scholarly journals A late Eocene palynological record of climate change and Tibetan Plateau uplift (Xining Basin, China)

2012 ◽  
Vol 344-345 ◽  
pp. 16-38 ◽  
Author(s):  
Carina Hoorn ◽  
Julia Straathof ◽  
Hemmo A. Abels ◽  
Yadong Xu ◽  
Torsten Utescher ◽  
...  
2021 ◽  
Author(s):  
Xiangyu Li ◽  
Zhongshi Zhang ◽  
Ran Zhang ◽  
Qing Yan

<p>Geological evidence shows that the Asian inland environment experienced enhanced aridity from the Early to the Late Eocene. The underlying mechanism for this enhanced Eocene aridity in the Asian inland is still not well illustrated and varies between global cooling and early Tibetan Plateau uplift. In this report, we evaluate the climate impact of three factors, global cooling, topographic uplift and land–sea reorganization, on the enhanced Eocene aridity in Asian inland, in the perspective view from paleoclimate modeling. Paleoclimate modeling supports the Eocene aridification in Asian inland explored by paleoclimate reconstruction. Both the early uplift of Tibetan Plateau and global cooling induced by atmospheric CO<sub>2</sub> reduction contributed to the enhanced aridity in Asian inland in the late Eocene. The Eocene land sea redistribution caused the precipitation increase in Asian inland and hence didn’t contribute to the enhanced aridity there. The uplift of the central Tibetan Plateau during the early stage of the India–Asia collision is emphasized more to be responsible for the long-term Asian inland aridification during the Eocene, playing at least an equally important role as the global cooling induced by decrease in atmospheric CO<sub>2</sub>. The variation of atmospheric CO<sub>2</sub> is likely more important in modulating the regional aridity, leading to the short-term fluctuations in this Eocene Asian inland aridification.</p>


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Young-Min Yang ◽  
June-Yi Lee ◽  
Bin Wang

Abstract The Tibetan Plateau (TP) and Himalayas have been treated as an essential external factor in shaping Asian monsoon and mid-latitude atmospheric circulation. In this study we perform numerical experiments with different uplift altitudes using the Nanjing University of Information Science and Technology Earth System Model to examine potential impacts of uplift of the TP and Himalayas on eastward propagation of the MJO and the associated mechanisms. Analysis of experimental results with dynamics-based MJO diagnostics indicates two potential mechanisms. First, the uplift considerably enhances low-level mean westerlies in the Indian Ocean and convection in the Maritime Continent, which in turn strengthens boundary layer moisture convergence (BLMC) to the east of the MJO convective center. The increased BLMC reinforces upward transport of moisture and heat from BL to free atmosphere and increases lower tropospheric diabatic heating by shallow and congestus clouds ahead of the MJO center, enhancing the Kelvin-Rossby wave feedback. Second, the uplift increases upper tropospheric mean easterlies and stratiform heating at the west of the MJO center, which contributes to eastward propagation of MJO by generating positive moist static energy at the east of MJO center. This study will contribute to a better understanding of the origin of the MJO and improvement in simulation of MJO propagation.


1970 ◽  
Vol 5 (7) ◽  
pp. 58 ◽  
Author(s):  
Anil K Gupta

DOI = 10.3126/hjs.v5i7.1260 Himalayan Journal of Sciences Vol.5(7) (Special Issue) 2008 p.58


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