasons ◽  
Autumn And Winter ◽  
Beijing China

AbstractHourly datasets obtained by automatic weather stations in Beijing, China, are developed and employed to analyze the spatial and temporal characteristics of relative humidity (RH) and urban dryness island intensity (UDII) over built-up areas. A total of 36 stations inside the sixth ring road are considered as urban sites, while six stations in suburban belts surrounding the built-up areas are taken as reference sites. Results show that the RH is obviously smaller in urban areas than in suburban areas, indicating the effect of urbanization on near-surface atmospheric moisture and RH. A further analysis of relations between RH and temperature on varied time scales shows that the variations in RH in the urban areas are not due solely to changes in temperature. The annual and seasonal mean UDII are high in central urban areas, with the strongest UDII values occurring in autumn and the weakest values occurring in spring. The diurnal UDII variations are characterized by a steadily strong UDII stage from 2000 to 0800 LT and a minimum at 1500 or 1600 LT. The rapid shifts of UDII from high (low) to low (high) occur during the periods 0800–1600 LT (1600–2000 LT). The occurrence time of the peaks varies among different seasons: the peaks appear at 0700, 2100, 2000, and 0800 LT for spring, summer, autumn, and winter, respectively. Further analysis shows that large UDII values appear in the evenings and early nights in late summer and early to midautumn and that low UDII values mainly occur in the afternoon hours of spring, winter, and late autumn.

scholarly journals Measurement report: Short-term variation in ammonia concentrations in an urban area increased by mist evaporation and emissions from a forest canopy with bird droppings

2020 ◽  
Vol 20 (20) ◽  
pp. 11941-11954
Author(s):  
Kazuo Osada
Keyword(s):  
Urban Areas ◽  
Forest Canopy ◽  
Anthropogenic Sources ◽  
Daily Maximum ◽  
Short Term ◽  
Daily Minimum ◽  
Bird Droppings ◽  
Morning Peak ◽  
Air Temperatures ◽  
Cloudy Weather

Abstract. Local meteorological conditions and natural and anthropogenic sources affect atmospheric NH3 concentrations in urban areas. To investigate potential sources and processes of NH3 variation in urban areas, hourly NH3 and NH4+ concentrations were measured during November 2017–October 2019 in Nagoya, a central Japanese megacity. Average NH3 concentrations are high in summer and low in winter. Daily minimum NH3 concentrations are linearly correlated with daily minimum air temperatures. By contrast, daily maximum NH3 concentrations increase exponentially with temperature, suggesting that different nighttime and daytime processes and air temperatures affect concentrations. Short-term increases in NH3 concentrations of two types were examined closely. Infrequent but large increases (11 parts per billion (ppb) for 2 h) occurred after mist evaporation during daytime. During 2 years of observations, only one event of this magnitude was identified in Nagoya, although evaporation of mist and fog occurs frequently after rains. Also, short-term increases occur with a large morning peak in summer. Amplitudes of diurnal variation in NH3 concentration (daily maximum minus minimum) were analyzed on days with nonwet and low wind conditions. Amplitudes were small (ca. 2 ppb) in winter, but they increased from early summer along with new leaf growth. Amplitudes peaked in summer (ca. 20 ppb) because of droppings from hundreds of crows before roosting in trees on the campus. High daily maximum NH3 concentrations were characterized by a rapid increase occurring 2–4 h after local sunrise. In summer, peak NH3 concentrations at around 08:00 local time (LT) in sunny weather were greater than in cloudy weather, suggesting that direct sunlight particularly boosts the morning peak. Daily and seasonal findings related to the morning peak imply that stomatal emission at the site causes the increase. Differences between daily amplitudes during the two summers was explained by the different input amounts of reactive nitrogen from bird droppings and rain, suggesting that bird droppings, a temporary rich source of NH3, affected the small forest canopy.

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