Formation and maintenance mechanisms of the Pacific-Japan pattern as an intraseasonal variability mode

Sun, Yuexiang; Chen, Gang; Tan, Benkui

doi:10.1007/s00382-021-05851-4

Cited by 6 publications

(4 citation statements)

References 42 publications

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“…To diagnose the daily energetics changes associated with the evolution of the NAO, we perform a budget analysis for the daily energy conversion terms using a set of energy tendency equations derived from the momentum and thermodynamic energy equations. The equations are derived in Zhuge and Tan (2021) and have been widely used to investigate the daily energy budget for the atmospheric teleconnection pattern (e.g., Sun et al, 2021; Wang & Tan, 2021). They differ slightly from the equations used in monthly energy budgets (Kim et al, 2021; Tanaka et al, 2016), which filter out the interactions between eddies except for high–high‐frequency eddy interactions.…”

Section: Methodsmentioning

confidence: 99%

Phase dependence of growth mechanisms in the daily energetics of the North Atlantic Oscillation

Kim,

Sung,

Yoo

2024

Quart J Royal Meteoro Soc

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The North Atlantic Oscillation (NAO) is a dominant atmospheric variability in the Northern Hemisphere that has a substantial impact on weather and climate on various time scales. Here, we investigate the role of energy conversion terms day‐by‐day during the NAO life cycle. The relative timing and contribution of the energy conversion terms are quantified by projecting the terms onto the eddy total energy, eddy kinetic energy (EKE), and eddy available potential energy (EAPE) patterns associated with the NAO. The results show a remarkable phase dependence in the growth and maintenance mechanisms. For positive NAOs, the initial growth is driven by the barotropic interactions between the eddies propagating over North America. This suggests that a non‐local growth mechanism plays an important role in the initiation of positive NAOs. In contrast, it is the baroclinic processes that initiate negative NAOs. The conversion of the mean APE into the EAPE and then into the EKE, processes which include eddy heat fluxes and vertical motions, results in the relatively local growth of negative NAOs. During the mature phase, the largest source of energy is the conversion of the mean APE into EAPE. Part of this is converted to EKE, making a substantial contribution to the maintenance of the EKE. This process is particularly important for negative NAOs.

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Section: Methodsmentioning

confidence: 99%

Phase dependence of growth mechanisms in the daily energetics of the North Atlantic Oscillation

Kim,

Sung,

Yoo

2024

Quart J Royal Meteoro Soc

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“…(Zhu et al 2020). The possible sources of the quasi-biweekly convections over the Phillippine Sea are also given within the dashed box Though the importance of tropical SST and convective heating in triggering the PJ pattern has been stressed, the PJ pattern is usually deemed a tropical-extratropical teleconnection with its main body in the midlatitudes (Kosaka and Nakamura 2006;Lin et al 2010;Stan et al 2017;Sun et al 2021). The formation and maintenance processes of the quasi-biweekly PJ pattern cannot be merely viewed as the Rossby wave propagation from the tropics, the atmospheric internal variability such as those around the subtropical westerly jet is important too (Lu et al 2006).…”

Section: Introductionmentioning

confidence: 99%

“…Jin et al (2006) suggested that the synoptic eddy and low-frequency flow feedback favors the occurrence of a PNA-like pattern and other recurrent patterns in winter. Some studies also indicate that both the effects of the high-and low-frequency transient eddy fluxes play profound roles in the formation of the teleconnections through eddy vorticity advection induced by Rossby wave breaking (Moore et al 2010;Rivière 2010;Michel and Rivière 2011;Tan et al 2015;Sun et al 2021). Recently, increasing attention have been paid to the feedback of the transient eddies on the distribution and intensification of the teleconnections in summer (Msadek et al 2011;Fogt et al 2011;Xu et al 2019b).…”

Section: Introductionmentioning

confidence: 99%

An investigation of the maintenance mechanisms of the quasi-biweekly Pacific-Japan teleconnection

et al. 2023

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The intraseasonal Pacific-Japan (PJ) pattern, characterized by a pronounced quasi-biweekly oscillation, is triggered by deep convection around the western North Pacific. Three possible dynamical mechanisms on multiple timescales responsible for the growth and decay of the quasi-biweekly PJ pattern are proposed in this study based on daily reanalysis data from the Japanese 55-year Reanalysis for the 1958-2021 period. First, the eastward-propagating wave energy associated with the quasi-biweekly circumglobal teleconnection in the upstream region enters the mid-latitude North Pacific and induces the wavelike barotropic geopotential height anomalies, amplifying the magnitudes of three mid-latitude centers of the PJ pattern by about 40% through their linear constructive interference. Secondly, the barotropic feedback forcing of both high-frequency and low-frequency transient eddies triggered by the pronounced meridional SST gradient over the mid-latitude Pacific is beneficial to the development and persistence of the PJ-related centers to the east of Japan and around the Bering Strait, whereas it damps the PJ-related center in the Gulf of Alaska, increasing the amplitude difference between the former two centers and the latter center. Such feedback forcing also leads to the asymmetry of the positive and negative PJ events. Thridly, dry energy conversion from the background atmospheric circulation and the moist process due to the convective heating over the western North Pacific are both efficient enough to energize the PJ pattern in the developing and mature stages, indicating that the quasi-biweekly PJ pattern can be viewed as a convectively coupled dynamical mode.

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“…The WNPSM convective heating has significant remote influence on the East Asian summer monsoon variability at various timescales from subseasonal to interannual timescales (Hirota & Takahashi, 2012; Hsu & Lin, 2007 and Kosaka et al, 2011, 2012, among others) through the exciting of a Rossby wave train, i.e. the Pacific‐Japan pattern (Gong et al, 2018; Kosaka & Nakamura, 2006, 2010; Nitta, 1987; Sun et al, 2021; Wang et al, 2016; Zhu et al, 2020). At the same time, both observational and numerical studies indicate that the WNPSM diabatic heating can further affect Southern Hemisphere circulations at interannual timescale, leading to the establishment of an anomalous high over Australia (Liu & Wang, 2013), and a Rossby wave train propagating from the subtropical eastern Indian Ocean southeastward to the high‐latitude South Pacific and then moving northeastward into South America (Lin, 2009).…”

Section: Introductionmentioning

confidence: 99%

A new subseasonal atmospheric teleconnection bridging tropical deep convection over the western North Pacific and Antarctic weather

Sun

Tan

2022

Atmospheric Science Letters

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Previous studies indicate that convective heating variability of the western North Pacific summer monsoon (WNPSM) influences strongly weather and climate over East Asia. Based on daily reanalysis data and interpolated outgoing longwave radiation (OLR) data, this study demonstrates that the WNPSM convection can also cause severe weather events remotely over the Antarctic through the exciting of the Australia-South Pacific-Atlantic wave train (ASPA pattern). Surface air temperature (SAT) rises over the Ross Sea-Mawson-Dumont d'Urville Seas sector and over the Weddell Sea, while the SAT drops over the Amundsen-Bellingshausen Seas. Concurrently, sea ice concentration (SIC) is reduced over the Ross Sea and enhanced over the Amundsen-Bellingshausen Seas. The result suggests that the newly found ASPA pattern may serve as an important bridge linking the WNPSM convection and the weather over the Antarctic region.The dynamics of ASPA's formation and propagation are also investigated comprehensively. Day-to-day energy budget analysis suggests that after its initiation by WNPSM convection, the ASPA pattern is driven by the baroclinic energy conversion from the climatological flow and nonlinear term. The barotropic energy conversion from the climatological flow contributes to positive KE tendency before day +1 and negative KE tendency after day +1. It is therefore extremely important to improve the representations of the climatological-mean sea ice and jet stream, wave-mean flow interaction and wave-wave interaction in the mid-and high-latitudes of the Southern Hemisphere, as well as the convection over the WNPSM region of the Northern Hemisphere in numerical model for a better weather prediction for the Antarctic.

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Formation and maintenance mechanisms of the Pacific-Japan pattern as an intraseasonal variability mode

Cited by 6 publications

References 42 publications

Phase dependence of growth mechanisms in the daily energetics of the North Atlantic Oscillation

Phase dependence of growth mechanisms in the daily energetics of the North Atlantic Oscillation

An investigation of the maintenance mechanisms of the quasi-biweekly Pacific-Japan teleconnection

A new subseasonal atmospheric teleconnection bridging tropical deep convection over the western North Pacific and Antarctic weather

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