scholarly journals In-situ measurements of seismic velocities at twelve locations in the San Francisco Bay region

1975 ◽  
Author(s):  
J.F. Gibbs ◽  
T.E. Fumal ◽  
R.D. Borcherdt
Keyword(s):  
San Francisco ◽  
San Francisco Bay ◽  
In Situ Measurements ◽  
Seismic Velocities

In-situ measurements of seismic velocities in the San Francisco Bay Region; part III

1977 ◽  
Author(s):  
James F. Gibbs ◽  
Thomas E. Fumal ◽  
Roger D. Borcherdt ◽  
Edward F. Roth
Keyword(s):  
San Francisco ◽  
San Francisco Bay ◽  
In Situ Measurements ◽  
Seismic Velocities

scholarly journals Measurements of N<sub>2</sub>O<sub>5</sub>, NO<sub>2</sub>, and O<sub>3</sub> east of the San Francisco Bay

2004 ◽  
Vol 4 (5) ◽  
pp. 6645-6665
Author(s):  
E. C. Wood ◽  
T. H. Bertram ◽  
P. J. Wooldridge ◽  
R. C. Cohen
Keyword(s):  
Steady State ◽  
San Francisco ◽  
San Francisco Bay ◽  
Intermediate Compound ◽  
In Situ Measurements ◽  
Mixing Ratios

Abstract. We report in situ measurements of N2O5, NO2, and O3 in Contra Costa County, California during January 2004. Mixing ratios of N2O5, an intermediate compound in the atmosphere's nocturnal cleansing process, ranged up to 200 pmol/mol at night. The highest N2O5 concentrations were correlated with low O3 and high NO2 concentrations. The calculated steady state lifetime for N2O5 ranged from 5 to 30 min. The total HNO3 produced by N2O5 hydrolysis over a 14 h night was comparable to ambient NO2 concentrations, and is estimated to be a factor of nine bigger than the HNO3 produced during the day.

scholarly journals Measurements of N<sub>2</sub>O<sub>5</sub>, NO<sub>2</sub>, and O<sub>3</sub> east of the San Francisco Bay

2005 ◽  
Vol 5 (2) ◽  
pp. 483-491 ◽  
Author(s):  
E. C. Wood ◽  
T. H. Bertram ◽  
P. J. Wooldridge ◽  
R. C. Cohen
Keyword(s):  
Steady State ◽  
San Francisco ◽  
San Francisco Bay ◽  
Intermediate Compound ◽  
In Situ Measurements ◽  
Mixing Ratios

Abstract. We report in situ measurements of N2O5, NO2, and O3 in Contra Costa County, California during January 2004. Mixing ratios of N2O5, an intermediate compound in the atmosphere's nocturnal cleansing process, ranged up to 200pmol/mol at night. The highest N2O5 concentrations were correlated with low O3 and high NO2 concentrations. The calculated steady state lifetime for N2O5 ranged from 5 to 30min. The total HNO3 produced by N2O5 hydrolysis over a 14h night was comparable to ambient NO2 concentrations, and is estimated to be a factor of nine bigger than the HNO3 produced during the day.

scholarly journals Mercury Dynamics in a San Francisco Estuary Tidal Wetland: Assessing Dynamics Using In Situ Measurements

2012 ◽  
Vol 35 (4) ◽  
pp. 1036-1048 ◽  
Author(s):  
Brian A. Bergamaschi ◽  
Jacob A. Fleck ◽  
Bryan D. Downing ◽  
Emmanuel Boss ◽  
Brian A. Pellerin ◽  
...  
Keyword(s):  
San Francisco ◽  
In Situ Measurements ◽  
San Francisco Estuary ◽  
Tidal Wetland

scholarly journals Quantification of Polychlorinated Biphenyl (PCB) Concentration in San Francisco Bay Using Satellite Imagery

2018 ◽  
Vol 10 (7) ◽  
pp. 1110 ◽  
Author(s):  
Annette Hilton ◽  
Jesse Bausell ◽  
Raphael Kudela
Keyword(s):  
San Francisco ◽  
Satellite Imagery ◽  
Polychlorinated Biphenyl ◽  
San Francisco Bay ◽  
Atmospheric Correction ◽  
Cost Effective ◽  
Landsat 8 ◽  
Valuable Insight ◽  
Sentinel 2A

The U.S. Environmental Protection Agency banned the use of polychlorinated biphenyls (PCBs) in 1979, due to the high environmental and public health risks with which they are associated. However, PCBs continue to persist in the San Francisco Bay (SFB), often at concentrations deemed unsafe for humans. In situ PCB monitoring within the SFB is extremely limited, due in large part to the high monetary costs associated with sampling. Here we offer a cost effective alternative to in situ PCB monitoring by demonstrating the feasibility of indirectly quantifying PCBs in the SFB via satellite remote sensing using a two-step approach. First, we determined the relationship between in situ PCB concentrations and suspended sediment concentrations (SSC) in the SFB. We then correlated in situ SSC with spatially and temporally consistent Landsat 8 and Sentinel 2A reflectances. We demonstrate strong relationships between SSC and PCBs in all three SFB sub-embayments (R2 > 0.28–0.80, p < 0.01), as well as a robust relationship between SSC and satellite measurements for both Landsat 8 and Sentinel 2A (R2 > 0.72, p < 0.01). These relationships held regardless of the atmospheric correction regime that we applied. The end product of these relationships is an empirical two-step relationship capable of deriving PCBs from satellite imagery. Our approach of estimating PCBs in the SFB by remotely sensing SSC is extremely cost-effective when compared to traditional in situ techniques. Moreover, it can also be utilized to generate PCB concentration maps for the SFB. These maps could one day serve as an important tool for PCB remediation in the SFB, as they can provide valuable insight into the spatial distribution of PCBs throughout the bay, as well as how this distribution changes over time.

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