scholarly journals Severe winter storms in Missouri from 1960-2010

2015 ◽  
Author(s):  
◽  
Katie Crandall
Keyword(s):  
Winter Season ◽  
Economic Loss ◽  
Positive Phase ◽  
Negative Phase ◽  
Insurance Company ◽  
Severe Winter ◽  
Heavy Snowfall ◽  
Winter Storm ◽  
Automobile Accidents ◽  
Winter Storms

Severe winter storms have cost the state of Missouri significant economic loss from property damage, crop destruction, and loss of livestock. Even worse than the economic loss from these storms are the injuries and deaths to humans that they sometimes cause. A severe winter storm is a storm with six inches or greater snowfall in 48 hours and/or an ice storm with [1/4] inch or greater ice accumulation from the storm. A severe winter storms climatology for Missouri from 1960-2010 was created to better understand the development, frequency, and intensity of severe winter storms in Missouri. From the climatology, it was found that heavy snowfall events were by far the most common severe winter storm type in Missouri with 318 heavy snowfall events. Heavy ice events were the second most common with 66 events. Texas/West Gulf originating mid-latitude cyclones was responsible for the majority of severe winter storms in Missouri followed by Colorado originating mid-latitude cyclones. When looking at El Nino Southern Oscillation (ENSO) variability with heavy snowfall events, there is only a slight variation between the number of heavy snowfall events and the phase of the ENSO cycle they occur in. When all of the heavy snowfall events were averaged together there was only a slight difference in the average number of events per winter season during the negative phase of the Pacific Decadal Oscillation (PDO) (6.2) and the number of events per winter season during the positive phase of the PDO (6.5). When all heavy snowfall events were averaged together there is a 1.4 difference in the average number of events per year during the negative phase of the North Atlantic Oscillation (NAO) (4.6) and the positive phase of the NAO (6). Shelter Mutual Insurance Company provided insurance data from 2000-2010 for 56 severe winter storms in Missouri. Claim payouts for these storms totaled $28,543,020.65. Data from the Missouri Department of Transportation (MoDOT) for automobile accidents on Missouri interstates from 2000-2010 showed that there was the most snowfall related automobile accidents when snowfall was between 0-2.9 inches. The number of automobile accidents decreased with increasing snowfall amounts.

scholarly journals FIELD MEASUREMENTS OF VERY OBLIQUE WAVE RUN-UP AND OVERTOPPING WITH LASER SCANNERS

2020 ◽  
pp. 20
Author(s):  
Patrick Oosterlo ◽  
Bas Hofland ◽  
Jentsje W. van der Meer ◽  
Maarten Overduin ◽  
Gosse Jan Steendam
Keyword(s):  
The Netherlands ◽  
Current Knowledge ◽  
Field Measurements ◽  
Severe Winter ◽  
Winter Storm ◽  
Winter Storms ◽  
Oblique Wave ◽  
Laser Scanners ◽  
Innovative System ◽  
Run Up

Oosterlo et al. (2019) developed a system using two terrestrial laser scanners, which can measure run-up heights, depths and velocities of waves on a dike in field situations. The system has now been placed next to two overtopping tanks on a dike in the Eems-Dollard estuary in the Netherlands to measure during actual severe winter storms. The goal of the present paper is to further validate this innovative system with data obtained during storm Ciara (10 - 12 February 2020), a severe winter storm with very oblique wave attack. Furthermore, the data gathered during storm Ciara will be compared to the current knowledge on wave overtopping, to possibly gain new insights in the influence of very oblique wave attack on wave overtopping.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/TwSwJuxb-Yo

scholarly journals Time delay and duration of ionospheric total electron content responses to geomagnetic disturbances

2010 ◽  
Vol 28 (3) ◽  
pp. 795-805 ◽  
Author(s):  
J. Liu ◽  
B. Zhao ◽  
L. Liu
Keyword(s):  
Time Delay ◽  
Local Time ◽  
Positive Phase ◽  
Negative Phase ◽  
Electron Content ◽  
Geomagnetic Disturbances ◽  
Total Electron ◽  
Low Latitudes ◽  
Summer Hemisphere ◽  
Winter Hemisphere

Abstract. Although positive and negative signatures of ionospheric storms have been reported many times, global characteristics such as the time of occurrence, time delay and duration as well as their relations to the intensity of the ionospheric storms have not received enough attention. The 10 years of global ionosphere maps (GIMs) of total electron content (TEC) retrieved at Jet Propulsion Laboratory (JPL) were used to conduct a statistical study of the time delay of the ionospheric responses to geomagnetic disturbances. Our results show that the time delays between geomagnetic disturbances and TEC responses depend on season, magnetic local time and magnetic latitude. In the summer hemisphere at mid- and high latitudes, the negative storm effects can propagate to the low latitudes at post-midnight to the morning sector with a time delay of 4–7 h. As the earth rotates to the sunlight, negative phase retreats to higher latitudes and starts to extend to the lower latitude toward midnight sector. In the winter hemisphere during the daytime and after sunset at mid- and low latitudes, the negative phase appearance time is delayed from 1–10 h depending on the local time, latitude and storm intensity compared to the same area in the summer hemisphere. The quick response of positive phase can be observed at the auroral area in the night-side of the winter hemisphere. At the low latitudes during the dawn-noon sector, the ionospheric negative phase responses quickly with time delays of 5–7 h in both equinoctial and solsticial months. Our results also manifest that there is a positive correlation between the intensity of geomagnetic disturbances and the time duration of both the positive phase and negative phase. The durations of both negative phase and positive phase have clear latitudinal, seasonal and magnetic local time (MLT) dependence. In the winter hemisphere, long durations for the positive phase are 8–11 h and 12–14 h during the daytime at middle and high latitudes for 20≤Ap<40 and Ap≥40.

scholarly journals Dynamics of Eddy-Driven Low-Frequency Dipole Modes. Part I: A Simple Model of North Atlantic Oscillations

2007 ◽  
Vol 64 (1) ◽  
pp. 3-28 ◽  
Author(s):  
Dehai Luo ◽  
Anthony R. Lupo ◽  
Han Wan
Keyword(s):  
Life Cycle ◽  
Theoretical Model ◽  
North Atlantic ◽  
Low Frequency ◽  
Positive Phase ◽  
Negative Phase ◽  
Synoptic Scale ◽  
Planetary Scale ◽  
The North ◽  
The North Atlantic Oscillation

Abstract A simple theoretical model is proposed to clarify how synoptic-scale waves drive the life cycle of the North Atlantic Oscillation (NAO) with a period of nearly two weeks. This model is able to elucidate what determines the phase of the NAO and an analytical solution is presented to indicate a high similarity between the dynamical processes of the NAO and zonal index, which is not derived analytically in previous theoretical studies. It is suggested theoretically that the NAO is indeed a nonlinear initial-value problem, which is forced by both preexisting planetary-scale and synoptic-scale waves. The eddy forcing arising from the preexisting synoptic-scale waves is shown to be crucial for the growth and decay of the NAO, but the preexisting low-over-high (high-over-low) dipole planetary-scale wave must be required to match the preexisting positive-over-negative (negative-over-positive) dipole eddy forcing so as to excite a positive (negative) phase NAO event. The positive and negative feedbacks of the preexisting dipole eddy forcing depending upon the background westerly wind seem to dominate the life cycle of the NAO and its life period. An important finding in the theoretical model is that negative-phase NAO events could be excited repeatedly after the first event has decayed, but for the positive phase downstream isolated dipole blocks could be produced after the first event has decayed. This is supported by observed cases of the NAO events presented in this paper. In addition, a statistical study of the relationship between the phase of the NAO and blocking activity over Europe in terms of the seasonal mean NAO index shows that blocking events over Europe are more frequent and long-lived for strong positive-phase NAO years, indicating that the positive-phase NAO favors the occurrence of European blocking events.

Manifestation of the Pacific Decadal Oscillation in the stationary planetary waves activity

2021 ◽  
Author(s):  
Daria Sobaeva ◽  
Yulia Zyulyaeva ◽  
Sergey Gulev
Keyword(s):  
Pacific Decadal Oscillation ◽  
North American ◽  
Lower Stratosphere ◽  
El Nino ◽  
Planetary Waves ◽  
Positive Phase ◽  
Negative Phase ◽  
Middle Troposphere ◽  
The Pacific ◽  
The Tropics

&lt;p&gt;Strong quasi-decadal oscillations of the stratospheric polar vortex (SPV) intensity are in phase with the Pacific decadal oscillation (PDO). A stronger SPV is observed during the positive phase of the PDO, and during the negative phase, the intensity of the SPV is below the mean climate values. The SPV intensity anomalies, formed by the planetary waves and zonal mean flow interaction, lead to the weakening/intensification of the vortex.&lt;/p&gt;&lt;p&gt;This research aimed to obtain the differences in the characteristics and the spatial propagation pattern of the planetary waves in the middle troposphere and lower stratosphere during different PDO phases. We analyzed composite periods of years when the PDO index has extremely high and low values. Two periods were constructed for both positive and negative phases, the first consisting of years with El-Nino/La-Nina events and the second without prominent sea surface temperature anomalies in the tropics.&amp;#160;&lt;/p&gt;&lt;p&gt;During the wintertime in the Northern Hemisphere (December-February), wave 2 with two ridges (Siberian and North American Highs) and two troughs (Icelandic and Aleutian Lows) dominates in the middle troposphere, along with wave 1 dominating in the lower stratosphere. In the middle troposphere, at the positive phase &amp;#8203;&amp;#8203;of the PDO, the amplitude of wave 2 is higher than in years with negative values of the PDO index. The differences in the Aleutian Low and the North American High intensity between the two phases are significant at the 97.5% level. In the lower stratosphere, the wave amplitude is lower at the negative phase &amp;#8203;&amp;#8203;of the PDO, but we can also talk about a slight shift of the wave phase to the east. The regions of the heavy rains in the tropics during El-Nino events are the planetary waves source. They propagate from low to high latitudes, which results in modifying the characteristics and locations of the intensification of the stationary planetary waves in mid-latitudes.&lt;/p&gt;

The Variability of the Atlantic Storm Track and the North Atlantic Oscillation: A Link between Intraseasonal and Interannual Variability

2011 ◽  
Vol 68 (3) ◽  
pp. 577-601 ◽  
Author(s):  
Dehai Luo ◽  
Yina Diao ◽  
Steven B. Feldstein
Keyword(s):  
North Atlantic Oscillation ◽  
Interannual Variability ◽  
North Atlantic ◽  
Storm Track ◽  
Positive Phase ◽  
Negative Phase ◽  
Time Interval ◽  
European Continent ◽  
Eddy Activity ◽  
Nao Index

Abstract The winter-mean North Atlantic Oscillation (NAO) index has been mostly positive since the 1980s, with a linear upward trend during the period from 1978 to 1990 (P1) and a linear downward trend during the period from 1991 to 2009 (P2). Further calculations show that the Atlantic storm-track eddy activity is more intense during P2 than during P1, which is statistically significant at the 90% confidence level for a t test. This study proposes a hypothesis that the change in the trend of the positive NAO index from P1 to P2 may be associated with the marked intensification of the Atlantic storm track during P2. A generalized nonlinear NAO model is used to explain the observed trend of the positive NAO index within P2. It is found that even when the Atlantic storm-track eddies are less intense, a positive-phase NAO event can form under the eddy forcing if the planetary-scale wave has an initial value with a low-over-high dipole structure during P1 and P2. A blocking flow can occur in the downstream side (over Europe) of the Atlantic basin as a result of the energy dispersion of Rossby waves during the decay of the positive-phase NAO event. This blocking flow does not strictly correspond to a negative-phase NAO event because the blocking stays mainly over the European continent. However, when the Atlantic storm-track eddies are rather strong, the blocking flow occurring over the European continent is enhanced and can retrograde into the Atlantic region and finally become a long-lived negative-phase NAO event. In this case, the NAO event can transit from the positive phase to the negative phase. Thus, the winter-mean NAO index during P2 will inevitably decline because of the increase in days of negative-phase NAO events in winter because the Atlantic storm track exhibits a marked intensification in the time interval. The transition of the NAO event from the positive phase to the negative phase can also be observed only when the downstream development of the Atlantic storm-track eddy activity is rather prominent. Thus, it appears that there is a physical link between intraseasonal and interannual time scales of the NAO when the Atlantic storm track exhibits an interannual variability.

A COMPUTER SIMULATION TECHNIQUE FOR OIL SPILLS OFF THE NEW JERSEY-DELAWARE COASTLINE1

1977 ◽  
Vol 1977 (1) ◽  
pp. 437-440
Author(s):  
I. M. Lissauer ◽  
J. C. Bacon ◽  
M. C. Miller
Keyword(s):  
New York ◽  
High Pressure ◽  
New Jersey ◽  
Oil Spills ◽  
Winter Storm ◽  
Wind Model ◽  
Pressure System ◽  
Winter Storms ◽  
New York Bight ◽  
Pressure Distributions

ABSTRACT Predictions of the trajectories of oil slicks and their impact locations along the shoreline of New Jersey and Delaware were determined for two potential deepwater ports and two potential drilling sites. A hydrodynamical-numerical model for the New York Bight area was coupled with a wind generating model to produce temporal patterns of concentration of oil. The wind model employs pressure distributions and storm movement to produce hourly patterns of the wind field produced by any storm for a predetermined grid area. Shoreline impact determinations were made for the four spill sites for the average winter storm conditions and average summer high pressure systems generated by the models. Winter storms moving through the study area do not pose a high risk to the shoreline should a spill occur. The maximum transport from the four sites toward the shore was 18 miles. This left the slick well offshore so that the ensuing wind shift from the frontal passage would rapidly transport the oil seaward. During a stagnant summer high pressure system, spills occurring within fifty miles of the shoreline have a high probability of impacting the shoreline if the spill should occur at the beginning of the period in which the system affects the area.

Photonic band gap materials comprising positive-phase-velocity and negative-phase-velocity layers in waveguides

2009 ◽  
Vol 56 (15) ◽  
pp. 1688-1697 ◽  
Author(s):  
Álvaro Gómez ◽  
María L. Martínez Ricci ◽  
Ricardo A. Depine ◽  
Akhlesh Lakhtakia
Keyword(s):  
Phase Velocity ◽  
Band Gap ◽  
Photonic Band Gap ◽  
Positive Phase ◽  
Negative Phase ◽  
Photonic Band Gap Materials ◽  
Photonic Band ◽  
Negative Phase Velocity
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