scholarly journals Climate index; Cold events; Extreme; Precipitations.

2021 ◽  
Vol 32 (2) ◽  
pp. 63
Author(s):  
Ali. J. Mohammed ◽  
Samir K. Mohammed ◽  
Jasim H. Kadhum
Keyword(s):  
Extreme Events ◽  
Large Scale ◽  
Grid Point ◽  
Significant Negative Correlation ◽  
Hysplit Model ◽  
Dynamical Mechanism ◽  
East Region ◽  
Cold Events ◽  
Extreme Cold ◽  
Middle East Region

The cold events and Precipitation conditions having special attention in the last years due to their impact on human health, ecosystems, and other aspects such as agriculture, hydrology. The ECMWF ERA-Interim 12-hourly (03 and 15 UTC) total precipitations and Tmin in a 1º x 1º grid covering Iraq, from 29° N to 38° N and from 39° W to 48° E, with a total of 10 by 10 cells, was used. At each grid point, extremes were defined as those events in which total precipitations were above 99th percentile for the 25 years period 1994-2018. For more investigation, the Hybrid Single-Particle Lagrangian Integrated The trajectory (HYSPLIT) model was used to study the dynamical mechanism that led to producing the cold events in Iraq. The number of extreme precipitations patterns shows an increasing behavior in the number of extreme events especially in the last decade, farther more there is a significant increase in the number of extreme precipitations in the last three years ago. No correlations were found with NAO, EA index, in contrast, there is a significant negative correlation with winter Arctic oscillations index. The aim of this work is studying the precipitation and cold extreme events in Iraq and their relations of most hemispheric pattern which influence in the Middle East region such as North Atlantic Oscillation (NAO), East Atlantic index (EA), Artic oscillation index (AO) and Mediterranean index (MOi). We speculate that the results of this study can provide a better understanding of extreme cold and precipitations anomalies in Iraq from a large-scale view.The cold events and Precipitations conditions having special attention in the last years due to their impact on human health, ecosystems and other aspects such as agriculture, hydrology. The ECMWF ERA-Interim 12-hourly (03 and 15 UTC) total precipitations and Tmin in a 1º x 1º grid covering the Iraq, from 29° N to 38° N and from 39° W to 48° E, with a total of 10 by 10 cells, was used. At each grid point, extremes were defined as those events in which total precipitations were above its 99th percentile for the 25 years’ period 1994-2018. For more investigation, the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to study the dynamical mechanism that led to produce the cold events over Iraq. The number of extreme precipitations pattern shows an increasing behavior in the number of extreme events especially in last decade, farther more there is a significant increase in the number of extreme precipitations in last three years ago. No correlations were found with NAO, EA index, in contrast, there is a significant negative correlation with winter Arctic oscillations index. The aim of this work is studying the precipitation and cold extreme events in Iraq and their relations of most hemispheric pattern which influence in the Middle East region such as North Atlantic Oscillation (NAO), East Atlantic index (EA), Artic oscillation index (AO) and Mediterranean index (MOi). We speculate that the results of this study can provide a better understanding of extreme cold and precipitations anomalies in Iraq a large-scale view.

scholarly journals Using Self-Organizing Maps to Identify Coherent CONUS Precipitation Regions

2019 ◽  
Vol 32 (22) ◽  
pp. 7747-7761 ◽  
Author(s):  
Leif M. Swenson ◽  
Richard Grotjahn
Keyword(s):  
Extreme Events ◽  
Annual Cycle ◽  
Large Scale ◽  
Robust Statistics ◽  
Grid Point ◽  
Future Application ◽  
Self Organizing Maps ◽  
Annual Cycles ◽  
Extreme Precipitation Events ◽  
Self Organizing

Abstract Extreme precipitation events have major societal impacts. These events are rare and can have small spatial scale, making statistical analysis difficult; both factors are mitigated by combining events over a region. A methodology is presented to objectively define “coherent” regions wherein data points have matching annual cycles. Regions are found by training self-organizing maps (SOMs) on the annual cycle of precipitation for each grid point across the contiguous United States (CONUS). Using the annual cycle for our intended application minimizes problems caused by consecutive dry periods and localized extreme events. Multiple criteria are applied to identify useful numbers of regions for our future application. Criteria assess these properties for each region: having many more events than experienced by a single grid point, good connectedness and compactness, and robustness to changing the number of regions. Our methodology is applicable across datasets and is tested here on both reanalysis and gridded observational data. Precipitation regions obtained align with large-scale geographical features and are readily interpretable. Useful numbers of regions balance two conflicting preferences: larger regions contain more events and thereby have more robust statistics, but more compact regions allow weather patterns associated with extreme events to be aggregated with confidence. For 6-h precipitation, 12–15 regions over the CONUS optimize our metrics. The regions obtained are compared against two existing region archetypes. For example, a popular set of regions, based on nine groups of states, has less coherent regions than defining the same number of regions with our SOM methodology.

scholarly journals The role of the observed tropical convection in the generation of frost events in the southern cone of South America

2008 ◽  
Vol 26 (6) ◽  
pp. 1379-1390 ◽  
Author(s):  
G. V. Müller ◽  
T. Ambrizzi ◽  
S. E. Ferraz
Keyword(s):  
South America ◽  
Large Scale ◽  
Rossby Waves ◽  
Tropical Convection ◽  
The Other ◽  
Linear Wave ◽  
Frequency Of Occurrence ◽  
The South ◽  
Cold Events ◽  
Extreme Cold

Abstract. Based on previous results obtained from observations and linear wave theory analysis, the hypothesis that large-scale patterns can generate extreme cold events in southeast South America through the propagation of remotely excited Rossby waves was already suggested. This work will confirm these findings and extend their analysis through a series of numerical experiments using a primitive equation model where waves are excited by a thermal forcing situated in positions chosen according to observed convection anomalies over the equatorial region. The basic state used for these experiments is a composite of austral winters with maximum and minimum frequency of occurrence of generalized frosts that can affect a large area known as the Wet Pampas located in the central and eastern part of Argentina. The results suggest that stationary Rossby waves may be one important mechanism linking anomalous tropical convection with the extreme cold events in the Wet Pampas. The combination of tropical convection and a specific basic state can generate the right environment to guide the Rossby waves trigged by the tropical forcing towards South America. Depending on the phase of the waves entering the South American continent, they can favour the advection of anomalous wind at low levels from the south carrying cold and dry air over the whole southern extreme of the continent, producing a generalized frost in the Wet Pampa region. On the other hand, when a basic state based on the composites of minimum frosts is used, an anomalous anticyclone over the southern part of the continent generates a circulation with a south-southeast wind which brings maritime air and therefore humidity over the Wet Pampas region, creating negative temperature anomalies only over the northeastern part of the region. Under these conditions even if frosts occur they would not be generalized, as observed for the other basic state with maximum frequency of occurrence of generalized frosts.

scholarly journals Simulated Links between Deforestation and Extreme Cold Events in South America

2012 ◽  
Vol 25 (11) ◽  
pp. 3851-3866 ◽  
Author(s):  
David Medvigy ◽  
Robert L. Walko ◽  
Roni Avissar
Keyword(s):  
South America ◽  
Extreme Events ◽  
Limited Area ◽  
Natural Ecosystems ◽  
Cold Event ◽  
Variable Resolution ◽  
Local Agriculture ◽  
Average Annual Temperature ◽  
Cold Events ◽  
Extreme Cold

Many modeling studies have indicated that deforestation will increase the average annual temperature in the Amazon. However, few studies have investigated the potential for deforestation to change the frequency and intensity of extreme events. This problem is addressed here using a variable-resolution GCM. The characteristic length scale (CLS) of the model’s grid mesh over South America is 25 km, comparable to that used by limited-area models. For computational efficiency, the CLS increases to 200 km over the rest of the world. It is found that deforestation induces large changes in the frequency of wintertime extreme cold events. Large increases in cold event frequency and intensity occur in the western Amazon and, surprisingly, in parts of southern South America, far from the actual deforested area. One possible mechanism for these remote effects involves changes in the position of the subtropical jet, caused by temperature changes in the Amazon. Increased understanding of these potential changes in extreme events will be important for local agriculture, natural ecosystems, and the human population.

Potential Arctic connections to eastern North American cold winters

2017 ◽  
Vol 7 (2) ◽  
pp. 232-243 ◽  
Author(s):  
James E. Overland ◽  
Muyin Wang
Keyword(s):  
Sea Ice ◽  
North American ◽  
Geopotential Height ◽  
Large Scale ◽  
Chukchi Sea ◽  
Height Anomaly ◽  
Positive Temperature ◽  
Temperature Anomalies ◽  
Cold Events ◽  
Extreme Cold

Far-field temperature and geopotential height fields associated with eastern North American early winter (DEC-JAN) extreme cold events are documented since 1950. Based on 19 cases of monthly extreme cold events, two large-scale patterns emerge. First, a strong Alaskan Ridge (AR) can develop with higher 700 hPa geopotential heights and positive temperature anomalies from Alaska south along the coastal northeastern Pacific Ocean, and low eastern North American geopotential height anomalies, the well-known North American ridge/trough pattern. A second subset of cases is a Greenland-Baffin Blocking (GBB) pattern that have positive temperature anomalies centered west of Greenland with a cut off tropospheric polar vortex feature over eastern North America; cold temperature anomalies extend from southeastern United States northwestward into central Canada. Both of these historical large-scale patterns associated with eastern North American cold events (AR and GBB) have the potential for future reinforcement by sea ice loss and associated warm Arctic regional temperature anomalies. An example of a GBB case is 15-22 December 2010 and an extreme AR case is in early 4-14 December 2016. In both cases lack of sea ice and warm temperature anomalies were colocated with local maximums in the geopotential height anomaly fields. Future regional delay of fall freeze up in the Chukchi Sea and Baffin Bay regions could reinforce these geopotential height patterns once they occur, but is not likely to initiate AR and GBB type events.

REVIEW OF CONSTRUCTION DISPUTE RESOLUTION PRACTICES IN THE MIDDLE EAST: CAUSES AND METHODS

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Boushra Barakat ◽  
Rita Awwad ◽  
Carol Menassa
Keyword(s):  
Middle East ◽  
Dispute Resolution ◽  
Large Scale ◽  
Continuous Growth ◽  
East Region ◽  
Foreign Countries ◽  
Construction Claims ◽  
Common Causes ◽  
Additional Costs ◽  
Middle East Region

The construction industry in the Middle East region is witnessing a continuous growth and is attracting international contractors and investors to its large-scale projects. However, this growth is accompanied by an inevitable increase in claims and disputes consequently leading to significant delays and additional costs. The purpose of this research is to identify the most common causes of disputes in the Middle East (ME) region, and shed the light on the most frequently used dispute resolution methods. It then goes further to briefly discuss the applicability of alternative dispute resolution methods in this region and compare the findings to the perspective of experts in the field. Findings show that disputes are mainly due to the lack of construction management expertise, as well as other contractual, cultural and legal factors. As for the most commonly used dispute resolution methods, they are identified to be negotiation, litigation and arbitration. This paper provides contractors, owners and professionals in the ME region and foreign countries with invaluable insights into construction claims’ types and dispute resolution systems in the ME region.

In Quest of a Second Boom

2018 ◽  
Vol 11 (1-2) ◽  
pp. 257-278 ◽  
Author(s):  
Shirzad Azad
Keyword(s):  
Foreign Policy ◽  
Middle East ◽  
Crucial Role ◽  
Gulf Cooperation Council ◽  
East Region ◽  
Personal Motivation ◽  
Policy Measures ◽  
The Republic ◽  
Middle East Region ◽  
Different Parts

In spite of her troubled presidency at home and premature, ignominious exit from power, Park Geun-hye made serious attempts to bolster the main direction of the Republic of Korea’s (ROK) foreign policy toward the Middle East. A collaborative drive for accomplishing a new momentous boom was by and large a dominant and recurring theme in the Park government’s overall approach to the region. Park enjoyed both personal motivation as well as politico-economic justifications to push for such arduous yet potentially viable objective. Although the ROK’s yearning for a second boom in the Middle East was not ultimately accomplished under the Park presidency, nonetheless, the very aspiration played a crucial role in either rekindling or initiating policy measures in South Korea’s orientation toward different parts of a greater Middle East region, extending from the Gulf Cooperation Council (GCC) to Morocco.

Regional and international strategic visions of actors In the Middle East

2019 ◽  
pp. 581
Author(s):  
Mohammed Moazaz Iskandar Al - Hadithi
Keyword(s):  
Middle East ◽  
East Region ◽  
Middle East Region

The Middle East region is of great importance in the strategic realization of regional and international actors. Therefore, the hypothesis that the research tries to prove is that the Middle East region is of great strategic importance due to the set of constituents, whether civilizational, economic or geopolitical. The emergence of different strategic visions, whether regional or international actors in the region.

US and Russian policies and strategies in the Middle East: Iraq and Syria as a model

2019 ◽  
pp. 220
Author(s):  
Esraa Aladdin Noori ◽  
Nasser Zain AlAbidine Ahmed
Keyword(s):  
Middle East ◽  
East Asia ◽  
Balance Of Power ◽  
Western World ◽  
International Conflicts ◽  
The South ◽  
The West ◽  
The North ◽  
East Region ◽  
Middle East Region

The Russian-American relations have undergone many stages of conflict and competition over cooperation that have left their mark on the international balance of power in the Middle East. The Iraqi and Syrian crises are a detailed development in the Middle East region. The Middle East region has allowed some regional and international conflicts to intensify, with the expansion of the geopolitical circle, which, if applied strategically to the Middle East region, covers the area between Afghanistan and East Asia, From the north to the Maghreb to the west and to the Sudan and the Greater Sahara to the south, its strategic importance will seem clear. It is the main lifeline of the Western world.

Turkey’s foreign policy priorities in the Middle East and Afghanistan

2020 ◽  
Vol 2020 (10-3) ◽  
pp. 228-237
Author(s):  
Marina Shpakovskaya ◽  
Oleg Barnashov ◽  
Arian Mohammad Hassan Shershah ◽  
Asadullah Noori ◽  
Mosa Ziauddin Ahmad
Keyword(s):  
United States ◽  
Foreign Policy ◽  
Middle East ◽  
The United States ◽  
Turkish Foreign Policy ◽  
Security Issues ◽  
New Approaches ◽  
East Region ◽  
History Of ◽  
Middle East Region

The article discusses the features and main approaches of Turkish foreign policy in the Middle East. Particular attention is paid to the history of the development of Turkish-American relations. The causes of the contradictions between Turkey and the United States on the security issues of the Middle East region are analyzed. At the same time, the commonality of the approaches of both countries in countering radical terrorism in the territories adjacent to Turkey is noted. The article also discusses the priority areas of Turkish foreign policy, new approaches and technologies in the first decade of the XXI century.

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