scholarly journals Evaluation of the Large-Scale and Regional Climatic Response Across North Africa to Natural Variability in Oceanic Modes and Terrestrial Vegetation Among the CMIP5 Models

2019 ◽  
Author(s):  
Michael Notaro ◽  
Fuyao Wang ◽  
Yan Yu ◽  
Jiafu Mao ◽  
Xiaoying Shi ◽  
...  
2021 ◽  
pp. 1-21
Author(s):  
Andrea Ghiselli ◽  
Pippa Morgan

Abstract The nexus between China's human and economic presence abroad and its security policy is increasingly important. Within this nexus, this study statistically explores whether and to what extent Chinese contractors reduce the number of Chinese nationals they send to work in North Africa, the Middle East and the Horn of Africa when the security situation in host states worsens. We find no significant evidence that either warnings from Chinese embassies and consulates to leave host countries or expert perceptions of host stability influence the number of Chinese workers. Worker numbers appear to decrease significantly only in the aftermath of large-scale violent events. These findings suggest that Chinese companies are relatively acceptant of security risks and uncertainties, despite the decade-long regulatory efforts of the Chinese government to make them more security-conscious overseas and, thus, to reduce pressure to use diplomatically and economically expensive military means for their protection.


2014 ◽  
Vol 670-671 ◽  
pp. 964-967
Author(s):  
Shu Hua Bai ◽  
Hai Dong Yang

Nowadays, energy crisis is becoming increasingly serious. Coal, petroleum, natural gas and other fossil energy tend to be exhausted due to the crazy exploration. In recent decades, several long lasting local wars broke out in large scale in Mideast and North Africa because of the fighting for the limited petroleum. The reusable green energy in our life like enormous wind power, solar power, etc is to become the essential energy. This article is to conduct a comparative exploration of mini wind turbine, with the purpose of finding a good way to effectively deal with the energy crisis.


Author(s):  
I. Labinskaya

Political developments in North Africa and the Middle East that have begun in January 2011 are gaining strength and involve an increasing number of Arab countries. The participants of the Roundtable – experts from IMEMO, Institute of Oriental Studies (RAS), Institute of the USA and Canada (RAS) and Mrs. E. Suponina from “Moscow News” newspaper analyzed a wide range of issues associated with these events. Among them are: 1) the reasons for such a large-scale explosion, 2) the nature of the discussed developments (revolutions, riots?) and who are the subjects of the current “Arab drama”, 3) the role of Islam and political Islamism, 4) the role of external factors.


2020 ◽  
Vol 13 (3) ◽  
pp. 232-248
Author(s):  
E. N. Fursova

The article is devoted to the study of the linguistic tradition of the Berbers, who are the indigenous people of North Africa. The Berbers have maintained a rich tradition of spoken language. At the turn of the 20th ‑21st centuries, against the backdrop of the intensification of the movement for self‑determination, their cultural and linguistic rights, the Berbers launched a large‑scale activity aimed at restoring the national written language. The author suggested that the need to develop standardized writing was partly due to the desire of the Berbers to consolidate the official status of their language in the Constitution. The author notes that the aggravation of the so‑called “Berber question” at the end of the 20th century spurred the interest of scientists and researchers in the Berber written heritage. Most of the surviving handwritten documents make Berber texts (mostly religious), recorded using the Arabic alphabet between the 15th and early 20th centuries. The study of conditions for their creation and fields of their application shows that these texts played a significant role in the dissemination of religious and scientific knowledge among the Berbers. It is concluded that despite the use of the predominantly oral form of the language, the Berbers managed to create a unique written tradition. The article discusses in detail the main problems of the study of Berber manuscripts, among which: the requirement from the researcher of serious pre‑knowledge in various fields; the problem of accessibility of texts stored in private collections; the need to develop unified approaches to the description of Berber manuscripts, their digitization and other important arrangements to ensure the availability of documents for the scientific‑research community. Particular attention is paid to the history of the creation of the first collections of Berber manuscripts and their cataloging. The author has also highlighted the work of scientists, who made a qualitative contribution to the study of the Berber manuscripts, most of which have not yet been discovered and carry significant potential aimed at pre‑ serving and enhancing the Berber cultural and historical heritage.


2020 ◽  
Author(s):  
Mohamadou Diallo ◽  
Manfred Ern ◽  
Felix Ploeger

Abstract. The stratospheric Brewer-Dobson circulation (BDC) is an important element of climate as it determines the transport and distributions of key radiatively active atmospheric trace gases, which affect the Earth’s radiation budget and surface climate. Here, we evaluate the inter-annual variability and trends of the BDC in the ERA5 reanalysis and inter-compare with the ERA-Interim reanalysis for the 1979–2018 period. We also assess the modulation of the circulation by the Quasi-Biennial Oscillation (QBO) and the El Niño-Southern Oscillation (ENSO), and the forcings of the circulation by the planetary and gravity wave drag. A comparison of ERA5 and ERA-Interim reanalyses shows a very good agreement in the morphology of the BDC and in its structural modulations by the natural variability related to QBO and ENSO. Despite the good agreement in the spatial structure, there are substantial differences in the strength of the BDC and of the natural variability impacts on the BDC between the two reanalyses, particularly in the upper troposphere and lower stratosphere (UTLS), and in the upper stratosphere. Throughout most regions of the stratosphere, the variability and trends of the advective BDC are stronger in the ERA5 reanalysis due to stronger planetary and gravity wave forcings, except in the UTLS below 20 km where the tropical upwelling is about 40 % weaker due to a weaker gravity wave forcings at the equatorial flank of the subtropical jet. In the extra-tropics, the large-scale downwelling is stronger in ERA5 than in ERA-Interim linked to significant differences in planetary and gravity wave forcings. Analysis of the BDC trend shows a global acceleration of the annual mean residual circulation with an acceleration rate of about 1.5 % per decade at 70 hPa due to the long-term intensification in gravity and planetary wave breaking, consistent with observed and future climate model predicted BDC changes.


2000 ◽  
Vol 6 ◽  
pp. 209-232 ◽  
Author(s):  
Scott L. Wing

Flowering plants are a classic example of a group arising late in Earth history and yet achieving very high diversity, abundance, and ecological and morphological variety in a great array of environments and climatic conditions on all continents. Thus, the success of flowering plants raises basic questions about how new lineages become inserted into existing terrestrial ecosystems. To what degree did flowering plants replace older lineages competitively, and to what extent did their expansion depend on large-scale environmental disruption or extinction of older groups? Is the higher taxonomic diversity of flowering plants a consequence of higher rates of speciation, lower rates of extinction, or both? Have flowering plants expanded the total area and range of habitats occupied by terrestrial vegetation? What were the effects of the diversification and spread of flowering plants on the structure of habitats and the types of resources available to terrestrial heterotrophs?


Atmosphere ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 931
Author(s):  
Zhichao Lu ◽  
Tianbao Zhao ◽  
Weican Zhou

As a coupled large-scale oceanic and atmospheric pattern in the Southern Ocean, the Antarctic circumpolar wave (ACW) has substantial impacts on the global climate. In this study, using the European Centre for Medium-Range Weather Forecasts ERA5 dataset and historical experiment outputs from 24 models of the Coupled Model Intercomparison Project Phase 5 and Phase 6 (CMIP5/CMIP6) spanning the 1980s and 1990s, the simulation capability of models for sea-level pressure (SLP) and sea surface temperature (SST) variability of the ACW is evaluated. It is shown that most models can capture well the 50-month period of the ACW. However, many simulations show a weak amplitude, but with various phase differences. Selected models can simulate SLP better than SST, and CMIP6 models generally perform better than the CMIP5 models. The best model for SLP simulation is the CanESM5 model from CMIP6, whereas the best model for SST simulation is the ACCESS1.3 model from CMIP5. It seems that the SST simulation benefits from the inclusion of both a carbon cycle process and a chemistry module, while the SLP simulation benefits from only the chemistry module. When both SLP and SST are taken into consideration, the CanESM5 model performs the best among all the selected models.


2018 ◽  
Vol 43 (4) ◽  
pp. 535-550
Author(s):  
Klaus Schoenbach

Abstract This study investigates the influence of season of birth on media use and media genre preferences later in life. An impressive body of research in Europe and Japan shows that the month of birth has a significant impact on one’s temperament: People born in the winter of the northern hemisphere, for instance, tend to be less cheerful, lively and self-assured. Reasons seem to be the experience of less light, of coldness and of living mostly inside the home. Mood-management theory suggests that media entertainment may be used to compensate for that lack of cheerfulness and liveliness. In this explorative study, we assume that in countries north of the equator, but with extremely hot temperatures, summer is the season with fewer outdoor activities. So, there, individuals with more summer months in their first half year of life should be comparatively less cheerful – which they may regulate by using more media entertainment. Indeed, a secondary analysis of large-scale surveys in six countries in the Middle East and North Africa in 2016 supports this assumption, albeit conditionally: In the countries with particularly hot summers, but also for younger people in general, the duration of summer directly after birth is correlated significantly with consuming more media entertainment as well as with preferring comedy and drama as genres on TV and online video.


2001 ◽  
Vol 58 (6) ◽  
pp. 1077-1088 ◽  
Author(s):  
G Wayne Minshall ◽  
Todd V Royer ◽  
Christopher T Robinson

We evaluated the effects of disturbance on stream benthic macroinvertebrates at the ecological scales of time, stream size, and burn extent in six segments of Cache Creek over the first 10 postfire years. Postfire changes in macroinvertebrate taxa richness, density, and dominant taxa in the burn streams were significantly different from those in the reference stream. Chironomidae and Baetis typically comprised 40–60% of the macroinvertebrate assemblages of burned streams but only 15–18% of the assemblage in the reference site. Coefficients of variation for the 10-year period indicated that richness, density, biomass, and Baetis abundance were more variable (1.2–3.5 times higher) in the burn streams than in the reference stream and that variability in Chironomidae abundance in burn sites increased with stream size. Fire effects were not attenuated progressively with increasing stream size, probably because the proportion of the catchment burned did not decrease. However, similar-sized streams in which 68–71% of their catchments burned were more severely disturbed than those in which only 39–47% burned. Long-term effects on the macroinvertebrate community were due largely to the loss of terrestrial vegetation and increased runoff, which caused severe alterations in stream channel conditions and large-scale bedload movement.


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