A Climatological Analysis of the Linkages between Tropopause Polar Vortices, Cold Pools, and Cold Air Outbreaks over the Central and Eastern United States

2021 ◽  
Vol 149 (1) ◽  
pp. 189-206
Author(s):  
Kevin A. Biernat ◽  
Lance F. Bosart ◽  
Daniel Keyser
Keyword(s):  
United States ◽  
The United States ◽  
Eastern United States ◽  
Cold Air ◽  
Cold Pools ◽  
Middle Latitudes ◽  
Coherent Vortices ◽  
Northern Regions ◽  
Northern United States ◽  
Cold Air Outbreaks

AbstractCoherent vortices in the vicinity of the tropopause, referred to as tropopause polar vortices (TPVs), may be associated with tropospheric-deep cold pools. TPVs and associated cold pools transported from high latitudes to middle latitudes may play important roles in the development of cold air outbreaks (CAOs). The purpose of this study is to examine climatological linkages between TPVs, cold pools, and CAOs occurring in the central and eastern United States. To conduct this study, 1979–2015 climatologies of TPVs and cold pools are constructed using the ERA-Interim dataset and an objective tracking algorithm, and are compared to a 1979–2015 climatology of CAOs occurring in six NCEI-defined climate regions over the central and eastern United States. The climatologies of TPVs and cold pools indicate that central and eastern North America is a preferred corridor for their equatorward transport, and that the occurrence frequency of TPVs and cold pools is higher over northern regions of the United States compared to southern regions of the United States. Correspondingly, there is a higher percentage of CAOs linked to cold pools associated with TPVs over northern regions of the United States (32.1%–35.7%) compared to southern regions of the United States (4.4%–12.5%). TPVs and cold pools contributing to CAOs form most frequently over northern Canada and the Canadian Archipelago, and generally move southeastward toward southern Canada and the northern United States. TPVs and cold pools contributing to CAOs tend to be statistically significantly colder and longer lived when compared to all TPVs and cold pools transported to middle latitudes.

MJO Modulation on 2009/10 Winter Snowstorms in the United States*

2012 ◽  
Vol 25 (3) ◽  
pp. 978-991 ◽  
Author(s):  
Ja-Yeon Moon ◽  
Bin Wang ◽  
Kyung-Ja Ha
Keyword(s):  
United States ◽  
High Latitude ◽  
Intraseasonal Variability ◽  
The United States ◽  
Teleconnection Pattern ◽  
Eastern United States ◽  
Moist Air ◽  
Central Pacific ◽  
Cold Air ◽  
Atmospheric Teleconnection

Abstract During the winter of 2009/10, a number of record-breaking snowfall events registered in the eastern United States are shown to have been modulated by the pulsation of tropical MJO through an atmospheric teleconnection pattern. The intraseasonal variability over the eastern subtropical Pacific near Mexico (the equatorial central Pacific) had reached the maximum (second largest) strength since 1979/80. From late December to mid-February, the convection over these two regions experienced a remarkable wet–dry–wet cycle; correspondingly, the daily snowfall over the eastern United States also exhibited a wet–dry–wet cycle. As the MJO convection reached the central Pacific, a teleconnection pattern extended to North America, resulting in a westward-tilted deep anomalous trough anchored over the eastern United States, producing a low-level pressure dipole anomaly with an anticyclone (cyclone) centered at the U.S. West (East) Coast. The convection over the Indian Ocean varied in phase with the central Pacific convection, reinforcing the extratropical atmospheric teleconnection pattern. As a result, the enhanced high-latitude cold air penetrated southward, affecting the central and eastern United States. Meanwhile, warmer moist air was transported from the tropical central Pacific by the existing El Niño through Mexico to the southern United States along with the upper-level subtropical westerly jet, which extended from the subtropical Pacific to the Atlantic Ocean. As such, the eastern United States was located in a convergence zone between the enhanced cold air from the high latitude and the warm, moist air supplied from the subtropics, resulting in favorable conditions for extremely heavy snowfall.

scholarly journals Prevalence of Botrytis Cryptic Species in Strawberry Nursery Transplants and Strawberry and Blueberry Commercial Fields in the Eastern United States

Plant Disease ◽  
2018 ◽  
Vol 102 (2) ◽  
pp. 398-404 ◽  
Author(s):  
Achour Amiri ◽  
Adrian I. Zuniga ◽  
Natalia A. Peres
Keyword(s):  
United States ◽  
The United States ◽  
Gray Mold ◽  
Sensu Stricto ◽  
Eastern United States ◽  
Low Frequencies ◽  
Genetic Groups ◽  
Northern United States ◽  
Almost All ◽  
Development And Management

Botrytis isolates from strawberry transplants originating from Canada and the northern United States as well as isolates collected from strawberry and blueberry commercial fields in the southeastern United States were investigated for the frequency of Botrytis cinerea, other cryptic Botrytis spp. reported recently, and the transposable elements (TE) using six genetic markers. B. cinerea sensu stricto was predominant (94%) in strawberry and blueberry in all surveyed regions. Botrytis group S, a newly reported clade on strawberry from Germany, was found at low frequencies (6%) in strawberry in the United States and Canada and on blueberry isolates from Florida. Neither B. caroliniana nor B. pseudocinerea were detected in the U.S. or Canadian populations. Transposa isolates containing the TE boty and flipper accounted for 74% of 410 isolates studied herein. Isolates containing boty only or flipper only elements were found at 21 and 2%, respectively. However, boty isolates were predominant in the blueberry population with more than 50%. The TE were found in B. cinerea and Botrytis group S at similar frequencies, except that flipper was more frequent (10.7%) in Botrytis group S, compared with 1.6% in B. cinerea. The sensitivity of 256 Botrytis isolates from the different genetic groups described above was evaluated to seven fungicides registered to control gray mold in commercial fields. Results indicate that B. cinerea and transposa isolates have higher resistance frequencies to almost all fungicides tested compared with the other Botrytis genotypes or species, whereas the TE flipper may be related to resistance to fludioxonil. Similarities observed between nursery and commercial field populations and their impact on gray mold development and management are discussed.

System-wide seismic vulnerability of aging multiple-span multiple-girder bridges in low-to-moderate seismic hazard regions

2021 ◽  
Vol 37 (1_suppl) ◽  
pp. 1626-1651
Author(s):  
John E Lens M.EERI ◽  
Mandar M Dewoolkar ◽  
Eric M Hernandez M.EERI
Keyword(s):  
United States ◽  
Seismic Hazard ◽  
Cross Sections ◽  
Seismic Vulnerability ◽  
Time History ◽  
The United States ◽  
National Database ◽  
Eastern United States ◽  
Girder Bridges ◽  
The Status

This article describes the approach, methods, and findings of a quantitative analysis of the seismic vulnerability in low-to-moderate seismic hazard regions of the Central and Eastern United States for system-wide assessment of typical multiple span bridges built in the 1950s through the 1960s. There is no national database on the status of seismic vulnerability of bridges, and thus no means to estimate the system-wide damage and retrofit costs for bridges. The study involved 380 nonlinear analyses using actual time-history records matched to four representative low-to-medium hazard target spectra corresponding with peak ground accelerations from approximately 0.06 to 0.3 g. Ground motions were obtained from soft and stiff site seismic classification locations and applied to models of four typical multiple-girder with concrete bent bridges. Multiple-girder bridges are the largest single category, comprising 55% of all multiple span bridges in the United States. Aging and deterioration effects were accounted for using reduced cross-sections representing fully spalled conditions and compared with pristine condition results. The research results indicate that there is an overall low likelihood of significant seismic damage to these typical bridges in such regions, with the caveat that certain bridge features such as more extensive deterioration, large skews, and varied bent heights require bridge-specific analysis. The analysis also excludes potential damage resulting from liquefaction, flow-spreading, or abutment slumping due to weak foundation or abutment soils.

Force, Fraud, and Coercion—What Do They Mean? A Study of Victimization Experiences in a New Destination Latino Sex Trafficking Network

2016 ◽  
Vol 13 (5) ◽  
pp. 456-476 ◽  
Author(s):  
Lauren Copley Sabon
Keyword(s):  
United States ◽  
Law Enforcement ◽  
Social Constructionism ◽  
Sex Trafficking ◽  
The United States ◽  
Social Forces ◽  
Eastern United States ◽  
Latina Immigrants ◽  
Strict Interpretation ◽  
New Destination

In response to increasing Latino new destination migration in the United States, Latino sex trafficking networks have emerged in many of these areas. This article examines victimization experiences of Latina immigrants trafficked by a regional network operating in the Eastern United States drawn from law enforcement records and interviews with legal actors involved in the criminal case. The stories shared with law enforcement by the Latina victims gives insight into their lives, experiences in prostitution, and the operation of a trafficking/prostitution network (all lacking in the literature). Through the analytical frame of social constructionism, this research highlights how strict interpretation of force, fraud, coercion, and agency used to define “severe forms of trafficking” in the TVPA limits its ability to recognize many victimization experiences in trafficking situations at the hands of traffickers. The forms of coercion used in the criminal enterprise under study highlights the numerous ways it can be wielded (even without a physical presence) and its malleability as a concept despite legal definitional rigidity. The lack of legal recognition of the plurality of lived experiences in which agency and choice can be mitigated by social forces, structural violence, intersectional vulnerabilities, and the actions of others contributes to the scholarly critique of issues prosecuting trafficking cases under the TVPA and its strict legal definitions.

Effects of temporal variations in seismicity on seismic hazard

1981 ◽  
Vol 71 (1) ◽  
pp. 321-334
Author(s):  
Robin K. McGuire ◽  
Theodore P. Barnhard
Keyword(s):  
United States ◽  
Seismic Hazard ◽  
Seismic Activity ◽  
Time Window ◽  
Hazard Analysis ◽  
The United States ◽  
Temporal Variations ◽  
Seismogenic Zone ◽  
Eastern United States ◽  
Ground Shaking

abstract The accuracy of stationary mathematical models of seismicity for calculating probabilities of damaging shaking is examined using the history of earthquakes in China from 1350 A.D. to 1949 A.D. During this time, rates of seismic activity varied periodically by a factor of 10. Probabilities of damaging shaking are calculated in 62 cities in North China using 50 yr of earthquake data to estimate seismicity parameters; the probabilities are compared to statistics of damaging shaking in the same cities for 50 yr following the data window. These comparisons indicate that the seismic hazard analysis is accurate if: (1) the maximum possible earthquake size in each seismogenic zone is determined from the entire seismic history rather than from a short-time window; and (2) the future seismic activity can be estimated accurately. The first condition emphasizes the importance of realistically estimating the maximum possible size of earthquakes on faults. The second indicates the need to understand possible trends in seismic activity where these exist, or to develop an earthquake prediction capability with which to estimate future activity. Without the capability of estimating future seismicity, stationary models provide less accurate but generally conservative indications of seismic ground-shaking hazard. In the United States, the available earthquake history is brief but gives no indication of changing rates of activity. The rate of seismic strain release in the Central and Eastern United States has been constant over the last 180 yr, and the geological record of earthquakes on the southern San Andreas Fault indicates no temporal trend for large shocks over the last 15 centuries. Both observations imply that seismic activity is either stationary or of such a long period that it may be treated as stationary for seismic hazard analyses in the United States.

The Origins of Western Dermatology

2010 ◽  
Vol 14 (6) ◽  
pp. 255-266
Author(s):  
J. Barrie Ross
Keyword(s):  
United States ◽  
Eighteenth Century ◽  
Middle Ages ◽  
The United States ◽  
Historical Background ◽  
Eastern United States ◽  
The West ◽  
Defining Moments ◽  
Late Eighteenth Century ◽  
Late Eighteenth

Objective: On the premise that historical background makes the present more understandable, this review covers the origins of Western dermatology from its Greek and Roman origins through the Middle Ages to the defining moments in the late eighteenth century. Background and Conclusion: The development of major European centers at this time became the background for future centers in the eastern United States in the midnineteenth century and, finally, to the West Coast of the United States and Canada by the midtwentieth century.

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