High Resolution Simulations of Regional Holocene Climate: North Africa and the Near East

1997 ◽  
pp. 565-593 ◽  
Author(s):  
Reid A. Bryson ◽  
Robert U. Bryson
Keyword(s):  
High Resolution ◽  
North Africa ◽  
Near East ◽  
Holocene Climate

scholarly journals The influence of land cover change in the Asian monsoon region on present-day and mid-Holocene climate

2011 ◽  
Vol 8 (6) ◽  
pp. 1499-1519 ◽  
Author(s):  
A. Dallmeyer ◽  
M. Claussen
Keyword(s):  
Middle East ◽  
Land Cover ◽  
Land Cover Change ◽  
North Africa ◽  
Asian Monsoon ◽  
Monsoon Season ◽  
Precipitation Change ◽  
Holocene Climate ◽  
Near Surface ◽  
Local Climate

Abstract. Using the general circulation model ECHAM5/JSBACH, we investigate the biogeophysical effect of large-scale afforestation and deforestation in the Asian monsoon domain on present-day and mid-Holocene climate. We demonstrate that the applied land cover change does not only modify the local climate but also change the climate in North Africa and the Middle East via teleconnections. Deforestation in the Asian monsoon domain enhances the rainfall in North Africa. In parts of the Sahara summer precipitation is more than doubled. In contrast, afforestation strongly decreases summer rainfall in the Middle East and even leads to the cessation of the rainfall-activity in some parts of this region. Regarding the local climate, deforestation results in a reduction of precipitation and a cooler climate as grass mostly has a higher albedo than forests. However, in the core region of the Asian monsoon the decrease in evaporative cooling in the monsoon season overcompensates this signal and results in a net warming. Afforestation has mainly the opposite effect, although the pattern of change is less clear. It leads to more precipitation in most parts of the Asian monsoon domain and a warmer climate except for the southern regions where a stronger evaporation decreases near-surface temperatures in the monsoon season. When prescribing mid-Holocene insolation, the pattern of local precipitation change differs. Afforestation particularly increases monsoon rainfall in the region along the Yellow River which was the settlement area of major prehistoric cultures. In this region, the effect of land cover change on precipitation is half as large as the orbitally-induced precipitation change. Thus, our model results reveal that mid- to late-Holocene land cover change could strongly have contributed to the decreasing Asian monsoon precipitation during the Holocene known from reconstructions.

scholarly journals Monsoonal response to mid-holocene orbital forcing in a high resolution GCM

2011 ◽  
Vol 7 (5) ◽  
pp. 3609-3652 ◽  
Author(s):  
J. H. C. Bosmans ◽  
S. S. Drijfhout ◽  
E. Tuenter ◽  
L. J. Lourens ◽  
F. J. Hilgen ◽  
...  
Keyword(s):  
High Resolution ◽  
North Africa ◽  
Climate Model ◽  
South American ◽  
Orbital Forcing ◽  
Model Studies ◽  
Summer Insolation ◽  
Moisture Advection ◽  
Monsoonal Precipitation ◽  
Monsoon Winds

Abstract. In this study we use a sophisticated high-resolution atmosphere-ocean coupled climate model, EC-Earth, to investigate the effect of Mid-Holocene orbital forcing on summer monsoons on both hemispheres. During the Mid-Holocene (6 ka), there was more summer insolation on the Northern Hemisphere than today, which intensified the meridional temperature and pressure gradients. Over North Africa, monsoonal precipitation is intensified through increased landward monsoon winds and moisture advection as well as decreased moisture convergence over the oceans and more convergence over land compared to the pre-industrial simulation. Precipitation also extends further north as the ITCZ shifts northward in response to the stronger poleward gradient of insolation. This increase and poleward extent is stronger than in most previous ocean-atmosphere GCM simulations. In north-westernmost Africa, precipitation extends up to 35° N. Over tropical Africa, internal feedbacks completely overcome the direct warming effect of increased insolation. We also find a weakened African Easterly Jet. Over Asia, monsoonal precipitation during the Mid-Holocene is increased as well, but the response is different than over North-Africa. There is more convection over land at the expense of convection over the ocean but precipitation does not extend further northward, monsoon winds over the ocean are weaker and the surrounding ocean does not provide more moisture. On the Southern Hemisphere, summer insolation and the poleward insolation gradient were weaker during the Mid-Holocene, resulting in a reduced South American monsoon through decreased monsoon winds and less convection, as well as an equatorward shift in the ITCZ. This study corroborates the findings of paleodata research as well as previous model studies, while giving a more detailed account of Mid-Holocene monsoons.

Epilogue Connecting to Muhammad?

2013 ◽  
Author(s):  
Fergus Millar
Keyword(s):  
Life History ◽  
Social History ◽  
North Africa ◽  
Near East ◽  
Religious Affiliation ◽  
Roman Provinces ◽  
History Of ◽  
To Receive ◽  
Shed Light ◽  
Roman Near East

This epilogue examines various strands of social history, religious affiliation and language in the Roman Near East in relation to the beginning of Muhammad's preaching in about 610. Muhammad was born, probably in about 570, in Mecca, where he began to receive divinely inspired messages in Arabic. After he died, Muhammad's followers invaded the nearest Roman provinces and conquered all of the Roman Near East, the Sasanid empire, Egypt and Roman North Africa. These are known as ‘the great Arab conquests’. This chapter considers whether the Arabian Peninsula can be properly treated under the title of ‘Arabia and the Arabs’. It also analyses evidence from the Mediterranean and Mesopotamian Near East, as well as the kingdom of Himyar. Finally, it looks at brief allusions to the life-history of Muhammad in a number of Christian sources to shed light on his preaching.

Sign in / Sign up

Export Citation Format

Share Document