Distribution of Organic Matter during the Toarcian in the Mediterranean Tethys and Middle East

Author(s):  
Francois Baudin ◽  
Jean-Paul Herbin ◽  
Jean-Paul Bassoullet ◽  
Jean Dercourt ◽  
Georges Lachkar ◽  
...  
2019 ◽  
Vol 70 (3) ◽  
pp. 135-146 ◽  
Author(s):  
Eddie John ◽  
Richard I. Vane-Wright

We report a recent observation of D. c. chrysippus f. 'alcippus' in Cyprus, a variant of the Plain Tiger or African Queen butterfly infrequently seen in the Mediterranean, especially in the east of the region. D. c. chrysippus f. 'alcippus' appears to have been recorded from Cyprus on just one previous occasion, by R. E. Ellison, in 1939. However, a specimen of the similar f. 'alcippoides' collected by D. M. A. Bate in Cyprus in 1901 could perhaps be the source of Ellison's otherwise undocumented claim. These records are assessed in relation to the known distributions of the various forms of D. chrysippus across the Mediterranean, North Africa and Middle East, and more briefly with respect to the vast range of this butterfly across much of the Old World tropics and subtropics. The ambiguity and potential confusion caused by using an available name to designate both a geographically circumscribed subspecies or semispecies, and a genetically controlled phenotype that can be found far beyond the range of the putative subspecies or semispecies, is also discussed.


2015 ◽  
Vol 28 (5) ◽  
pp. 1977-1996 ◽  
Author(s):  
Isla R. Simpson ◽  
Richard Seager ◽  
Tiffany A. Shaw ◽  
Mingfang Ting

Abstract In summer, the atmospheric circulation over the Mediterranean is characterized by localized intense subsidence and low-level northerlies over the central to eastern portion of the basin. Here, simulations with the Community Atmosphere Model, version 5 are used to investigate the influence of the elevated terrain of North Africa and the Middle East on this summertime circulation. This builds on previous work that recognized a role for North African topography in localizing the Mediterranean subsidence. By flattening the two regions of elevated terrain in the model, it is demonstrated that, while they both conspire to produce about 30% of the summertime subsidence, contrary to previous work, the mountains of the Middle East dominate in this topographic contribution by far. This topography, consisting primarily of the Zagros mountain range, alters the circulation throughout the depth of the troposphere over the Mediterranean and farther east. The model results suggest that about 20% of the Mediterranean summertime moisture deficit can be attributed to this mountain-induced circulation. This topography, therefore, plays an important role in the climate of the Mediterranean and the large-scale circulation over the rest of Eurasia during the summer. Further stationary wave modeling reveals that the mountain influence is produced via mechanical forcing of the flow. The greatest influence of the topography occurs when the low-level incident flow is easterly, as happens during the summer, primarily because of the presence of condensational heating over Asia. During other seasons, when the low-level incident flow is westerly, the influence of Middle East topography on the Mediterranean is negligible.


2021 ◽  
Author(s):  
Ece Yavuzsoy ◽  
Yasemin Ezber ◽  
Omer Lutfi Sen

<p>El Nino Southern Oscillation (ENSO) is a phenomenon in the equatorial Pacific that could have profound effects on climate around the world. Although ENSO impacts are fairly well-defined for south and north America, Australia and south-eastern Asia, they are not very clear for Euro-Mediterranean region. Some studies indicate that the negative phase of ENSO in Nino3 and Nino3.4 indices have similar effects in the negative phase of North Atlantic Oscillation (NAO).  ENSO impacts and teleconnection patterns are mostly studied using the Nino3.4 index. However, some recent studies indicate that the Nino1+2 index has higher correlation with climate variability over the Euro-Mediterranean region.</p><p>In this study, we investigate impacts of ENSO over the Euro-Mediterranean climate variability and atmospheric dynamics using the Nino1+2 and Nino3.4 indices. Additionally, we also tried to understand if there is any relation between ENSO and the Mediterranean and East Asian troughs. NCEP/NCAR Reanalysis surface air temperature, precipitation and 500 hPa geopotential height datasets and SST-based ENSO indices from ERSSTv4 were used in the analysis for boreal winter (December-January-February) for a period of 1950 - 2019. We utilized the Pearson correlation analysis to reveal the relation between these indices and climate parameters and the composite analysis  to define the pattern differences between the cold and warm phases of the indices.</p><p>Our preliminary findings show that there is a distinct correlation pattern between Nino indices and surface air temperature over the region of interest. Nino1+2 index has a more distinct dipole pattern with a significant positive correlation pole over central Europe and negative pole over north-eastern Africa. However, Nino3.4 indicates a rather zonal correlation dipole pattern whose poles are over northwest Africa (strongly positive) and northeast Africa (negative). It is also found that the Mediterranean trough location is sensitive to the phase of ENSO for both indices. Namely, the Mediterranean trough tends to be in the west of its climatological location for La Nina phases of Nino1+2 and Nino3.4, which affects the distribution of surface temperature and precipitation over the Euro-Mediterranean and Middle East and Northern Africa (MENA) regions. We concluded that the La Nina phase of Nino1+2 seems to play a more distinctive role in the dipole pattern. The surface air temperature is colder over the entire Europe while it is opposite in the Middle East region including Turkey. This dipole pattern is also detected for the La Nina phase of Nino3.4, but it is mostly observed over southwestern Europe and northern Africa. Comparison between the La Nina and El Nino phases of the Nino1+2 index indicates that for the La Nina phase precipitation is larger over the Aegean Sea and Italy and smaller in northern Europe.</p>


Sign in / Sign up

Export Citation Format

Share Document