scholarly journals Coastal response to the passage of tropical cyclone Juliette on the Central Pacific Coast of Mexico

2021 ◽  
Vol 60 (4) ◽  
pp. 357-366
Author(s):  
Anatoliy Filonov ◽  
Iryna Tereshchenko ◽  
Lydia Ladah ◽  
Cesar Monzon ◽  
Jorge Montes-Arrechiga ◽  
...  
Keyword(s):  
Water Column ◽  
Sea Level ◽  
Pacific Coast ◽  
Meteorological Data ◽  
Central Pacific ◽  
Data Set ◽  
Wind Speeds ◽  
Level Data ◽  
Before And After

In situ coastal oceanographic and meteorological data were collected on the Mexican Tropical Pacific coast near Barra de Navidad, Jalisco, Mexico during September 2001 from before and after the passing of Hurricane Juliette. When the leading and trailing edges of the hurricane passed through the study area, wind speeds reached 15 m s-1 and caused a significant deepening of the thermocline, mixing of the upper 40 m of the water column, and a rise in sea level of almost 50 cm at the coast, with effects lasting for about 5 days. A decrease in temperature and an increase in salinity occurred in the upper 20 m, with the opposite occurring below 20 m. Although analyses of open ocean responses to hurricanes are widely available from satellite data, in situ coastal water-column and sea-level data are difficult to acquire, yet crucial to inform coastal flooding models and risk assessment studies. This short data set provides a rare opportunity to explore in situ hurricane effects on this understudied coast.

Large earthquakes, mean sea level, and tsunamis along the Pacific Coast of Mexico and Central America

1983 ◽  
Vol 73 (2) ◽  
pp. 553-570
Author(s):  
Gonzalo Cruz ◽  
Max Wyss
Keyword(s):  
Central America ◽  
Sea Level ◽  
Pacific Coast ◽  
Tide Gauge ◽  
Mean Sea Level ◽  
Coseismic Change ◽  
Level Data ◽  
The Pacific ◽  
Before And After ◽  
The Difference

abstract Along the Pacific Coast of Mexico and Central America, 26 local tsunamis have been reported during the period 1732 to 1973. Nine of these were caused by earthquakes with teleseismic hypocenters, all of which were located well inland. If these epicenters were correct, these earthquakes could not have generated tsunamis. Under the assumption that the true epicenters must have been located at the coast or off shore, it was estimated that teleseismic hypocenters in this area are mislocated by about 75 km toward the northeast, and 20 km toward greater depth. We propose that most teleseismic locations in this area are afflicted by this same error. The most likely cause for the mislocations are shorter than expected travel times for rays in the down-dip direction of the subducted lithospheric slab. These rays travel to North American stations which contribute strongly to hypocenter locations in Middle America. The annual mean sea level of 13 tide gauge stations along the Pacific coast of Mexico and Central America were examined for evidence of vertical crustal deformation changes that could have been associated with earthquakes along this coast. Only one coseismic change could be identified in the annual mean sea level data. It occurred at Acapulco, Mexico, during the 11 May (Ms = 7.0) and 19 May (Ms = 7.2) 1962 earthquakes. The crustal uplift was about 22 cm, estimated from the difference of the 10-yr sea level means before and after the events. By comparing annual mean with daily mean sea level data, it appears that about 23 per cent of the permanent uplift observed at Acapulco was due to aseismic slip or aftershocks in this area. If tide gauge data in this area are kept current, long-term precursory crustal movements might be detectable if they exceed several centimeters.

scholarly journals Returns to compensation in trucking: Does safety pay?

2019 ◽  
Vol 30 (2) ◽  
pp. 262-284 ◽  
Author(s):  
Michael R Faulkiner ◽  
Michael H Belzer
Keyword(s):  
Net Present Value ◽  
Retention Rates ◽  
Firm Level ◽  
Data Set ◽  
Motor Carrier ◽  
Level Data ◽  
Motor Carrier Industry ◽  
The Us ◽  
Before And After ◽  
Trucking Companies

Large truck crashes remain a significant problem in the truckload sector of the US motor carrier industry. Employing a unique firm-level data set from a large US truckload motor carrier, we identified two different driver groups hired during two distinct pay regimes. Before-and-after data on wages and safety outcomes created a natural experiment. Higher wages paid to experienced drivers in the new pay regime led to higher driver retention rates. Experienced drivers had lower average crash costs and were more productive during each tenure month. Experienced drivers had a much larger expected discounted net present value when compared with inexperienced drivers. As the previously inexperienced drivers gained additional experience, their crash probabilities and their value began to mirror those of the experienced drivers, demonstrating the value of greater tenure. This research supports ‘safe rates’ public policy because safety pays – for trucking companies, for cargo owners and for society. JEL Codes: J24, J28, J33

In situ ground based measurements of low level clouds during 10 years of Pallas cloud experiments.

2020 ◽  
Author(s):  
Konstantinos Doulgeris ◽  
David Brus
Keyword(s):  
Water Content ◽  
Liquid Water ◽  
Meteorological Data ◽  
Liquid Water Content ◽  
Data Set ◽  
Radiative Balance ◽  
Low Level ◽  
Major Factors

<p>Clouds and their interaction with aerosols are considered one of the major factors that are connected with uncertainties in predictions of climate change and are highly associated with earth radiative balance. Semi long term in-situ measurements of Arctic low-level clouds have been conducted during last 10 year (2009 - 2019) autumns at Sammaltunturi station (67◦58´N, 24◦07´E, and 560 m a.s.l.), the part of Pallas Atmosphere - Ecosystem Supersite and Global Atmosphere Watch (GAW) programme. During these years a unique data set of continuous and detailed ground-based cloud observations over the sub-Arctic area was obtained. The in-situ cloud measurements were made using two cloud probes that were installed on the roof of the station: the Cloud, Aerosol and Precipitation Spectrometer probe (CAPS) and the Forward Scattering Spectrometer Probe<strong> (</strong>FSSP<strong>)</strong>, both made by droplet measurement technologies (DMT, Longmont, CO, USA). CAPS in­cludes three instruments: the Cloud Imaging Probe (CIP, 12.5 μm-1.55 mm), the Cloud and Aerosol Spectrometer (CAS-DPOL, 0.51-50 μm) with depolarization feature and the Hotwire Liquid Water Content Sensor (Hotwire LWC, 0 - 3 g/m<sup>3</sup>). Vaisala FD12P weather sensor was used to measure all the meteorological data. The essential cloud microphysical parameters we investigated during this work were the size distributions, the total number concentrations, the effective radius of cloud droplets and the cloud liquid water content. The year to year comparison and correlations among semi long term in situ cloud measurements and meteorology are presented.</p>

scholarly journals Estimation of bubble-mediated air–sea gas exchange from concurrent DMS and CO<sub>2</sub> transfer velocities at intermediate–high wind speeds

2017 ◽  
Vol 17 (14) ◽  
pp. 9019-9033 ◽  
Author(s):  
Thomas G. Bell ◽  
Sebastian Landwehr ◽  
Scott D. Miller ◽  
Warren J. de Bruyn ◽  
Adrian H. Callaghan ◽  
...  
Keyword(s):  
Wind Speed ◽  
Gas Exchange ◽  
North Atlantic ◽  
Gas Transfer ◽  
Data Set ◽  
Wind Speeds ◽  
Wide Range ◽  
Carbon Dioxide Co2 ◽  
The Impact

Abstract. 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 (Δkw) over a range of wind speeds up to 21 m s−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 Δkw, consistent with enhanced bubble-mediated transfer of the less soluble CO2 relative to that of the more soluble DMS. However, the correlation of Δkw with whitecap fraction is no stronger than with wind speed. Models used to estimate bubble-mediated transfer from in situ whitecap fraction underpredict the observations, particularly at intermediate wind speeds. Examining the differences between gas transfer velocities of gases with different solubilities is a useful way to detect the impact of bubble-mediated exchange. More simultaneous gas transfer measurements of different solubility gases across a wide range of oceanic conditions are needed to understand the factors controlling the magnitude and scaling of bubble-mediated gas exchange.

Validation of sea level data in the east Asian marginal seas: Comparison between TOPEX/POSEIDON altimeter and in-situ tide gauges

2003 ◽  
Vol 20 (4) ◽  
pp. 650-660
Author(s):  
Yong-Hoon Youn ◽  
Im Sang Oh ◽  
Ki-Hyun Kim ◽  
Young-Hyang Park ◽  
Jong Woo Kim
Keyword(s):  
Sea Level ◽  
East Asian ◽  
Tide Gauges ◽  
Marginal Seas ◽  
East Asian Marginal Seas ◽  
Level Data

scholarly journals Global distribution of sea salt aerosols: new constraints from in situ and remote sensing observations

2011 ◽  
Vol 11 (7) ◽  
pp. 3137-3157 ◽  
Author(s):  
L. Jaeglé ◽  
P. K. Quinn ◽  
T. S. Bates ◽  
B. Alexander ◽  
J.-T. Lin
Keyword(s):  
Wind Speed ◽  
Source Function ◽  
Sea Salt ◽  
Global Network ◽  
High Wind ◽  
Central Pacific ◽  
Wind Speeds ◽  
Sea Salt Aerosols ◽  
The Tropics

Abstract. We combine in situ measurements of sea salt aerosols (SS) from open ocean cruises and ground-based stations together with aerosol optical depth (AOD) observations from MODIS and AERONET, and the GEOS-Chem global chemical transport model to provide new constraints on SS emissions over the world's oceans. We find that the GEOS-Chem model using the Gong (2003) source function overestimates cruise observations of coarse mode SS mass concentrations by factors of 2–3 at high wind speeds over the cold waters of the Southern, North Pacific and North Atlantic Oceans. Furthermore, the model systematically underestimates SS over the warm tropical waters of the Central Pacific, Atlantic, and Indian Oceans. This pattern is confirmed by SS measurements from a global network of 15 island and coastal stations. The model discrepancy at high wind speeds (>6 m s −1) has a clear dependence on sea surface temperature (SST). We use the cruise observations to derive an empirical SS source function depending on both wind speed and SST. Implementing this new source function in GEOS-Chem results in improved agreement with in situ observations, with a decrease in the model bias from +64% to +33% for the cruises and from +32% to −5% for the ground-based sites. We also show that the wind speed-SST source function significantly improves agreement with MODIS and AERONET AOD, and provides an explanation for the high AOD observed over the tropical oceans. With the wind speed-SST formulation, global SS emissions show a small decrease from 5200 Mg yr−1 to 4600 Mg yr−1, while the SS burden decreases from 9.1 to 8.5 mg m−2. The spatial distribution of SS, however, is greatly affected, with the SS burden increasing by 50% in the tropics and decreasing by 40% at mid- and high-latitudes. Our results imply a stronger than expected halogen source from SS in the tropical marine boundary layer. They also imply stronger radiative forcing of SS in the tropics and a larger response of SS emissions to climate change than previously thought.

Five years’ central pacific sea level from in situ array, satellite altimeter and numerical model: Research note

1994 ◽  
Vol 32 (2) ◽  
pp. 495-506 ◽  
Author(s):  
Kathleen A. Donohue ◽  
Mark Wimbush ◽  
Xiaoli Zhu ◽  
Stephen M. Chiswell ◽  
Roger Lukas ◽  
...  
Keyword(s):  
Numerical Model ◽  
Sea Level ◽  
Research Note ◽  
Central Pacific ◽  
Satellite Altimeter ◽  
Model Research

scholarly journals A field study to estimate the impact of noise barriers on mitigation of near road air pollution

2021 ◽  
Author(s):  
Ranga Rajan Thiruvenkatachari ◽  
Yifan Ding ◽  
David Pankratz ◽  
Akula Venkatram
Keyword(s):  
Air Pollution ◽  
Field Study ◽  
Dispersion Model ◽  
Meteorological Data ◽  
Dispersion Models ◽  
Noise Barriers ◽  
Data Set ◽  
Wind Speeds ◽  
Sonic Anemometers ◽  
The Impact

AbstractAir pollution associated with vehicle emissions from roadways has been linked to a variety of adverse health effects. Wind tunnel and tracer studies show that noise barriers mitigate the impact of this pollution up to distances of 30 times the barrier height. Data from these studies have been used to formulate dispersion models that account for this mitigating effect. Before these models can be incorporated into Federal and State regulations, it is necessary to demonstrate their applicability under real-world conditions. This paper describes a comprehensive field study conducted in Riverside, CA, in 2019 to collect the data required to evaluate the performance of these models. Eight vehicles fitted with SF6 tracer release systems were driven in a loop on a 2-km stretch of Interstate 215 that had a 5-m tall noise barrier on the downwind side. The tracer, SF6, was sampled at over 40 locations at distances ranging from 5 to 200 m from the barrier. Meteorological data were measured with several 3-D sonic anemometers located upwind and downwind of the highway. The data set, corresponding to 10 h collected over 4 days, consists of information on emissions, tracer concentrations, and micrometeorological variables that can be used to evaluate barrier effects in dispersion models. An analysis of the data using a dispersion model indicates that current models are likely to overestimate concentrations, or underestimate the mitigation from barriers, at low wind speeds. We suggest an approach to correct this problem.

scholarly journals A post-glacial sea level hinge on the central Pacific coast of Canada

2014 ◽  
Vol 97 ◽  
pp. 148-169 ◽  
Author(s):  
Duncan McLaren ◽  
Daryl Fedje ◽  
Murray B. Hay ◽  
Quentin Mackie ◽  
Ian J. Walker ◽  
...  
Keyword(s):  
Sea Level ◽  
Pacific Coast ◽  
Central Pacific
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