scholarly journals Modeling sensitivity study of the possible impact of snow and glaciers developing over Tibetan Plateau on Holocene African-Asian summer monsoon climate

2009 ◽  
Vol 5 (3) ◽  
pp. 457-469 ◽  
Author(s):  
L. Jin ◽  
Y. Peng ◽  
F. Chen ◽  
A. Ganopolski
Keyword(s):  
Tibetan Plateau ◽  
Southeast Asia ◽  
South Asia ◽  
North Africa ◽  
Vegetation Cover ◽  
Asian Summer Monsoon ◽  
Climate Feedback ◽  
The Tibetan Plateau ◽  
Asian Monsoon Region ◽  
Vegetation Feedback

Abstract. The impacts of various scenarios of a gradual snow and glaciers developing over the Tibetan Plateau on climate change in Afro-Asian monsoon region and other regions during the Holocene (9 kyr BP–0 kyr BP) are studied by using the Earth system model of intermediate complexity, CLIMBER-2. The simulations show that the imposed snow and glaciers over the Tibetan Plateau in the mid-Holocene induce global summer temperature decreases over most of Eurasia but in the Southern Asia temperature response is opposite. With the imposed snow and glaciers, summer precipitation decreases strongly in North Africa and South Asia as well as northeastern China, while it increases in Southeast Asia and the Mediterranean. For the whole period of Holocene (9 kyr BP–0 kyr BP), the response of vegetation cover to the imposed snow and glaciers cover over the Tibetan Plateau is not synchronous in South Asia and in North Africa, showing an earlier and a more rapid decrease in vegetation cover in North Africa from 9 kyr BP to 6 kyr BP while it has only minor influence on that in South Asia until 5 kyr BP. The precipitation decreases rapidly in North Africa and South Asia while it decreases slowly or unchanged during 6 kyr BP to 0 kyr BP with imposed snow and glacier cover over the Tibetan Plateau. The different scenarios of snow and glacier developing over the Tibetan Plateau would result in differences in variation of temperature, precipitation and vegetation cover in North Africa, South Asia and Southeast Asia. The model results suggest that the development of snow and ice cover over Tibetan Plateau represents an additional important climate feedback, which amplify orbital forcing and produces a significant synergy with the positive vegetation feedback.

scholarly journals Modeling sensitivity study of the possible impact of snow and glaciers developing over Tibetan Plateau on Holocene African-Asian summer monsoon climate

2008 ◽  
Vol 4 (6) ◽  
pp. 1265-1287 ◽  
Author(s):  
L. Jin ◽  
Y. Peng ◽  
F. Chen ◽  
A. Ganopolski
Keyword(s):  
Climate Change ◽  
Tibetan Plateau ◽  
Southeast Asia ◽  
South Asia ◽  
North Africa ◽  
Vegetation Cover ◽  
Asian Monsoon ◽  
The Tibetan Plateau ◽  
Monsoon Region ◽  
Asian Monsoon Region

Abstract. The impacts of various scenarios of snow and glaciers developing over the Tibetan Plateau on climate change in Afro-Asian monsoon region and other regions during the Holocene (9 kyr BP–0 kyr BP) are studied by using the coupled climate model of intermediate complexity, CLIMBER-2. The simulations show that the imposed snow and glaciers over the Tibetan Plateau in the mid-Holocene induce global summer temperature decreases, especially in the northern parts of Europe, Asia, and North America. At the same time, with the imposed snow and glaciers, summer precipitation decreases strongly in North Africa and South Asia as well as northeastern China, while it increases in Southeast Asia and the Mediterranean. For the whole period of Holocene (9 kyr BP–0 kyr BP), the response of vegetation cover to the imposed snow and glaciers cover over the Tibetan Plateau is not synchronous in South Asia and in North Africa, showing an earlier and a more rapid decrease in vegetation cover in North Africa from 9 to 6 kyr BP while it has only minor influence on that in South Asia until 5 kyr BP. Imposed gradually increased snow and glacier cover over the Tibetan Plateau causes temperature increases in South Asia and it decreases in North Africa and Southeast Asia during 6 kyr BP to 0 kyr BP. The precipitation decreases rapidly in North Africa and South Asia while it decreases slowly or unchanged during 6 kyr BP to 0 kyr BP with imposed snow and glacier cover over the Tibetan Plateau. The different scenarios of snow and glacier developing over the Tibetan Plateau would result in differences in variation of temperature, precipitation and vegetation cover in North Africa, South Asia and Southeast Asia. The model results show that the response of climate change in African-Asian monsoon region to snow and glacier cover over the Tibetan Plateau is in the way that the snow and glaciers amplify the effect of vegetation feedback and, hence, further amplify orbital forcing.

Why Is There an Early Spring Cooling Shift Downstream of the Tibetan Plateau?

2005 ◽  
Vol 18 (22) ◽  
pp. 4660-4668 ◽  
Author(s):  
Jian Li ◽  
Rucong Yu ◽  
Tianjun Zhou ◽  
Bin Wang
Keyword(s):  
Tibetan Plateau ◽  
North Africa ◽  
North Atlantic ◽  
Radiative Forcing ◽  
Temperature Shift ◽  
Early Spring ◽  
Climate Feedback ◽  
The Tibetan Plateau ◽  
The North ◽  
The North Atlantic

Abstract The temperature shift over the eastern flank of the Tibetan Plateau is examined using the last 50 yr of Chinese surface station observations. It was found that a strong cooling shift occurs in early spring (March and April) and late summer (July, August, and September) in contrast to the warming shift in other seasons. The cause of the March–April (MA) cooling is investigated in this study. The MA cooling shift on the lee side of the Tibetan Plateau is found to be not a local phenomenon, but rather it is associated with an eastward extension of a cooling signal originating from North Africa that is related to the North Atlantic Oscillation (NAO) in the previous winter. The midtropospheric westerlies over the North Atlantic and North Africa tend to intensify during positive NAO phases. The enhanced westerlies, after passing over the Tibetan Plateau, result in strengthened ascending motion against the lee side of the plateau, which favors the formation of midlevel stratiform clouds. The increased amount of stratus clouds induces a negative net cloud–radiative forcing, which thereby cools the surface air and triggers a positive cloud–temperature feedback. In this way, the cooling signal from the upstream could “jump” over the Tibetan Plateau and leave a footprint on its lee side. The continental stratiform cloud–climate feedback plays a significant role in the amplification of the cooling shift downstream of the Tibetan Plateau.

scholarly journals Effect of Indian Ocean SST on Tibetan Plateau Precipitation in the Early Rainy Season

2017 ◽  
Vol 30 (22) ◽  
pp. 8973-8985 ◽  
Author(s):  
Xiaoyang Chen ◽  
Qinglong You
Keyword(s):  
Indian Ocean ◽  
Tibetan Plateau ◽  
South Asia ◽  
Rainy Season ◽  
Asian Summer Monsoon ◽  
Phase Relationship ◽  
The Tibetan Plateau ◽  
South Asian Summer Monsoon ◽  
The South ◽  
Monsoon System

The onset of the South Asian summer monsoon (SASM) indicates the beginning of the rainy season in the South Asia region. It is not only critical for the local agriculture and animal husbandry but also important for water and life security. Precipitation in the early rainy season (May) increases rapidly and has a large interannual variability, especially in the Tibetan Plateau (TP) region. One of the starting mechanisms of the monsoon system is the land–sea thermal contrast (LSTC) between the Indian Ocean (IO) and South Asia region. Therefore, the IO can be considered as a crucial factor for the intensity of the monsoon system, as well as the TP precipitation. In this study, the relationships between IO sea surface temperature (SST) and TP precipitation on the interannual time scale are investigated. Correlation maps show that IO SST variability contains a portion that is independent from the tropical Pacific Ocean SST and is negatively correlated with the TP precipitation. Here the authors define an LSTC index to determine the thermal condition over the IO and South Asia region. The SASM reveals an out-of-phase relationship with LSTC between land and ocean, which means it would be suppressed by the enhanced LSTC. The daily data are used to further analyze the relationship between the SASM and TP precipitation in detail. Results show that the anomalous TP precipitation in May is mainly caused by the Bay of Bengal monsoon and that the Indian monsoon is responsible for the TP precipitation in June. More specifically, warmer SST enlarges the LSTC between the IO and South Asia region. The SASM is weaker than the mean state, resulting in less precipitation over the TP. In negative years the opposite occurs.

scholarly journals Condensing Life Substances within the House: The Rice-Boiling Shuhi of Southwest China

2017 ◽  
Vol 71 (1) ◽  
Author(s):  
Elisabeth Hsu ◽  
Franz K. Huber ◽  
Caroline S. Weckerle
Keyword(s):  
Tibetan Plateau ◽  
Southeast Asia ◽  
High Altitude ◽  
Sea Level ◽  
Ethnic Groups ◽  
Southwest China ◽  
Cultural Practice ◽  
The Tibetan Plateau ◽  
Regional Culture ◽  
Fault Line

AbstractThe Shuhi of Muli County, Sichuan Province, are one of multiple ethnic groups inhabiting the river gorges of the Qinghai-Gansu-Sichuan corridor between the Tibetan plateau and the Chinese lowlands. The Shuhi have grown paddy rice since times immemorial at an unusually high altitude (ca. 2,300 m above sea level). This article aims to explain this conundrum not merely through the ecology (as is common among Tibetan area specialists), but by researching the cultivation and consumption of rice as a historically-evolved cultural practice. According to a recently formulated agro-archaeological hypothesis regarding the macro-region of Eurasia, it is possible to identify two supra-regional culture complexes distinguished by their respective culinary technologies: rice-boiling versus wheat-grinding-and-baking. The hypothesis posits that the fault line between the two supra-regional cultural complexes is precisely along this river gorges corridor. In this article we provide support for this hypothesis arguing that Shuhi ritual and kinship practices have much affinity with those of other rice-boiling peoples in Southeast Asia, whereas certain of their current religious practices are shared with the wheat-grinding Tibetans.

scholarly journals Impacts of atmospheric transport and biomass burning on the inter-annual variation in black carbon aerosols over the Tibetan Plateau

2020 ◽  
Vol 20 (21) ◽  
pp. 13591-13610
Author(s):  
Han Han ◽  
Yue Wu ◽  
Jane Liu ◽  
Tianliang Zhao ◽  
Bingliang Zhuang ◽  
...  
Keyword(s):  
East Asia ◽  
South Asia ◽  
Biomass Burning ◽  
Annual Variation ◽  
Atmospheric Transport ◽  
Asian Summer Monsoon ◽  
Central China ◽  
The Tibetan Plateau ◽  
Source Regions ◽  
Non Local

Abstract. Atmospheric black carbon (BC) in the Tibetan Plateau (TP) can largely impact regional and global climate. Still, studies on the inter-annual variation in atmospheric BC over the TP and associated variation in BC sources and controlling factors are rather limited. In this study, we characterize the variations in atmospheric BC over the TP surface layer through analysis of 20-year (1995–2014) simulations from a global chemical transport model, GEOS-Chem. The results show that surface BC concentrations over the TP vary largely in space and by season, reflecting complicated interplays of BC sources from different origins. Of all areas in the TP, surface BC concentrations are highest over the eastern and southern TP, where surface BC is susceptible to BC transport from East Asia and South Asia, respectively. Applying a backward-trajectory method that combines BC concentrations from GEOS-Chem and trajectories from the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model, we assess the contributions of worldwide source regions to surface BC in the TP. We estimate that on the 20-year average, 77 % of surface BC in the TP comes from South Asia (43 %) and East Asia (35 %). Regarding seasonal variation in non-local influences, South Asia and East Asia are dominant source regions in winter and summer, respectively, in terms of the amount of BC imported. However, in terms of affected areas in the TP, South Asia is the dominant contributor throughout the year. Inter-annually, surface BC over the TP is largely modulated by atmospheric transport of BC from non-local regions year-round and by biomass burning in South Asia, mostly in spring. We find that the extremely strong biomass burning in South Asia in the spring of 1999 greatly enhanced surface BC concentrations in the TP (31 % relative to the climatology). We find that the strength of the Asian monsoon correlates significantly with the inter-annual variation in the amount of BC transported to the TP from non-local regions. In summer, a stronger East Asian summer monsoon and a stronger South Asian summer monsoon tend to, respectively, lead to more BC transport from central China and north-eastern South Asia to the TP. In winter, BC transport from central China is enhanced in years with a strong East Asian winter monsoon or a strong Siberian High. A stronger Siberian High can also bring more BC from northern South Asia to the TP. This study underscores the impacts of atmospheric transport and biomass burning on the inter-annual variation in surface BC over the TP. It reveals a close connection between the Asian monsoon and atmospheric transport of BC from non-local regions to the TP.

scholarly journals Numerical study of surface energy partitioning on the Tibetan Plateau: comparative analysis of two biosphere models

2009 ◽  
Vol 6 (6) ◽  
pp. 10849-10881
Author(s):  
J. Hong ◽  
J. Kim
Keyword(s):  
Comparative Analysis ◽  
Tibetan Plateau ◽  
Surface Energy ◽  
Summer Monsoon ◽  
Numerical Study ◽  
Asian Summer Monsoon ◽  
Energy Partitioning ◽  
In Situ Observation ◽  
Observation Data ◽  
The Tibetan Plateau

Abstract. The Tibetan Plateau is a critical region in the research of biosphere-atmosphere interactions on both regional and global scales due to its relation to Asian summer monsoon and El Niño. The unique environment on the Plateau provides valuable information for the evaluation of the models' surface energy partitioning associated with the summer monsoon. In this study, we investigated the surface energy partitioning on this important area through comparative analysis of two biosphere models constrained by the in-situ observation data. Indeed, the characteristics of the Plateau provide a unique opportunity to clarify the structural deficiencies of biosphere models as well as new insight into the surface energy partitioning on the Plateau. Our analysis showed that the observed inconsistency between the two biosphere models was mainly related to: 1) the parameterization for soil evaporation; 2) the way to deal with roughness lengths of momentum and scalars; and 3) the parameterization of subgrid velocity scale for aerodynamic conductance. Our study demonstrates that one should carefully interpret the modeling results on the Plateau especially during the pre-monsoon period.

The South Asia Monsoon Break Promotes Grass Growth on the Tibetan Plateau

2021 ◽  
Author(s):  
Yanghang Ren ◽  
Kun Yang ◽  
Han Wang
Keyword(s):  
Soil Moisture ◽  
Tibetan Plateau ◽  
Solar Radiation ◽  
Climate Variability ◽  
South Asia ◽  
The Tibetan Plateau ◽  
The South ◽  
Central Eastern ◽  
Grass Growth ◽  
The Impact

<p>As region that is highly sensitive to global climate change, the Tibetan Plateau (TP) experiences an intra-seasonal soil water deficient due to the reduced precipitation during the South Asia monsoon (SAM) break. Few studies have investigated the impact of the SAM break on TP ecological processes, although a number of studies have explored the effects of inter-annual and decadal climate variability. In this study, the response of vegetation activity to the SAM break was investigated. The data used are: (1) soil moisture from in situ, satellite remote sensing and data assimilation; and (2) the Normalized Difference Vegetation Index (NDVI) and Solar-Induced chlorophyll Fluorescence (SIF). We found that in the region impacted by SAM break, which is distributed in the central-eastern part of TP, photosynthesis become more active during the SAM break. And temporal variability in the photosynthesis of this region is controlled mainly by solar radiation variability and has little sensitivity to soil moisture. We adopted a diagnostic process-based modeling approach to examine the causes of enhanced plant activity during the SAM break on the central-eastern TP. Our analysis indicates that active photosynthetic behavior in the reduced precipitation is stimulated by increases in solar radiation absorbed and temperature. This study highlights the importance of sub-seasonal climate variability for characterizing the relationship between vegetation and climate.</p>

scholarly journals Observational evidence of particle hygroscopic growth in the upper troposphere–lower stratosphere (UTLS) over the Tibetan Plateau

2019 ◽  
Vol 19 (13) ◽  
pp. 8399-8406 ◽  
Author(s):  
Qianshan He ◽  
Jianzhong Ma ◽  
Xiangdong Zheng ◽  
Xiaolu Yan ◽  
Holger Vömel ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Tibetan Plateau ◽  
Lower Stratosphere ◽  
Fine Particles ◽  
Asian Summer Monsoon ◽  
Radiative Properties ◽  
Aerosol Layer ◽  
The Tibetan Plateau ◽  
Hygroscopic Growth ◽  
Upper Troposphere

Abstract. We measured the vertical profiles of backscatter ratio (BSR) using the balloon-borne, lightweight Compact Optical Backscatter AerosoL Detector (COBALD) instruments above Linzhi, located in the southeastern Tibetan Plateau, in the summer of 2014. An enhanced aerosol layer in the upper troposphere–lower stratosphere (UTLS), with BSR (455 nm) > 1.1 and BSR (940 nm) > 1.4, was observed. The color index (CI) of the enhanced aerosol layer, defined as the ratio of aerosol backscatter ratios (ABSRs) at wavelengths of 940 and 455 nm, varied from 4 to 8, indicating the prevalence of fine particles with a mode radius of less than 0.1 µm. We find that unlike the very small particles (mode radius smaller than 0.04 µm) at low relative humidity (RHi < 40 %), the relatively large particles in the aerosol layer were generally very hydrophilic as their size increased dramatically with relative humidity. This result indicates that water vapor can play a very important role in increasing the size of fine particles in the UTLS over the Tibetan Plateau. Our observations provide observation-based evidence supporting the idea that aerosol particle hygroscopic growth is an important factor influencing the radiative properties of the Asian Tropopause Aerosol Layer (ATAL) during the Asian summer monsoon.

scholarly journals Transport of Asian surface pollutants to the global stratosphere from the Tibetan Plateau region during the Asian summer monsoon

2020 ◽  
Vol 7 (3) ◽  
pp. 516-533 ◽  
Author(s):  
Jianchun Bian ◽  
Dan Li ◽  
Zhixuan Bai ◽  
Qian Li ◽  
Daren Lyu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Global Climate ◽  
Pollutant Emissions ◽  
The Tibetan Plateau ◽  
Plateau Region ◽  
Radiative Processes ◽  
Asian Summer ◽  
The Impact

Abstract Due to its surrounding strong and deep Asian summer monsoon (ASM) circulation and active surface pollutant emissions, surface pollutants are transported to the stratosphere from the Tibetan Plateau region, which may have critical impacts on global climate through chemical, microphysical and radiative processes. This article reviews major recent advances in research regarding troposphere–stratosphere transport from the region of the Tibetan Plateau. Since the discovery of the total ozone valley over the Tibetan Plateau in summer from satellite observations in the early 1990s, new satellite-borne instruments have become operational and have provided significant new information on atmospheric composition. In addition, in situ measurements and model simulations are used to investigate deep convection and the ASM anticyclone, surface sources and pathways, atmospheric chemical transformations and the impact on global climate. Also challenges are discussed for further understanding critical questions on microphysics and microchemistry in clouds during the pathway to the global stratosphere over the Tibetan Plateau.

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