scholarly journals A 5-yr 40-km-Resolution Global Climatology of Superrefraction for Ground-Based Weather Radars

2009 ◽  
Vol 48 (1) ◽  
pp. 89-110 ◽  
Author(s):  
Philippe Lopez
Keyword(s):  
United States ◽  
Electromagnetic Waves ◽  
Vertical Gradient ◽  
Radar Data ◽  
The United States ◽  
Horizontal Resolution ◽  
Trade Wind ◽  
Late Afternoon ◽  
The Balkans ◽  
Radar Images

Abstract The propagation of electromagnetic waves emitted from ground-based meteorological radars is determined by the stratification of the atmosphere. In extreme superrefractive situations characterized by strong temperature inversions or strong vertical gradients of moisture, the radar beam can be deflected toward the ground (ducting or trapping). This phenomenon often results in spurious returned echoes and misinterpretation of radar images such as erroneous precipitation detection. In this work, a 5-yr global climatology of the frequency of superrefractive and ducting conditions and of trapping-layer base height has been produced using refractivity computations from ECMWF temperature, moisture, and pressure analyses at a 40-km horizontal resolution. The aim of this climatology is to better document how frequent such events are, which is a prerequisite for fully benefiting from radar data information for the multiple purposes of model validation, precipitation analysis, and data assimilation. First, the main climatological features are summarized for the whole globe: high- and midlatitude oceans seldom experience superrefraction or ducting whereas tropical oceans are strongly affected, especially in regions where the trade wind inversion is intense and lying near the surface. Over land, seasonal averages of superrefraction (ducting) frequencies reach 80% (40%) over tropical moist areas year-round but remain below 40% (15%) in most other regions. A particular focus is then laid on Europe and the United States, where extensive precipitation radar networks already exist. Seasonal statistics exhibit a pronounced diurnal cycle of ducting occurrences, with averaged frequencies peaking at 60% in summer late afternoon over the eastern half of the United States, the Balkans, and the Po Valley but no ducts by midday. Similarly high ducting frequencies are found over the southwestern coast of the United States at night. A potentially strong reduction of ducting occurrences with increased radar height (especially in midlatitude summer late afternoon) is evidenced by initiating refractivity vertical gradient computations from either the lowest or the second lowest model level. However, installing radar on tall towers also brings other problems, such as a possible amplification of sidelobe clutter echoes.

scholarly journals Upright Convection in Extratropical Cyclones: A Survey Using Ground‐Based Radar Data Over the United States

2020 ◽  
Vol 47 (4) ◽  
Author(s):  
Jeyavinoth Jeyaratnam ◽  
James F. Booth ◽  
Catherine M. Naud ◽  
Z. Johnny Luo ◽  
Cameron R. Homeyer
Keyword(s):  
United States ◽  
Radar Data ◽  
The United States ◽  
Extratropical Cyclones

scholarly journals Precipitation and Fatal Motor Vehicle Crashes: Continental Analysis with High-Resolution Radar Data

2019 ◽  
Vol 100 (8) ◽  
pp. 1453-1461 ◽  
Author(s):  
Scott E. Stevens ◽  
Carl J. Schreck ◽  
Shubhayu Saha ◽  
Jesse E. Bell ◽  
Kenneth E. Kunkel
Keyword(s):  
United States ◽  
High Resolution ◽  
Motor Vehicle ◽  
Radar Data ◽  
The United States ◽  
Motor Vehicle Crashes ◽  
Vehicle Crashes ◽  
Fatal Crash ◽  
Fatal Crashes ◽  
High Resolution Radar

AbstractMotor vehicle crashes remain a leading cause of accidental death in the United States, and weather is frequently cited as a contributing factor in fatal crashes. Previous studies have investigated the link between these crashes and precipitation typically using station-based observations that, while providing a good estimate of the prevailing conditions on a given day or hour, often fail to capture the conditions present at the actual time and location of a crash. Using a multiyear, high-resolution radar reanalysis and information on 125,012 fatal crashes spanning the entire continental United States over a 6-yr period, we find that the overall risk of a fatal crash increases by approximately 34% during active precipitation. The risk is significant in all regions of the continental United States, and it is highest during the morning rush hour and during the winter months.

Department of State Rewards Program Update and Technical Corrections Act of 2012

2013 ◽  
Vol 52 (3) ◽  
pp. 861-867
Author(s):  
Michael A. Newton
Keyword(s):  
United States ◽  
World Trade Center ◽  
International Criminal Tribunal ◽  
The United States ◽  
International Terrorism ◽  
National Interests ◽  
American Military ◽  
Department Of State ◽  
The Balkans ◽  
Trade Center

For nearly three decades, the United States has offered monetary rewards designed to facilitate the apprehension and transfer for trial of suspects when their trial would directly advance American national interests. In the 1990s, for example, posters and matchbooks appeared across the Balkans with contact information available to anyone who might be willing to assist in the transfer of Slobodan Milošević or Radovan Karadžić to face charges before the International Criminal Tribunal for the former Yugloslavia. In Congress’s view, this rewards program has helped to generate actionable intelligence that has prevented terrorist attacks, aided convictions of key suspects charged with participation in other acts of international terror, and served as “one of the most valuable assets the U.S. Government has in the fight against international terrorism.” In his public comments introducing this legislation, the United States Ambassador-at-Large for War Crimes acknowledged that fourteen payments were made under existing legislation in the two years prior to passage of this bill, averaging $400,000 per person. Details remain classified of course, but the rewards have provided instrumental incentives in numerous high profile cases, inter alia, the arrest of the architect of the 1993 World Trade Center bombing and the deaths of Uday and Qusay Hussein at the hands of American military forces following the 2003 invasion of Iraq.

Much could upset deal on Bosnian state government

2019 ◽  
Keyword(s):  
United States ◽  
State Government ◽  
The United States ◽  
The West ◽  
Content Type ◽  
The Balkans ◽  
The Us

Significance Under pressure from the US and EU ambassadors, Bosnia's leaders have reached agreement to form a state government. The breakthrough has provided a badly needed respite from political paralysis; it required difficult concessions from all sides. Impacts By emphasising each side's concessions, politically affiliated media could jeopardise a shaky settlement. The United States and EU are too preoccupied with mainly internal problems to re-engage in Bosnia or the Balkans more concretely. Tensions between Russia and the West are being reflected in Bosnian politics.

Comparison of Ground-Based Radar and Geosynchronous Satellite Climatologies of Warm-Season Precipitation over the United States

2008 ◽  
Vol 47 (12) ◽  
pp. 3264-3270 ◽  
Author(s):  
John D. Tuttle ◽  
Richard E. Carbone ◽  
Phillip A. Arkin
Keyword(s):  
United States ◽  
Brightness Temperature ◽  
Satellite Data ◽  
Warm Season ◽  
Propagation Speed ◽  
Radar Data ◽  
The United States ◽  
Temperature Threshold ◽  
Brightness Temperatures ◽  
The Difference

Abstract Studies in the past several years have documented the climatology of warm-season precipitation-episode statistics (propagation speed, span, and duration) over the United States using a national composited radar dataset. These climatological studies have recently been extended to other continents, including Asia, Africa, and Australia. However, continental regions outside the United States have insufficient radar coverage, and the newer studies have had to rely on geostationary satellite data at infrared (IR) frequencies as a proxy for rainfall. It is well known that the use of IR brightness temperatures to infer rainfall is subject to large errors. In this study, the statistics of warm-season precipitation episodes derived from radar and satellite IR measurements over the United States are compared and biases introduced by the satellite data are evaluated. It is found that the satellite span and duration statistics are highly dependent upon the brightness temperature threshold used but with the appropriate choices of thresholds can be brought into good agreement with those based upon radar data. The propagation-speed statistics of satellite events are on average ∼4 m s−1 faster than radar events and are relatively insensitive to the brightness temperature threshold. A simple correction procedure based upon the difference between the steering winds for the precipitation core and the winds at the level of maximum anvil outflow is developed.

scholarly journals On Oblivion: the Case of Yugoslavian Monopoly

2019 ◽  
Vol 13 (1) ◽  
pp. 111-122
Author(s):  
Zala Pavšič
Keyword(s):  
United States ◽  
Public Space ◽  
Significant Role ◽  
Cultural Memory ◽  
The United States ◽  
Historical Overview ◽  
Board Game ◽  
The Public ◽  
The Balkans ◽  
Board Games

This article on the Yugoslavian version of the board game Monopoly is based on the assumption that things make people. In accordance with this a concept, the contribution begins with a historical overview of the development of this game in the United States, from its origins when it spreads around the country as a popular game, to the current day, when Monopoly is marketed a leading corporation in the field of board games, Hasbro. The popularity of the game is also evident from its presence in the public space in the form of metaphors: because of its emphasis on trading, it is sometimes referred to “greed”, and in the Balkans it can also serve as a metaphor for the nation state.In the memories of my interlocutors who helped me with their testimonies, the Yugoslav version of Monopoly is associated with pleasant memories: especially of childhood, youth and relatives or friends with whom they used to play the game. In my interviews I focused on two topics which did not play such a significant role in the testimonies of the interlocutors, but were, however, common in the testimonies of interviewees who got acquainted with the game as children: to the question of the supposed superiority of Slovenia, as Bled and Bohinj were the most expensive properties, and the presumption that Monopoly is a game which can reproduce cultural memory, in this case knowing the geography of the former common state. The thesis on Slovene superiority proved to rely on generations to which my interviewees belonged, since it appeared especially in the answers of the interlocutors who were born in the late 1980s. Hence, I assume that this thesis was more likely a projection of the outside reality of my interlocutors into the game than vice versa.Analysing the answers of my interlocutors more thoroughly, I reached the conclusion that Monopoly often appeared as the first reference through which they heard about a certain resort in the regions of the former Yugoslavia. This means that Monopoly contained traces of cultural memory which other sources of our everyday lives, education and upbringing ceased to transmit.

scholarly journals Yugoslavia on the brink of break-up: was it possible to avoid the war?

2019 ◽  
pp. 479-499
Author(s):  
Elena Guskova
Keyword(s):  
United States ◽  
Foreign Policy ◽  
The United States ◽  
Mutual Understanding ◽  
Full Understanding ◽  
Mikhail Gorbachev ◽  
Policy Issues ◽  
The Balkans ◽  
Full Support ◽  
The Times

The article is devoted to the times when the foreign policy of the USSR in relation to socialist countries changed, and the “Gorbachev Doctrine” appeared in perestroika. M. S. Gorbachev was actively engaged in foreign policy issues, lying his particular attention to Europe. The author tries to fi nd an answer to the question: to what extent was he interested in the Balkans? To answer this question, the author refers to one of the signifi cant events of that time - M. S. Gorbachev's visit to Yugoslavia in 1988. It was then when the foundations of the country's Balkan policy were laid, which manifested itself in the 1990s. The visit gave Mikhail Gorbachev an opportunity to get to know Yugoslavia better, to get a better idea of the life of the peoples of this country, to feel the love of the Yugoslavs for Russia and the Russian people. As Gorbachev's close party comrades supposed, it was during the years of perestroika that a full understanding was reached between the leadership of the USSR and Yugoslavia. The contents of the conversations, and the fi nal documents gave the Yugoslav side the assurance that mutual understanding reached will in case of possible difficulties allow it to be provided with Soviet help and support. It is this kind of assistance that Yugoslavia would need in two years, when the country began to fall apart, when Slovenia and Croatia decided to leave the Federation on their own and received full support from Germany and the United States. But Moscow refused to help.

scholarly journals The American-Turkish Political Relations 1991-2001 A.D.

2021 ◽  
Vol 12 (2) ◽  
pp. 2451-2458
Author(s):  
Ahmed Mahmood Alaw Al-Samarrae , Et. al.
Keyword(s):  
United States ◽  
Soviet Union ◽  
Middle East ◽  
Political Process ◽  
The United States ◽  
The Other ◽  
The Black Sea ◽  
The Balkans ◽  
East Region ◽  
Middle East Region

The U.S. Turkish relations are one of the issues of interest to the researcher in the field of politics as it is a relationship between two important and active parties in the international arena, especially the Middle East region. The United States had a great interest in Turkey's siding with the West. Turkey also found its interest in that, so we found it a member of the NATO. In contrast to the expected after the collapse of the Soviet Union in 1991, Turkey's importance in the strategic perception of the United States did not end, especially since Turkey's geographical proximity seemed to be more strained and changing, not to mention the Western model adopted by Turkey, which the United States wants to be an example in the region. The American- Turkish relations for the period (1991-2001) were influenced by radical and fundamental changes. These variables are either internal or international. The internal factors influencing this relationship lie in the Turkish political parties which play a major role in the political process. The other factor is the Kurdish issue, which Turkey is dealing with very cautiously, while the United States has used it as a pressure card on the Turkish governments. It has not pursued a consistent policy on the issue and has always appeared against human  rights violations. The other external factors, including the Cyprus issue, are a source of concern for the alliance strategy between the two countries from the 1960s until the present, and there is the matter of dealing with terrorism especially after the events of 11 September 2001. The other factor is the question of the EU accession which is the Turkish dream and the source of interest for its foreign policy. Which the United States is trying to show that it is the only one who able to persuade the Europeans to accept the membership of Turkey. Turkut Ouzel's government has sought to play a pivotal role at the regional and global levels and in the realization of Turkish interests in the Central Asian republics, the Black Sea basin, the Mediterranean basin, the Middle East region, the Arab neighbors, Israel, Iran and the Balkans, beside achieving the economic development and self-sufficiency; efforts are incessant to fulfill those ambitions. Turkey has acted to change the unilateral approach towards the United States and the NATO to another one that includes multilateral policies related to the normalization of relations with the African and Asian worlds as well as neighboring countries.

scholarly journals THE SECURITY AND INFLUENCE OF AMERICAN DIPLOMACY IN THE BALKANS

2019 ◽  
Vol 30 (6) ◽  
pp. 1487-1490
Author(s):  
Alban Kadriu
Keyword(s):  
United States ◽  
The United States ◽  
Point Of View ◽  
The Political ◽  
Democratic Values ◽  
The Balkans ◽  
Individual Approach ◽  
Knowing That ◽  
Contemporary Politics ◽  
American Diplomacy

Convinced that I train a topic that is extremely important at the time and at the same time very relevant to the circumstances in which the United States and its allies are doing today, continue to play a very important role on the international stage, as well as in Europe and elsewhere and still remain with great influence.The goal of this thesis is to motivate more precisely the socio-political circumstances that not only differ from moment to moment, but also include ideas and successive situations that sometimes even the most exciting scientists find it difficult to identify what is happens and appears at certain moments. With the greatest dedication and knowing that what I am saying from this point can be changed, it was also reasonable to give some ideas from my point of view and to approach my ideas now called the political and international scene with a sophisticated expression of democratic values with a very strong dose of indications that we can call moderate invasions. Shortly, this is, in the present, making American contemporary politics through its allies and influences, which in fact tend to be many factors; economic, political, military, and primarily geostrategic.My job is aimed not to look at this issue in detail, but to give an individual approach in comparison with the appearance and the case, as it seems from my point of view, which I do not think includes several challenges that are drawn into circles; today this has happened with concrete and diverse diplomatic actions, but my will attract those who are most interested in Europe, the Balkans and elsewhere in the current and current circumstances.

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