Indian summer monsoon variability during the holocene as recorded in sediments of the Arabian Sea: Timing and implications

2007 ◽  
Vol 63 (6) ◽  
pp. 1009-1020 ◽  
Author(s):  
Meloth Thamban ◽  
Hodaka Kawahata ◽  
Venigalla Purnachandra Rao
Keyword(s):  
Summer Monsoon ◽  
Indian Summer Monsoon ◽  
Arabian Sea ◽  
The Holocene ◽  
Monsoon Variability

scholarly journals Influence of Indian summer monsoon variability on the surface waves in the coastal regions of eastern Arabian Sea

2016 ◽  
Vol 34 (10) ◽  
pp. 871-885 ◽  
Author(s):  
V. Sanil Kumar ◽  
Jesbin George
Keyword(s):  
Surface Waves ◽  
Wave Height ◽  
Summer Monsoon ◽  
Indian Summer Monsoon ◽  
Arabian Sea ◽  
Series Data ◽  
High Positive Correlation ◽  
Monsoon Variability ◽  
Eastern Arabian Sea ◽  
Wavelet Coherence Analysis

Abstract. We assess the influence of monsoon variability on the surface waves using measured wave data covering 7 years and reanalysis data from 1979 to 2015 during the Indian summer monsoon (JJAS) in the eastern Arabian Sea. The inter-annual comparison shows that the percentage of higher wave heights ( >  2.5 m) is higher ( ∼  26%) in 2014 than in other years due to the higher monsoon wind speed (average speed ∼ 7.3 m s−1) in 2014. Due to the delayed monsoon, monthly average significant wave height (Hm0) of June was lowest (∼ 1.5 m) in 2009. The spectral peak shifted to lower frequencies in September due to the reduction of wind seas as a result of decrease in monsoon intensity. The study shows high positive correlation (r ∼ 0.84) between average low-level jet (LLJ) for the block 0–15° N, 50–75° E and Hm0 of eastern Arabian Sea in all the months except in August (r ∼ 0.66). The time series data on wave height shows oscillations with periods 5 to 20 days. Wavelet coherence analysis indicates that the LLJ and Hm0 are in-phase related (phase angle 0°) almost all the time and LLJ leads Hm0. The monsoon seasonal anomaly of Hm0 is found to have a negative relationship with the Oceanic Niño Index indicating that the monsoon average Hm0 is relatively low during the strong El Niño years.

scholarly journals Indian summer monsoon variability and vegetation changes in the core monsoon zone, India, during the Holocene: A multiproxy study

The Holocene ◽  
2018 ◽  
Vol 29 (1) ◽  
pp. 110-119 ◽  
Author(s):  
Kamlesh Kumar ◽  
Shailesh Agrawal ◽  
Anupam Sharma ◽  
Shilpa Pandey
Keyword(s):  
Magnetic Susceptibility ◽  
Summer Monsoon ◽  
Indian Summer Monsoon ◽  
Central India ◽  
Vegetation Changes ◽  
Sudden Increase ◽  
The Holocene ◽  
The Core ◽  
Monsoon Variability ◽  
Three Stages

We present the results of sediment texture, δ13C values, TOC, TN, TOC/TN, and magnetic susceptibility (χlf) of a 1.54-m deep sediment trench recovered from the core monsoon zone (CMZ) of central India, to understand the paleovegetational history and Indian summer monsoon (ISM) variability during the Holocene. The lower δ13C values, TOC/TN ratio, and magnetic susceptibility (χlf) from ~11.4 to 9.5 ka BP suggest enhanced ISM intensity, which is well correlated with other available ISM records from both terrestrial as well as marine archives. A gradual stepwise expansion of C4 plants during ~8.1 and 6.3 ka BP, ~6.3 to 4.7 ka BP, and ~3.0 to 2.0 ka BP suggests a gradual weakening of ISM. The highest δ13C values (–18.7‰) recorded at ~2.0 ka BP indicate the dominance of C4 plants suggesting the weakest phase of ISM in the study area. The expansion of C3 plants from ~2.0 to 1.6 ka BP indicates a sudden increase in ISM intensity. Subsequently, three stages of enhanced ISM have been recorded between ~1.6 and 0.93 ka BP, ~0.76 and 0.42 ka BP, and ~0.28 ka BP to present.

Holocene climate variability and Indian Summer Monsoon: An overview

The Holocene ◽  
2020 ◽  
Vol 30 (5) ◽  
pp. 744-773 ◽  
Author(s):  
Upasana S Banerji ◽  
P Arulbalaji ◽  
D Padmalal
Keyword(s):  
Indian Ocean ◽  
Summer Monsoon ◽  
Indian Summer Monsoon ◽  
Indian Subcontinent ◽  
Ice Age ◽  
Interglacial Period ◽  
Northern Indian Ocean ◽  
The Holocene ◽  
Indian Landmass ◽  
Holocene Period

The response of the Indian Summer Monsoon (ISM) to forcing factors and climate variables has not yet fully explored, even though the ISM plays a pivotal role in the socio-economics of the Indian subcontinent and nearby areas. The ISM progression over Indian landmass is a manifestation of the Intertropical Convergence Zone (ITCZ) migration over the northern Indian Ocean and the Indian subcontinent. The recent anomalous behaviour of ISM raises the need for a better understanding of its spatio-temporal changes during the ongoing interglacial period termed as the Holocene period. The Holocene period has been classified further based on the globally observed abrupt climatic events at 8.2 and 4.2 ka. The 8.2 ka global cooling events have been recorded from northern Indian Ocean marine archives but limited records from the continental archives of the Indian landmass has demonstrated the 8.2 ka event. At the same time, the 4.2 ka dry climate has been endorsed by both marine as well as continental records and agrees with the global studies. During the ‘Little Ice Age’ (LIA), in the India subcontinent, wet conditions prevailed in the northern, central and western regions while a dry climate existed over the greater part of peninsular India. The present review offers an account of ISM signatures and possible mechanisms associated with the monsoon variability in the Indian subcontinent and the northern Indian Ocean during the Holocene period.

Influence of the Arabian Sea on the Indian summer monsoon

Tellus ◽  
1978 ◽  
Vol 30 (2) ◽  
pp. 117-125 ◽  
Author(s):  
S. K. Ghosh ◽  
M. C. Pant ◽  
B. N. Dewan
Keyword(s):  
Summer Monsoon ◽  
Indian Summer Monsoon ◽  
Arabian Sea
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