South Asian Summer Monsoon precipitation variability during late Pliocene: Role of Indonesian Throughflow

2021 ◽  
Vol 574 ◽  
pp. 110447
Author(s):  
T. Sarathchandraprasad ◽  
Manish Tiwari ◽  
Padmasini Behera
Keyword(s):  
South Asian ◽  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Precipitation Variability ◽  
Indonesian Throughflow ◽  
Monsoon Precipitation ◽  
South Asian Summer Monsoon ◽  
Late Pliocene ◽  
Asian Summer

scholarly journals Remote and local drivers of Pleistocene South Asian summer monsoon precipitation: A test for future predictions

2021 ◽  
Vol 7 (23) ◽  
pp. eabg3848
Author(s):  
Steven C. Clemens ◽  
Masanobu Yamamoto ◽  
Kaustubh Thirumalai ◽  
Liviu Giosan ◽  
Julie N. Richey ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
South Asian ◽  
Summer Monsoon ◽  
Large Scale ◽  
Asian Summer Monsoon ◽  
Precipitation Amount ◽  
Monsoon Precipitation ◽  
Orbital Eccentricity ◽  
South Asian Summer Monsoon ◽  
Asian Summer

South Asian precipitation amount and extreme variability are predicted to increase due to thermodynamic effects of increased 21st-century greenhouse gases, accompanied by an increased supply of moisture from the southern hemisphere Indian Ocean. We reconstructed South Asian summer monsoon precipitation and runoff into the Bay of Bengal to assess the extent to which these factors also operated in the Pleistocene, a time of large-scale natural changes in carbon dioxide and ice volume. South Asian precipitation and runoff are strongly coherent with, and lag, atmospheric carbon dioxide changes at Earth’s orbital eccentricity, obliquity, and precession bands and are closely tied to cross-equatorial wind strength at the precession band. We find that the projected monsoon response to ongoing, rapid high-latitude ice melt and rising carbon dioxide levels is fully consistent with dynamics of the past 0.9 million years.

South Asian summer monsoon in warm epochs of Mid-Holocene and end of 21st century; new insights from high resolution simulations

2020 ◽  
Author(s):  
Lekshmi Mudra B ◽  
Thazhe Purayil Sabin ◽  
Raghavan Krishnan
Keyword(s):  
High Resolution ◽  
South Asian ◽  
Asian Summer Monsoon ◽  
Hadley Cell ◽  
Monsoon Precipitation ◽  
South Asian Summer Monsoon ◽  
Indus Valley ◽  
Asian Summer ◽  
Northwest India

<p>The mid-Holocene (MH) was a warmer period, similar to the end of the 21st century climate under high emission realizations. The Indus valley civilization believed to be flourished under the expense of enhanced south Asian summer monsoon precipitation associated with the northward migration of the Inter Tropical Convergence Zone (ITCZ) during the mid-Holocene (MH). However, such an enhanced precipitation is not visible over the northwest India and Pakistan belt in future projection. The role of dynamical and various teleconnection factors behind the enhanced MH precipitation over the Indus valley region is still elusive due to the limitation of course resolution modelling efforts available so far as part of the various phases of Paleoclimate Modelling Intercomparison Projects (PMIP).  To overcome this limitation, we have designed high resolution Paleo-climate simulations using a state-of-the-art variable resolution global climate model (LMDZ: Laboratoire Meteorologie Dynamique and Z stand for zoom) which configured with a 35 km spatial resolution over the South Asian region. We conducted various sensitivity experiments to understand the role of dynamics and teleconnection in enhancing monsoon precipitation over the Indus valley in addition to the MH orbital conditions. Boundary conditions from the PMIP-3, CMIP5 and HadISST datasets utilized for various sensitive experiments. High resolution, clearly demonstrates value addition in simulating the enhanced MH precipitation over Northwest India and adjoining Indus basin associated with the northward migration of the ITCZ and shift in the ascending branch of Hadley cell. We explored the role of various oceanic and atmospheric factors responsible for this enhanced Indus valley precipitation through linearized moisture budget analysis and comparing the relative strength and position of Hadley cell. By further decomposing the thermodynamic and dynamic term into their advection and divergence component, we could demonstrate the role of moisture convergence due to the strengthened atmospheric circulation through the oceanic teleconnection, which additionally  plays a crucial role in enhanced MH precipitation comparing to the dynamical factors. Idealized simulation with the end of 21<sup>st</sup> century warm condition with the MH orbital forcing and various teleconnection patterns affirms that the thermodynamically induced future precipitation and circulation changes, may not be adequate to make a profound shift in the northern limit of the ITCZ towards its MH locale rather producing enhanced precipitation over the north Indian ocean and localized extreme precipitation over Indian landmass.</p><p><strong>Keywords: </strong>Indus Valley civilization, Mid-Holocene, Monsoons, Teleconnection, ITCZ and Hadley circulation</p>

scholarly journals Suppression of south Asian summer monsoon precipitation in the 21st century

2009 ◽  
Vol 36 (1) ◽  
Author(s):  
Moetasim Ashfaq ◽  
Ying Shi ◽  
Wen-wen Tung ◽  
Robert J. Trapp ◽  
Xueijie Gao ◽  
...  
Keyword(s):  
South Asian ◽  
Summer Monsoon ◽  
21St Century ◽  
Asian Summer Monsoon ◽  
Monsoon Precipitation ◽  
South Asian Summer Monsoon ◽  
Asian Summer

Projections of South Asian summer monsoon precipitation based on 12 CMIP5 models

2016 ◽  
Vol 37 (1) ◽  
pp. 94-108 ◽  
Author(s):  
Ruiqing Li ◽  
Shihua Lv ◽  
Bo Han ◽  
Yanhong Gao ◽  
Xianhong Meng
Keyword(s):  
South Asian ◽  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Cmip5 Models ◽  
Monsoon Precipitation ◽  
South Asian Summer Monsoon ◽  
Asian Summer

scholarly journals Accelerated increases in global and Asian summer monsoon precipitation from future aerosol reductions

2020 ◽  
Author(s):  
Laura Wilcox ◽  
Zhen Liu ◽  
Bjørn Samset ◽  
Ed Hawkins ◽  
Marianne Lund ◽  
...  
Keyword(s):  
South Asian ◽  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Relative Magnitude ◽  
Monsoon Precipitation ◽  
South Asian Summer Monsoon ◽  
Anthropogenic Aerosol ◽  
Asian Summer ◽  
Aerosol Emissions ◽  
The Impact

<div> <div> <div> <p>There is large uncertainty in future aerosol emissions scenarios explored in the Shared Socioeconomic Pathways (SSPs), with plausible pathways spanning a range of possibilities from large global reductions in emissions to 2050 to moderate global increases over the same period. Diversity in emissions across the pathways is particularly large over Asia. CMIP6 models indicate that rapid anthropogenic aerosol and precursor emission reductions between the present day and the 2050s lead to enhanced increases in global and Asian summer monsoon precipitation relative to scenarios with weak air quality policies. However, the effects of aerosol reductions don’t persist in precipitation to the end of the 21st century, when response to greenhouse gases dominates differences across the SSPs. The relative magnitude and spatial distribution of aerosol changes is particularly important for South Asian summer monsoon precipitation changes. Precipitation increases here are initially suppressed in SSPs 2-4.5 and 5-8.5 relative to SSP 1-1.9 and 3-7.0 when the impact of East Asian emission decreases is counteracted by that due to continued increases in South Asian emissions.</p> </div> </div> </div>

scholarly journals Accelerated increases in global and Asian summer monsoon precipitation from future aerosol reductions

2020 ◽  
Author(s):  
Laura J. Wilcox ◽  
Zhen Liu ◽  
Bjørn H. Samset ◽  
Ed Hawkins ◽  
Marianne T. Lund ◽  
...  
Keyword(s):  
South Asian ◽  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Relative Magnitude ◽  
Monsoon Precipitation ◽  
South Asian Summer Monsoon ◽  
Anthropogenic Aerosol ◽  
Asian Summer ◽  
Aerosol Emissions ◽  
The Impact

Abstract. There is large uncertainty in future aerosol emissions scenarios explored in the Shared Socioeconomic Pathways (SSPs), with plausible pathways spanning a range of possibilities from large global reductions in emissions to 2050 to moderate global increases over the same period. Diversity in emissions across the pathways is particularly large over Asia. Rapid anthropogenic aerosol and precursor emission reductions between the present day and the 2050s lead to enhanced increases in global and Asian summer monsoon precipitation relative to scenarios with weak air quality policies. However, the effects of aerosol reductions don't persist in precipitation to the end of the 21st century, when response to greenhouse gases dominates differences across the SSPs. The relative magnitude and spatial distribution of aerosol changes is particularly important for South Asian summer monsoon precipitation changes. Precipitation increases here are initially suppressed in SSPs 2–4.5 and 5–8.5 relative to SSP 1–1.9 and 3–7.0 when the impact of East Asian emission decreases is counteracted by that due to continued increases in South Asian emissions.

scholarly journals Accelerated increases in global and Asian summer monsoon precipitation from future aerosol reductions

2020 ◽  
Vol 20 (20) ◽  
pp. 11955-11977 ◽  
Author(s):  
Laura J. Wilcox ◽  
Zhen Liu ◽  
Bjørn H. Samset ◽  
Ed Hawkins ◽  
Marianne T. Lund ◽  
...  
Keyword(s):  
South Asian ◽  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Relative Magnitude ◽  
Monsoon Precipitation ◽  
South Asian Summer Monsoon ◽  
Anthropogenic Aerosol ◽  
Asian Summer ◽  
Aerosol Emissions ◽  
The Impact

Abstract. There is a large range of future aerosol emissions scenarios explored in the Shared Socioeconomic Pathways (SSPs), with plausible pathways spanning a range of possibilities from large global reductions in emissions by 2050 to moderate global increases over the same period. Diversity in emissions across the pathways is particularly large over Asia. Rapid reductions in anthropogenic aerosol and precursor emissions between the present day and the 2050s lead to enhanced increases in global and Asian summer monsoon precipitation relative to scenarios with weak air quality policies. However, the effects of aerosol reductions do not persist to the end of the 21st century for precipitation, when instead the response to greenhouse gases dominates differences across the SSPs. The relative magnitude and spatial distribution of aerosol changes are particularly important for South Asian summer monsoon precipitation changes. Precipitation increases here are initially suppressed in SSPs 2-4.5, 3-7.0, and 5-8.5 relative to SSP1-1.9 when the impact of remote emission decreases is counteracted by continued increases in South Asian emissions.

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