scholarly journals Impact of Snow Darkening by Deposition of Light-Absorbing Aerosols on Snow Cover in the Himalayas–Tibetan Plateau and Influence on the Asian Summer Monsoon: A Possible Mechanism for the Blanford Hypothesis

Atmosphere ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 438 ◽  
Author(s):  
William Lau ◽  
Kyu-Myong Kim
Keyword(s):  
Tibetan Plateau ◽  
Snow Cover ◽  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Wave Train ◽  
The Tibetan Plateau ◽  
Gangetic Plain ◽  
Asian Summer ◽  
Absorbing Aerosols ◽  
The Impact

The impact of snow darkening by deposition of light-absorbing aerosols (LAAs) on snow cover over the Himalayas–Tibetan Plateau (HTP) and the influence on the Asian summer monsoon were investigated using the NASA Goddard Earth Observing System Model Version 5 (GEOS-5). The authors found that during April–May–June, the deposition of LAAs on snow led to a reduction in surface albedo, initiating a sequence of feedback processes, starting with increased net surface solar radiation, rapid snowmelt in the HTP and warming of the surface and upper troposphere, followed by enhanced low-level southwesterlies and increased dust loading over the Himalayas–Indo-Gangetic Plain. The warming was amplified by increased dust aerosol heating, and subsequently amplified by latent heating from enhanced precipitation over the Himalayan foothills and northern India, via the elevated heat pump (EHP) effect during June–July–August. The reduced snow cover in the HTP anchored the enhanced heating over the Tibetan Plateau and its southern slopes, in conjunction with an enhancement of the Tibetan Anticyclone, and the development of an anomalous Rossby wave train over East Asia, leading to a weakening of the subtropical westerly jet, and northward displacement and intensification of the Mei-Yu rain belt. The authors’ results suggest that the atmosphere-land heating induced by LAAs, particularly desert dust, plays a fundamental role in physical processes underpinning the snow–monsoon relationship proposed by Blanford more than a century ago.

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.

scholarly journals How can aerosols affect the Asian summer monsoon? Assessment during three consecutive pre-monsoon seasons from CALIPSO satellite data

2010 ◽  
Vol 10 (10) ◽  
pp. 4673-4688 ◽  
Author(s):  
J. Kuhlmann ◽  
J. Quaas
Keyword(s):  
Tibetan Plateau ◽  
Radiative Transfer ◽  
Summer Monsoon ◽  
Satellite Data ◽  
Asian Summer Monsoon ◽  
Lower Troposphere ◽  
Transfer Model ◽  
The Tibetan Plateau ◽  
Asian Summer ◽  
The Impact

Abstract. The impact of aerosols above and around the Tibetan Plateau on the Asian Summer Monsoon during pre-monsoon seasons March-April-May 2007, 2008, and 2009 is investigated by means of remote sensing and radiative transfer modelling. Four source regions are found to be responsible for the high aerosol loading around the Tibetan Plateau: the Taklamakan Desert, the Ganges Plains, the Indus Plains, and the Arabian Sea. CALIPSO lidar satellite data, providing vertically resolved images of aerosols, shows aerosol concentrations to be highest in the lower 5 km of the atmosphere with only little amounts reaching the Tibetan Plateau altitude. Using a radiative transfer model we find that aerosol plumes reduce shortwave radiation throughout the Monsoon region in the seasonal average by between 20 and 30 W/m2. Peak shortwave heating in the lower troposphere reaches 0.2 K/day. In higher layers this shortwave heating is partly balanced by longwave cooling. Although high-albedo surfaces, such as deserts or the Tibetan Plateau, increase the shortwave heating by around 10%, the overall effect is strongest close to the aerosol sources. A strong elevated heating which could influence large-scale monsoonal circulations as suggested by previous studies is not found.

scholarly journals How can aerosols affect the Asian summer monsoon? Assessment during three consecutive pre-monsoon seasons from CALIPSO satellite data

2010 ◽  
Vol 10 (2) ◽  
pp. 4887-4926 ◽  
Author(s):  
J. Kuhlmann ◽  
J. Quaas
Keyword(s):  
Tibetan Plateau ◽  
Radiative Transfer ◽  
Summer Monsoon ◽  
Satellite Data ◽  
Asian Summer Monsoon ◽  
Lower Troposphere ◽  
Transfer Model ◽  
The Tibetan Plateau ◽  
Asian Summer ◽  
The Impact

Abstract. The impact of aerosols above and around the Tibetan Plateau on the Asian Summer Monsoon during pre-monsoon seasons March-April-May 2007, 2008, and 2009 is investigated by means of remote sensing and radiative transfer modelling. Four source regions are found to be responsible for the high aerosol loading around the Tibetan Plateau: the Taklamakan Desert, the Ganges Plains, the Indus Plains, and the Arabian Sea. CALIPSO lidar satellite data, providing vertically resolved images of aerosols, shows aerosol concentrations to be highest in the lower 5 km of the atmosphere with only little amounts reaching the Tibetan Plateau altitude. Using a radiative transfer model we find that aerosol plumes reduce shortwave radiation throughout the Monsoon region in the seasonal average by between 20 and 30 W/m2. Peak shortwave heating in the lower troposphere reaches 0.2 K/day. In higher layers this shortwave heating is partly balanced by longwave cooling. Although high-albedo surfaces, such as deserts or the Tibetan Plateau, increase the shortwave heating by around 10%, the overall effect is strongest close to the aerosol sources. A strong elevated heating which could influence large-scale monsoonal circulations as suggested by previous studies is not found.

scholarly journals Impact of Snow-Darkening by Deposition of Light-Absorbing Aerosols on Snow Cover in the Himalaya-Tibetan-Plateau and Influence on the Asian Monsoon: A Possible Mechanism for the Blanford Hypothesis 

2018 ◽  
Author(s):  
William K. Lau ◽  
Kyu-Myong Kim
Keyword(s):  
Tibetan Plateau ◽  
Snow Cover ◽  
Asian Monsoon ◽  
The Tibetan Plateau ◽  
Surface Solar Radiation ◽  
Gangetic Plain ◽  
Northern India ◽  
Absorbing Aerosols ◽  
The Impact ◽  
The Himalaya

The impact of snow darkening by deposition of light absorbing aerosols (LAAs) on snow cover over the Himalaya-Tibetan-Plateau (HTP) and influence on the Asian monsoon are investigated using the NASA Goddard Earth Observing System Model Version 5 (GEOS-5). We find that during April-May-June, deposition of LAAs on snow leads to a reduction in surface albedo, initiating a sequence of feedback processes, starting with increased surface solar radiation, rapid snowmelt in HTP and warming of the surface and upper troposphere, followed by enhanced low-level southwesterlies and increased dust loading over the Himalayas-Indo-Gangetic Plain. The warming is amplified by increased dust aerosol heating, and subsequently amplified by latent heating from enhanced precipitation over the Himalaya foothills and northern India, via the Elevated Heat Pump (EHP) effect during June-July-August. The reduced snow cover in the HTP anchors the enhanced heating over the Tibetan Plateau and its southern slopes, in conjunction with an enhancement of the Tibetan Anticyclone, and the development of an anomalous Rossby wavetrain over East Asia, leading to weakening of the subtropical westerly jet, and northward displacement and intensification of the Mei-Yu rainbelt. Our results suggest that atmosphere-land heating by LAAs, particularly desert dust play a fundamental role in physical processes underpinning the snow-monsoon relationship proposed by Blandford more than a century ago.

Asian Summer Monsoon changes the pollen flow on the Tibetan Plateau

2020 ◽  
Vol 202 ◽  
pp. 103114 ◽  
Author(s):  
Jin-Feng Li ◽  
Gan Xie ◽  
Jian Yang ◽  
David K. Ferguson ◽  
Xiao-Dong Liu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Pollen Flow ◽  
The Tibetan Plateau ◽  
Asian Summer

Radiation and aerosol measurements over the Tibetan Plateau during the Asian summer monsoon period

2020 ◽  
Vol 11 (9) ◽  
pp. 1543-1551
Author(s):  
Jinqiang Zhang ◽  
Xiangao Xia ◽  
Hongrong Shi ◽  
Xuemei Zong ◽  
Jun Li
Keyword(s):  
Tibetan Plateau ◽  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
The Tibetan Plateau ◽  
Monsoon Period ◽  
Asian Summer

Sensitivity of East Asian summer monsoon precipitation to the location of the Tibetan Plateau

2021 ◽  
pp. 1-36
Author(s):  
Soo-Hyun Seok ◽  
Kyong-Hwan Seo
Keyword(s):  
Tibetan Plateau ◽  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
General Circulation ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Circulation Model ◽  
Dynamical Response ◽  
The Tibetan Plateau ◽  
Asian Summer

AbstractRecent studies have highlighted that a primary mechanism of the East Asian summer monsoon (EASM) is the fluid dynamical response to the Tibetan Plateau (TP), that is, orographically forced Rossby waves. With this mechanism in mind, this study explores how changes in the location of the TP affect the EASM precipitation. Specifically, the TP is moved in the four cardinal directions using idealized general circulation model experiments. The results show that the monsoon aspects are entirely determined by the location of the TP. Interestingly, the strongest EASM precipitation occurs when the TP is situated near its current location, a situation in which downstream southerlies are well developed from the surface to aloft. However, southerlies into the EASM region weaken as the TP moves, which in turn reduces the precipitation. Nevertheless, as long as it moves in the east–west direction, the TP is likely to force the stationary waves that induce precipitation over the mid-latitudes (not necessarily over East Asia). In contrast, moving the TP well north of its original location does not induce strong monsoon flows over the EASM region, resulting in the driest case. Meanwhile, although the southward movement of the TP triggers downstream southerlies to some extent, it does not lead to an increase in the precipitation. Overall, these results show that the location of the TP is crucial in determining the EASM precipitation, and the latter is much more sensitive to the displacement of the TP in the meridional direction than in the zonal direction.

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