Regional-scale boundary layer ozone variations in the eastern United States and their association with meteorological variations

1995 ◽  
Vol 29 (17) ◽  
pp. 2259-2273 ◽  
Author(s):  
F Vukovich
Keyword(s):  
United States ◽  
Boundary Layer ◽  
Regional Scale ◽  
Eastern United States ◽  
Boundary Layer Ozone ◽  
Ozone Variations

Simulating regional-scale ozone climatology over the eastern United States: model evaluation results

2004 ◽  
Vol 38 (17) ◽  
pp. 2627-2638 ◽  
Author(s):  
C Hogrefe ◽  
J Biswas ◽  
B Lynn ◽  
K Civerolo ◽  
J.-Y Ku ◽  
...  
Keyword(s):  
United States ◽  
Model Evaluation ◽  
Regional Scale ◽  
Eastern United States

An Evaluation of Linear Site-Response Parameters in the Central and Eastern United States and the Importance of Empirical Site-Response Estimations

2020 ◽  
Vol 110 (2) ◽  
pp. 489-507
Author(s):  
N. Seth Carpenter ◽  
Zhenming Wang ◽  
Edward W. Woolery
Keyword(s):  
United States ◽  
Site Response ◽  
Regional Scale ◽  
Eastern United States ◽  
S Wave ◽  
Site Factors ◽  
Simplified Approach ◽  
Multiple Observations ◽  
Linear Viscoelastic ◽  
Sediment Layers

ABSTRACT Site response at many locations in the central and eastern United States is a resonance-based phenomenon, which site factors based on the VS30 proxy may not reliably capture. Alternative factors, fundamental frequency, f0, and fundamental-mode amplification, A0, calculated from simplified expressions were evaluated against 1D linear, viscoelastic SH-wave full-resonance (FR) site responses. Tests were conducted using S-wave velocity profiles to bedrock at 11 seismic stations. The results showed that simplified expressions approximate FR f0 and A0 at most stations. However, at two sites with intermediate-depth strong impedance contrasts, the simplified approach underestimates A0 by ∼40%. In addition, FR f0 and A0 were compared with weak-motion earthquake S-wave horizontal-to-vertical (H/V) spectral ratios. Measuring f0 and A0 from S-wave H/V for our comparisons required considering multiple observations at the regional scale. The first S-wave H/V peaks occurred between ∼1 and ∼3  Hz at all seven stations in the Illinois basin (IB), which is a much lower f0 than expected for five of these sites. Thus, we used the first S-wave H/V peaks at f>3  Hz at these five sites in our comparisons. The S-wave H/V peaks we evaluated indicate that S-wave H/V can approximate FR f0. However, although the A0 measured from S-wave H/V is positively correlated with theoretical A0, it overestimated FR A0 by more than 40% at all but three sites, indicating that additional study is needed to determine the appropriate use of A0 from S-wave H/V. The observed, unmodeled amplifications between ∼1 and ∼3  Hz are of similar magnitudes as those from the shallower sediment layers at most stations, which highlights the importance of collecting empirical site-response estimations. Furthermore, the amplifications indicate the need to investigate deeper velocity structures in the IB to account for site responses within the frequency band of engineering interest.

Sign in / Sign up

Export Citation Format

Share Document