scholarly journals Atmospheric Thermal and Dynamic Vertical Structures of Summer Hourly Precipitation in Jiulong of the Tibetan Plateau

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 505
Author(s):  
Yonglan Tang ◽  
Guirong Xu ◽  
Rong Wan ◽  
Xiaofang Wang ◽  
Junchao Wang ◽  
...  
Keyword(s):  
Wind Speed ◽  
Tibetan Plateau ◽  
Precipitation Amount ◽  
Summer Precipitation ◽  
The Tibetan Plateau ◽  
Hourly Precipitation ◽  
Air Convection ◽  
Precipitation Variation ◽  
Long Term Observation

It is an important to study atmospheric thermal and dynamic vertical structures over the Tibetan Plateau (TP) and their impact on precipitation by using long-term observation at representative stations. This study exhibits the observational facts of summer precipitation variation on subdiurnal scale and its atmospheric thermal and dynamic vertical structures over the TP with hourly precipitation and intensive soundings in Jiulong during 2013–2020. It is found that precipitation amount and frequency are low in the daytime and high in the nighttime, and hourly precipitation greater than 1 mm mostly occurs at nighttime. Weak precipitation during the daytime may be caused by air advection, and strong precipitation at nighttime may be closely related with air convection. Both humidity and wind speed profiles show obvious fluctuation when precipitation occurs, and the greater the precipitation intensity, the larger the fluctuation. Moreover, the fluctuation of wind speed is small in the morning, large at noon and largest at night, presenting a similar diurnal cycle to that of convective activity over the TP, which is conductive to nighttime precipitation. Additionally, the inverse layer is accompanied by the inverse humidity layer, and wind speed presents multi-peaks distribution in its vertical structure. Both of these are closely related with the underlying surface and topography of Jiulong. More studies on physical mechanism and numerical simulation are necessary for better understanding the atmospheric phenomenon over the TP.

scholarly journals Atmospheric Water Vapor Budget and its Long-term Trend over the Tibetan Plateau

2020 ◽  
Author(s):  
Hongru Yan ◽  
Jianping Huang ◽  
Yongli He ◽  
Yuzhi Liu ◽  
Tianhe Wang ◽  
...  
Keyword(s):  
Water Vapor ◽  
Tibetan Plateau ◽  
Atmospheric Water Vapor ◽  
The Tibetan Plateau ◽  
Atmospheric Water ◽  
Term Trend ◽  
Long Term Trend ◽  
Water Vapor Budget

scholarly journals Diachronous Tibetan Plateau landscape evolution derived from lava field geomorphology

2020 ◽  
Author(s):  
Mark Allen ◽  
Robert Law
Keyword(s):  
Tibetan Plateau ◽  
Landscape Evolution ◽  
Tectonic Geomorphology ◽  
Normal Faults ◽  
The Tibetan Plateau ◽  
Lava Field ◽  
Northern Tibetan Plateau ◽  
Tectonic Processes ◽  
Stepwise Evolution

<p><strong>Evolution of the Tibetan Plateau is important for understanding continental tectonics because of its exceptional elevation (~5 km above sea level) and crustal thickness (~70 km). Patterns of long-term landscape evolution can constrain tectonic processes, but have been hard to quantify, in contrast to established datasets for strain, exhumation and paleo-elevation. This study analyses the relief of the bases and tops of 17 Cenozoic lava fields on the central and northern Tibetan Plateau. Analyzed fields have typical lateral dimensions of 10s of km, and so have an appropriate scale for interpreting tectonic geomorphology. Fourteen of the fields have not been deformed since eruption. One field is cut by normal faults; two others are gently folded with limb dips <6<sup>o</sup></strong><strong>. </strong><strong>Relief of the bases and tops of the fields is comparable to modern, internally-drained, parts of the plateau, and distinctly lower than externally-drained regions. The lavas preserve a record of underlying low relief bedrock landscapes at the time they were erupted, which have undergone little change since. There is an overlap in each area between younger published low-temperature thermochronology ages and the oldest eruption in each area, here interpreted as the transition </strong><strong>between the end of significant (>3 km) exhumation and plateau landscape development. </strong><strong>This diachronous process took place between ~32.5<sup>o</sup> - ~36.5<sup>o</sup> N between ~40 and ~10 Ma, advancing northwards at a long-term rate of ~15 km/Myr. Results are consistent with incremental northwards growth of the plateau, rather than a stepwise evolution or synchronous uplift.</strong></p>

scholarly journals IMPACT OF TIBETAN PLATEAU SNOW COVER ON ABRUPT INTERDECADAL PRECIPITATION CHANGE OVER THE INDOCHINA PENINSULA IN THE MID-1990S

2019 ◽  
Vol XLII-3/W9 ◽  
pp. 57-62
Author(s):  
Y. Ha ◽  
Y. M. Zhu ◽  
Y. J. Hu ◽  
Z. Zhong
Keyword(s):  
Tibetan Plateau ◽  
Snow Cover ◽  
Summer Precipitation ◽  
Tropical Indian Ocean ◽  
Western Pacific Subtropical High ◽  
Precipitation Change ◽  
Interdecadal Change ◽  
Northwestern Pacific ◽  
The Tibetan Plateau ◽  
Indochina Peninsula

Abstract. Abrupt interdecadal changes in summer precipitation (May – September) over the Indochina Peninsula in the past 40 years have been investigated based on the NCEP-NCAR reanalysis product over 1979–2013 and multiple precipitation datasets. The mechanism for the abrupt change is explored. Results indicate that an abrupt interdecadal change in summer precipitation over the Indochina Peninsula occurred in the middle 1990s, and the annual mean summer precipitation during 1994–2002 increased by about 10% compared to that during 1982–1993. The most significant precipitation change occurred in the central and northern peninsula. Further analysis reveals that the interdecadal decrease in snow cover over the Tibetan Plateau in the winter and spring contributed to the summer precipitation increase over the Indochina Peninsula. The decrease in snow cover over the Tibetan Plateau actually increased the thermal contrast between the Tibetan Plateau and the tropical Indian Ocean-northwestern Pacific, leading to intensified summer monsoon over the northwestern Pacific and the South China Sea. As a result, westerly anomalies occurred from the Bay of Bengal to the northwestern Pacific, while anomalous cyclonic circulation prevailed in the upper levels above East Asia. Correspondingly, the western Pacific subtropical high weakened and shifted eastward. Under the joint effects of the above circulation patterns, the atmosphere became wetter in the Indochina Peninsula and summer precipitation increased. Results of the present study provide a theoretical basis for the prediction of long-term summer precipitation change in the Indochina Peninsula.

scholarly journals Understanding precipitation recycling over the Tibetan Plateau using tracer analysis with WRF

2020 ◽  
Vol 55 (9-10) ◽  
pp. 2921-2937
Author(s):  
Yanhong Gao ◽  
Fei Chen ◽  
Gonzalo Miguez-Macho ◽  
Xia Li
Keyword(s):  
Tibetan Plateau ◽  
Land Surface ◽  
Precipitation Amount ◽  
Interaction Strength ◽  
Convective Precipitation ◽  
High Mountain ◽  
The Tibetan Plateau ◽  
Important Indicator ◽  
Precipitation Recycling ◽  
Atmosphere Interaction

Abstract The precipitation recycling (PR) ratio is an important indicator that quantifies the land-atmosphere interaction strength in the Earth system’s water cycle. To better understand how the heterogeneous land surface in the Tibetan Plateau (TP) contributes to precipitation, we used the water-vapor tracer (WVT) method coupled with the Weather Research and Forecasting (WRF) regional climate model. The goals were to quantify the PR ratio, in terms of annual mean, seasonal variability and diurnal cycle, and to address the relationships of the PR ratio with lake treatments and precipitation amount. Simulations showed that the PR ratio increases from 0.1 in winter to 0.4 in summer when averaged over the TP with the maxima centered at the headwaters of three major rivers (Yangtze, Yellow and Mekong). For the central TP, the highest PR ratio rose to over 0.8 in August, indicating that most of the precipitation was recycled via local evapotranspiration in summer. The larger daily mean and standard deviation of the PR ratio in summer suggested a stronger effect of land-atmosphere interactions on precipitation in summer than in winter. Despite the relatively small spatial extent of inland lakes, the treatment of lakes in WRF significantly impacted the calculation of the PR ratio over the TP, and correcting lake temperature substantially improved both precipitation and PR ratio simulations. There was no clear relationship between PR ratio and precipitation amount; however, a significant positive correlation between PR and convective precipitation was revealed. This study is beneficial for the understanding of land-atmosphere interaction over high mountain regions.

scholarly journals Long-term snow disasters during 1982–2012 in the Tibetan Plateau using satellite data

2016 ◽  
Vol 8 (2) ◽  
pp. 466-477 ◽  
Author(s):  
Hang Yin ◽  
Chunxiang Cao ◽  
Min Xu ◽  
Wei Chen ◽  
Xiliang Ni ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Satellite Data ◽  
The Tibetan Plateau

Denisovan DNA in Late Pleistocene sediments from Baishiya Karst Cave on the Tibetan Plateau

Science ◽  
2020 ◽  
Vol 370 (6516) ◽  
pp. 584-587
Author(s):  
Dongju Zhang ◽  
Huan Xia ◽  
Fahu Chen ◽  
Bo Li ◽  
Viviane Slon ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Amino Acid ◽  
Tibetan Plateau ◽  
Late Pleistocene ◽  
Amino Acid Substitution ◽  
Middle Pleistocene ◽  
The Tibetan Plateau ◽  
Karst Cave ◽  
Late Middle Pleistocene

A late Middle Pleistocene mandible from Baishiya Karst Cave (BKC) on the Tibetan Plateau has been inferred to be from a Denisovan, an Asian hominin related to Neanderthals, on the basis of an amino acid substitution in its collagen. Here we describe the stratigraphy, chronology, and mitochondrial DNA extracted from the sediments in BKC. We recover Denisovan mitochondrial DNA from sediments deposited ~100 thousand and ~60 thousand years ago (ka) and possibly as recently as ~45 ka. The long-term occupation of BKC by Denisovans suggests that they may have adapted to life at high altitudes and may have contributed such adaptations to modern humans on the Tibetan Plateau.

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