The Relation of Intraseasonal Variations With Local Onset and Demise of the Indian Summer Monsoon

Karmakar, Nirupam; Misra, Vasubandhu

doi:10.1029/2018jd029642

Cited by 22 publications

(17 citation statements)

References 66 publications

(121 reference statements)

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“…In addition to the basic large-scale features, namely, continental heating, the northward shift in meridional wind, and the associated increase in water vapor transport, other large-scale and regional mechanisms have been documented to drive the transition. The latter include circulation anomalies induced by intraseasonal oscillations (Karmakar and Misra, 2019), the passage of deep convection over the adjacent ocean (e.g., the Bay of Bengal) propagating into the continent, and the influence of the Tibetan plateau on circulation (Fasullo & Webster 2003;Yanai et al 1992). Furthermore, large-scale earlier or advanced monsoon onset have been associated with sea surface temperatures (SSTs) anomalies over the Indian and Pacific oceans (Lau & Yang 1997;Sun et al 2017).…”

Section: Introductionmentioning

confidence: 99%

Interannual variability of monsoon onset and withdrawal in Bangladesh

Montes

Acharya

Stiller-Reeve

et al. 2021

Atmospheric Science Letters

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This research investigates the interannual variability of monsoon onset and withdrawal in Bangladesh, both of which are major climate features shaping multiple societal activities. There is considerable research on the monsoon timing in South Asia, but with much less focus on Bangladesh. We applied a local monsoon onset and withdrawal definition to observations and the latest-generation high-resolution gridded precipitation data from the Climate Hazards Center for the period 1981 through 2018. We analyzed the interannual variability in monsoon timing in Bangladesh and its teleconnection with the sea surface temperature anomalies (SSTA) over the Pacific Ocean (El Niño Southern Oscillation, ENSO) and the Indian Ocean (IO). The monsoon starts with early significant rains in northeast Bangladesh and propagates westward, and a similar pattern is observed for withdrawal, which tends to be more homogeneous in time and space. A high spatial and temporal variability in monsoon onset and withdrawal is observed in Bangladesh, with a within-country average range of around 1 month despite it being a country of relatively small size. The association between monsoon onset and withdrawal and ENSO and IO is addressed at the country and regional level by analyzing composites for different ENSO and IO phases and associated atmospheric circulation and moisture transport. A similar association between monsoon onset and ENSO and IO phases was found, with generally earlier (later) onset dates during the negative (positive) phase of ENSO and IO. Monsoon withdrawal shows a clearer association with ENSO, with earlier (later) dates during the positive (negative) phase. Monsoon withdrawal is earlier during the negative IO phase. SSTA-induced anomalies in circulation and moisture transport contribute to anomalies in monsoon timing. Results suggest both ENSO and IOD can be potentially used as sources of predictability of monsoon onset and withdrawal over specific regions of Bangladesh.

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Section: Introductionmentioning

confidence: 99%

Interannual variability of monsoon onset and withdrawal in Bangladesh

Montes

Acharya

Stiller-Reeve

et al. 2021

Atmospheric Science Letters

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“…El Niño is known to exert a strong influence on the Asian monsoon variability at interannual timescale (Lau & Nath, 2000; B. Wang et al. 2000, 2013), while the onset of the rainy season is related to the active and break spells of the monsoon modulated by intraseasonal monsoon oscillations (e.g., Karmakar & Misra, 2019). A better representation of these features is crucial for seasonal monsoon forecasts (Achuthavarier et al., 2012; Z. Wu et al., 2009), as well as the establishment of low‐level wind reversal and rainfall season (Qi et al., 2009; H. Wang et al., 2018).…”

Section: Resultsmentioning

confidence: 99%

“…Wang et al 2000B. Wang et al , 2013, while the onset of the rainy season is related to the active and break spells of the monsoon modulated by intraseasonal monsoon oscillations (e.g., Karmakar & Misra, 2019). A better representation of these features is crucial for seasonal monsoon forecasts (Achuthavarier et al, 2012;Z.…”

Section: The Response Of the El Niño-monsoon Relationship And Monsoon Onset Datesmentioning

confidence: 99%

Contrasting the Role of Regional and Remote Circulation in Driving Asian Monsoon Biases in MetUM GA7.1

et al. 2021

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The Asian monsoon is a key component of the global atmospheric circulation. During the summer, the monsoon southerlies provide around two thirds of the annual precipitation to about half of the world's population, while during the winter northerly winds can lead to cold surges and severe weather (e.g., Li & Yang, 2010;B. Wang 2006). Given the complexity and spatial extent of the monsoon, its simulation has proven to be a challenging task for climate models, as well as a key testbed to evaluate their processes (Sperber et al., 2013).Numerous studies have documented the model monsoon biases, as well as their spatio-temporal evolution with the annual cycle (e.g., Kang & Shukla, 2006;T. Zhou et al., 2009). Many of these shortcomings have been persisting for decades (Ramesh & Goswami, 2014;Song & Zhou, 2014a). These include the excessive summer rainfall over the northwestern Pacific associated with an anomalously weak Western Pacific Subtropical High (WPSH), and a dipole precipitation anomaly over the Indian monsoon region with a rainfall deficit over the subcontinent and excess precipitation over the tropical Indian Ocean (e.g., Rodríguez et al., 2017;Sperber et al., 2013). The pervasiveness of these biases across both coupled and uncoupled models (M. Bollasina & Nigam, 2009;Song & Zhou, 2014b) suggests the underlying causes could be rooted in their atmospheric component. However, there is some evidence that coupled models can better reproduce monsoon precipitation than atmosphere-only models (Kumar et al., 2005;Zou, 2020) from two main reasons: the damped atmospheric interval variability due to negative feedback from the ocean (Z. Q. Zhou et al., 2018) and the compensating effects between atmospheric and sea surface temperature (SST) biases (Prodhomme et al., 2014;Yang et al., 2019).Model biases hinder reliable attribution of past monsoon variations to anthropogenic forcing (e.g., Wilcox et al., 2015), which in turn hampers our confidence in future projections. One of the limiting factors is the interaction between external forcing and internal variability, especially at interannual to decadal time scales (e.g., Deser et al. 2012). Large uncertainties stem from the atmospheric dynamical response Abstract Monsoon precipitation affects nearly half of the world's population, but monsoon biases are a long-standing problem in climate simulations. We apply dynamical nudging either globally or regionally to demonstrate the role of regional and remote circulation in generating Asian monsoon biases in an atmospheric general circulation model. Monsoon precipitation biases are substantially reduced in response to global nudging but may also be exacerbated over the warm oceanic equatorial areas because of unconstrained sub-grid convection. Regional nudging over Asia appears to be more efficient than nudging outside Asia in reducing seasonal precipitation biases over eastern China and India. This suggests a predominant role of local circulation anomalies in generating monsoon precipitation errors in these regions. An exception i...

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“…Extensive research has been done on the impact of intra-seasonal oscillations (ISOs) on the monsoon onset over the Indian region [25][26][27] . Intraseasonal oscillations are of low-frequency (ISO-1) and high-frequency (ISO-2) with periods of oscillations of 30-60 days and 20-40 days respectively.…”

Section: Conditions For Direct and Two-step Transitionsmentioning

confidence: 99%

Maddening intermittence of rain and two types of critical transitions to monsoon

Surovyatkina

George²

2022

Preprint

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According to folk knowledge, in some years, monsoon comes as a thundering elephant, while in others, it enters gently, like a deer, or sets foot erratic like a chicken. The "elephant" brings good continuous rains and prosperity, while the "deer" or the "chicken" bode a dry spell and a ruinous planting season for farmers. The classical understanding of monsoon onset implies a sudden increase in precipitation and sustainable rains that only fit the "elephant" case. Here, we show that there are two types of critical transitions to monsoon: a direct transition, with a sudden increase in precipitation, and a two/multiple-step transition, with a dry spell after initial rain. We present evidence that 70$\%$ of the last 47 years show two/multiple-step transition, which went overlooked. We uncover that the cause of rainfall cessation is the hidden phenomenon of intermittence emerging between two successive phase transitions. Remarkably, the second type of transition prevails under climate change. Our discovery fills the gap in understanding the transition to monsoon and paves the way to explore its climate resilience in India and other tropical countries.

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The Relation of Intraseasonal Variations With Local Onset and Demise of the Indian Summer Monsoon

Cited by 22 publications

References 66 publications

Interannual variability of monsoon onset and withdrawal in Bangladesh

Interannual variability of monsoon onset and withdrawal in Bangladesh

Contrasting the Role of Regional and Remote Circulation in Driving Asian Monsoon Biases in MetUM GA7.1

Maddening intermittence of rain and two types of critical transitions to monsoon

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