scholarly journals The role of the westerlies and orography in Asian hydroclimate since the late Oligocene

Geology ◽  
2020 ◽  
Vol 48 (7) ◽  
pp. 728-732 ◽  
Author(s):  
Xin Wang ◽  
Barbara Carrapa ◽  
Yuchen Sun ◽  
David L. Dettman ◽  
James B. Chapman ◽  
...  
Keyword(s):  
Central Asia ◽  
Late Oligocene ◽  
Geological Evidence ◽  
Climate Simulations ◽  
Oxygen Isotopic ◽  
Tian Shan Mountains ◽  
Stable Oxygen ◽  
Soil Carbonates ◽  
Tian Shan

Abstract Interactions between midlatitude westerlies and the Pamir–Tian Shan mountains significantly impact hydroclimate patterns in Central Asia today, and they played an important role in driving Asian aridification during the Cenozoic. We show that distinct west-east hydroclimate differences were established over Central Asia during the late Oligocene (ca. 25 Ma), as recorded by stable oxygen isotopic values of soil carbonates. Our climate simulations show that these differences are present when relief of the Pamir–Tian Shan is higher than 75% of modern elevation (∼3000 m). Integrated with geological evidence, we suggest that a significant portion of the Pamir–Tian Shan orogen had reached elevations of ∼3 km and acted as a moisture barrier for the westerlies since ca. 25 Ma.

Uplift of the Pamir and Tian Shan set hydroclimate patterns in central Asia since the late Oligocene

2021 ◽  
Author(s):  
Xin Wang ◽  
Barbara Carrapa ◽  
Xu Zhang ◽  
Ilhomjon Oimuhammadzoda ◽  
Fahu Chen
Keyword(s):  
Central Asia ◽  
Climate Modeling ◽  
Isotope Geochemistry ◽  
Climate Modelling ◽  
Late Oligocene ◽  
Active Deformation ◽  
Sedimentary Sequences ◽  
Carbon And Oxygen Isotope ◽  
Tian Shan Mountains ◽  
Tian Shan

<p>The Cenozoic Asian aridification has been related to the retreat of the Paratethys, the uplift of the Tibet, and/or global cooling. However, the details of the mechanisms responsible for this paleoclimate shift remain poorly constrained. Modern observations indicate that interactions between mid-latitude westerlies and the Pamir-Tian Shan Mountains significantly impact hydroclimate patterns in central Asia today, and may have played an important role in driving Asian aridification during the Cenozoic. However, the timing when this topographic-atmospheric framework was established remains poorly constrained.</p><p>Here, we present magnetostratigraphy, U-Pb geochronology, thermochronology, paleoclimatology, stable carbon and oxygen isotope geochemistry, and climate modelling techniques to the Cenozoic sedimentary sequences in the Tajik Basin. Our results show that: 1) the penultimate and ultimate retreat of the Paratethys from central Asia occurred at ~41 and ~37.4 Ma, respectively; 2) the Pamirs have experienced active deformation and accelerated exhumation during the late Oligocene to early Miocene; 3) the windward (western) side of the Pamir and Tian Shan has been characterized by a wetter climate changes, whereas, the leeward (eastern) side of the orogen has been characterized by more arid conditions since the Late Oligocene; 4)  This distinct east-west hydroclimate differences, when integrated with climate modeling results, suggests that at least part of the Pamir-Tian Shan mountains had reached elevations ≥ 3 km and acted as a moisture barrier for the westerlies since ~25 Ma. We suggest that the interactions between the westerlies and the Pamir-Tian Shan orogen played an important role in driving Asian aridification since the Late Oligocene.</p>

Climate as the great equalizer of continental-scale erosion

2021 ◽  
Author(s):  
Gilby Jepson ◽  
Barbara Carrapa ◽  
Jack Gillespie ◽  
Ran Feng ◽  
Peter DeCelles ◽  
...  
Keyword(s):  
Central Asia ◽  
Regional Scale ◽  
Continental Scale ◽  
Active Tectonic ◽  
Tectonically Active ◽  
High Precipitation ◽  
Tectonic Boundaries ◽  
Great Equalizer ◽  
Tian Shan

<p>Central Asia is one of the most tectonically active and orographically diverse regions in the world and is the location of the highest topography on Earth resulting from major plate tectonic collisional events. Yet the role of tectonics versus climate on erosion remains one of the greatest debates of our time. We present the first regional scale analysis of 2526 published low-temperature thermochronometric dates from Central Asia spanning the Altai-Sayan, Tian Shan, Tibet, Pamir, and Himalaya. We compare these dates to tectonic processes (proximity to tectonic boundaries, crustal thickness, seismicity) and state-of-the-art paleoclimate simulations in order to constrain the relative influences of climate and tectonics on the topographic architecture and erosion of Central Asia. Predominance of pre-Cenozoic ages in much of the interior of central Asia suggests that significant topography was created prior to the India-Eurasia collision and implies limited subsequent erosion. Increasingly young cooling ages are associated with increasing proximity to active tectonic boundaries, suggesting a first-order control of tectonics on erosion. However, areas that have been sheltered from significant precipitation for extensive periods of time retain old cooling ages. This suggests that ultimately climate is the great equalizer of erosion. Climate plays a key role by enhancing erosion in areas with developed topography and high precipitation such as the Tian Shan and Altai-Sayan during the Mesozoic and the Himalaya during the Cenozoic. Older thermochronometric dates are associated with sustained aridity following more humid periods.</p>

Eutrema tianshanense (Brassicaceae), a new species from Tian Shan Mountains of central Asia

Phytotaxa ◽  
2016 ◽  
Vol 286 (1) ◽  
pp. 23 ◽  
Author(s):  
GUOQIAN HAO ◽  
IHSAN A. AL-SHEHBAZ ◽  
QIANLONG LIANG ◽  
QIAN WANG ◽  
JIANQUAN LIU
Keyword(s):  
New Species ◽  
Central Asia ◽  
Phylogenetic Analyses ◽  
Tibet Plateau ◽  
Long Distance ◽  
North Asia ◽  
Tian Shan Mountains ◽  
Qinghai Tibet Plateau ◽  
A New Species ◽  
Tian Shan

Eutrema tianshanense, a new species of Brassicaceae growing near to the permanent glaciation area in the Tian Shan Mountains of central Asia, is described. It is quite similar morphologically to E. heterophyllum, and E. racemosum from the Qinghai-Tibet Plateau and adjacent regions, and to E. edwardsii of Qinghai-Tibet Plateau, Central and North Asia, and northern North America, but with rounder and smaller leaves. In addition to its long-distance disjunction from the ranges of the above three species, phylogenetic analyses based on sequence variations of multiple chloroplast DNA markers and nuclear ITS suggested that E. tianshanense and these species represent two independently evolved lineages in Tian Shan Mountains and the Qinghai-Tibet Plateau. Their morphological similarities may have resulted from the same selection pressures in the alpine habitats where they grow.

ADAPTATION OF LABOUR MIGRANTS FROM CENTRAL ASIA IN CONTEMPORARY RUSSIA: THE ROLE OF DIGITAL TECHNOLOGY

2019 ◽  
pp. 122-144
Author(s):  
Vadim E. Vasilev ◽  
◽  
Julia I. Eremenkova ◽  
Alina N. Ermokhina ◽  
Alexander A. Nikiforov ◽  
...  
Keyword(s):  
Central Asia ◽  
Digital Technology

Supplemental Material: The role of the westerlies and orography in Asian hydroclimate since the late Oligocene

2020 ◽  
Author(s):  
Xin Wang
Keyword(s):  
Model Simulation ◽  
Late Oligocene ◽  
Geological Setting

Detailed description of sample analyses, geological setting, model simulation, and the data presented in the paper.<br>

scholarly journals A warm jet in a cold ocean

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jennifer A. MacKinnon ◽  
Harper L. Simmons ◽  
John Hargrove ◽  
Jim Thomson ◽  
Thomas Peacock ◽  
...  
Keyword(s):  
The Arctic ◽  
Bering Strait ◽  
Near Surface ◽  
Ice Melt ◽  
Beaufort Gyre ◽  
The Pacific ◽  
Climate Simulations ◽  
Initial Evolution ◽  
Forecast Models

AbstractUnprecedented quantities of heat are entering the Pacific sector of the Arctic Ocean through Bering Strait, particularly during summer months. Though some heat is lost to the atmosphere during autumn cooling, a significant fraction of the incoming warm, salty water subducts (dives beneath) below a cooler fresher layer of near-surface water, subsequently extending hundreds of kilometers into the Beaufort Gyre. Upward turbulent mixing of these sub-surface pockets of heat is likely accelerating sea ice melt in the region. This Pacific-origin water brings both heat and unique biogeochemical properties, contributing to a changing Arctic ecosystem. However, our ability to understand or forecast the role of this incoming water mass has been hampered by lack of understanding of the physical processes controlling subduction and evolution of this this warm water. Crucially, the processes seen here occur at small horizontal scales not resolved by regional forecast models or climate simulations; new parameterizations must be developed that accurately represent the physics. Here we present novel high resolution observations showing the detailed process of subduction and initial evolution of warm Pacific-origin water in the southern Beaufort Gyre.

scholarly journals How the Belt and Road Initiative Can Help Strengthen the Role of the SCO and Deepen China’s Cooperation with Russia and the Countries of Central Asia

2019 ◽  
Vol 75 (1) ◽  
pp. 56-68 ◽  
Author(s):  
Lu Na-Xi ◽  
Huang Meng-Fang ◽  
Lu Shan-Bing
Keyword(s):  
Central Asia ◽  
Free Trade Area ◽  
Asia Pacific ◽  
Regional Economic ◽  
Trade Area ◽  
Belt And Road ◽  
Shanghai Cooperation Organisation ◽  
Improved Model ◽  
The Belt And Road

China and Russia issued a joint statement on 8 May 2015 outlining the main approaches to linking the Silk Road Economic Belt (SREB) and the Eurasian Economic Union (EAEU) projects. Both parties believe that to build the ‘Belt and Road’ project, it is necessary to use economic integration laws and actively enhance the role of the Shanghai Cooperation Organisation (SOC) in stimulating regional economic cooperation, promoting construction of the SREB and linkage to and cooperation with the EAEU, creating a Free Trade Area (FTA) in the Asia-Pacific region (APR) and simultaneously begin creating a similar FTA among China, Russia and Central Asia to gradually stimulate interstate trade and promote regional economic development, actively developing—along with an improved model of energy cooperation—infrastructure and related industry and strengthening business contacts and jointly promoting construction of the SREB.

scholarly journals Role of sea surface temperature responses in simulation of the climatic effect of mineral dust aerosol

2011 ◽  
Vol 11 (12) ◽  
pp. 6049-6062 ◽  
Author(s):  
X. Yue ◽  
H. Liao ◽  
H. J. Wang ◽  
S. L. Li ◽  
J. P. Tang
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Radiative Forcing ◽  
Mineral Dust ◽  
Dust Aerosol ◽  
Sea Surface ◽  
Climatic Effect ◽  
Radiative Effects ◽  
Climate Simulations

Abstract. Mineral dust aerosol can be transported over the nearby oceans and influence the energy balance at the sea surface. The role of dust-induced sea surface temperature (SST) responses in simulations of the climatic effect of dust is examined by using a general circulation model with online simulation of mineral dust and a coupled mixed-layer ocean model. Both the longwave and shortwave radiative effects of mineral dust aerosol are considered in climate simulations. The SST responses are found to be very influential on simulated dust-induced climate change, especially when climate simulations consider the two-way dust-climate coupling to account for the feedbacks. With prescribed SSTs and dust concentrations, we obtain an increase of 0.02 K in the global and annual mean surface air temperature (SAT) in response to dust radiative effects. In contrast, when SSTs are allowed to respond to radiative forcing of dust in the presence of the dust cycle-climate interactions, we obtain a global and annual mean cooling of 0.09 K in SAT by dust. The extra cooling simulated with the SST responses can be attributed to the following two factors: (1) The negative net (shortwave plus longwave) radiative forcing of dust at the surface reduces SST, which decreases latent heat fluxes and upward transport of water vapor, resulting in less warming in the atmosphere; (2) The positive feedback between SST responses and dust cycle. The dust-induced reductions in SST lead to reductions in precipitation (or wet deposition of dust) and hence increase the global burden of small dust particles. These small particles have strong scattering effects, which enhance the dust cooling at the surface and further reduce SSTs.

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