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Articles 61 - 90 of 151

Full-Text Articles in Atmospheric Sciences

Methanethiol, Dimethyl Sulfide And Acetone Over Biologically Productive Waters In The Southwest Pacific Ocean, Sarah J. Lawson, Cliff S. Law, Mike J. Harvey, Thomas G. Bell, Carolyn F. Walker, Warren J. De Bruyn, Eric S. Saltzman Mar 2020

Methanethiol, Dimethyl Sulfide And Acetone Over Biologically Productive Waters In The Southwest Pacific Ocean, Sarah J. Lawson, Cliff S. Law, Mike J. Harvey, Thomas G. Bell, Carolyn F. Walker, Warren J. De Bruyn, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Atmospheric methanethiol (MeSHa), dimethyl sulfide (DMSa) and acetone (acetonea) were measured over biologically productive frontal waters in the remote southwest Pacific Ocean in summertime 2012 during the Surface Ocean Aerosol Production (SOAP) voyage. MeSHa mixing ratios varied from below the detection limit (< 10 ppt) up to 65 ppt and were 3 %–36 % of parallel DMSa mixing ratios. MeSHa and DMSa were correlated over the voyage (R2=0.3, slope = 0.07) with a stronger correlation over a coccolithophore-dominated phytoplankton bloom (R2=0.5, slope 0.13). The diurnal cycle for MeSHa shows similar behaviour to DMSa with mixing ratios …


Air/Sea Transfer Of Highly Soluble Gases Over Coastal Waters, J. G. Porter, Warren J. De Bruyn, S. D. Miller, E. S. Saltzman Jan 2020

Air/Sea Transfer Of Highly Soluble Gases Over Coastal Waters, J. G. Porter, Warren J. De Bruyn, S. D. Miller, E. S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The deposition of soluble trace gases to the sea surface is not well studied due to a lack of flux measurements over the ocean. Here we report simultaneous air/sea eddy covariance flux measurements of water vapor, sulfur dioxide (SO2), and momentum from a coastal North Atlantic pier. Gas transfer velocities were on average about 20% lower for SO2 than for H2O. This difference is attributed to the difference in molecular diffusivity between the two molecules (D SO 2/D H 2O = 0.5), in reasonable agreement with bulk parameterizations in air/sea gas …


Long-Term Aerosol Trends And Variability Over Central Saudi Arabia Using Optical Characteristics From Solar Village Aeronet Measurements, Mohammed Al Otaibi, Ashraf Farahat, Bassam Tawabini, M. Hafidz Omar, Emad Ramadan, Abdelgadir Abuelgasim, Ramesh Singh Nov 2019

Long-Term Aerosol Trends And Variability Over Central Saudi Arabia Using Optical Characteristics From Solar Village Aeronet Measurements, Mohammed Al Otaibi, Ashraf Farahat, Bassam Tawabini, M. Hafidz Omar, Emad Ramadan, Abdelgadir Abuelgasim, Ramesh Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

Natural and anthropogenic aerosols over the Kingdom of Saudi Arabia (KSA) play a major role in affecting the regional radiation budget. The long-term variability of these aerosols’ physical and optical parameters, including aerosol optical depth (AOD) and Ångström exponent (α), were measured at a location near central KSA using the Solar Village (SV) AERONET (Aerosol Robotic Network) station during the period December 1999–January 2013. The AERONET measurements show an overall increase in AOD on an annual basis. This upward trend is mainly attributed to a prolonged increase in the monthly/seasonal mean AOD during March–June and during August– September. In contrast, …


The Effect Of The 21 August 2017 Total Solar Eclipse On The Phase Of Vlf/Lf Signals, A. Rozhnoi, M. Solovieva, S. Shalimov, Dimitar Ouzounov, P. Gallagher, G. Verth, J. Mccauley, S. Shelyag, V. Fedun Nov 2019

The Effect Of The 21 August 2017 Total Solar Eclipse On The Phase Of Vlf/Lf Signals, A. Rozhnoi, M. Solovieva, S. Shalimov, Dimitar Ouzounov, P. Gallagher, G. Verth, J. Mccauley, S. Shelyag, V. Fedun

Mathematics, Physics, and Computer Science Faculty Articles and Research

An experimental study of the phase and amplitude observations of sub‐ionospheric very low and low frequency (VLF/LF) signals is performed to analyze the response of the lower ionosphere during the 21 August 2017 total solar eclipse in the United States of America. Three different sub‐ionospheric wave paths are investigated. The length of the paths varies from 2,200 to 6,400 km, and the signal frequencies are 21.4, 25.2, and 40.75 kHz. The two paths cross the region of the total eclipse, and the third path is in the region of 40–60% of obscuration. None of the signals reveal any noticeable amplitude …


Coccidioidomycosis: Medical And Spatio-Temporal Perspectives, Nikias Sarafoglou, Rafael Laniado-Laborin, Menas Kafatos Sep 2019

Coccidioidomycosis: Medical And Spatio-Temporal Perspectives, Nikias Sarafoglou, Rafael Laniado-Laborin, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Coccidioidomycosis (CM) is a disease of major public health importance due to the challenges in its diagnosis and treatment. To understand CM requires the attributes of a multidisciplinary network analysis to appreciate the complexity of the medical, the environmental and the social issues involved: public health, public policy, geology, atmospheric science, agronomy, social sciences and finally humanities, all which provide insight into this population transformation.

In section 1 of this paper, we describe the CM-epidemiology, the clinical features, the diagnosis and finally the treatment.

In section 2, we highlight the most important contributions and controversies in the history of the …


Urban Health Related Air Quality Indicators Over The Middle East And North Africa Countries Using Multiple Satellites And Aeronet Data, Maram El-Nadry, Wenzhao Li, Hesham El-Askary, Mohamed A. Awad, Alaa Ramadan Awad Sep 2019

Urban Health Related Air Quality Indicators Over The Middle East And North Africa Countries Using Multiple Satellites And Aeronet Data, Maram El-Nadry, Wenzhao Li, Hesham El-Askary, Mohamed A. Awad, Alaa Ramadan Awad

Mathematics, Physics, and Computer Science Faculty Articles and Research

Air pollution is reported as one of the most severe environmental problems in the Middle East and North Africa (MENA) region. Remotely sensed data from newly available TROPOMI - TROPOspheric Monitoring Instrument on board Sentinel-5 Precursor, shows an annual mean of high-resolution maps of selected air quality indicators (NO2, CO, O3, and UVAI) of the MENA countries for the first time. The correlation analysis among the aforementioned indicators show the coherency of the air pollutants in urban areas. Multi-year data from the Aerosol Robotic Network (AERONET) stations from nine MENA countries are utilized here to study the aerosol optical depth …


Studying The Impact On Urban Health Over The Greater Delta Region In Egypt Due To Aerosol Variability Using Optical Characteristics From Satellite Observations And Ground-Based Aeronet Measurements, Wenzhao Li, Elham Ali, Islam Abou Al-Magd, Moustafa Mohamed Mourad, Hesham El-Askary Aug 2019

Studying The Impact On Urban Health Over The Greater Delta Region In Egypt Due To Aerosol Variability Using Optical Characteristics From Satellite Observations And Ground-Based Aeronet Measurements, Wenzhao Li, Elham Ali, Islam Abou Al-Magd, Moustafa Mohamed Mourad, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

This research addresses the aerosol characteristics and variability over Cairo and the Greater Delta region over the last 20 years using an integrative multi-sensor approach of remotely sensed and PM10 ground data. The accuracy of these satellite aerosol products is also evaluated and compared through cross-validation against ground observations from the AErosol RObotic NETwork (AERONET) project measured at local stations. The results show the validity of using Multi-angle Imaging Spectroradiometer (MISR) and Moderate Resolution Imaging Spectroradiometer (MODIS) sensors on the Terra and Aqua platforms for quantitative aerosol optical depth (AOD) assessment as compared to Ozone Monitoring Instrument (OMI), Sea-viewingWide Field-of-view …


Global Sinusoidal Seasonality In Precipitation Isotopes, Scott T. Allen, Scott Jasechko, Wouter R. Berghuijs, Jeffrey M. Welker, Gregory R. Goldsmith, James W. Kirchner Aug 2019

Global Sinusoidal Seasonality In Precipitation Isotopes, Scott T. Allen, Scott Jasechko, Wouter R. Berghuijs, Jeffrey M. Welker, Gregory R. Goldsmith, James W. Kirchner

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Quantifying seasonal variations in precipitation δ2H and δ18O is important for many stable isotope applications, including inferring plant water sources and streamflow ages. Our objective is to develop a data product that concisely quantifies the seasonality of stable isotope ratios in precipitation. We fit sine curves defined by amplitude, phase, and offset parameters to quantify annual precipitation isotope cycles at 653 meteorological stations on all seven continents. At most of these stations, including in tropical and subtropical regions, sine curves can represent the seasonal cycles in precipitation isotopes. Additionally, the amplitude, phase, and offset parameters of …


Land – Atmosphere – Meteorological Coupling Associated With The 2015 Gorkha (M 7.8) And Dolakha (M 7.3) Nepal Earthquakes, Feng Jing, Ramesh P. Singh, Xuhui Shen May 2019

Land – Atmosphere – Meteorological Coupling Associated With The 2015 Gorkha (M 7.8) And Dolakha (M 7.3) Nepal Earthquakes, Feng Jing, Ramesh P. Singh, Xuhui Shen

Mathematics, Physics, and Computer Science Faculty Articles and Research

Multiple parameters (brightness temperature, soil moisture, surface latent heat flux, surface air temperature and carbon monoxide) before and after the 2015 Nepal M7.8 Gorkha main earthquake and M7.3 Dolakha aftershock were analysed using satellite observation data. The thermal anomalies from optical and microwave data appear about two months prior to the 2015 Gorkha earthquake. Some of the parameters show anomalous changes at different altitudes about 20 days prior to the main earthquake event and 10 days prior to the strong aftershock. Our results show that pre-earthquake anomalous signals propagate from the in situ to the top of atmosphere, and the …


Tropospheric And Ionospheric Anomalies Induced By Volcanic And Saharan Dust Events As Part Of Geosphere Interaction Phenomena, Valerio Tramutoli, Francesco Marchese, Alfredo Falconieri, Carolina Filizzola, Nicola Genzano, Katsumi Hattori, Mariano Lisi, Jann-Yenq Liu, Dimitar Ouzounov, Michel Parrot, Nicola Pergola, Sergey Pulinets Apr 2019

Tropospheric And Ionospheric Anomalies Induced By Volcanic And Saharan Dust Events As Part Of Geosphere Interaction Phenomena, Valerio Tramutoli, Francesco Marchese, Alfredo Falconieri, Carolina Filizzola, Nicola Genzano, Katsumi Hattori, Mariano Lisi, Jann-Yenq Liu, Dimitar Ouzounov, Michel Parrot, Nicola Pergola, Sergey Pulinets

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this work, we assessed the possible relation of ionospheric perturbations observed by Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions (DEMETER), Global Positioning System total electron content (GPS TEC), National Oceanic and Atmospheric Administration (NOAA)-derived outgoing longwave-Earth radiation (OLR), and atmospheric chemical potential (ACP) measurements, with volcanic and Saharan dust events identified by ground and satellite-based medium infrared/thermal infrared (MIR/TIR) observations. The results indicated that the Mt. Etna (Italy) volcanic activity of 2006 was probably responsible for the ionospheric perturbations revealed by DEMETER on 4 November and 6 December and by GPS TEC observations on 4 November and 12 …


Ecological Determinants Of Respiratory Health: Examining Associations Between Asthma Emergency Department Visits, Diesel Particulate Matter, And Public Parks And Open Space In Los Angeles, California, Jason A. Douglas, Reginald S. Archer, Serena E. Alexander Mar 2019

Ecological Determinants Of Respiratory Health: Examining Associations Between Asthma Emergency Department Visits, Diesel Particulate Matter, And Public Parks And Open Space In Los Angeles, California, Jason A. Douglas, Reginald S. Archer, Serena E. Alexander

Health Sciences and Kinesiology Faculty Articles

Los Angeles County (LAC) low-income communities of color experience uneven asthma rates, evidenced by asthma emergency department visits (AEDV). This has partly been attributed to inequitable exposure to diesel particulate matter (DPM). Promisingly, public parks and open space (PPOS) contribute to DPM mitigation. However, low-income communities of color with limited access to PPOS may be deprived of associated public health benefits. Therefore, this novel study investigates the AEDV, DPM, PPOS nexus to address this public health dilemma and inform public policy in at-risk communities. Optimized Hotspot Analysis was used to examine geographic clustering of AEDVs, DPM, and PPOS at the …


Impact Of Deadly Dust Storms (May 2018) On Air Quality, Meteorological, And Atmospheric Parameters Over The Northern Parts Of India, Sudipta Sarkar, Akshansa Chauhan, Rajesh Kumar, Ramesh P. Singh Feb 2019

Impact Of Deadly Dust Storms (May 2018) On Air Quality, Meteorological, And Atmospheric Parameters Over The Northern Parts Of India, Sudipta Sarkar, Akshansa Chauhan, Rajesh Kumar, Ramesh P. Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

The northern part of India, adjoining the Himalaya, is considered as one of the global hot spots of pollution because of various natural and anthropogenic factors. Throughout the year, the region is affected by pollution from various sources like dust, biomass burning, industrial and vehicular pollution, and myriad other anthropogenic emissions. These sources affect the air quality and health of millions of people who live in the Indo‐Gangetic Plains. The dust storms that occur during the premonsoon months of March–June every year are one of the principal sources of pollution and originate from the source region of Arabian Peninsula and …


Coupling Between Land–Ocean–Atmosphere And Pronounced Changes In Atmospheric/Meteorological Parameters Associated With The Hudhud Cyclone Of October 2014, Akshansa Chauhan, Rajesh Kumar, Ramesh P. Singh Dec 2018

Coupling Between Land–Ocean–Atmosphere And Pronounced Changes In Atmospheric/Meteorological Parameters Associated With The Hudhud Cyclone Of October 2014, Akshansa Chauhan, Rajesh Kumar, Ramesh P. Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

India is vulnerable to all kinds of natural hazards associated with land, ocean, biosphere, atmosphere, and snow/glaciers. These natural hazards impact large areas and the population living in the affected regions. India is surrounded by ocean on three sides and is vulnerable to cyclonic activities. Every year cyclones hit the east and west coasts of India, affecting the population living along the coasts and infrastructure and inland areas. The extent of the affected inland areas depends on the intensity of the cyclone. On 12 October 2014, a strong cyclone “Hudhud” hit the east coast of India that caused a high …


Earth-Observation-Based Estimation And Forecasting Of Particulate Matter Impact On Solar Energy In Egypt, Panagiotis G. Kosmopoulos, Stelios Kazadzis, Hesham El-Askary, Michael Taylor, Antonis Gkikas, Emmanouil Proestakis, Charalampos Kontoes, Mohamed Mostafa El-Khayat Nov 2018

Earth-Observation-Based Estimation And Forecasting Of Particulate Matter Impact On Solar Energy In Egypt, Panagiotis G. Kosmopoulos, Stelios Kazadzis, Hesham El-Askary, Michael Taylor, Antonis Gkikas, Emmanouil Proestakis, Charalampos Kontoes, Mohamed Mostafa El-Khayat

Mathematics, Physics, and Computer Science Faculty Articles and Research

This study estimates the impact of dust aerosols on surface solar radiation and solar energy in Egypt based on Earth Observation (EO) related techniques. For this purpose, we exploited the synergy of monthly mean and daily post processed satellite remote sensing observations from theMODerate resolution Imaging Spectroradiometer (MODIS), radiative transfer model (RTM) simulations utilizing machine learning, in conjunction with 1-day forecasts from the Copernicus Atmosphere Monitoring Service (CAMS). As cloudy conditions in this region are rare, aerosols in particular dust, are the most common sources of solar irradiance attenuation, causing performance issues in the photovoltaic (PV) and concentrated solar power …


Impacts Of Pacific Ssts On Atmospheric Circulations Leading To California Winter Precipitation Variability: A Diagnostic Modeling, Boksoon Myoung, Sang-Wook Yeh, Jinwon Kim, Menas Kafatos Nov 2018

Impacts Of Pacific Ssts On Atmospheric Circulations Leading To California Winter Precipitation Variability: A Diagnostic Modeling, Boksoon Myoung, Sang-Wook Yeh, Jinwon Kim, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

One of the primary meteorological causes of the winter precipitation deficits and droughts in California (CA) is anomalous developments and maintenance of upper-tropospheric ridges over the northeastern Pacific. In order to understand and find the key factors controlling the winter precipitation variability in CA, the present study examines two dominant atmospheric modes of the 500 hPa geopotential height in the Northern Hemisphere using an Empirical Orthogonal Function (EOF) and their associated large-scale circulation patterns for the last 41 winters (1974/75–2014/15). Explaining 17.5% of variability, the second mode (EOF2) shows strong anti-cyclonic circulations in the North Pacific and cyclonic circulations in …


Elevated Black Carbon Concentrations And Atmospheric Pollution Around Singrauli Coal-Fired Thermal Power Plants (India) Using Ground And Satellite Data, Ramesh Singh, Sarvan Kumar, Abhay K. Singh Nov 2018

Elevated Black Carbon Concentrations And Atmospheric Pollution Around Singrauli Coal-Fired Thermal Power Plants (India) Using Ground And Satellite Data, Ramesh Singh, Sarvan Kumar, Abhay K. Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

The tropospheric NO2 concentration from OMI AURA always shows high concentrations of NO2 at a few locations in India, one of the high concentrations of NO2 hotspots is associated with the locations of seven coal-fired Thermal Power plants (TPPs) in Singrauli. Emissions from TPPs are among the major sources of black carbon (BC) soot in the atmosphere. Knowledge of BC emissions from TPPs is important in characterizing regional carbonaceous particulate emissions, understanding the fog/haze/smog formation, evaluating regional climate forcing, modeling aerosol optical parameters and concentrations of black carbon, and evaluating human health. Furthermore, elevated BC concentrations, over the …


Eddy Flux Measurements Of Sulfur Dioxide Deposition To The Sea Surface, Jack G. Porter, Warren J. De Bruyn, Eric S. Saltzman Oct 2018

Eddy Flux Measurements Of Sulfur Dioxide Deposition To The Sea Surface, Jack G. Porter, Warren J. De Bruyn, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Deposition to the sea surface is a major atmospheric loss pathway for many important trace gases, such as sulfur dioxide (SO2). The air–sea transfer of SO2 is controlled entirely on the atmospheric side of the air–sea interface due to high effective solubility and other physical– chemical properties. There have been few direct field measurements of such fluxes due to the challenges associated with making fast-response measurements of highly soluble trace gases at very low ambient levels. In this study, we report direct eddy covariance air–sea flux measurements of SO2, sensible heat, water vapor, and momentum. The measurements were made over …


Evaluation Of The Bsc-Dream8b Regional Dust Model Using The 3d Livas-Calipso Product, Dimitra Konsta, Ioannis Binietoglou, Antonis Gkikas, Stavros Solomos, Eleni Marinou, Emmanouil Proestakis, Sara Basart, Carlos Pérez García-Pando, Hesham El-Askary, Vassilis Amiridis Sep 2018

Evaluation Of The Bsc-Dream8b Regional Dust Model Using The 3d Livas-Calipso Product, Dimitra Konsta, Ioannis Binietoglou, Antonis Gkikas, Stavros Solomos, Eleni Marinou, Emmanouil Proestakis, Sara Basart, Carlos Pérez García-Pando, Hesham El-Askary, Vassilis Amiridis

Mathematics, Physics, and Computer Science Faculty Articles and Research

The ability of regional atmospheric models to accurately represent long-range transport of dust is crucial for describing dust effects on radiation and clouds and for reducing their uncertainties on these processes. The optimized CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) pure-dust product that provides the three-dimensional patterns of dust and its transport pathways is a unique tool that can address the aforementioned model's issues. In this study we use the CALIPSO dust extinction profiles as a tool for examining the performance of the regional dust model BSC-DREAM8b in space and time, for the period 2009–2013 over Northern Africa, the …


Assessment Of Indoor & Outdoor Black Carbon Emissions Rural Areas Of Indo-Gangetic Plain: Seasonal Characteristics, Source Apportionment And Radiative Forcing, Mohammad Arif, Rajesh Kumar, Ramesh Kumar, Eric Zusman, Ramesh Singh, Akhilesh Gupta Aug 2018

Assessment Of Indoor & Outdoor Black Carbon Emissions Rural Areas Of Indo-Gangetic Plain: Seasonal Characteristics, Source Apportionment And Radiative Forcing, Mohammad Arif, Rajesh Kumar, Ramesh Kumar, Eric Zusman, Ramesh Singh, Akhilesh Gupta

Mathematics, Physics, and Computer Science Faculty Articles and Research

Black Carbon (BC) has been widely recognized as the second largest source of territorial and global climate change as well as a threat to human health. There has been serious concern of BC emission and its impact in Indo-Gangetic Plains (IGP) due to the use of biomass and fossil fuels for cooking, transportation and industrial activities. An attempt has been made to study indoor (Liquefied Petroleum Gas- LPG & Traditional cookstoves users households) and outdoor concentrations; seasonal characteristics; radiative forcing and source of apportionment of BC in three districts (Sitapur, Patna and Murshidabad) of IGP during January to December 2016. …


Crop Residue Burning In Northern India: Increasing Threat To Greater India, S. Sarkar, Ramesh P. Singh, A. Chauhan Jun 2018

Crop Residue Burning In Northern India: Increasing Threat To Greater India, S. Sarkar, Ramesh P. Singh, A. Chauhan

Mathematics, Physics, and Computer Science Faculty Articles and Research

Crop residue burning (CRB) is a recurring problem, during October–November, in the northwestern regions (Punjab, Haryana, and western Uttar Pradesh) of India. The emissions from the CRB source regions spread in all directions through long-range transport mechanisms, depending upon the meteorological conditions. In recent years, numerous studies have been carried out dealing with the impact of CRB on the air quality of Delhi and surrounding areas, especially in the Indo-Gangetic Basin (also referred to as Indo-Gangetic Plain). In this paper, we present detailed analysis using both satellite- and ground-based sources, which show an increasing impact of CRB over the eastern …


Aerosol And Meteorological Parameters Associated With The Intense Dust Event Of 15 April 2015 Over Beijing, China, Sheng Zheng, Ramesh P. Singh Jun 2018

Aerosol And Meteorological Parameters Associated With The Intense Dust Event Of 15 April 2015 Over Beijing, China, Sheng Zheng, Ramesh P. Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

The northeastern parts of China, including Beijing city, the capital of China, were hit by an intense dust storm on 15 April 2015. The present paper discusses aerosol and meteorological parameters associated with this dust storm event. The back trajectory clearly shows that the dust originated from Inner Mongolia, the border of China, and Mongolia regions. Pronounced changes in aerosol and meteorological parameters along the dust track were observed. High aerosol optical depth (AOD) with low Ångström exponent (AE) are characteristics of coarse-mode dominated dust particles in the wavelength range 440–870 nm during the dusty day. During dust storm, dominance …


Predicting Spatial Patterns In Precipitation Isotope (Δ2h And Δ18o) Seasonality Using Sinusoidal Isoscapes, Scott T. Allen, James W. Kirchner, Gregory R. Goldsmith May 2018

Predicting Spatial Patterns In Precipitation Isotope (Δ2h And Δ18o) Seasonality Using Sinusoidal Isoscapes, Scott T. Allen, James W. Kirchner, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Understanding how precipitation isotopes vary spatially and temporally is important for tracer applications. We tested how well month‐to‐month variations in precipitation δ18O and δ2H were captured by sinusoidal cycles, and how well spatial variations in these seasonal cycles could be predicted, across Switzerland. Sine functions representing seasonal cycles in precipitation isotopes explained between 47% and 94% of the variance in monthly δ18O and δ2H values at each monitoring site. A significant sinusoidal cycle was also observed in line‐conditioned excess. We interpolated the amplitudes, phases, and offsets of these sine functions across the landscape, using multiple linear …


Spatio-Temporal Pattern Estimation Of Pm2.5 In Beijing-Tianjin-Hebei Region Based On Modis Aod And Meteorological Data Using The Back Propagation Neural Network, Xialing Ni, Chunxiang Cao, Yuke Zhou, Xianghui Cui, Ramesh Singh Mar 2018

Spatio-Temporal Pattern Estimation Of Pm2.5 In Beijing-Tianjin-Hebei Region Based On Modis Aod And Meteorological Data Using The Back Propagation Neural Network, Xialing Ni, Chunxiang Cao, Yuke Zhou, Xianghui Cui, Ramesh Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

With the economic growth and increasing urbanization in the last three decades, the air quality over China has continuously degraded, which poses a great threat to human health. The concentration of fine particulate matter (PM2.5) directly affects the mortality of people living in the polluted areas where air quality is poor. The Beijing-Tianjin-Hebei (BTH) region, one of the well organized urban regions in northern China, has suffered with poor air quality and atmospheric pollution due to recent growth of the industrial sector and vehicle emissions. In the present study, we used the back propagation neural network model approach to estimate …


Estimating Live Fuel Moisture From Modis Satellite Data For Wildfire Danger Assessment In Southern California Usa, Boksoon Myoung, Seung Hee Kim, Son V. Nghiem, Shenyue Jia, Kristen Whitney, Menas Kafatos Jan 2018

Estimating Live Fuel Moisture From Modis Satellite Data For Wildfire Danger Assessment In Southern California Usa, Boksoon Myoung, Seung Hee Kim, Son V. Nghiem, Shenyue Jia, Kristen Whitney, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

The goal of the research reported here is to assess the capability of satellite vegetation indices from the Moderate Resolution Imaging Spectroradiometer onboard both Terra and Aqua satellites, in order to replicate live fuel moisture content of Southern California chaparral ecosystems. We compared seasonal and interannual characteristics of in-situ live fuel moisture with satellite vegetation indices that were averaged over different radial extents around each live fuel moisture observation site. The highest correlations are found using the Aqua Enhanced Vegetation Index for a radius of 10 km, independently verifying the validity of in-situ live fuel moisture measurements over a large …


No Evidence For Trace Metal Limitation On Anaerobic Carbon Mineralization In Three Peatland Soils, Jason K. Keller, Jillian Wade Nov 2017

No Evidence For Trace Metal Limitation On Anaerobic Carbon Mineralization In Three Peatland Soils, Jason K. Keller, Jillian Wade

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Peatlands store roughly one-third of the terrestrial soil carbon and release the potent greenhouse gas methane (CH4) to the atmosphere, making these wetlands among the most important ecosystems in the global carbon cycle. Despite their importance, the controls of anaerobic decomposition of organic matter to carbon dioxide (CO2) and CH4 within peatlands are not well understood. It is known, however, that the enzymes responsible for CH4 production require cobalt, iron and nickel, and there is a growing appreciation for the potential role of trace metal limitation in anaerobic decomposition. To explore the possibility of …


Thermal Radiation Anomalies Associated With Major Earthquakes, Dimitar Ouzounov, Sergey Pulinets, Menas Kafatos, Patrick Taylor Sep 2017

Thermal Radiation Anomalies Associated With Major Earthquakes, Dimitar Ouzounov, Sergey Pulinets, Menas Kafatos, Patrick Taylor

Mathematics, Physics, and Computer Science Faculty Articles and Research

Recent developments of remote sensing methods for Earth satellite data analysis contribute to our understanding of earthquake related thermal anomalies. It was realized that the thermal heat fluxes over areas of earthquake preparation is a result of air ionization by radon (and other gases) and consequent water vapor condensation on newly formed ions. Latent heat (LH) is released as a result of this process and leads to the formation of local thermal radiation anomalies (TRA) known as OLR (outgoing Longwave radiation, Ouzounov et al, 2007). We compare the LH energy, obtained by integrating surface latent heat flux (SLHF) over the …


Estimation Of Bubble-Mediated Air–Sea Gas Exchange From Concurrent Dms And Co2 Transfer Velocities At Intermediate–High Wind Speeds, Thomas G. Bell, Sebastian Landwehr, Scott D. Miller, Warren J. De Bruyn, Adrian H. Callaghan, Brian Scanlon, Brian Ward, Mingxi Yang, Eric S. Saltzman Jul 2017

Estimation Of Bubble-Mediated Air–Sea Gas Exchange From Concurrent Dms And Co2 Transfer Velocities At Intermediate–High Wind Speeds, Thomas G. Bell, Sebastian Landwehr, Scott D. Miller, Warren J. De Bruyn, Adrian H. Callaghan, Brian Scanlon, Brian Ward, Mingxi Yang, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Simultaneous air–sea fluxes and concentration differences of dimethylsulfide (DMS) and carbon dioxide (CO2/ were measured during a summertime North Atlantic cruise in 2011. This data set reveals significant differences between the gas transfer velocities of these two gases (1kw/ over a range of wind speeds up to 21ms􀀀1. These differences occur at and above the approximate wind speed threshold when waves begin breaking. Whitecap fraction (a proxy for bubbles) was also measured and has a positive relationship with 1kw, consistent with enhanced bubble-mediated transfer of the less soluble CO2 relative to that of the more soluble DMS. However, the correlation …


Satellite Observation Of Ch4 And Co Anomalies Associated With The Wenchuan Ms 8.0 And Lushan Ms 7.0 Earthquakes In China, Y. Cui, Dimitar Ouzounov, N. Hatzopoulos, K. Sun, Z. Zou, J. Du Jun 2017

Satellite Observation Of Ch4 And Co Anomalies Associated With The Wenchuan Ms 8.0 And Lushan Ms 7.0 Earthquakes In China, Y. Cui, Dimitar Ouzounov, N. Hatzopoulos, K. Sun, Z. Zou, J. Du

Mathematics, Physics, and Computer Science Faculty Articles and Research

Spatial and temporal variations of total column of CH4 and CO (TotCH4 and TotCO) associated with the 12 May 2008 Wenchuan and 20 April 2013 Lushan earthquakes in western Sichuan, China were investigated using satellite data from AQUA AIRS in order to understand the lithospheric and atmospheric interactions during the seismic activity. The Wenchuan MS 8.0 and Lushan MS7.0 earthquakes occurred in the Longmenshan fault zone. It was observed that large amounts of gases emitted from the earth's crust into the atmosphere before, during and after the earthquakes. The anomalies of TotCH4 and TotCO occurred along the …


The Spatiotemporal Distribution Of Air Pollutants And Their Relationship With Land-Use Patterns In Hangzhou City, China, Sheng Zheng, Xueyuan Zhou, Ramesh Singh, Yuzhe Wu, Yanmei Ye, Cifang Wu Jun 2017

The Spatiotemporal Distribution Of Air Pollutants And Their Relationship With Land-Use Patterns In Hangzhou City, China, Sheng Zheng, Xueyuan Zhou, Ramesh Singh, Yuzhe Wu, Yanmei Ye, Cifang Wu

Mathematics, Physics, and Computer Science Faculty Articles and Research

Air pollution contributes to a large fraction of the total mortality estimated under the global burden of disease project (GBD) of the World Health Organization (WHO). This paper discusses an integrated study to obtain the spatiotemporal characteristics of particulate matter (PM10 and PM2.5) and trace gases (O3, SO2, NO2, and CO) pollutants in Hangzhou City (China) for the years 2014–2016. Our detailed analysis shows a relationship between air pollutants and land-use/land-cover change. Air quality parameters (PM2.5 and PM10) and trace gases (SO2, NO2, and CO) show strong monthly variations in the months of January (higher values) and July (lower values). …


Application Of Recurrent Neural Networks For Drought Projections In California, J. A. Le, Hesham El-Askary, Mohamed Allali, Daniele C. Struppa Jan 2017

Application Of Recurrent Neural Networks For Drought Projections In California, J. A. Le, Hesham El-Askary, Mohamed Allali, Daniele C. Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

We use recurrent neural networks (RNNs) to investigate the complex interactions between the long-term trend in dryness and a projected, short but intense, period of wetness due to the 2015-2016 El Niño. Although it was forecasted that this El Niño season would bring significant rainfall to the region, our long-term projections of the Palmer Z Index (PZI) showed a continuing drought trend, contrasting with the 1998-1999 El Niño event. RNN training considered PZI data during 1896-2006 that was validated against the 2006-2015 period to evaluate the potential of extreme precipitation forecast. We achieved a statistically significant correlation of 0.610 between …