scholarly journals Seasonal changes in Fe species and soluble Fe concentration in the atmosphere in the Northwest Pacific region based on the analysis of aerosols collected in Tsukuba, Japan

2013 ◽  
Vol 13 (15) ◽  
pp. 7695-7710 ◽  
Author(s):  
Y. Takahashi ◽  
T. Furukawa ◽  
Y. Kanai ◽  
M. Uematsu ◽  
G. Zheng ◽  
...  
Keyword(s):  
Fossil Fuel ◽  
Fuel Combustion ◽  
Anthropogenic Sources ◽  
Anthropogenic Activity ◽  
Northwest Pacific ◽  
Pacific Region ◽  
Fossil Fuel Combustion ◽  
Factors Affecting ◽  
X Ray ◽  
Fe Species

Abstract. Atmospheric iron (Fe) can be a significant source of nutrition for phytoplankton inhabiting remote oceans, which in turn has a large influence on the Earth's climate. The bioavailability of Fe in aerosols depends mainly on the fraction of soluble Fe (= [FeSol]/[FeTotal], where [FeSol] and [FeTotal] are the atmospheric concentrations of soluble and total Fe, respectively). However, the numerous factors affecting the soluble Fe fraction have not been fully understood. In this study, the Fe species, chemical composition, and soluble Fe concentrations in aerosols collected in Tsukuba, Japan were investigated over a year (nine samples from December 2002 to October 2003) to identify the factors affecting the amount of soluble Fe supplied into the ocean. The soluble Fe concentration in aerosols is correlated with those of sulfate and oxalate originated from anthropogenic sources, suggesting that soluble Fe is mainly derived from anthropogenic sources. Moreover, the soluble Fe concentration is also correlated with the enrichment factors of vanadium and nickel emitted by fossil fuel combustion. These results suggest that the degree of Fe dissolution is influenced by the magnitude of anthropogenic activity, such as fossil fuel combustion. X-ray absorption fine structure (XAFS) spectroscopy was performed in order to identify the Fe species in aerosols. Fitting of XAFS spectra coupled with micro X-ray fluorescence analysis (μ-XRF) showed the main Fe species in aerosols in Tsukuba to be illite, ferrihydrite, hornblende, and Fe(III) sulfate. Moreover, the soluble Fe fraction in each sample measured by leaching experiments is closely correlated with the Fe(III) sulfate fraction determined by the XAFS spectrum fitting, suggesting that Fe(III) sulfate is the main soluble Fe in the ocean. Another possible factor that can control the amount of soluble Fe supplied into the ocean is the total Fe(III) concentration in the atmosphere, which was high in spring due to the high mineral dust concentrations during spring in East Asia. However, this factor does not contribute to the amount of soluble Fe to a larger degree than the effect of Fe speciation, or more strictly speaking the presence of Fe(III) sulfate. Therefore, based on these results, the most significant factor influencing the amount of soluble Fe in the North Pacific region is the concentration of anthropogenic Fe species such as Fe(III) sulfate that can be emitted from megacities in Eastern Asia.

scholarly journals Seasonal changes in Fe species and soluble Fe concentration in the atmosphere in the Northwest Pacific region based on the analysis of aerosols collected in Tsukuba, Japan

2013 ◽  
Vol 13 (3) ◽  
pp. 7599-7641 ◽  
Author(s):  
Y. Takahashi ◽  
T. Furukawa ◽  
Y. Kanai ◽  
M. Uematsu ◽  
G. Zheng ◽  
...  
Keyword(s):  
Fossil Fuel ◽  
Fuel Combustion ◽  
Anthropogenic Sources ◽  
Anthropogenic Activity ◽  
Northwest Pacific ◽  
Pacific Region ◽  
Fossil Fuel Combustion ◽  
Factors Affecting ◽  
X Ray ◽  
Fe Species

Abstract. Atmospheric iron (Fe) can be a significant source of nutrition for phytoplankton inhabiting remote oceans, which in turn has a large influence on the Earth's climate. The bioavailability of Fe in aerosols depends mainly on the fraction of soluble Fe (= [FeSol]/[FeTotal], where [FeSol] and [FeTotal] are the atmospheric concentrations of soluble and total Fe, respectively). However, the numerous factors affecting the soluble Fe fraction have not been fully understood. In this study, the Fe species, chemical composition, and soluble Fe concentrations in aerosols collected in Tsukuba, Japan were investigated over a year (nine samples from December 2002 to October 2003) to identify the factors affecting the amount of soluble Fe supplied into the ocean. The soluble Fe concentration in aerosols is correlated with those of sulfate and oxalate originated from anthropogenic sources, suggesting that soluble Fe is mainly derived from anthropogenic sources. Moreover, the soluble Fe concentration is also correlated with the enrichment factors of vanadium and nickel emitted by fossil fuel combustion. These results suggest that the degree of Fe dissolution is influenced by the magnitude of anthropogenic activity, such as fossil fuel combustion. X-ray absorption fine structure (XAFS) spectroscopy was performed in this study to identify the Fe species in aerosols. The fitting of XAFS spectra coupled with micro X-ray fluorescence analysis (XRF) determined the main Fe species in aerosols in Tsukuba to be illite, ferrihydrite, hornblende, and Fe(III) sulfate. Moreover, the soluble Fe fraction in each sample measured by leaching experiments is closely correlated with the Fe(III) sulfate fraction determined by the XAFS spectrum fitting, suggesting that Fe(III) sulfate is the main soluble Fe in the ocean. Another possible factor that can control the amount of soluble Fe supplied into the ocean is the total Fe(III) concentration in the atmosphere, which was high in spring due to the high mineral dust concentrations during spring in East Asia. However, this factor does not contribute to the amount of soluble Fe to a larger degree than the effect of Fe speciation, or more strictly speaking the presence of Fe(III) sulfate. Therefore, based on these results, the most significant factor influencing the amount of soluble Fe in the North Pacific region is the concentration of anthropogenic Fe species such as Fe(III) sulfate that can be emitted from megacities in Eastern Asia.

scholarly journals Weekly cycle of NO<sub>2</sub> by GOME measurements: a signature of anthropogenic sources

2003 ◽  
Vol 3 (6) ◽  
pp. 2225-2232 ◽  
Author(s):  
S. Beirle ◽  
U. Platt ◽  
M. Wenig ◽  
T. Wagner
Keyword(s):  
Atmospheric Chemistry ◽  
Fossil Fuel ◽  
Fuel Combustion ◽  
Weekend Effect ◽  
Anthropogenic Sources ◽  
Anthropogenic Source ◽  
Total Production ◽  
Fossil Fuel Combustion ◽  
Weekly Cycle ◽  
Tropospheric No2

Abstract. Nitrogen oxides (NO+NO2=NOx and reservoir species) are important trace gases in the troposphere with impact on human health, atmospheric chemistry and climate. Besides natural sources (lightning, soil emissions) and biomass burning, fossil fuel combustion is estimated to be responsible for about 50% of the total production of NOx. Since human activity in industrialized countries largely follows a seven-day cycle, fossil fuel combustion is expected to be reduced during weekends. This "weekend effect" is well known from local, ground based measurements, but has never been analysed on a global scale before. The Global Ozone Monitoring Experiment (GOME) on board the ESA-satellite ERS-2 allows measurements of NO2 column densities. By estimating and subtracting the stratospheric column, and considering radiative transfer, vertical column densities (VCD) of tropospheric NO2 can be determined (e.g. Leue et al., 2001). We demonstrate the statistical analysis of weekly cycles of tropospheric NO2 VCDs for different regions of the world. In the cycles of the industrialized regions and cities in the US, Europe and Japan a clear Sunday minimum of tropospheric NO2 VCD can be seen. Sunday NO2 VCDs are about 25-50% lower than working day levels. Metropolitan areas with other religious and cultural backgrounds (Jerusalem, Mecca) show different weekly patterns corresponding to different days of rest. In China, no weekly pattern can be found. The presence of a weekly cycle in the measured tropospheric NO2 VCD may help to identify the different anthropogenic source categories. Furthermore, we estimated the lifetime of tropospheric NO2 by analysing the mean weekly cycle exemplarily over Germany, obtaining a value of about 6 h in summer and 18-24 h in winter.

scholarly journals Oxygenated organic functional groups and their sources in single and submicron organic particles in MILAGRO 2006 campaign

2009 ◽  
Vol 9 (1) ◽  
pp. 4567-4607 ◽  
Author(s):  
S. Liu ◽  
S. Takahama ◽  
L. M. Russell ◽  
S. Gilardoni ◽  
D. Baumgardner
Keyword(s):  
Functional Groups ◽  
Biomass Burning ◽  
Fossil Fuel ◽  
Sampling Period ◽  
Fuel Combustion ◽  
Ftir Spectra ◽  
Submicron Particles ◽  
Fossil Fuel Combustion ◽  
X Ray ◽  
Organic Functional Groups

Abstract. Fourier Transform Infrared (FTIR) and X-ray Fluorescence (XRF) were used to measure organic functional groups and elements of submicron particles collected during MILAGRO in March 2006 on three platforms: the Mexico City urban area (SIMAT), the high altitude site at 4010 m (Altzomoni), and the NCAR C130 aircraft. Scanning transmission X-ray Microscopy (STXM) and Near-Edge X-ray Absorption Fine Structure (NEXAFS) were applied to single particle organic functional group abundance analysis of particles simultaneously collected at SIMAT and C130. Correlations of elemental concentrations showed different groups of source related elements at SIMAT, Altzomoni, and C130, suggesting different processes affecting the air masses sampled at the three platforms. Cluster analysis resulted in seven distinct Clusters of FTIR spectra, with the last three clusters consisting of spectra collected almost exclusively on the C130 platform, reflecting the variety of sources contributing to C130 samples. Positive Matrix Factorization (PMF) of NEXAFS-STXM spectra identified three main factors representing soot, secondary, and biomass burning type spectra. PMF of FTIR spectra resulted in three fossil fuel combustion type factors, one biomass burning factor, and one mixed or processed factor. The fossil fuel combustion type factors were found to have the largest contributions to OM, while the processed factor has the largest O/C among all factors. Alkane, carboxylic acid, and amine functional groups were mainly associated with combustion related sources, while alcohol groups were likely from atmospheric processing of mixed sources. While the processed factor has the highest O/C, half of the OM and O/C measured could be attributed directly to fossil fuel combustion sources. Both PMF of NEXAFS-STXM spectra and PMF of FTIR spectra indicate that the combustion type factors are more affected by fluctuations in local sources, while the processed factors are more consistent during the sampling period.

scholarly journals Weekly cycle of NO<sub>2</sub> by GOME measurements: A signature of anthropogenic sources

2003 ◽  
Vol 3 (4) ◽  
pp. 3451-3467 ◽  
Author(s):  
S. Beirle ◽  
U. Platt ◽  
M. Wenig ◽  
T. Wagner
Keyword(s):  
Biomass Burning ◽  
Fossil Fuel ◽  
Fuel Combustion ◽  
Weekend Effect ◽  
Anthropogenic Sources ◽  
Total Production ◽  
Fossil Fuel Combustion ◽  
Natural Sources ◽  
Weekly Cycle ◽  
Tropospheric No2

Abstract. Nitrogen oxides (NO+NO2=NOx) are important trace gases in the troposphere with impact on human health, atmospheric chemistry and climate. Besides natural sources (lightning, soil emissions) and biomass burning, fossil fuel combustion is estimated to be responsible for about 50\\% of the total production of  NOx. Since human activity in industrialized countries largely follows an artificial seven-day cycle, fossil fuel combustion is expected to  be reduced during weekends. This "weekend effect" is well known from local, ground based measurements, but has never been analysed on a global scale before. The Global Ozone Monitoring Experiment (GOME) on board the ESA-satellite ERS-2 allows measurements of  NO2 column densities. Applying sophisticated algorithms, vertical column densities (VCD) of tropospheric NO2 can be determined. We demonstrate the statistical analysis of weekly cycles of tropospheric NO2 VCDs for different regions of the world. In the cycles of the industrialized regions and cities in the US, Europe and Japan a clear Sunday minimum of tropospheric NO2 VCD can be seen. Sunday NO2 VCDs are about 25–50% lower than working day levels. Metropolitan areas with other religious and cultural backgrounds (Jerusalem, Mecca) show different weekly patterns corresponding to different days of rest. In China, no weekly pattern can be found. The presence of a weekly cycle in the measured tropospheric NO2 VCD allows the identification of anthropogenic sources. In addition, the fraction of emissions subjected to a weekly cycle (mainly transport, power generation) with respect to a constant background (all kind of natural sources, biomass burning, heavy industry) can be estimated. Furthermore, we estimated the lifetime of tropospheric NO2 by analysing the mean weekly cycle over Germany in detail, obtaining a value of about 12 h.

Response : Sulfur Mobilization as a Result of Fossil Fuel Combustion

Science ◽  
1972 ◽  
Vol 175 (4027) ◽  
pp. 1279-1279
Author(s):  
K. K. Bertine ◽  
Edward D. Goldberg
Keyword(s):  
Fossil Fuel ◽  
Fuel Combustion ◽  
Fossil Fuel Combustion

Ultrasonic Creep Damage Detection by Frequency Analysis for Boiler Piping

2006 ◽  
Vol 129 (4) ◽  
pp. 713-718 ◽  
Author(s):  
Hiroaki Hatanaka ◽  
Nobukazu Ido ◽  
Takuya Ito ◽  
Ryota Uemichi ◽  
Minoru Tagami ◽  
...  
Keyword(s):  
Power Generation ◽  
High Temperature ◽  
Damage Detection ◽  
Fossil Fuel ◽  
Creep Damage ◽  
High Energy ◽  
Assessment Method ◽  
Nondestructive Method ◽  
Fuel Combustion ◽  
Fossil Fuel Combustion

Boiler piping of fossil-fuel combustion power generation plants are exposed to high-temperature and high-pressure environments, and failure of high-energy piping due to creep damage has been a concern. Therefore, a precise creep damage assessment method is needed. This paper proposes a nondestructive method for creep damage detection of piping in fossil-fuel combustion power generation plants by ultrasonic testing. Ultrasonic signals are transformed to signals in a frequency domain by Fourier transform, and a specific frequency band is chosen. To determine the creep damage, the spectrum intensities are calculated. Calculated intensities have a good correlation to life consumption of the weld joints, and this method is able to predict the remaining life of high-temperature piping, which has been already installed.

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