On the weakening relationship between the South China Sea summer monsoon onset and cross‐equatorial flow after the late 1990s

Hu, Peng; Chen, Wen; Huang, Ruping; Nath, Debashis

doi:10.1002/joc.5472

Cited by 36 publications

(30 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The original March AO index is dominated by interannual variability. By contrast, time series of the original SCSSM onset data exhibit both interannual variability and interdecadal changes (e.g., Hu et al ., 2018, 2020b). Following previous studies (e.g., Cao et al ., 2015; Chen et al ., 2018), a 10 year high pass filter is applied to extract the interannual variability, and the results are shown in Figure 1b.…”

Section: Resultsmentioning

confidence: 99%

Impact of the March Arctic Oscillation on the South China Sea summer monsoon onset

Chen

et al. 2020

Intl Journal of Climatology

Self Cite

View full text Add to dashboard Cite

This study reveals that the South China Sea summer monsoon (SCSSM) onset is closely linked to the preceding March Arctic oscillation (AO), the dominant mode of atmospheric circulation over extratropical Northern Hemisphere. The physical processes for the impact of the March AO on the SCSSM onset are further examined. March AO leads to an anomalous low-level cyclone over subtropical western North Pacific (WNP) via eddy-mean flow interaction. The southwesterly wind anomalies to the southeastern side of the anomalous cyclone weaken the climatological trade winds, which contribute to warm sea surface temperature (SST) anomalies over tropical western-central North Pacific via reduction of surface evaporation and latent heat flux. These warm SST anomalies excite an atmospheric Rossby wave response and reinforce the anomalous cyclone over the subtropical WNP. Via the above positive atmosphere-ocean interaction, the anomalous cyclone induced by the March AO could persist through the whole spring and shift equatorward. This anomalous cyclone creates favourable environment for the SCSSM onset via weakening the WNP subtropical high and is conducive to the transition of the lowlevel zonal wind. Further analysis indicates that the March AO-SCSSM onset relationship is independent of El Niño-Southern Oscillation (ENSO). This result suggests that, besides the dominant tropical system (i.e., ENSO), interannual variation of the SCSSM onset also has a close relation with the dominant extratropical atmospheric system (i.e., AO), which may provide additional source for the seasonal prediction of the monsoon onset.

show abstract

Section: Resultsmentioning

confidence: 99%

Impact of the March Arctic Oscillation on the South China Sea summer monsoon onset

Chen

et al. 2020

Intl Journal of Climatology

Self Cite

View full text Add to dashboard Cite

show abstract

“…() and National Climate Center (). Since the zonal wind is the most prominent parameter of the SCSSM and is widely used in determining the SCSSM onset (e.g., Wang et al ., ; Kajikawa and Wang, ; Luo and Lin, ; Hu et al ., ), thus the zonal wind is also employed to determining the SCSSM withdrawal day in this study as in previous studies (Luo and Lin, ; Hu et al ., ; ; ; Martin et al ., ). Namely, the monsoon withdrawal is regarded as the nearest day to the withdrawal pentad of National Climate Center () when the westerly to easterly transition occurs.…”

Section: Methodsmentioning

confidence: 99%

“…One of the major roadblocks in the South China Sea (SCS) summer monsoon (SCSSM) research is the lack of a universally accepted definition for the monsoon onset (Lau and Yang, 1997;Qian and Yang, 2000;He et al, 2001;Wang et al, 2004;Zhou and Chan, 2005;He et al, 2017;Luo and Lin, 2017;Hu and Chen, 2018;Hu et al, 2018a), and a similar situation appears for SCSSM withdrawal (e.g., Lam et al, 2005;Zhang et al, 2014;Luo and Lin, 2017;Hu et al, 2018b). As a result, the variability of SCSSM withdrawal, as well as the underlying mechanism, is still poorly understood.…”

Section: Introductionmentioning

confidence: 99%

Statistical analysis of the impacts of intra‐seasonal oscillations on the South China Sea summer monsoon withdrawal

Chen

et al. 2019

Intl Journal of Climatology

Self Cite

View full text Add to dashboard Cite

Based on multiple data sets and methods, this study investigates the impacts of intra‐seasonal oscillations (ISOs) on the South China Sea summer monsoon (SCSSM) withdrawal. A daily SCSSM withdrawal date is established, which can capture reasonably the consistent transition of low‐level zonal wind from westerly to easterly over the South China Sea (SCS). The bandpass‐filtered outgoing longwave radiation and low‐level winds are then composited with respect to the monsoon withdrawal date. It is found that a 30–60‐day oscillation originating from the equatorial Indian Ocean and a quasi‐biweekly oscillation (QBWO) propagating from the equatorial western Pacific collectively contribute to the SCSSM withdrawal. Under the background of slow annual cycle (weak zonal wind during late September), the local convectively inactive phases of these ISOs induce anomalous easterly winds, which could trigger monsoon withdrawal over the SCS. The boreal summer ISO indices also confirm that both the 30–60‐day oscillation and the QBWO could modulate SCSSM withdrawal, which is more likely to occur when the suppressed convection caused by these ISOs is either encroaching on or occupying the SCS.

show abstract

“…This late 1990s shift has been detected by Huangfu et al (2015), and they suggested that the large-scale atmospheric and oceanic change associated with this shift exhibits a more systematically significant interdecadal change signal around 1998/99. It was also emphasized that the late 1990s shift of the SCSSM onset was due to the interdecadal warming over the tropical western Pacific around late 1990s (Huangfu et al, 2015;Hu et al, 2018).…”

Section: Summary and Discussionmentioning

confidence: 99%

Interdecadal Change of the Winter-Spring Tropospheric Temperature Over Asia and its Impact on the South China Sea Summer Monsoon Onset

You

Jian

et al. 2021

Front. Earth Sci.

View full text Add to dashboard Cite

The interdecadal change of the winter-spring tropospheric temperature over Asia and its impact on the South China Sea summer monsoon (SCSSM) onset are investigated in this study. The SCSSM onset experiences a significant advance around the mid-1990s, which is attributed to the positive interdecadal anomaly of meridional temperature gradient in the mid-upper troposphere in May over the South China Sea monsoon region. This positive interdecadal anomaly can be traced back to the previous winter and spring, mainly associated with the mid-upper tropospheric warming in the East Asian subtropics. During the interdecadal anomalous seasonal evolution of the East Asian subtropical mid-upper tropospheric temperature, advection of the warm temperature anomaly by climatological mean wind overtakes the effects of anomalous adiabatic cooling and diabatic cooling, leading to a net interdecadal seasonal warming in winter. In spring, the adiabatic heating caused by the interdecadal anomalous subsidence flow cannot offset the effects of interdecadal anomalous cold advection and diabatic cooling, resulting in a net interdecadal seasonal cooling. However, the interdecadal seasonal cooling in spring is not strong enough to offset the interdecadal seasonal warming in winter, preserving an interdecadal mid-upper tropospheric warming over the subtropical East Asia in late spring. This interdecadal warming provides a favorable condition for the interdecadal advance of the SCSSM onset. Both observational analyses and numerical experiments suggest that the interdecadal change of atmospheric thermodynamic processes in winter−spring is related to the interdecadal warming in the tropical western Pacific. The enhanced convection and condensation heating over the regions from the South China Sea to the Philippines, forced by the tropical western Pacific warming, stimulates an anomalous anticyclone in the upper troposphere and warming in the whole troposphere over the subtropical East Asia.

show abstract

On the weakening relationship between the South China Sea summer monsoon onset and cross‐equatorial flow after the late 1990s

Cited by 36 publications

References 34 publications

Impact of the March Arctic Oscillation on the South China Sea summer monsoon onset

Impact of the March Arctic Oscillation on the South China Sea summer monsoon onset

Statistical analysis of the impacts of intra‐seasonal oscillations on the South China Sea summer monsoon withdrawal

Interdecadal Change of the Winter-Spring Tropospheric Temperature Over Asia and its Impact on the South China Sea Summer Monsoon Onset

Contact Info

Product

Resources

About